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LIBRARY

Michigan State
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ABSTRACT

FEEDING HABITS OF THE RING-NECKED PHEASANT CHICK,
PHASIANUS COLCHIUS, AND THE EVALUATION
OF AVAILABLE FOODS

BY

Harry Hill

The feeding behavior of the ring-neck pheasant
chick, Phasianus colchius, has been studied by placing them
with foster hens in three structurally different plant
communities. After the young pheasants were allowed to
forage about the fields for several days, the chick crops
were examined and compared with available foods. No appar-
ent feeding preferences were detected. It appeared that
young pheasants eat the available invertebrates, primarily
leathppers and slugs.

Slugs can provide the chick with large quantities of
food during cool, wet periods. Yet, another implication
regarding the land slug is the high concentration of calcium
in its body tissue which could provide an excellent source
of this mineral.

Sweep netting was used to capture more mobile plant

inhabiting arthropoda while baited boards were used to

Harry Hill

sample ground dwelling invertebrates. Using these tech-
niques biomass estimates were determined for 11 fields.

The relationship between the quantity of available
foods and the weight changes of pheasants in different field
types was studied. Weight changes in the young pheasants
were different for the three plant communities.

Three major types of vegetative communities were
examined as potential pheasant producing areas. More mature
communities appeared to offer more available foods. Clover
fields studied exhibited lower biomass levels and their stem
structure does not allow the young pheasant good mobility.

The results of this study have provided an under-
standing of invertebrate foods upon which pheasant chicks
subsist. Several management techniques have been pr0posed

based upon this study.

FEEDING HABITS OF THE RING-NECKED PHEASANT CHICK,

PHASIANUS COLCHIUS, AND THE EVALUATION

 

OF AVAILABLE FOODS

BY

HarrylHill

A DISSERTATION

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY
Department of Fisheries and Wildlife

1976

ACKNOWLEDGMENTS

I wish to thank Mr. Lloyd Breckhiezen who allowed me
permission to use his farmland for this study.

Thanks are due to Dr. Homer Sprague of the Michigan
Department of Public Health for his statistical advice and
constant encouragement during the analysis and writing of
this thesis.

An expression of graditude is extended to the
Michigan Department of Natural Resources for providing me
with 500 pheasant eggs. Mr. Vic Janson was most helpful in
this effort. Thanks are also due to Mr. Keith Heezen of the
DNR's Rose Lake Wildlife Station for his suggestion of this
study.

I am most appreciative of the efforts of my guidance
committee. Dr. Dean L. Haynes provided me with many helpful
suggestions regarding statistical procedures and insect
sampling techniques. Thanks are due to Dr. Cal Flegal for
his gudiance in the area of poultry science. Drs. Harold
H. Prince and Leslie Gysel suggested many helpful ideas

throughout the duration of this investigation. I wish to

ii

also thank Dr. Gysel for serving as my committee chairman
and providing financial support through the Agricultural
Experiment Station.

Thanks are due to many other peOple who made contri-
butions to this study.

A special expression of graditude is due my wife,
Jeanne, without whose sacrifices, patience and encouragement

this research effort could not have been accomplished.

iii

TABLE OF CONTENTS

Page

LIST OF TABLES. C O O O O O O O O O O O O Vii

\ld

LIST OF FIGURES ._ O O O O O O O O O O O 0 ix
INT RODUCT I ON 0 O O O O O O O O O O O O O 1
STUDY AREAS O O O O O O O O O 0 O O O 0 O 4
METHODS O O O O O O O O O O O O O O O O 7
Selection of Fields . . . . . . . . . . .
Sampling of Vegetation . . . . . . . . . .
Available Biomass: Insects Sampled
By Sweep Netting. . . . . . . . . . . . 8
Sweep Net Samples . . . . . . . . . . . 8
Accuracy of Sweeping . . . . . . . . . . 9
Insect Weights . . . . . . . . . . . . 10
Biomass Per Unit Area . . . . . . . . . . 12
Available Biomass: Ground Dwelling
Invertebrates. . . . . . . . . . . . . 12
Pheasant Chicks. . . . . . . . . . . . . 13
CrOps Contents of Pheasant Chicks. . . . . . . 17
Feeding Preferences . . . . . . . . . . . 19

Feeding Preferences Based Upon Physical

Characteristics of Insect Foods . . . . . . 19
Physical Characteristics of Pheasant Chick

Foods Eaten in Three Structurally

Different Plant Communities . . . . . . . 20

Age Contrasts. . . . . . . . . . . . . 20

Weight Gains of Chicks in Various Fields . . . . 21

Nutritional Value of Invertebrate Material. . . . 21
Laboratory Studies on Growth and Passage of

Food Through the Digestive System . . . . . . 21

iv

MSULTS O O O O O O O O O O O O O O

Vegetative Analysis . . . . . .
Available Biomass: Insects Captured by
Sweep Netting . . . . . . . . .

Available Biomass: Ground Dwelling
Invertebrates . . . . . . . . . .
Predicted Insect Weights Versus Actual
Insect Weights . . . . . . . . . .
Predicted and Actual Crop Biomass . . . .
Weight Changes of Chicks in
Various Fields . . . . . . . . . .
Feeding Preferences . . . . . . . . .

Feeding Preferences Based Upon Physical
Characteristics of Insect Foods. . . .

A Comparison of Physical Characteristics of
Pheasant Chick Foods Eaten in Three
Structurally Different Plant Communities.

Age Contrasts in Feeding Behavior. . . .

Growth and Digestion in the Laboratory. . .
DISCUSIONS AND CONCLUSIONS . . . . . . .

Available Foods in the Study Fields. . . .
Validity and Usage of Estimated Biomass . .
Comments Concerning the Chick's Diets . . .
Food Preferences . . . . . . . . . .

Feeding Preferences Based Upon Physical
Characteristics of Insect Foods. . .

A Comparison of Physical Characteristics of
Pheasant Chick Foods Eaten in Three
Structurally Different Plant Communities.

Age Contrasts . . . . . . . . . .

Weight Changes. . . . . . . . . . .
Nutritional Considerations of
Available Foods. . . . . . . . .
Vegetation: Comments and Suggestions . . .
SUMMARY. . . . . . . . . . . . . .

LITERATURE CITED. . . . . . . . . . .

Page
23
23
25
33

34
34

37
38
38
42
44
44
48

48
53

54
56
57
58

59

60
62

65
67

Page

APPENDICES
Appendix
A. Some Common Plants of Northeast Barry
County Oldfields. . . . . . . . . . . 69
2

B. Insect Numbers Collected by Sweeping 312.5 ft
Areas From Fifteen Study Fields
(July 3-18, 1973) . . . . . . . . . . 70

vi

LIST OF TABLES

Table Page

1. Percent of vegetative cover contributed by
selected plant groups for nine study fields
in Northeast Barry County (July 13—24, 1973). . 24

2. Simi1arity indices* demonstrating the degree
of likeness of plant communities in
study fields 0 O O O O O O O O O O O 26

3. Number of insects caught by sweeping
compared with absolute counts. . . . . . . 28

4. Multiplication factors used to convert sweep
net insect numbers to obtain a more accurate
estimate of the absolute number . . . . . . 29

5. Mean dry weight for 26 invertebrate groups . . . 3O

6. Estimated biomass for each insect group
expressed in mg/ft2 for eleven
study fields . . . . . . . . . . . . 31

7. Similarity indices for insect communities
inhabiting the experimental fields . . . . . 32

8. Number of slugs and sowbugs collected from
6 in. x 12 in. sample boards for selected study
fields (Sept. 19 - Oct. 7, 1973). . . . . . 33

9. Analyses of variance of body weight changes of
pheasants feeding in three field types on
three different dates . . . . . . . . . 39

10. Correlation coefficients showing the relationship
between the available foods and the pheasant
ChiCk' S diet 0 I O O O O I O O O O O 40

ll. Correlation coefficients between the percent
biomass in the pheasant chick crops and the
percent biomass present in the field for 19
characteristics of insect prey . . . . . . 41

vii

Table Page

12. Analyses of variance of relative feeding
preferences by field type for selected
insect groups. . . . . . . . . . . . 45

13. Analyses of variance of relative feeding
preferences by age group for selected
insect groups. . . . . . . . . . . . 46

14. Weight of pen reared pheasant chicks
through 30 days . . . . . . . . . . . 47

viii

LIST OF FIGURES

Figure Page

1A Brooding coop used to house pheasants
in the field. 0 O O O O O O O O O O 16

1B Brooding coop with attached pen used to
acclimate the chicks to the
foster hens . . . . . . . . . . . . 16

2. Relationship between estimated and actual
weight of insects in the field
samples . . . . . . . . . . . . . 35

3. Relationship between estimated and actual
biomass of pheasant chick crop
contents 0 O O O O O O O O O O O O 36

4. Correlations between selected characteristics

of insect prey found in the
pheasant chick crops . . . . . . . . . 43

ix

INT RODUCT ION

The ring-necked pheasant, Phasianus colchius, is an

 

imported game bird which has experienced extreme population
fluctuations. Although much research has been done on the
pheasant‘s life cycle, the reasons for these fluctuations
remain poorly understood. Since the young of the year come
prise approximately three-fourths of the fall p0pu1ation,
the brooding period has been considered a crucial stage in
the success of the species. weather, habitat changes, and
brood food have long been suspected as critical factors in
brood success (Ginn 1962, MacMullen 1957, and Shick 1952).
The major objective of this investigation was to
evaluate food habits of young pheasants. In order to
accomplish this goal, three prerequisite requirements were
necessary. Representative community types had to be chosen
from an area known to produce pheasants and the foods
available in these communities had to be quantatively and
qualitatively evaluated. The next objective was to obtain
enough young pheasant crops to make statements about feeding

preferences.

Two major problems exist which make any field study
of brooding pheasants very difficult. Brooding pheasants
are not easily observed in the field because of their
secretive behavior and the dense cover they inhabit during
the brooding period.

The role of changing agricultural practices and its
influence on pheasant habitat has been recognized for many
years. Although sound data is lacking regarding the produc-
tivity of selected retired agricultural land, my empirical
data suggests that such areas contribute substantially as
pheasant producing areas. What qualities do these inactive
agricultural lands possess that encourage brood production?
Obviously these areas provide adequate nesting sites and
cover. Preliminary studies for this project indicate that
agricultural monocultures discourage vegetative cover often
used by pheasants for brooding areas. Lack of vegetative
cover affects insect populations and invertebrate biomass
upon which pheasants subsist during their first 4 weeks of
life. The dependency of gallinaceous chicks on invertebrate
fauna is well documented by Buss (1946), Dalke (1935),
Erickson (1951), Ford et a1. (1938), Fried (1940), Leffing-
well (1928), Loughery (1951), Martin (1972), Shick (1952),
Southwood and Cross (1969), and Stiven (1961). The insect
food provides the young pheasants with a high protein diet
required for their rapid growth.

Although numerous qualitative studies have been

conducted on "feeding preferences" of pheasant chicks in the

wild, none have been quantitatively evaluated in the field.
To establish feeding preferences, it is first necessary to
quantify available foods and secondly to evaluate the foods
eaten. The quality and quantity of insect foods available
in the various field types has been largely unknown. Which
field types provide adequate food for pheasant productivity?

A study of brood success cannot neglect the impor-
tance of weather. Meteorological conditions dictate the
phenology of plant communities. The insects upon which
young pheasants feed are also affected by weather. Weather
throughout the season affects insect activity as well as
that of the chick. Not only does weather affect the
activity patterns of both insects and chicks, but it also
influences the interface upon which insects and chicks
interact.

A major focal point of this project was the evalu-
ation of potential relationship between arthropod fauna and
the survival of pheasant chicks. Some of the questions
have been answered, other questions have not. It is hoped
that this study stimulates a renewed interest in important

factors effecting pheasant brood production.

STUDY AREAS

Throughout much of the pheasant range, a few basic
plant communities produce a majority of the pheasant crop
each year (Wagner 1965). For this study, three plant com-
munities were considered. Preliminary work eliminated row
crops as brooding areas as these fields were devoid of most
vegetative cover and provided almost no inserts on which
the chicks could feed.

Oldfields, clover fields, and bromegrass fields are
considered to be good pheasant producing areas throughout
much of the pheasant's range (Ginn 1962 and Wagner et a1.
1965). Not only are these plant communities common but they
offer an opportunity to evaluate the effect of plant struc-
ture on brood usage. Oldfield communities are composed of
both forbes and grasses and therefore are structurally
heterogeneous. Clover fields are characterized by their
homogeneous plant structure and dense canopies. Bromegrass
fields are generally homogeneous and represent a structurally
different community type.

The history of these three important community types

requires some consideration. Clover fields usually

originiate from seed sown in conjunction with winter wheat
planting. In mid-July the wheat is harvested and frequently
the plant stalks hailed for straw. At this time the larger
varieties of clover grow rapidly. The biennial clover
matures rapidly in the following season providing a dense
plant canopy. The clover fields are often in a short term
government land retirement program. In contrast, most old-
field and bromegrass communities may have been developed
from long term land retirement programs. Many bromegrass
fields may also originate from alfalfa-brome hayfields. As
the biennial alfalfa dies off, the bromegrass spreads and
frequently takes over an entire field. Bromegrass communi-
ties can exist for many years as they continually reseed
themselves. Oldfields find their origin from fields that
are allowed to grow wild.

This study was conducted in northeast Barry County
during the summers of 1972 and 1973. Study plots were
situated in a one square mile area located at T4N, R7W,

Wl/2 Section 34. This portion of Barry County is considered
good agricultural land and has produced moderate pheasant
pOpulations in recent years. A reasonable pheasant popula-
tion was a prerequisite for the study area.

Conover silt loam is the dominant soil type of this
area (USDA 1957). Conover silt loam is considered a fertile,
heavy soil. The tOpography of the area exhibits gentle
slopes interspersed with small woodlots. Low, poorly

drained sections can occassionly be found throughout the

study area. Moisture tolerant plants such as smartweed,

Polgonum pennsylvanicum, nightshade, Solanum nigrum, and

 

teasel, Dipsacus sylvestris, are commonly found in these

lower areas.

METHODS

Selection of Fields

 

Fifteen fields were chosen: five fields for each of
three major community types mentioned. Where possible, a
set of three fields (Oldfield, clover, and bromegrass) were
located within 100 yards of each other. This arrangement
was utilized in an effort to eliminate variance other than
that attributable to community effects. The study fields
were all within a one square mile area to minimize differ-

ences associated with regional effects and soils.

Sampling of Vegetation

The vegetative composition of each field was
qualitatively and quantatively evaluated. A wooden frame
measuring one meter square was divided into quandrants
used to estimate the percent of cover of each species. To
locate each sampling point an initial point representative
of the field was chosen on the edge of the field. Twenty
samples were taken at 30 foot intervals along a line perpen-

dicular to the edge of the field.

Available Biomass: Insects Sampled
Bijweep Netting

 

Sweep Net Samples

In each experimental field, sweep net samples were
taken with a 1.25 foot diameter net to collect the insect
fauna present. Five samples comprised ofle sweeps each
were collected from each field. Since an average sweep
covers a length of 5 feet, 10 sweeps with a 1.25 diameter
net covers an area of 62.5 square feet. The total area
covered for all 5 samples in each field was 312.5 square
feet.

The collection sites for each sample were systema-
tically within those areas considered representative for
that field in much the same manner as the vegetative samples.
Each sample was comprised of ten sweeps which were spaced
30 feet apart. Four clover fields, four oldfields, and
three bromegrass fields, were sampled in this manner.

The arthropoda collected were immediately placed in
a labeled plastic bag and anesthisized with pyrethrium.

The insects were then sorted to the ordinal level. Where
functional or behavioral differences were thought to be
important, as with large and small dipterans, size groupings
were established.

Although insects are known to move up and down
vegetation in response to temperature, moisture and diurnal
behavior, it was hoped that subjective selection of an

evening sample would minimize this source of variance.

Sampling emphasis was directed at the total community and

not at Specific insect populations.

Accuracy of Sweeping

 

It was desirable to know what portion of the insect
fauna was captured by sweep netting. A technique utilizing
a complete count was used to establish effectiveness of
sweep net sampling for each important insect group (Ruesink
and Haynes 1973).

A representative field was selected for each of the
three major vegetative community types studied. A nylon
bottomless screen tent measuring 6 feet on a side was used
to obtain the absolute count. With each of the three fields,
five randomly selected 6 foot square areas were evaluated.
The tents were positioned in a manner that would minimize
disturbance of the insects within. Three sweeps, 1.25 feet
in width, were then taken in the tent commencing at one side
of the tent and terminating on the opposite side.

A hedge trimmer powered by a portable generator was
used to cut down all vegetation within the confines of the
tent. Insects inhabiting the vegetation generally sought
the sides of the tent to escape capture and for resting.
The insects were then collected by a small one amp vacuum
cleaner. Most insect types were readily caught; however, a
few arthropod groups such as daddy longlegs, (Opiliones),

and other ground surface dwellers were difficult to collect.

10

From these fifteen samples the number of each group
captured by sweep netting could be compared with the absolute
number found within the tent and the percent captured by
sweeping could be established. To equate the sweep samples
to the absolute counts, multiplication factors were used.
Multiplication factors were established by obtaining the
reciprical of the proportion of an insect group caught by
sweeping. This procedure was used to calculate the multi-
plication factors for each of the 16 major groups. The
effectiveness of sweeping varies with the plant structure
and thus a different set of multiplication factors was
required for each community type.

In some instances no insects were found in the sweep
samples for a specified community type while in other
instances the sweeps caught a disproportionately large
number of an insect group. To handle these sampling prob-
lems it was necessary to establish replacement values. In
an effort to obtain the best possible replacement values,
the combined data for all samples were used. The total
number of insects collected by sweeping was compared to the
total absolute count for each insect group. The need for
adjustment, in this case, replacement values, was necessary

because of the limited number of samples.

Insect Weights

 

One of the major objectives of this study was to

estimate the invertebrate biomass in a number of different

11

plant communities. The diversity of the insect fauna and
the size ranges encountered within each insect taxa compli-
cated biomass estimates. If the total biomass for a
selected field was desired, the task would have been easier.
However, the real objective was to develop techniques that
provide a more general application. To accomplish this end,
insects were grouped into functional taxa. A functional
taxon included insects possessing similar size, appearance,
mode of locomotion and other behavioral features. Twenty-
four taxa were originally selected. For other purposes of
analysis the 24 taxa were later combined into sixteen
groups.

For each of the 24 taxa, a mean dry weight was
calculated. Where possible, an attempt was made to collect
enough insects from each taxa to provide a representative
sample. For several taxonomic groups inadequate numbers
were available and therefore the resulting mean weights may
have been somewhat inaccurate. Several of the taxa were not
available at the time of collection so values for these
groups were taken from the literature (Cross 1966).

The insects collected were taken to the laboratory,
the dry weight determined, and the weight per insect for
each taxa calculated. The dry weights obtained were very

comparable with those calculated by Cross (1966).

12

Biomass Per Unit Area

 

The biomass of an area sampled can be calculated by
multiplying the number of individuals for each taxa times
the mean dry weight established for that taxa. This product
was then multiplied by the reciprocal of that portion
collected by sweep netting, the multiplication factor
(Ruesink and Haynes 1973). A summation of the biomass of
each component group was then used as an estimate of the
total biomass. This procedure was used for each of the
study fields.

Available Biomass: Ground Dwelling
Invertebrates

 

 

Examination of pheasant chick crops revealed that
sweep net samples did not adequately survey all of the
available foods. For example, slugs were found in over 50
percent of the crOps and in several fields, slugs exceeded
50 percent of the Chick's diet. To a lesser extent, sowbugs,
millipeds, and other ground surface dwelling invertebrates
were found in the crOp contents.

In response to this condition an additional sampling
technique was required to estimate the numbers and biomass
of peri-soil dwelling invertebrates. Several sampling
techniques were tried and eliminated. A sampling system
using baited boards was used with good results. Boards
measuring 6 in. x 12 in. were soaked in water for eight
hours, baited and then placed in the study fields in a grid

pattern. Areas 6 in. x 12 in. were cleared of vegetation

13

and boards were placed on the bare soil surface and their
location marked with florescent colored stakes. Dog food
was used as the bait as it was found superior to lettuce and
other baits tried. The rationale of using baited boards as
traps was based on behavior patterns. Slugs are attracted
to the boards as they search out moist cover and having
found suitable food and cover remain beneath the boards.

The ideal time to sample slugs was during a rainy
period. Nine fields (three from each of the major community
types) were sampled. The number of slugs in these samples
was accepted as an underestimate but it was felt that a
large portion of the population was collected in the samples.
Boards were removed from the fields after a couple of days
to prevent the inclusion of slugs attracted from areas
beyond the 40 foot square sampling area. The distribution
and behavioral pattern of these groups of arthrOpoda make

adequate sampling extremely difficult.

Pheasant Chicks

 

A total of over 700 pheasant eggs were obtained for
this study; 500 eggs were procured from the Department of
Natural Resources' Mason Hatchery, and 200 eggs were obtained
from Michigan State University's Poultry Science Department.
The genetic composition of the eggs is open to question,
but for the most part the genetic sources were similar i.e.,

Mason stock birds originated from M.S.U. stock. It should

14

also be noted that no discernable differences were observed
in feeding behavior from any of the genetic sources.

The young chicks were held in an incubator for a
period of from one to three days before introduction to
their foster hens. Experience demonstrated that this short
period allowed the young pheasants to gain strength enough
to avoid trampling by the hen and yet respond to the heat
source beneath the hen. No negative behavioral characteris-
tics were observed using this procedure. Evidently, the
critical period of imprinting in the pheasant chick occurs
after the third day.

Introduction of the brood to their foster mother was
the most crucial point for the experimental chicks. The
foster hens were "barnyard banties" for the most part while
a few pure strains of chickens, such as the New Hampshire
Reds and Japanese Silkies were sparingly used. Banties
possessed desirable qualities such as their foraging skills,
frequency of broodiness, and a body size comparable to that
of a hen pheasant. Niney "banty" hens were maintained in
anticipation of the fact that some of the hens would never
set, some would set only once and some would probably set
several times.

The procedure for introducing chicks to the foster
hens evolved through trial and error. The first step was to
select a suitable broody hen. Broody hens were recognized
by behavioral patterns such as clucking and brooding posture.

Once the hens were chosen, they were placed in a closed

15

brooding c00p with about 12 pheasant chicks (Figure la). It
was found that the hens were easier to handle after dark and
were less anxious. On most occasions the hens would be
found brooding the chicks by the following morning. Once
the hen adopted her brood, the slated doors were Opened
allowing the chicks to feed, water, and move about in the
small, screened runway (Figure lb). The hen and her brood
were fed identical diets which consisted of a game bird
starter diet. They also ate additional insects which strayed
into the confined area.

The entire coop and its attached runway were kept on
a mowed section of grass and moved daily to minimize disease.
When the chicks became adequately acclimated to their mother
and environment, they were transferred to a 10 foot square
pen. These pens were made of 1 in. chicken netting nailed
onto a wooden frame measuring 3 feet in height. Their con-
struction made the pens extremely portable. Although the
chicks were allowed to range the enclosed grass area, the
hens were still restrained within the c00ps. It was found
essential that the young pheasants adjust to vegetation and
become acquainted with insect food that may stray into the
pens. In the previous years work, pheasant chicks raised
indoors with no exposure to natural sunlight, vegetation,
nor a mother to brood them did not respond as desired.

When placed in outdoor pens, the pheasant chicks

reared with a foster hen in outdoor pens, behaved in manner

16

 

Figure 1a. Brooding coop used to house pheasants in the
field.

 

 

Figure lb. Brooding coop with attached pen used to
acclimate the chicks to the foster hens.

17

similar to that observed for wild pheasants. This normal
behavior was assumed in the treatment of the data and the
inferences based upon the data.

Again, through experience, it was found that chicks
should be two weeks old before field release. Chicks one
week of age and younger were field released but high losses
were incurred. The two week old birds develOped stronger
behavioral bonds towards their mother and the rest of the
brood. The chicks communicated between themselves and hunted
in social groups in a fashion similar to resident wild
pheasant chicks.

At two weeks of age, the young pheasants were wing
banded, weighed, and had their right primary feathers clipped
to prevent flight. In the evening the broods along with
their c00ps were moved into the fields. At daybreak the
chicks were allowed to roam at will in the field and were
observed feeding upon arthrOpods throughout the day. A
container of fresh, clean water was placed at the entrance
of the coop. At night, when the chicks had returned to the
coop the door was closed. Not all chicks returned at night:
some returned a day or two later while many were never seen
again.

Crop Contents of
Pheasant Chicks

 

 

The young chicks and their foster mother were
randomly assigned to selected fields and given one day to

acclimate to their new surroundings. Most chicks were

18

observed foraging for and eating insect material throughout
the first day, but not enough food was eaten to allow any
accumulation within the crop during the day. This event
caused some concern initially, but it was discovered that a
substantial amount of food begins to accumulate in the crop
towards evening. For this reason, chicks to be sacrificed
were collected soon after they returned to the brooding coop
at sunset.

The sacrificed chicks were individually placed in a
labeled plastic bag and returned to the field laboratory.
The creps and gizzards were put in labeled vials containing
95 percent ethyl alcohol and stored for analysis. The
remainder of the Chick's body was placed in plastic bags for
future examination.

The sorting of crOp contents into the various insect
groups followed the same methodology as that used for sweep
net samples. This procedure was required for comparison of
crop contents to insect biomass collected in the field. The
number of insects and other invertebrates were tabulated for
each of the pre-established groups. A total of 148 pheasant
chick crops were examined.

Comparison of the raw number of insects does not
provide an adequate basis for comparative purposes. The
percent biomass contributed by each insect group was cal-
culated by multiplying the mean weight for each insect group

times the number of insects in that category. The total

19

biomass was also calculated. The proportion of crop content

comprised by each of the component groups was established.

Feedinngreferences

 

Feeding Preferences Based Upon
Physical Characteristics of
Insect Foods

 

 

Five characteristics were selected which could
influence how the pheasant predators preceived available
food and thus selected their insect prey. Physical charac-
teristics considered were size, shape and color. Two
additional features that could have also influenced the
pheasant's feeding behavior were the prey's mode of
locomotion and the vertical strata occupied by the prey.

Prey species were grouped into 5 size categories;
<2 mm, 2-4 mm, 4-6 mm, 6-10 mm, and >10 mm. Insect shapes
were classified as oval, wormlike, oblique, long appendaged
and minute. Insects were also grouped according to whether
they were green, light brown or grey, dark brown or black and
dark green. The mode of locomotion of insect prey were
walking, flying, jumping, crawling and resting.

Insects found in three strata were evaluated. The
strata under consideration were the ground surface, from the
ground to 12 inches and 12-36 inches. Ground beetles and
ants typify ground dwellers, leathppers are considered
representative of the 0-12 inch strata while most flying
insects were categorized as inhabitants of the 12-36 inch

strata.

20

Only those insects regularly caught by sweeping were
considered. Each insect was placed in one classification for
each of the characteristics evaluated. The number in each
category was multiplied by their respective estimated weights
and then by their multiplication factor. The total weights
for each category were then tallied. The prOportion of the
biomass of each category in a pheasants crop was compared
with its respective biomass available in the field.

Physical Characteristics of Pheasant

ChickIFoods Eatenin Three Structurally
Different Plant Communities

 

 

Ninety-nine pheasant chicks were placed in three
major community types to evaluate and contrast foods eaten.
The data represent the combined information gathered from 4
clover fields, 4 oldfields, and 3 bromegrass fields. Only
those insect categories which were thought to be meaningful

and provided adequate data were analyzed.

Age Contrasts

 

Three ages of young pheasants were selected to
demonstrate differences in feeding behavior attributable to
age. The age groups studied were 1 week, 2 weeks and 3
weeks. Each age group was randomly assigned adjacent sites
in a representative area of an oldfield community. The
young birds were allowed to feed throughout the day and were
captured when they returned to their coops in the evening.
The techniques used to handle the crOp material has been

explained in an earilier section.

21

Weight-Gains of Chicks
in Various Fields

 

 

Each pheasant chick was weighed every other morning.
The weight changes were recorded to an accuracy of one—tenth
of a gram. Predicted foul weather occassionally altered
this study because the young birds used in this section were
critical to other studies and therefore could not be risked
to bad weather.

Nutritional Value of
Invertebrate‘Material-

 

 

The nutritional aspects of insect materials have
been thoroughly explored by several authors (Beck and Beck
1955, Cross 1966, and Korschgen 1964). Since the values in
these references are in agreement, the decision to bypass
nutritional analysis of the invertebrate material was made
with one major exception. The land slug, Limax spp., an
invertebrate found in numerous pheasant crops was not
analyzed in any of these previous studies. A sample of 15
grams live weight of slugs was collected in the field and
taken to the biochemistry laboratory at Michigan State
University for an approximate analysis.

Laboratory Studies on Growthgand

Passage of Food Through"
the Digestive System

 

 

 

The genetic composition of the experimental chicks
was uncertain and therefore it was not known if the growth
performances of these chicks would be comparible with that

of native birds. Eight randomly selected experimental birds

22

were reared in captivity for 30 days to detect any differ-
ences in growth patterns. The chicks were weighed every
morning for 10 days and then weighed every other day
thereafter. The pheasants were weighed in the morning prior
to feeding. For the remainder of the day they were allowed
to feed ad lib.

These same chicks were also used to determine the
rate of food passage through the digestive tract. Chromium
oxide, an inert material often used for studying digestive
rates, was mixed with the starter ration. The chicks were
placed in individual cages with a white paper drop cloth.

A greenish stool indicated the length of time required for

the chromium oxide to pass through the digestive system.

RESULTS

Vegetative AnaLysis

 

Since the major soil type of the entire study area
is a Conover loam, the vegetative communities would be
expected to show analogous characteristics. Also, all
fields assigned to each set of community types possessed
identical histories. Furthermore, the proximity of all
fields to each other also contributed to their expected
likeness.

Table 1 presents the vegetative composition for nine
of the major fields studied. The percent values represent
the average obtained from 20 one meter square vegetative
samples in each of the study fields. One clover field was
not included in this table because it was mowed before the
vegetative analysis was completed. Twenty-five of the more
abundant plants of the area are listed in Appendix A.

Simi1arity indices were calculated for the nine
fields. The analogue used to compute these similarity

indices is that presented by Murdock et a1. (1972) and is:

23

24

Table l.--Percent of vegetative cover contributed by
selected plant groups for nine study fields in
Northeast Barry County (July 13-24, 1973).

 

 

 

 

Clover Bromegrass Oldfield
Plant groups 12 15 6 l3 l4 4 5 ll
Clover , 94 89 17
Bromegrass 98 100 98 55
Daisy Fleabain l 27
Wild lettuce 5 3
Quackgrass 3 l6 5
Timothy grass 2 l 28
Dandelion 6 5
Goldenrod 2 23
Queen Anne's lace 16
Yellow rocket 36
Regal'sjplantain
Bluegrass 7
Wild strawberry 13
Miscellaneous 3 5 2 l3 4

 

The percents listed are the mean values calculated
from 20 vegetative samples obtained from each of nine
fields. Scientific names are listed in Appendix A.

where:

a. is the proportion of the total individuals
in Sample A that belongs to species i

bi is the proportion in Sample B belonging to
spec1es 1, and there are s spec1es.

This is an elementary method of demonstrating the
degree of likeness or dissimilarity. Complete similarity
produces I = 1 while complete dissimilarity gives I = 0.
Similarity indices are presented in Table 2.

The results show that bromegrass and clover fields
are extremely similar in plant composition. Oldfield
communities vary widely in their similarity to each other
due to their heterogeneous composition.

Available Biomass: Insects
Captured by Sweep Netting

 

 

Fifteen fields were sampled utilizing a sweep net.
The data presented in Appendix B are the totals of five
samples taken in each field. Each total presented in this
table represents the number of insects collected for each
category in an area covering 312.5 square feet. The data
showing the numbers of insects for each sample that contri-
buted to these totals has been omitted for the sake of
brevity.

Clearly, not all insects in any area were captured.

A comparison of insects caught in the sweep net samples were

.va cameo
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26

ea vamflmoao

 

 

 

 

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pamflmoao mmmummeoum Hm>oHU

 

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IAGSEEOO ocean mo mmmcmxfia mo moummp mop mcwumuumGOEmo «mmofloofi muwHMHHEHmII.N manna

27

compared to those captured in the nylon screen tents in a
field considered to be representative of that major habitat
type (Table 3). The insects caught in each of the five
samples were totaled along with their respective tent counts.
Since the area sampled by the sweep net was 52 percent of
the area sampled by the cage, it was necessary to multiply
the sweep sample numbers by 1.92 to obtain the results.

The number of insects caught in the sweep samples
were divided by the total captured within the tent area.

The reciprocal of these proportions, multiplication factors,
are presented (Table 4) and when multiplied times the sweep
net numbers provides an estimate of the total insects
present. The data also demonstrates that sweeping effic-
iency varies with the structure of the vegetation.

As previously mentioned in the methods section,
replacement values were required for completeness in
analysis. Replacement values are also presented in Table 4.
Rather than arbitrarily assigning some value, the use of
replacement values provided the direction and relative order
of magnitude for those parameters not measurable.

By knowing the relative efficiency of the sweeping,
estimates of insect numbers per unit area were determined.
Calculation of the biomass per square foot for each group
was done be multiplying the mean dry weight per insect

group (Table 5) times the estimated number of insects per

28

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29

Table 4.--Multiplication factors used to convert sweep net insect
numbers to obtain a more accurate estimate of the absolute

 

 

 

number.
Community type Replacement
Insect group C10ver Bromegrass Oldfield value*
Coleoptera —- -- 6.77 1.10
Diptera (>4mm) 27.77 -- -- 38.46
Diptera (<4mm) 5.74 -- 15.62 4.02
Hemiptera 2.28 6.80 3.32 2.52
Hymenoptera (>4mm) 5.20 -- 4.69 6.80
Hymenoptera (<4mm) 1.27 -- 6.49 2.02
Leafhopper 3.77 2.93 5.81 4.02
Grasshopper -- 1.04 -- 4.69
Lepidoptera -- -- 7.29 5.46
Spiders -- 1.56 2.35 2.99

 

*Replacement values were required where inadequate data was
available for a specific field type. Replacement values were calculated
from the totals for all field types combined.
square foot for each group times the multiplication factor
for that group. The resultant values are presented in
Table 6.

The similarities of the insect groups comprising the
biomass of 11 fields is presented in Table 7. Generally,
fields of the same major community types demonstrated high
similarity indices in biomass composition. As would have
been expected, the mean value calculated for similarity
indices amongst all fields in the general vicinity of the
one square mile study area were more similar than would have
been expected if the fields had been chosen randomly from

various regions.

30

Table 5.--Mean dry weight for 26 invertebrate groups.

 

INSECT WEIGHTS IN NUMBER IN
MILLIGRAMS SAMPLE
Order Common groups Ave. dry wts. Est. live wt.

 

ColeOptera (<4mm)

Coleoptera (4-6mm)
Coleoptera (>4mm)

Diptera (>4mm)
Diptera (<4mm)
Hemiptera
HymenOptera (>4mm)
Hymenoptera (<4mm)
Hymenoptera
Homoptera (>4mm)

Homoptera (<4mm)

Homoptera
Lepidoptera 8
Hymenoptera
(symphyta) larva
Coleoptera larva
Collembola
Orthoptera
Lepidoptera
Lepidoptera
Araneida
Phalangida
Acarina
Thysanoptera
Neuroptera
Millipedes
Isopoda
Stylommatophora

Snout beetles &
mixed spp.

Mixed species

Ground beetles &
mixed spp.

Mixed species

Mixed species

Miridae & mixed Spp.

Mixed species

Mixed species

Ants

Mainly Otiocerus sp.

and other leathppers

Leafhoppers and spittle-
bugs

Aphids

Mixed species
Coccinellidae

Grasshopper & cricket
Microlepidoptera
Macrolepidoptera
Spider
Daddy-Longlegs
Mites

Thrips

Lacewings
Thousandleggers
Sowbugs

Slugs

.30
3.90

37.36
2.50
.10
2.20
1.50
.10
1.50

4.20

.60
.10

10.20
1.30
.10
10.00
2.50
19.10
5.30
15.30
.10
.10
4.80
46.90
3.70
18.40

.86
11.14

106.74
9.26
.37
8.15
5.00
.33
5.00

10.77

1.54
.40

51.00
5.20
.33
33.00
10.00
76.40
17.67
50.99
.30
.30
14.40
117.25
9.25
110.84

50

109

137

301
62
50

est.

171

34
est.

est.

est.
57
73
1000
1100

 

31

 

 

 

 

 

 

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32

 

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33

Available Bigmass: Ground Dwelling
Invertebrates

 

Virtually no reference has been made in the litera-
ture concerning the role of soil invertebrates as a food
source for pheasant chicks. The distribution of soil
dwelling organisms is poorly understood as is the methodo-
logy of sampling slugs and associated arthropoda.

The results of the slug and sowbug samples collected
in 9 experimental fields are presented (Table 8). For the
entire area sampled, an averaged of 11.52 slugs per sample
(.18 slugs/ftz) was calculated. If the slugs were evenly
distributed throughout the study area, a minimum of 3.3 mg
of additional biomass per square foot would have been
available.

Table 8.--Number of slugs and sowbugs collected from 6 in.

x 12 in. sample boards for selected study fields
(Sept. 19 - Oct. 7, 1973).

 

 

Slugs Sowbugs
Field N if 1 SD R i so

Clover 7 20 3.55 3:~ 3.29 .30 i --
Clover 12 20 24.50 i 9.72 6.30 i 3.85
Clover 15 20 20.70 i 6.64 4.60 i 2.48
Bromegrass 6 20 19.80 1 10.27 2.20 i --
Bromegrass 13 20 8.55 i 2.74 5.40 i 4.33
Bromegrass 14 20 16.75 i 5.06 11.65 i 5.87
Oldfield 4 20 2.95 i 3.74 6.20 i 3.69
Oldfield ll 20 .45 i .99 19.40 : 13.05
Oldfield 16 20 5.85 i 4.60 16.15 i 9.36

 

34

Predicted Insect Weights Versus
Actual Insect Weights

 

It was necessary to use estimates of insect weights
in this study as it would have been impossible to record the
weight of each individual insect and selected insect groups.
Even if the measurement of each insect had been possible, the
values and conclusions drawn from such data would have been
specific to this experiment. The establishment of estimated
mean values, application of the values with real data, and
the accuracy of results based upon these estimates is the
measure of their value. If, after testing, these estimates
remain relatively reliable, wider application makes the
estimates more valuable.

Figure 2 is a scatter plot demonstrating the corre-
lation between actual and predicted weights of total field
biomass. A correlation coefficient of .96 was found using

the data from one sample from each of 11 fields.

Predicted and Actual Crop Biomass

 

The crop contents of 63 chicks were weighed. These
measurements were compared with estimates derived by multi-
plying each insect group by estimated dry weights. A
correlation coefficient of .813 was calculated with explained
66 percent of the association between the two variables
(Figure 3).

Insects (including arachnida) and ground dwelling
invertebrates were evaluated separately. Ground dwelling

invertebrates presented problems in the determination of

Estimated weight of insects in the field samples (mg/ftz)

35

16.88 4r .'

15.68 1r

14.48 '-

13.28 ‘b O

12.08 1-

10.88 4-

8.48 «b

7.28 «r ’

 

.
6.08 _4 1 1 1 . 1 1 1. 1 l
8.33 9'57 11.02 12'37 13.71 15'06 15.41

Actual weight of insects in the field samples (mg/ftz)

Figure 2. Relationship between estimated and actual weight of insects in
the field samples.

36

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37

feeding preferences since their population numbers were
difficult to ascertain. The portion of the total insect
biomass was calculated for each insect group for 148 young
pheasants. This procedure was necessary because it was felt
that reliable estimates of invertebrate groups was restricted
only to those captured in the sweep net samples.

Weight Changes of Chicks
in Various Fields

 

Pheasant chicks were weighed daily for three days.
On the first day in the field large weight losses were
observed. After the initial adjustment of foraging for
their food, most chicks began to gain weight. Over a three
day period the weight gains often did not compensate for
large losses of weight during their first day in the field.
One field from each of the three major plant communities are
represented for each of the three time periods used. The
time interval between each set of study fields was approxi-
mately one week.

The weight changes were recorded as a proportion of
the body weight. This method of comparison was necessitated
because of large variations in body weights.

A one way analysis of variance was used to evaluate
the weight changes between each set of fields. No compari-
son was made between fields evaluated on different dates
because of the compounding problems of weather, plant
phenology and between field variation. The analysis of

variance statistics for each set of fields are presented in

38

Table 9. Significant differences were observed between the
chick weight gains for the three field types on each of the

sampling dates.

Feedinngreferences

 

Feeding preferences were calculated by a comparison
of a selected food to its availability. The analytical
techniques used evaluate feeding preferences utilized 90
pheasants taken from 11 fields. The biomass composition
varied with each field as was demonstrated in Table 6.

A table of correlation coefficients (Table 10) was
used to show the association between diets and availability
of 11 insect groups. Only those cases where both the diet
and food availability were known were used to calculate the
correlation coefficients. The number of valid cases used
are found in parenthesis beneath the correlation coeffi-
cients. Correlations based on few observations should be
viewed with caution.

Feeding Preferences Based Upon Physical
CharacteriEtics of Insect Foods

 

 

Characteristics of insect prey were evaluated to
establish which features influence feeding preferences of
the young pheasants. Of the 19 characteristics examined, 10
were significantly correlated with their respective avail-
ability (Table 11). The correlation coefficients that were

significant range from .3033 to .7677. Three of the

39

 

 

 

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HnuouHmmo HasoHvoa>umH .muommoaumuqo 1550A. .850Ao Hasvv. Hasvxo enavvo monHm Hooam
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NIB 2H mm‘ZOHm

 

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BUQmZH HHm¢AH¢>¢

 

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41

Table ll.--Correlation coefficients between the percent biomass in the
pheasant chick crops and the percent biomass present in the
field for 19 characteristics of insect prey.

 

Number of Correlation Significance

 

Characteristics crops (N) coefficient level
Walking 123 .4425 .01
Flying 60 -.1000 n.s.
Mode of Jumping 119 .5145 .01
locomotion Crawling 51 .7035 .01
Resting 17 .2657 n.s.
Minute (<2mm) 78 .0703 n.s.
Small (2-4mm) 120 .0856 n.s.
Size Medium (4-6mm) 126 .3033 .01
Large (6-10mm) 79 .0094 n.s.
Very Large (>10mm) 40 .0628 n.s.
Light brown/grey 117 .4284 .01
Color Brown/black 126 .4562 .01
Green (dark) 81 .3484 .01
Oval 103 .1860 n.s.
Shape WOrmlike 32 .7677 .01
Oblique 120 .4431 .01
Long appendages 73 -.0037 n.s.
Vertical Ground to 12 in. 125 .4485 .01
strata 12-36 in. 69 -.0811 n.s.

 

42

correlation coefficients were negative which reflects the
inability of the sampling methods to estimate these groups.

The significant correlation coefficients associated
with color were of the same order of magnitude with a range
of .3484 to .4284. This minor difference would not suggest
any food preference based upon color.

Three methods of locomotion, one size category,
three of the four colors, two shape categories and the
middle strata were highly significant. Since each insect
was assigned to one characteristic for each of the major
categories, could the jumping insects be related to the
oblique shaped insects? To answer this question the signi-
ficant correlations are presented in Figure 4.

Many of the criteria used to classify insects into
categories were correlated. Jumping and oblique shaped
insects were highly correlated (r = .987, p<.01) as were
crawling and wormlike insects (r = .987, p<.01). The insect
common to jumping and oblique shape categories was the
leathpper while crawling and wromlike insects consisted
of numerous insect larvae. These high correlations suggest
that wormlike or crawling insects were a measure of the
same group.

A Comparison of Physical Characteristics
of Pheasant Chick FoodsIEatenJin Three
Structurally Different Plant Communities
The proportion of an insect category found in each

cr0p was subtracted from its respective proportion available

43

 

These correlation coeficients are all significant (p<.01)
with a sample size ranging from 72 to 120.

Figure 4. Correlations between selected characteristics
of insect prey found in the pheasant chick crops.

44

in the field. This methodology allowed the data to be
analyzed with a one way analysis of variance test. Only
seven characteristics possessed sufficient sample sizes for
analysis (Table 12). Some of the means were negative values
indicating that chicks ate a higher proportion of a group
than was available.

Five of the seven insect groups evaluated were
significant (p<.05). Two groups, crawling and vertical
strata were highly significant (p<.01). From these results,
it would appear that vegetative structure alters feeding
patterns of pheasant chicks.

Age Contrasts in Feeding
BehaVIor

 

The proportion of crOp biomass consisting of selected
insect categories was used to contrast the feeding behavior
of three age groups of pheasant chicks. Only those cate-
gories with adequate sample sizes were compared (Table 13).

Only two groups, crawling and brown/black, were
significantly different (p<.05). These two groups have been
shown to be highly correlated (r = .987) and therefore should
be considered as two measurements of the same insect group.

Growth and Digestion
in the Laboratory

 

 

Pheasant chicks were confined to rearing pens in the
laboratory and weighed. Mean weights for five day intervals

are listed in Table 14. The growth recorded was much like

45

 

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mmmmqueuu.0H mHnma

46

 

 

 

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mom an mmocmummmum msHommm m>HumHmH mo mOGMHHm> mo mmmmHmndll.mH mHnma

47

Table l4.--Weight of pen reared pheasant chicks through

 

 

30 days.
Weight in gms.
Age N=8 (x : SE)

Hatch 21.27 i 0.39
5 days 34.56 i 1.27
10 55.23 i 2.52
15 90.32 i 5.68
20 115.27 1 7.23
25 157.77 : 10.07
30 198.17 : 13.54

 

that described for young pheasants in other studies and
provides a basis of comparison for growth rates in the
field (Loughrey 1951 and Suomalainen 1965). In addition,
these results demonstrated that these chicks had a growth
pattern similar to other strains of pheasants.

The results of the digestive rate studies show that
it took 132 :jl4 S.D. minutes for the chromium oxide to pass
the entire length of the digestive tract. Assimilation

rates were not monitored in these experiments.

DISCUSIONS AND CONCLUSIONS

Available Foods in the Study_Fields

The insect samples collected from the study fields
reveal several conditions which may play an important role
in determining the suitability of a specific field for
pheasant production. Data from this study suggests that a
crucial requirement for brood production would be the
quantity of available invertebrate biomass. The minimum
level of invertebrate biomass required by brooding pheasants
can usually be found in only densely vegetated fields. As
was previously pointed out, sparsely vegetated areas would
probably lack an adequate supply of insect biomass to sus-
tain growing pheasants. Support of this statement is
demonstrated by extremely low insect biomass found in the
row crops and the first year fallow fields mentioned in the
methods section. The weeds associated with newly established
fallow fields i.e., velvet leaf, lambs quarter, smartweed,
and ragweed do not host a large variety nor quantity of
invertebrate foods. Uncultiviated fields left alone for
several years soon become inhabited by biennials and

perennials and thus attract and perpetuate a multitude of

48

49

insect species and also sustain a greater standing crop of
insects upon which pheasant chicks feed.

General insect feeders such as pheasant chicks
appear to find a vegetatively diverse field more suitable
because the absence of one insect food can be readily
substituted for another. As was found throughout the 1973
season, certain insect species became abundant for a period
of time and then declined. Other species remained in the
field for the entire brooding season. The length of time
that a high biomass level of an insect pOpulation remained
in the field was dependent on the develOpmental time of that
species and the total time during which that species is an
available food source (Southwood 1966).‘ Insect species with
a rapidly peaking and declining population that can not
readily replenish itself may have limited value to foraging
predators. In contrast, an invertebrate species possessing
a short developmental time coupled with a longer reproduc-
tive period can continually replenish the available biomass
even though the peak population may not be as high. The
biomass level of each insect population followed through
time can be expressed with a curve. The composite of all
biomass curves for insect pOpulations reflects the total
available biomass at any point in time. A sudden rise or
fall in a single important insect pOpulation may have

important survival implications to the brooding pheasants.

50

The success of brooding pheasants in Bromegrass
Field 6 may have been due to the ability of leafhoppers to
continually replace that portion of their biomass removed by
the foraging chicks. Other invertebrate species such as the
land slug may provide a large biomass for an instant in
time but may not be able to replace that biomass removed by
the pheasants.

The topic of biomass levels through time should
receive careful consideration in any future feeding studies
of gallinaceous gamebird chicks. A single sampling window
has limited value and can be likened to a snapshot picture
while periodic sampling throughout the brooding period best
expresses the dynamic features encountered in field situa-
tions. The young pheasant's survival depends on an adequate
food supply through time and therefore food studies should
periodically monitor insect biomass throughout the entire
brooding season. Fulton and Haynes (1976) present the
methodology of periodic sampling.

The problem of varying biomass levels would not
appear to be as critical in heteorgeneous communities since
numerous species can substitute and replace other Species.
This condition may account for the brood success often
observed in oldfield communities. The ability of genera-
lized insect predators to switch from one food source to
another is important for survival. Wide variation of
pheasant chick food is well documented. Chick crops from

this study provide further evidence of this. Several crOps

51

contained only slugs, other crOps were filled with leafhop-
pers, while most crops contained assorted combinations of
invertebrate groups.

Full crops were most often encountered for those
chicks taken from heterogenious plant communities. In
addition, most of these crops contained a variety of insect
species. The evidence gathered in this study lends further
support to the theory that pheasant chicks as well as adults
are, indeed, opportunists.

The field that provided the highest biomass of
invertebrate foods was Bromegrass Field 6 with 100.19

milligrams/ft2

(9.6 lbs/acre). Following Field 6, were
Oldfields 4 and 5 with an estimated 99.65 and 71.95 mg/ft2
respectively. The remaining 8 fields possessed biomass
estimates ranging from 18.00 to 25.40 mg/ftz. It is
interesting to note that in 1973 at least one wild brood
inhabited Oldfield 4 and Bromegrass Field 6, the fields with
the highest biomass levels. Subjectively speaking, Oldfield
4 and Bromegrass Field 6 were good pheasant producing areas.
Wild broods were also observed at the edge of field 6 in
both 1974 and 1975.

One bromegrass field possessed the highest inverte-
brate biomass while the other two bromegrass fields
possessed extremely low biomass levels. An explanation for
this discrepancy is lacking. One possible explanation for

such a wide difference could be the relationship between

the bromegrass fields and the adjacent fields which might

 

52

have been effected differentially by agricultural practices
such as weed and insect control. A monoculture such as
bromegrass field is much more sensitive to change.

Clover fields were more predictable in terms of
biomass quantity as well as species composition. In the
clover fields evaluated, most insect groups were represented
and when compared with other field types, lower biomass
quantities were found. The sampling efficiency of sweeping
in clover fields was evaluated and found to be quite com-
parable to other field types (Table 3). However, underesti-
mates of biomass in clover fields could exist.

Another feature unique to clover fields was the
apparent difficulty of chicks to move through the tangled
network of stems below the vegetative canopy. Although no
detailed experimentation was made regarding vertical
stratification of available insect foods, it appeared that
most motile insects remained in the canOpy and thus were
more difficult for the small pheasants to reach. The ground
dwelling, moisture sensitive invertebrates were more
available in the feeding zones of foraging chicks. Ground
dwelling invertebrates were frequently found in chick crops
collected from clover fields. As a result of certain
structural features, clover communities probably retain
moisture better than other community types evaluated. This
factor could explain why more slugs were found in the crOps

of birds taken from clover fields. Another factor that

53

might have contributed to the high portion of slugs in crOps
is the fact that slugs constituted a large portion of
available biomass in clover fields.

Validity and Usage of
Estimated Biomass

 

 

A correlation coefficient of .96 was found between
the estimated insect biomass and actual biomass collected
from the sweep net samples. This correlation was based upon
one sample from each of eleven fields. A high correlation
was expected since the dependent variable was an estimation
of the independent variable. Such estimates possess inher-
ent sources of error. The mean dry weights per insect
group cannot be expected to explain all situations. For
example, the size of beetles may vary with the field types,
conditions of collection or season of the year.

Comments Concerning
the Chick‘s Diets

 

 

The insect groups that constituted a majority of the
pheasant's diet were generally larger, more common inverte-
brates such as leafhoppers, caterpillars, larger beetles,
true bugs, and slugs. Occasionally, large less common
invertebrates comprised a large portion of a few chick crops.
Collectively however, invertebrate groups such as earthworms,
snails, mites, millipeds and centipeds contribute little to
the pheasant Chick's diet under normal conditions. There-
fore, these invertebrate groups do not warrant any special

attention in establishment of estimated biomass levels.

54

Small invertebrate groups such as collembola, small
flies, small hymenoptera, and small bettles also provide
little food accounting for only 0.3 percent of the pheasant's
diet. In fact, nutritional value contributed by these small
insects may not equal the energy expended to capture them.

A notable exception to this statement was a single chick
which had its crop completely filled with 948 aphids, which
would suggest that this bird encountered a cluster of aphids

and took advantage of a food source.

Food Preferences

 

Establishment of feeding preferences are usually
calculated by a comparison of an animals' diet to available
foods. A table of correlation coefficients is provided to
show how the various available foods were selected by
young pheasants (Table 10). A notable positive correlation
exists between the percent of leathppers in the crops and
leafhopper availability. A correlation coefficient of .644
demonstrates a highly significant relationship (p<.0000).
This correlation would have been higher if several extreme
values had been eliminated. One explanation of these
deviate values is the fact that several chicks were observed
foraging in neighboring plant communities in which the
insect biomass was not known. Total restriction of chick
movement was impossible.

A second possible explanation could be the insect

distribution within each study field. Non-uniform and

55

clumped distributions are expected in oldfield communities.
Even homogeneous plant communities such as bromegrass and
clover may experience uneven insect distributions and thus
effect the calculation of feeding preferences.

A third factor that might influence the calculated
relationship between food availability and diets is the
fact that both values are estimates. This is an accepted
source of error.

Leathppers, according to this study, provide an
excellent means of evaluating feeding preferences. Gen-
erally, large numbers of leafhoppers were present in the
fields and lent themselves to sweep net sampling. According
to the absolute numbers from the tent samples 17 percent
were caught by sweeping in oldfields while 34 percent were
collected in bromegrass demonstrating the effectiveness of
sweeping. Since one species of leafhopper comprised the
majority of those captured, the uniformity of size provided
an excellent basis on which to estimate available biomass.

The negative correlations reflect the fact that the
presence of one insect group in diets is negatively related
to the presence of other groups in the field. Leathppers
in the field were negatively correlated with the presence
of large and small coleopterans, large dipterans, hemipte-
rans, large hymenopterans, and spiders in the crOps.
Collectively, these groups comprise 85 percent of the
biomass excluding leathppers. This pattern of negative

correlations can be observed to a lesser extent with other

56

insect groups. The negative correlations between spiders
and grasshoppers in crops and their availability in the
field reflects the difficulties of the sampling techniques.
These two groups were not properly sampled by sweeping.
Sweeping does not adequately sample areas commonly occupied
by spiders and crickets nor does sweeping truly represent
elusive grasshoppers.

Feedinngreferences Based Upon

Physical Characteristics of
Insect Foods

 

 

 

Examination of the relationships between the
characteristics of insect prey and their presence in crops
provides many interesting insights into the feeding
responses of young pheasants. Of the five size classes
evaluated, only the medium sized insects correlate signifi-
cantly (p<.01). One explanation for this high correlation
is the fact that leafhoppers comprise most of the biomass
for this size class.

Three of the four colors examined (light brown/grey,
brown/black, and dark green) yielded highly significant
correlations (p<.01). The three correlation coefficients
were not only highly significant but also very similar which
would indicate a lack of color preference.

Insect shapes were extremely difficult to evaluate.
Although two correlation coefficients were significant
(p<.05), the meaning of these findings was not clear. Worm-

like insects were eaten in prOportion to their availability.

57

Oblique shaped insects were also highly significant but
this could have been attributable to the large biomass of
leafhoppers.

Three vertical strata were examined with only the
ground surface of 12 inch strata showing significance. A
major problem with contrasting vertical strata was the fact
that many of the insects and invertebrate fauna may have
occupied all three strata at some time. Meteorological
conditions and diurnal movement dictate where most insects
will be found at a given time.

Examination of significant correlation coefficients
for physical characteristics of insect foods reveal that
they range from .3033 to .7677. Removal of the 2 correla-
tion coefficient associated with the characteristics of
worms limits the range to .3033 to .5145. The fact that
most of these correlations are of the same order of magni-
tude strengthens the postulate that young pheasants eat
what is available. Extreme values would have reflected
differential selection of foods.

A Comparison of Physical Characteristics

of Pheasant :hick Foods Eaten in Three
Structurallijifferent Plant Communities

 

 

 

Five of the seven insect categories tested were
significant. However, the two groups that were not signi-
ficant comprised a majority of the biomass for their res-

pective groups.

58

Walking insects were significantly different at the
.05 level. Examination of the mean values for the three
field types provides some insight as to why these field
types were different. A positive mean would indicate a lack
of preference because the scores were obtained by subtract-
ing the proportion of the insect in the crop from the
proportion found in the field. A negative mean would indi-
cate a preference. Walking insects were least preferred in
bromegrass and most preferred in clover with oldfields
intermediate. It appeared that vegetative structure was
somehow related to these apparent preferences. In four out
of the five significant tests the order of the means was
either bromegrass, oldfield and clover or the reverse.
Walking insects, crawling insects and large insects were
most preferred in clover while small insects and insects
occupying the 0-12 inch strata were least preferred.
Difference in the foods eaten in the three field types did
exist. It appeared that the feeding preferences shown here
reflect effects of plant structure. In spite of the
adjustments made to the insect numbers to account for the
differences due to vegetative structure, some error still
remained. Insect density could have also effected the

results.

Age Contrasts

 

Of the eleven physical characteristics of insect

prey evaluated, two were significantly different. One week

59

old chicks fed especially heavy on caterpillars. The reason
for this behavior is not fully understood although it is
suspected that the slow moving caterpillars experienced an
uneven distribution and were encountered more frequently by
the younger pheasants. This situation demonstrated the
ability of a small chick to feed upon very large inverte-
brates.

The second characteristic of statistical significance
was the brown/black colored insects. This group was com-
prised principally of beetles and ants, both of which were
difficult to capture by sweeping.

In spite of the 2 categories that were significantly
different, it is doubtful if various aged chicks fed

differently.

Weight Changes

 

Examination of the 3 day weight change for chicks
feeding in the experimental fields shows a significant
difference between each set of fields (p<.05) (Table 9).

The mean weight changes observed for each of the three
fields compared on July 3 are in the same order as that
observed for their respective biomass levels. The fields
with more available foods showed the most favorable weight
changes for those chicks feeding in these fields.

The fields evaluated on July 12 show that the chicks
in Oldfield 11 had the best growth of all the fields studied

in spite of the fact that the estimated biomass for that

60

field is quite low. Oldfield 11 was difficult to adequately
sample by sweeping because of the high timothy grass and for
this reason the biomass estimate appears to be low.

The third set of fields compared is difficult to
explain because of the unknown influence of strong winds
which may have been responsible for the loss of 9 of the 12
chicks in the clover field. This condition casts serious
doubt on any conclusions concerning the value of field 15.
Why were so many chicks lost in this field? Did these young
birds have to travel further to procure food and at this
point lose vocal communication with their foster hen
because of the noise created by the wind?

It is apparent that pheasant chicks do not fare well
for the first few days in the field. Had these broods been
measured over a longer period of time, better weight gains
would probably have been observed. It was necessary to
terminate this section of the study since these birds were
needed in the feeding preference work. However, five
pheasant chicks in field 5 were periodically weighed and
after an initial weight loss approached normal size at the
end of thirty days.

Nutritional Considerations
of Available Foods

 

 

The nutritional analysis of insect material was
ommited from this study as other studies have thoroughly

evaluated the nutritional values for numerous insect taxa.

61

The results of these studies are in good agreement (Beck and
Beck 1955, Cross 1966, Korschgen 1964). These data reveal
that the high protein levels and M.E. are available in insect
material.

As the study progressed, it became evident that slugs
frequently comprised a large portion of a Chick's diet. The
significant findings of this analysis was the extremely high
level of ash content of slugs as compared with insects,
almost 11 percent of the dry weight as compared to 3.3 per-
cent for insects (Cross 1966). Analysis of the ash content
left from the approximate analysis revealed a calcium con—
tent of 19.2 percent, which amounts to 2 percent of the
total dry weight of slugs. Beck and Beck (1955) claim that
beetles, grasshoppers and lepidoptera larva contain 1.208,
1.279 and 1.050 percent calcium by body weight respectively.

It is apparent that slugs can provide a abundant
source of calcium. If evidence becomes available pointing
to calcium as a limited factor in pheasant distribution,
slugs could provide a source of the needed calcium.
Korschgen (1964) investigated several sources of calcium and
concluded that pheasants can probably differentiate calcium
rich food sources such as the common land snail.

Another ramification of the role of slugs as chick
food was observed. During wet and cold days insect activity
declines while the activity level of slugs drastically
increases. Most insects seek cover and/or become quiescent

under these meteorological conditions which would minimize

62

their exposure to foraging pheasant chicks and thus effec-
tively reduce available foods. Under these conditions slugs
may provide a readily available food source.

When it was first discovered that slugs constituted
a large portion of the pheasant Chick's diet in several
experimental fields, the feeding behavior of the artificially
reared chicks was questioned. However, 3 of the 6 native
pheasant chicks collected from several locations in Michigan
had also fed on slugs. Examination of weather data for
these areas revealed that these chicks had been collected
following rain. Why have slugs been overlooked as pheasant
food in the past? Were the collection sites in southern and
central Michigan unique? The presence of slugs in the crOps
of young pheasants truly suggest opportunistic feeding
behavior.

Vegetation: Comments
and Suggestions

 

 

The biomass collected from the study fields suggests
that oldfield communities offer adequate biomass to fulfill
the food requirements of young pheasants. Oldfields also
provide more community stability than do either bromegrass
or clover. Two apparent reasons for this stability are
species diversity and lack of periodic disturbances.
Oldfields may remain in land retirement programs for a
decade thus providing nesting cover in the spring, brooding

cover in the summer and escape cover for the duration of the

63

year. However, the future of land retirement programs looks
dim as government subsidies dwindle. Agricultural economics
are not compatable with productive areas left idle.

These conditions reflect the importance of maximiz-
ing pheasant productivity of the residual lands available.
Several considerations may enhance productivity of these
areas. Pheasant broods are often observed feeding along
paths and mowed road shoulders. Examination of these out
areas reveal high insect populations which attract foraging
chicks. Several reasons could account for this interaction
of predator chicks and their prey. Available insects have
only one strata to occupy in cutover areas and are therefore,
easy prey. Insects may also seek the succulent shoots of
young plants becoming established in these areas. Roadsides
may also provide the flora which insect prey find attractive.

A possible cultural recommendation suggested by this
observation is the mowing of strips through oldfields.

These strips would provide the same function as roadsides
without the additional hazard of traffic. The mowed strips
could be the width of a farm lane and possibly spaced 100
yards apart. Too many mowed strips would increase the
chance of nest destruction. Experimentation of this
technique is suggested.

The roadside flora frequently includes bromegrass.
As has been previously shown, bromegrass can sustain
extremely high insect biomass. The evidence found in this

study suggest that bromegrass can be an important plant in

64

pheasant producing areas. Bromegrass interspersed with
forbes provides food and cover for general insectivorous
feeders such as pheasant chicks.

The value of clover or alfalfa fields for foraging
broods is questionable. The mobility of young pheasants is
somewhat hampered by the dense horizontal stem structure of
these plants. Furthermore, the evidence presented suggests
a marginal level of available foods and a large portion of
that food may remain in the plant canopy beyond the reach of
the small chicks. Under certain conditions clover fields
may provide abundant foods. In early June high population
levels of spittlebugs and green cloverworm are common and
appear to be very accessable to young pheasants.

Another problem of clover and alfalfa fields is the
conflict between cutting and pheasant broods. Early mowing
has been shown to destroy pheasant nests. Even if the young
escape, the cutover field offers little food and cover.

The values of legume fields as pheasant producing
areas is questionable. However, these fields do provide

excellent cover throughout much of the growing season.

SUMMARY

Three major types of plant communities were examined
and the invertebrate fauna that inhabit them was evaluated.
Several sampling techniques were used. The efficiency of
sweep netting which was evaluated varies with the plant com-
munity and insect species. The use of baited boards
provided a means of sampling a large portion of the slug
population. Some fields revealed high slug populations
while others did not.

Leafhoppers of the genus Otiocerus constituted a

 

large portion of available arthrOpoda biomass. This leaf-
hopper was extremely abundant in bromegrass communities.
The young pheasants exhibited no difficulty in capturing the
fast moving leathppers. The diet of young pheasants appears
to be a function of food availability. It should be
cautioned that this statement is based upon data which
minimizes the effects of insect density. Possibly a labor-
atory study utilizing varying insect densities could provide
the answer to this question.

Insect populations associated with three structurally

different plant communities have been studied. However, it

65

66

appears at this time that a vegetatively diverse community
offers more stability in the amount of insect foods than the
homogeneous communities studied.

No behavioral problems were detected with the
experimental pheasant chicks. The crop contents of both
native and experimental chicks were similar. The experimen-
tal pheasants, if allowed sufficient time to adjust to their
new environment, demonstrated growth comparable to native
chicks.

Empirical data suggests that usage of roadsides by
brooding pheasants seems to be related to insect food found
in these cutover areas. Cutting strips in fields used as
brooding areas could provide advantages offered by roadsides
without the danger of traffic.

Oldfields have demonstrated their role as important
pheasant producing areas. This study has, in part, brought
forth some of the possible reasons why oldfields produce
pheasants.

The vegetative composition of plant communities and
the knowledge of the insect communities inhabiting them
provides another useful management tool. This information
provides a basis upon which communities can be evaluated for
available pheasant foods and possibly indicates how the food

sources in these communities can be monitored.

LITERATURE CITED

LITERATURE CITED

Beck, J. R., and Doris 0. Beck. 1955. A method for
nutritional evaluation of wildlife foods. J. Wildl.
Mgmt. 16:398.

Buss, I. O. 1946. Wisconsin pheasant papulations. Wisc.
Conser. Dept. Publ. 326, A-46. 184 pp.

Buss, A. C. 1963. Life Histories of N. A. Gallinaceous
Birds. Dover Publ. Inc. New York. 490 pp.

Cross, David J. 1966. Approaches toward an assessment of
the role of insect food in the ecology of game birds
especially the partidge (Perdix perdix). Ph. D.
Thesis. University of London, London, England.

 

Dalke, Paul D. 1935. Food of young pheasants in Michigan.

Erickson, Arnold B., D. B. Vessal, C. Carlson, and C. T.
Rollings. 1951. Minnesota's most important game
bird--the pheasant. Flicker 23(3), 23-49.

Ford, J. H., H. Chitty and A. D. Middleton. 1938. The food
of partidge chicks (Perdix perdix) in Great Britian.

 

Fried, Lousi A. 1940. The food habits of the ring-necked
pheasant in Minnesota. J. Wildl. Mgmt. 4(1):27-36.

Fulton, W. C. and D. L. Haynes. 1976. The influence of
population maturity on biological monitoring for
pest management. Michigan Agric. Exp. Stn. Journal
Article No.

Ginn, William E. 1962. The ring-neck pheasant in Indiana.
Pittman Robertson, Bulletin No. 6. 107 pp.

Korschgen, L. J. 1964. Foods and nutrition of Missouri and

Midwestern pheasants. N. A. Wildlife and Natural
Resources Conference Transactions 29:159-180.

67

68

Leffingwell, Dana J. 1928. Occasional papers of the
Charles R. Conner Museum. State College of Washing-
ton. Pullman, Washington, 28 pp.

Loughrey, Alan G. 1951. A food habit study of juvenile
ring-necked pheasant on Pelee Island, Ontario.
Unpublished M. W. Thesis. University of Western
Ontario. London, Ontario. 1-60 pp.

MacMullen, Ralph A. 1957. The life and times of Michigan
pheasants. Michigan Department of Conservation,
Lansing, Michigan. 63 pp.

Martin, Dennis D. 1972. Evaluation of forest clearings for
insect availability to wild turkeys. Unpublished
M. S. Thesis. Virginia Polytechnic Institute and
State University. Blacksburg, Virginia.

Murdock, W. W., F. C. Evans, and C. H. Peterson. 1972.
Diversity and pattern in plants and insects.
Ecology 53(5):819-828.

Ruesink, William G. and Dean L. Haynes. 1973. Sweepnet
sampling for the Cereal Leaf Beetle, Oulema
melanOpus. Environmental Entomology 2(2)l6l-172.

Shick, Charles. 1952. A study of pheasants on the 9000
acre Praire Farm, Saginaw County, Michigan. Mich.
Dept. Cons. 134 pp.

Southwood, T. R. E. 1966. Ecological Methods. Methuen and
Co. Ltd., London. 391 pp.

Southwood, T. R. E. and D. J. Cross. 1969. The Cology of
the partridge III. Breeding success and the
abundance of insects in natural mabitats. J. An.
Ecol. 38:547-553.

Suomalainen, Paavo and Esko Suomalainen. 1965. Studies on
the activity patterns of pheasant chicks. Ann. Acad.
SC]... Fenno A. IV. 97:10-15.

United States Department of Agriculture. 1957. National
Cooperative Soil Survey Maps: Barry Conty. USDA
Soil Conservation Service. Washington, D.C.

Wagner. F. H., D. D. Besadny and C. Kabat. 1965. P0pula-
tion ecology and management of Wisconsin pheasants.
Wisc. Conserv. Dept. Tech. Wildlife Bull. No. 34
168 pp.

APPENDICES

APPENDIX A

APPENDIX A

SOME COMMON PLANTS OF NORTHEAST
BARRY COUNTY OLDFIELDS

Common name

Scientific name

 

Bluegrass
Bromegrass
Burdock

Clover (Red Mammoth)
Curled dock

Daisy fleabane
Dandelion
Goldenrod

Ground cherry
Horseweed
Milkweed

Plantain (Regal's)
Plantain (Staghorn)
Quackgrass

Queen Ann's Lace
Ragweed

Smartweed

Sweet clover
Teasel

Thistle

Timothy

Wild flax

Wild lettuce

Wild rose

Yellow rocket

2.92 sp-

Bromus inernis
Arctium minus
Trifolium pratense
Rpmex crispus
Erigeron strigosus
Taraxacum officinale
Soidago nemoralis
Physalis heterophylla
Erigeron canadensis
AsclepIas syriaca
Plantago rugeIii
Plantago lanceoIata
Agropyron repens
Daucus carata
Ambrosia artemisiifolia
Polgonum pennsylvanicum
Melitotus officinalis
Dipsacus sylvestris
CirSium sp,

Phleum pratense
Coreopsis tinctoria
Lactuca canadensis
Rosa sp.

Barbarea vulgaris

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

69

APPENDIX B

INSECT NUMBERS COLLECTED BY SWEEPING 312.5 ft

APPENDIX B

AREAS PROM FIFTEEN STUDY FIELDS (July 3-18, 1973)

 

 

 

 

FIELD TYPE
Invertebrate Clover Bromegrass Oldfield Fallow Wheat Brush
9m“? 3 7 9 12 15 6 13 14 4 s 11 16 1 2 10
Coleoptera 4 58 351 15 27 6 7 10 26 42 27 14 4 4 7
(<4nIn)
Coleoptera 10 23 45 33 21 2 3 ll 17 19 9 12 4 2 10
(Mun)
Diptera 5 10 41 70 34 4 10 2 14 33 10 7 l 7 5
(Man)
Diptera 746 248 385 163 433 184 496 266 758 211 93 105 90 73 139
(<4uu0
Hemiptera 4 92 174 79 76 31 14 12 59 155 26 27 27 8 26
(>4mm)
Hemiptera 9 58 31 40 123 2 3 7 23 8 53 28 49
(<4mm)
Hymenoptera 3 2 8 S 1 2 2 2 1 l 2 2 2 l
(>4mm)
Hymenoptera 40 45 81 90 82 50 186 42 171 63 38 35 64 4 27
(<4uu0
Ants 2 2 12 l 14 15
Leafhoppers 153 243 155 54 72 2356 329 588 979 532 124 76 77 l 71
(>4mm)
Leafhoppers 65 95 79 22 123 45 13 33 88 20 9 33 20 8 65
(<4mm)
Aphids 137 10 7 3 3 44 3 2 19 38 112
Lepidoptera 1 4 1 3 l 2
larvae(1>cm)
Lepidoptera 18 4 24 1 4 l 2 l 3 4 3 3
larvae(<1cm)
Coleoptera 5
larvae(>6mm)
Coleoptera 1 3 1 1 ll 8 l
larvae(<6mm)
Collembola 1 S9 1 3 2 1 3
Grasshopper 2 6 1 3 12 6 7 8 l9 2 2 1 1
Lepidoptera l l 2 1
adult(>1cm)
Lepidoptera 3 5 4 2 18 4 2 2 S l l 2 7
adu1t(<1cm)
Spider l l l 5 4 5 2 1 3 2 l l
(>4mm)
Spider 1 l 5 2 3 2 5 9 7 1 2 16 1 18
(<4mm)
Daddy long- 1 1
legs
Mites 3 1 1 14 23 12 3 5 2 l 4
Thrips 2 3 1 2 3 2 7 l 2 1 1 20
Pscoptera 3 2 1 3 1
Tbtal 1197 894 1410 584 1070 2723 1082 996 2203 1115 372 406 358 156 556

70

 

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