122 915 THS l ml "”0"“ 3 1293 10239 43 3 . U I 1'. ’MiChigan State s, U . 'ty "HES“ This is to certify that the thesis entitled USE OF THREE SOUTHERN MICHIGAN LAKES BY WATERBIRDS DURING SPRING MIGRATION presented by Douglas Arnold Reeves has been accepted towards fulfillment of the requirements for Fisheries 6 Wildlife M.S. degreein Date May 12) 1980 0-7839 OVERDUE FINES: 25¢ per day P" “U .j {{fl-‘Mv ~ mm mam “turning. ‘ .‘h‘ ‘23.. ‘3‘":1!!! ._ P1.“ "I M" ”to w dam from ctrculamtion new USE OF THREE SOUTHERN MICHIGAN LAKES BY WATERBIRDS DURING SPRING MIGRATION BY Douglas Arnold Reeves A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Fisheries and Wildlife 1980 ABSTRACT USE OF THREE SOUTHERN MICHIGAN LAKES BY WATERBIRDS DURING SPRING MIGRATION By Douglas Arnold Reeves Daily counts of migrant waterbirds were conducted on three southern Michigan lakes during spring 1978 and 1979. Numbers and locations of waterbirds were recorded by species on lake outline maps. water depth, aquatic macrophytes. and benthos were sampled along transects on the lakes. Levels of the habitat variables were compared with distributions of waterbirds, by species, using stepwise multiple regression. Comparisons of the spatial distributions of four Ayggngspp. were made using a niche overlap measure. Avian species come position and extent of use varied between lakes. Although the distributions of mallard (Agggyplatyrhynchos), canvas- back, (Ayggzg_valisneria), redhead (A, americana), scaup (A. affinis, A, QAEAAA), ring-necked duck (A, collaris), red- breasted merganser (Mgggg§_serrator), and American coot (Eggégg_americana)‘were described to varying degrees by sub- sets of the habitat variables, the distribution of bufflehead (Bucephala albeola) was not. Niche overlap among the A1522; spp. was greatest early in the season. Canvasback and ring- necked duck distributions overlapped least. Scaup and red- head distributions overlapped most. Species dominance Douglas Arnold Reeves interactions and differences in foraging strategy are hypothe- sized as the mechanisms that separate the Aythya spp. during spring migration. ACKNOWLEDGEMENTS Funding for this project was provided by the United States Environmental Protection Agency through the Clean Lakes Program. I thank Harold Prince, my research advisor, for his guidance throughout this study and for his careful editing of the manuscript. I thank Clarence McNabb for serving on my research committee and for providing helpful sug- gestions concerning collection of macrophyte and benthos data. Don Deaver also served on my research committee and provided suggestions on the manuscript. I wish to thank Richard Kaminski for kindly providing direction during the project design and making helpful suggestions concerning data collection. ‘ Finally, I am grateful for the assistance of Rick Rusz, who helped collect data on Lake Lansing, and my wife Dianne who recorded data for me on her "days off." ii TABLE OF CONTENTS Page LIST OF TABLES ........ , ........... ,..-...-..-- ..... ’ ..... iv LIST OF FIGURES ...................................... v INTRODUCTION ......................................... 1 DESCRIPTION OF THE STUDY AREA ........................ 3 METHODS AND MATERIALS ................................ 6 RESULTS .............................................. 11 Social Activity .................................. ll Waterfowl Use Within Lakes ....................... 15 Lake Lansing ................................. 15 Lake O'Hills ................................. 18 Park Lake .................................... 21 Species Relationships Among the Aythya spp. ...... 23 Lake Communities ................................. 27 Aquatic macrophytes .......................... 27 Benthos ...................................... 30 Relationships Between Waterbird Use and Habitat Variables ............................... 32 DISCUSSION ........................................... 35 LITERATURE CITED ..................................... 39 APPENDIX ............................................. 41 iii LIST OF TABLES Table Page 1 The number of waterbird use-days, by species, as determined from daily ground censuses,fiarLake Lansing, Park Lake, and Lake O'Hills during the periods 7-30 April, 1978 and 24 March through 1 May, 1979 ....... 12 2 Total waterbird density (numbers/hectare), by year, for Lake Lansing, Lake O'Hills, and Park Lake ............................... 14 3 Percentage of waterbirds observed feeding, by species, during morning ground counts .... 16 4 Directional niche overlaps of the Aythya spp. on Park Lake calculated for 2 our day periods in 1978 ............................. 5 Percent occurrence, by species, of aquatic macrophytes on the three study lakes ........ 28 6 Distribution, by depth, of the common aquatic macrophyte species on the three study lakes ................................. 29 7 Frequency 8f occurrence and mean density (numbers/m ) of benthos taxa found in samples taken on the three study lakes .............. 8 Results of stepwise multiple regression analysis (P<.l) relating waterbird abundance with selected environmental variables for Park Lake ................................... 34 iv Figure A-l A-2 LIST OF FIGURES Page Location and relative sizes of the lakes on which waterbird studies were conducted .... Distribution of waterbird use over Lake Lansing during the spring migrations of 1978 and 1979. Use-areas based on a com- posite of use during both years are identified ................................... Distribution of waterbird use over Lake O'Hills during the spring migrations of 1978 and 1979. Use-areas based on a com- posite of use during both years are identified ................................... Distribution of waterbird use over Park Lake during the spring migrations of 1978 and 1979. Use-areas based on a composite of use during both years are identified ...... Niche overlaps and population levels of the A th’a spp. on Park Lake during spring 1979. OéerIaps were calculated by summing species by area, over four day periods ............... Location of transects on Lake Lansing ........ Location of transects on Lake O'Hills ........ Location of transects on Park Lake ........... 22 26 41 42 43 INTRODUCTION Hydraulic dredging is being tested as a lake restoration technique on Lake Lansing, Michigan. Much of the littoral zone will be dredged to a depth of 3-4 m. Studies on the impact of dredging are being conducted on physical, chemical, and biotic components of the lake. The predredging status of macrobenthos, phytoplankton and aquatic macrophytes have been evaluated by Siami (1979) and Wilson (1980). Because few waterbirds use Lake Lansing as a breeding area, significant numbers of birds can be observed on the lake only during spring and fall. Although some birds probably use the lake only because it provides refuge from hunting during autumn, during spring they may use any locally available habitats without being disturbed by hunters. Most springtime activity occurs during the month of April. Congeneric species are often found together on lakes at this time. Lists of migrant species are available for some Michigan areas (3g. , Lerg 1975, and McWhirter and Beaver 1977) but associations of species on lakes are not well understood. Studies relating spatial organization, behavior, and habitat preferences are needed to provide additional information about species interactions. Information from other areas may provide some sug- gestions as to how migrant waterfowl might respond to, and behave while on, Michigan lakes. For example, Thornburg (1973) and Sangster (1977) presented evidence that different waterfowl species respond to different macrohabitats (lakes or riverine pools) during migration. Also, Alexander and Hair (1979) reported species dominance relationships among the Aythya spp. on wintering areas. The purposes of this study were to evaluate pre-dredging use of Lake Lansing and two other nearby lakes by waterbirds, to determine habitat preferences by the waterbirds, and to investigate niche overlap relationships among the Azthya spp. during spring. DESCRIPTION OF THE STUDY AREA The study area includes three shallow, waterwater lakes in south-central Michigan (Figure 1). All three lakes have substantial numbers of houses, cottages, or apartment buildings along their shores. Lake Lansing is a natural basin, 182 hectares in size. It occupies portions of sections 2, 3, 10, and 11 of T 4 N, R l'W, Meridian Township, Ing- ham.County. Although the lake has a maximum depth of 11.3 meters (Humphrys and Green 1962), approximately 77% of it is contained in the zone that lies shallower than the 3 meter depth contour (Mich. Cons. Dept. 1939). At least 38 species of aquatic macrophytes occur in Lake Lansing (Wilson 1980). During midsummer the most conspicuous species is the macro-alga known as muskgrass (Chara globularis Thuilln). Common vascular hydrophytes (nomenclature following Scott and Wasser 1979) are naiad (Najas flexilis Willd.), waterstar mudplantain (Heteran- thera dubia Jacq.), American wild celery (Vallisneria ameri- g§3§.Michx.), common hornwort (Ceratophyllum demersum L.), cattail (EXEEE sp. L.), and bulrush (Scirpus sp. L.). Lake O'Hills is a 12 hectare impoundment that was created for recreational and aesthetic purposes in conjunction with a housing project. It was created in 1972 and is located in sections 9 and 10 of T 4 N, R l W, Meridian 3 2)» Park Lake Clinton County | Lake lnghgm ty . oun Lake a Lansnng O’The East Lansing 9 l 2 3 ‘l Kilometer Figure 1. Location and relative sizes of the lakes on which waterbird studies were conducted. Township, Ingham County. The approximate maximum.depth of Lake O'Hills is 3 meters. Most of the lake is included in the 2-3 meter depth zone. Muskgrass and naiads are the most common macrophytes in Lake O'Hills. Other species present in the lake are largeleaf pondweed (Pctamogeton amplifolius Tuckerm.), curlyleaf pondweed (POtamogetOn criSpus L.), and fennel- leaf pondweed (Potamogeton peerinatus L.). Patches of cattail make up the small amount of shoreline cover. Park Lake is a natural basin located in sections 28 and 29 of T 5 N, R l W, Bath Township, Clinton County. It has a surface area of 73 hectares and a maximum depth of 8.2 meters (Humphrys and Green 1962). Approximately 92% of the lake is shallower than three meters (Mich. Cons. Dept. 1939). Muskgrass is the most conspicuous macrophyte on Park Lake. Common vascular hydrophytes include largeleaf pond- weed, fennelleaf pondweed, naiad, white waterlily (Nymphaea sp. L), cowlily (Nuphar sp. Sm.), watermilfoil and water- star mudplantain. Shoreline cover includes bulrush, cat- tail, and swamp loosestrife (Decodon verticillatus L.). METHODS AND MATERIALS Complete counts of waterfowl were made each morning at Park Lake, Lake Lansing, and Lake O'Hills beginning on the first day that Park Lake was ice free. The counts were conducted throughout spring until no more than twenty water- birds were observed on Park Lake. During 1978 the starting time for the censuses varied from 0700 EST to 1100 EST. During 1979 all censuses were conducted beginning between 0700 EST and 0745 EST. A 10-60X variable power spotting scope aided field observations. During the censuses numbers by species and locations of waterbirds were recorded on field maps. Precise locations of birds were recorded by triangulation using aerial photographs to identify land- marks. Locations of flocks including more than 20 indivi- duals were determined in a similar manner except that lflmits of the distribution of the flock were determined in addition to the flock center. The numbers of individuals engaged in feeding, resting, and courtship activities were also recorded during 24 of 32 mornings in 1979. Grid systems were constructed on acetate outline maps of each of the lakes such that each square in the grid represented 0.25 ha (50 m X 50 m) of lake surface. The acetate maps were superimposed over each daily field map and the number of birds, by species was recorded for each square in the grid. In instances where flocks occupied more than one square the number of birds in the flock was distributed evenly (to the nearest whole bird) over each occupied square. One bird from one daily count was considered to represent one waterbird use-day. Daily species distributions were summed over the season, then all species were summed for each grid. The result was a distribution of total waterbird use-days for each 50 m X 50 m square area on the lakes for the season. Finally isopleths of bird use-days were generated by enclosing grids that contained more than a specified number of use- days. The isopleths for each year were compared and by occular estimation use-area boundaries were drawn where minima of bird use surrounded a maximum or where a minimum divided two maxima. Chi-square goodness—of-fit was used to test the dis- tributions of common waterbird species on the lakes. Expected values for the test statistic were calculated by multiplying the total number of use-days for the species by the proportion of the lake surface that was included in the use-area. Only those species for which the yearly total amounted to fifty or more use-days were tested. Each lake-year combination was tested separately. Directional niche overlap probabilities were calcuated for the purpose of examining spatial interrelationships among the Aythya spp. on Park Lake using the four use-areas as separate reSources. At least six. niche overlap indices have been proposed. The most recent and readily applicable are the Petraitis (1979) and Hurlbert (1978) techniques. Petraitis' technique was chosen over Hurlbert's for two reasons. First, it is directional, (that is, it allows examination of overlap by each species onto the other species) and second, it calculates a unique value for every dis- tribution of the two species of interest. Although the Hurlbert technique is more easily understood and it can be calculated to include areas where only one of the species occurs, it calculates the same overlap for two distributions (Hulbert and Keith 1978, Petraitis 1979). Petraitis' over- lap value (¢) is a more abstract way of describing species overlap. It is the probability that the two species utilize the resources (in this case areas) equally. Petraitis' overlap is calculated from the equation: ¢ = rE where 9 is species overlap, r is the number of resource levels (in this case areas), and E is defined by the equation E = £(plj log r ij) - 2(plj log r plj) where pij for this study is the proportion of individuals of species i that are observed in area j. Species overlaps were calculated using totals that were obtained by summing species use, by area, over four day periods. Summing over four day periods makes general seasonal relationships apparent while masking daily fluctuations. After use-areas had been determined transects were chosen for the collection of vegetational, depth and benthos data. Transects were chosen so as to include heavily used areas, areas that received moderate use, and low use areas (Figure A-l through A-3). Park Lake and Lake O'Hills were sampled most intensively because they were most extensively used by waterbirds. Data were collected during June and July 1979. Water depth was measured to the nearest one- tenth meter at intervals of 10 meters from shore using a 2 weighted sounding line. A 0.25m. weighted wooden frame 2 containing 25 equal 0.01m squares was used to determine percent occurrence of aquatic macrophytes. The frame was lowered into the water and the number of occupied 0.01m2 squares was recorded for each taxon. Percent occurrence was calculated as the ratio of the number of occupied squares to 25 (the total number of squares). Vegetational data were collected from a canoe in shallow water and by swimming in deeper water. Benthos samples were collected using a 15.2 cm X 15.2 cm ponar grab. Four or five samples were collected on each transect depending on transect length. A sample was taken at each end and one each at one-third and two-thirds the length of the transect in most cases. If a fifth sample was collected it was taken at the mid- point of the transect. Samples were transported to the laboratory where they were examined within twenty-four hours after collection. The samples were screened through 10 a number 30 U.S. standard seive (595 microns) and placed in a flat porcelain lined pan for examination. A liberal amount of sucrose solution (2 liters water/l kg sucrose) 4 was applied and the samples were stirred vigorously to dis- lodge invertebrates from the detritus matrix. Benthos from each sample were counted by taxon and preserved together in 90 percent ethanol. Later the alcohol was decanted off and the invertebrates were placed in an aluminum boat, oven dried at 60°C for 24 hours, and weighed to the nearest milli- gram on an electronic balance. Multiple regression analysis relating waterbird species to environmental variables was done on the CDC 6500 computer at Michigan State University using procedures outlined by Kim and Kohout (1975) in the McGraweHill manual for version 6.0 of the Statistical Package for the Social Sciences. RESULTS The 1978 spring migration lasted from 7 April until 30 April (22 days). Totals of 1385, 456, and 6770 waterbird use-days representing 17, 9, and 20 species, respectively, were observed on Lake Lansing, Lake O'Hills, and Park Lake (Table 1). Spring migration was much more protracted in 1979. The 39 day census period began on 23 March and ended on May 1. Totals of 8599, 1783, and 22612 use-days repre- senting 23, 14, and 24 species were observed on Lake Lansing, Lake O'Hills, and Park Lake during the 1979 season. Compared with 1978 this represents 6.2, 3.9, and 3.3 times as many use-days. Seasonal waterbird abundances varied by lake (Table l) . American coot (Fulica americana Gme.) was the most common species on Lake Lansing. Scaup (Aythya affinis Eyton and A, marila L.) and mallard (Anas platyrhynchos L.) were the most common species on Lake O'Hills. The Aythya spp. were most common on Park Lake. Densities (use-days/hectare) of waterbirds were greatest on Park Lake and least on Lake Lansing (Table 2). Social Activity Waterbirds were observed feeding, resting, and engaged in courtship behavior during the 1979 morning counts. Less 11 12 Table 1. The number of water bird use-days, by species, as , determined from daily ground censuses, for Lake Lansing, Lake O'Hills and Park Lake during the periods 7-30 April, 1978 and 24 March through 1 May, 1979. Lake Lansing Lake O'Hills Park Lake (183 ha) (12 ha) (73 ha) Species 1978 1979 1978 1979 1978 1979 Gavia immer Brun. 16 46 3 15 Podiceps auritus L. 2 162 1 14 104 Podiceps nigricollis L. 7 Podilymbus podiceps L. 59 55 1 5 57 63 Branta canadensis L. 1 32 24 92 28 70 Aix sponsa L. 4 2 22 Anas americana Gme. 8 16 31 24 Anas strepera L. 4 5 Anas crecca L. 2 Anas platyrhynchos L. 65 195 228 514 50 192 Anas rubripes Brew. 5 8 1 1 23 Anas acuta L. 5 Anas discors L. l 4 1 34 14 Anas clypeata L. 2 1 9 Aythya valisneria Wil. 21 23 2 7 790 2172 Aythya americana Eyt. 28 35 4 238 1268 Aythya collaris Don. 14 52 33 220 1167 Aythya affinis Eyt., A. marila L. 254 276 133 925 3586 12576 Bucephala albeola L. 41 78 12 137 309 265 Bucephala clangula L. 9 4 26 81 Mergus cucullatus L. 5 Mergus serrator L. 170 908 4 8 Mergus merganser L. 4 3 Table l. (cont'd.) 13 Lake Lansing Lake O'Hills Park Lake (183 ha) ' (12 ha) (73 ha) Species 1978 1979 1978 1979. 1978 1979 Oxyura jamaicensis Gme. 8 64 5 67 104 Fulica americana Gme. 651 6634 3 54 1264 4374 Larus argentatus Pont.,Ih delawa- rensis 0rd. 49 23 23 2 Larus philadelphia 0rd. 6 Total 1385 8599 456 1783 6770 22612 14 Table 2. Total waterbird density (numbers/hectare), by year, for Lake Lansing, Lake O'Hills, and Park Lake. Lake 1978 1978 Lake Lansing 7 47 Lake O'Hills 38 148 Park Lake 93 309 15 than 10% of the individuals of all species, except buffle- head, (Bucephala albeola L.) exhibited courtship behavior. Forty-eight percent of the bufflehead were engaged fincourt- ship. Between one-third and two-thirds of all waterbirds were feeding during the censuses (Table 3). Chi-square tests indicate that a significantly (P<0.05) greater per- centage of red-breasted merganser (Mergus serrator) were observed feeding compared with other species. American coot had the next highest feeding percentage. Approximately 50% of the redhead (Aythya americana), canvasback (A. valis- neria), scaup, and bufflehead observed were feeding. Ring- neck duck (A. collaris ) and mallard fed the least. Waterfowl use Within Lakes Lake Lansing Approximately 7.5 times as much of Lake Lansing was used in 1979 ('used' here meaning 10 or more use-days/0.25 ha grid) as compared to 1978 (Figure 2). Use did not exceed 115 bird days ina grid during either year. Six use-areas were outlined in Lake Lansing based on the isograms. Chi-square goodness-of-fit tests indicated that all species, except pied-billed grebe (Podilymbus podicgps) during 1978, and horned grebe (Podiceps auritus) during 1979, were distributed unevenly over the use-areas on Lake Lansing during both years. Area 1 (Figure 2) includes approximately 17 hectares in the northwest portion of the lake. It was used most 16 Table 3. Percentage of waterbirds observed feeding, by species, during morning ground counts. Total Number Percent Species Observed Feeding Red-breasted merganser 458 79 ba American coot 7171 62 c Canvasback 1120 52 d Bufflehead 132 50 d Scaup spp. 6313 48 de Redhead 569 47 de Mallard 102 36 e Ring-necked duck 726 35 e aPercentages followed by the same letter are not different (P< .05). 17 .powmwucopw mum whom» anon wawuau on: mo ouwmomaoo n no momma anomalous .mmma pan msma mo cowumuwwa magnum one magnum Madonna oxwg Ho>o on: vufinuoumz mo soaunnwuumwn .N oudmwm 18 by mallard. Area 2 (20 hectares in the north-central portion of the lake) was relatively unused during the 1978 season. During 1979 it accomodated fairly large numbers of ruddy duck, Oxyura jamaicensis) American coot, and common loon (Gavia immgr). Area 3 is a 66 ha area in the central portion of the lake that received little use by waterfowl. Area 4 is 28 ha in extent. It was used by pied-billed grebe, scaup, bufflehead and American coot. Use-area 5 is a 19 ha area that was used by pied-billed grebe. Area 6 has a surface area of 33 ha. It was used by common loon, horned grebe, pied-billed grebe and red-breasted merganser. The distributions of scaup, red-breasted merganser, and American coot over use areas on Lake Lansing were sig- nificantly different (P<0.01) between years. Lake O'Hills Approxflmately 3 times as much of Lake O'Hills was used by waterbirds during the 1979 season as was used during 1978 (Figure 3). Use did not exceed 85 bird-days on any grid during either year. Based on the isograms five use-areas were delineated in the lake. Chi-square goodness-of-fit tests indicated (P<0.05) that, except for mallard in 1978, waterbirds were distributed unevenly over Lake O'Hills. Area 1 (Figure 3) occupies 1.5 ha. It received light use during 1978 but was used by mallard in 1979. Area 2 is a 3 ha area that was used by ring-necked duck, scaup, and bufflehead. Area 3 is a 1.5 ha area that received little use. 19 Figure 3. Distribution of waterbird use over Lake O'Hills during the spring migrations of 1978 and 1979. Use-areas based on a composite of use during both years are identified. 20 mxmw 38.53 85.3: a ....... .m ouswdm mnmw 21 Area 4 has a surface area of 2.2 ha. It was used by mallard, Canada goose (Branta canadensis), scaup, and bufflehead. Area 5 includes 3.9 ha. It too, was used by Canada goose, mallard, scaup, and bufflehead. Chi-square analyses indicated that the distributions of mallard and scaup over Lake O'Hills varied significantly (P<0.01) between years. Park Lake Although 3.3 times as many waterbird use-days were counted on Park Lake during 1979 as compared to 1978, only 1.5 times as much of the lake surface was used. Four use- areas were identified on Park Lake based on isograms of bird use (Figure 4).. Chi-square goodness-of-fit indicated that during 1978 pied-billed grebe use was distributed evenly over the use areas. Other species had uneven distributions. Area 1 (Figure 4) includes 13 ha of Park Lake. It was used by redhead, scaup, bufflehead, and American coot. Area 2 is a 22 ha area that was used by canvasback, redhead, scaup, and American coot. Area 3 was used by horned grebe, pied-billed grebe, the AXEAXA spp., and ruddy duck. It has a surface area of 33 ha. Area 4 is a 5 ha area that was used by American coot. Chi-square analyses indicated that the distributions of pied-billed grebe, canvasback, redhead, ring-necked duck, 22 .vofimaucopa one annex Suon magnum on: no ouwuomaoo u so come: uuoumaoma .anma new Quad «0 anoauewwaa madame any mnauan oxuq xuam uo>o on: unannouus mo «nodusawuuuaa 8. o 2 E353 33-3: 3.338.888 .e ousmfim 23 scaup, bufflehead, ruddy duck and American coot varied significantly (P<0.01) between years. Species Relationships Among_the Aythya spp. During 1978 the four Aythya species were observed to- gether on Park Lake during eleven mornings. Although niche overlaps were calculated for the periods 15-18 April and 19-22 April, overlaps involving redhead could not be calculated for the latter period. Overlaps were higher during 15-13 April than during 19-22 April (Table 4). Canvasback overlapped less than other species, particularly during the 19-22 April period. Redhead overlapped to a similar degree with all other species. Scaups and redhead overlapped most. Overlap values were calculated for 5 four day periods from 29 March until 19 April in 1979 (Figure 5). Overlaps were highest early in the season. In ten of fifteen cases, canvasback overlapped equally with or to a greater extent onto other species. Overlaps involving canvasback were smaller than overlaps among the other species. Redheads overlapped less or equally onto other species in twelve of the fifteen cases. They overlapped most with scaup. Ring- necked duck overlapped variably with redhead and scaup. They overlapped least with canvasback. Scaup overlaps were variable. 24 mm. ma. mm. mm. ease eoaomc-maam aamom mm. Hm. madam pmonpmm mm. Na. ease nmxooa-weum emmnemm me. mm. mm. mm. endow xownmm>cmo mm. on. «a. ma. ease emxuma-maam xomnmm>cau mm. mm. pmonpom xomnmw>cmo < co m m co < < co m m co - - m .. < N~\e-ae\e me\s-me\s mmaoomm How noDMHSUHmo .wmma ca muoauom map know N mwa xumm co .aam mNsuN< mnu mo mamauo>o onoac choauoouwn .e «Heme 25 Figure 5. Niche overlaps and population levels of the A th a spp. on Park Lake during spring 1979. OverIaps were calculated by summing species use by area, over four day periods. 26 legal... .. 0.85:0: on 0512. 96 ll Ila-5-3.1.2. 1:2. m 0228692» .--— III-II-IIIIII-I - ----—--- vvvcvvvv V ilLLLJ N a TTIIIITIII féééuii.... won—ammo m mnmcc ITI'II [I'TT'I I nlilil II 22:82. :v. .q‘ . d. i. I . )I '- . . \\ II, IIIIIIIIIIIl-I [Manta-6.9a \\\ \ . \ m L 1.1. r i II. 6.55%.: r II 3.3x. 2.1.2. ac; 5.5-32er acnr llllLL Overlap ((1)) 43 In ‘IHTVHII Number of Birds (Thousands) ’rnuirnl I 6.55.9.2 r I, . I . l U —.o WI \ lull Ill-I, 1H3... 52 .3 -- I I II“ I... ._ I on mm II. III II T. J an .. I. u u h "m x x l n u. .- un I. — .u n .. I- ll .- i .u "u u" i o I. .- .l. A 53.77.: r .0 rl _ .L u . r. lineage: 1 I 1 I1 N u W. 1 r .I l — l I I f: twtm .55: 13:5 tawtfle Umam w\~ mwmcem m. 27 Lake'Communities Aquatic macrophytes Thirteen species of aquatic macrophytes were found in Lake Lansing (Table 5):. Muskgrass was the most common. Flatstem pondweed (Potamogeton‘zosteriformis Fern.) was the most important vascular hydrophyte. It was found in water 1.5-2.0 m deep (Table 6). The other pondweeds occurred infrequently. Non-vegetated substrate was found in over 39% of the samples. The two most important vascular hydrophytes in Lake O'Hills are naiad and fennelleaf pondweed (Table 5). Naiad was found at depths greater than 1.5m (Table 6). Fennel- leaf pondweed was restricted to depths of 1.5-2.0m. Plants in Lake O'Hills were not covered by calcium encrustations. They appeared brighter and more crisp than plants in the other lakes. Muskgrass was found in over 57% of the Park Lake samples (Table 5). Bare substrate occurred less than 17% of the time. Fennelleaf pondweed, largeleaf pondweed, and water star mudplantain were the most important vascular hydro- phytes in Park Lake. Fennelleaf pondweed and large leaf pondweed occurred at depths of 1.0-1.5m (Table 6). Water- star mudplantain was found in water 2.0m deep. Naiad was found on all transects and at all depths. waterlily occurred across the western portion of the lake. It was found in water less than 1.5m deep. 28 Table 5. Percent occurrence, by species, of aquatic macro- phytes on the three study lakes. Lake Lake Park Lansing O'Hills Lake Species (n3255) (n=115) (n=420) Chara sp. 39.6 41.8 57.1 Potamageton zosteriformis 6.8 P. pectinatus Tra 5.6 4.8 P. amplifolius 0.9 4.3 P. crispus 0.6 Tr P. robbinsii (Oakes) Tr P. richardsonii (Benn.) Tr Najas sp. 6.4 33.6 3.5 Elodea canadensis (Michx.) 0.8 1.5 Vallisneria americana 0.1 . Tr Scirpus sp. Tr Tr Heteranthera dubia 2.1 4.4 Ceratophyllum demersum. 3.6 0.6 Nymphaea sp. 3.0 Nuphar sp. 1.9 Myriophyllum.sp. 1.6 2.8 Non-vegetated substrate 39.4 22.0 20.2 aTrace amounts are less than 0.1 percent. 29 .mm Enaamnmowhhz mason .3 .am anaahnmoAth .mm mwfimz abmuoaou .0 .am mmnmz .mm dunno .am mwnwz .no.~ A msamwuo .m .am abaahnmoauhz msumcauoom .m .am mmnmz «Hosp .3 .mm mwnmz mwahomauoumou .m .mm dunno .am mumsu .mm dunno E o.m mammano couowosmuom .am mwnwz .mm mmnmz maaaomaamam .m maumaauooa .m mHBHOMHHoumou mvumafiuoom .m .mm mwnmz couowoamuom .mm dunno .mm dunno .mm dunno .8 m.H muwuono .z mnwaowwanam aouomoawuom wamowuoam wwuocmaaaw> maumCHuoom .m mwmconmnmo mouon .mm dunno .am dunno .am «Hero 8 o.H .am Hananz mumuopo womnaahz .mm mmnmz .mm muwso Ammumamv .mm dunno AomHmamv .mm dunno a m.o mama xumm mHHa=.o oxau_ maamamu mama enema .mome henna mounu use so anemone mMoB was» mofioomm ouhsmouome owuwsvm aoaaoo osu mo .aumop mp .:o«unnwuumwn .0 manna 30 Benthos Midge larvae (Chironomidae) were the most numerous and widely distributed benthic invertebrates in Lake Lansing (Table 7). Scuds (Amphipoda) and mayfly nymphs (Epheme- roptera) were next in importance. Both taxa were present in approximately the same densities and frequencies. Numbers and frequencies of phantom midge larvae (Chaoboridae) and biting midge larvae (Ceratopogonidae) in Lake Lansing samples were also similar. Biting midge larvae occurred in samples taken from sandy substrate along the eastern shore of the lake (transects 6-A and 7) whereas phantom midge larvae were found in all areas except the northwest portion of the lake (transect 2). Water mites (Hydra- carina) were found on all transects with a 28% frequency of occurrence. Midge larvae were found in every sample that was taken from Lake O'Hills (Table 7). Mayfly nymphs and scuds were widely distributed at low densities. They were found in samples taken from all transects. Snails (Gastropoda), horse and deer fly larvae (Tabanidae) and fingernail clams (Sphaeriidae) were also evenly distributed at low densities. Park Lake contained a greater number of benthos taxa compared with the other lakes (Table 7). Although mayfly nymphs were the most numerous and widely distributed, numbers from two samples accounted for over 50% of the total. Midge larvae were found in nearly 98% of the samples and were about as numerous as mayfly nymphs. 31 omwmo ooflmm H.mm w.m~ maaumomuuhm moe+ooa 4.H~ om+m4 m.4~ omegaummeam mnommooaom Hmflmm m.m 4num~ c.3m meoaouumac i «Hewoma m.me I omeacmnae ma+a~a n.4H I mnwem o.m~ «seasonoano i ma+~4e m.mH o4+mn m.m~ omeacowoaoumumo oom+-a o.am mmmnmooe o.ooH momflomm o.ooH «meaaoaouueu «Reagan m4HHHnH m.m . aumuaomaoo HNeHmNH m.m~ 4uuoe a.mH mumuaonoaue Hembm m.m wuoumowhN mom+mmH w.m~ «Houmomaq< wumcono moomuuace ~.4~ ANHHANH m.em 4AHHA4H 4.44 mumuaoumameam o~N+mm~ n.4o m~+m~ H.~4 o4H+mAH m.wm aeoaeeaa< xuwmcoa hocoavouh xuwmcoa homosvouh huwmaoa mucosdoum coxwu mozuamm and: and: and: Am4uav Aaeuav homage mean euam QHHH=.o mama waemama wean .moxma henna mourn onu no coxmu monEmm cw pczom axon monucon mo A~s\muonascv huwmcon some can monouunooo mo mucosaoum .a means 32 Relationships Between Waterbird Use and Habitat Variables The relationshipsof selected habitat variables with numbers of waterbird species use-days (number of use-days/ 0.25km2) by location within a lake during 1979 were analyzed using stepwise multiple regression. waterbird species were included in the regression analysis if they occurred in at least 10 of the 0.25 km2 areas in which benthos data were collected (3.3., if benthos sample size was greater than or equal to 10 for the waterbird species). The multiple regression analysis of Lake Lansing data compared amounts of use, at specific locations,. by red-breasted merganser and American coot with water depth; densities of muskgrass, curlyleaf pondweed, flatstem.pond- weed, naiad, watermilfoil and waterstar mudplantain; numbers of scuds, mayfly nymphs, and midge larvae; and total dry biomass of invertebrates. Water depth explained a signi- ficant (P<0.l) amount of the variation in the distribution of red-breasted merganser. The relationship was negative (r = -0.43). Waterstar mudplantain density explained a significant amount of the the variation in American coot distribution. The multiple regression analysis of Lake O'Hills data compared amounts of use, by location, for mallard, ring-necked duck, scaup, and bufflehead with water depth; densities of muskgrass, fennelleaf pondweed, and naiad; numbers of mayfly nymphs and midge larvae; and total dry 33 bimmass of invertebrates. Mayfly nymph numbers were cor- related with locations of mallard (P<0.l). The densities of muskgrass, naiad, and fennelleaf pondweed were associated 2 = 0.70), Water depth was related with locations of scaup (r with locations of ring-necked duck (P<0.l). The relationship was negative (r = -053). No variables were related to locations of bufflehead. The multiple regression analysis of Park Lake data compared amounts of use by canvasback, redhead, ring-necked duck, scaup, and American coot with water depth; the densities of muskgrass, largeleaf pondweed, fennelleaf pondweed, naiad, waterweed, watermilfoil, waterstar mudplantain, waterlily, and cowlily; numbers of scuds, mayfly nymphs, caddisfly nymphs (Trichoptera) and midge larvae; and total dry bio- mass of invertebrates. Densities of largeleaf pondweed and watermilfoil were related (P<0.10) with locations of canvasback (Table 8). Numbers of midge larvae, density of muskgrass, and water depth were associated with the dis- tribution of redheads. Ring-necked duck use was related with densities of cowlily and watermilfoil, while locations of scaup related with numbers of midge larvae and density of waterweed. The densities of muskgrass, waterweed, waterstar mudplantain and total dry biomass of invertebrates were associated with use by American coot. 34 mo.vm um usaoemuememes oH.vm um unmoamacmam« own. rewao. maumwan> .0 ammo. unwaos mun oumuoouuo>cH «rmoa. manor mudguawuouom xwma. mamaovmamo .< uooo amoauos< cam. shoe. mamampmcmo mocoam samba. unpwaocouano .mmm endow emu. «ewe. .em asaahaaoauhz *Nma. .mm Hmnmnz zone voxooaiwcam ooq. sews. sumac armmo. mHHme=> «Hugo «rmmm. outwaocouwnu undated «mm. smma. .am abaahnaowuzz «awe. msaaomaaaam couomoswuom xomnmo>coo kuoh HmHunMI moanmwuw> Houaoaaona>cm mmfioomm Amuv coammouwou ofimwuasz .oqu xumm pom moaowwum> kuaoaaoufi>ao wouooaom sues occupasnm unannoums megawaou A~.vmv mamzawcm coammoumon oaawuana oma3moum mo muHSmoM .w manna DISCUSSION Cold weather early in the 1979 season delayed migration. Greater daily numbers of waterbirds on the lakes over an ex- tended period of time resulted in an increase in bird use compared to 1978. A greater number of species was also observed in 1979. . The area of lake surface that was used on both Lake Lansing and Lake O'Hills during 1979 as compared to 1978 increased proportionally with number of waterbird use-days. Additional use of Park Lake resulted in increased densities of birds since the amount of surface area that was used was not proportional to the increase in use-days. Although relative abundance of common species on in- dividual lakes remained constant from 1978 to 1979, water- bird communities varied by lake. Lake Lansing was used by American coot and piscivorous species such as common loon, horned grebe, pied-billed grebe, and red-breasted merganser. Lake O'Hills was used by Canada geese, mallard, ring-necked duck, scaup, and bufflehead. Park Lake was used by pochards, bufflehead, and American coot. Although distributions of common waterbird species dif- fered by year, niche overlaps among the Aythya spp. on Park Lake were similar during both years. Overlaps were greatest 35 36 early in the seasons. Observations indicate that this may be because early spring migrants required several days to acclimate to the lake environment. During this period individuals of many species were found together in one large group. After 2-3 days the large aggregation broke up as smaller groups left and occupied other portions of the lake. Thereafter newly arriving migrants joined established groups across much of the lake. The aquatic macrophyte and benthos communities of the three lakes are different. Lake Lansing contains more pondweed species but has a less diverse benthos than Park Lake. Lake O'Hills has the least diverse flora. It has a benthos diversity similar to Lake Lansing. Park Lake contains the overall most diverse biota. It has nearly as rich a macrophyte community as Lake Lansing and it contains the richest benthos composition. It also contains the least amount of nonevegetated substrate. Mallard use was related to mayfly nymph numbers on Lake O'Hills. Mallard were nesting during April. Hens require large amounts of protein during laying. ”Mayfly nymphs might have provided an available supply of protein on Lake O'Hills. The negative correlation between red-breasted merganser distributions and depth could possibly be related to mer- ganser foraging strategy on Lake Lansing. Perhaps their 37 primary food items were more abundant or more available in shallow areas (one meter) than in deeper areas. When considered in conjunction with niche overlap relationships, the correlations of use by the Aythya spp. with habitat variables on Park Lake provide additional in- formation about the interactions of the species. Canvasback use was not described by habitat variables that described redhead and scaup use. This suggests that canvasbacks use areas that are different from the areas that redhead and scaup use. The distribution of canvasback overlapped only moderately with the distributions of redhead and scaup. This supports the hypothesis that canvasback use different areas. Alexander and Hair (1979) found that canvasbacks defended foraging sites and were dominant over other Aythya spp. Siegfried (1976) mentioned that he had observed ag- gressive encounters between canvasback and redhead. Perhaps canvasback aggressively exclude redhead and scaup from.use- areas. Distributions of canvasback and ring-necked duck were correlated with a common habitat variable (water- milfoil density). The distributions of the two species overlapped little. This indicates that canvasback and ring- necked duck use similar areas but are not found together. Alexander and Hair (1979) observed that canvasback were most frequently involved in aggressive encounters with ring-necked duck. Distributions of redhead and scaup on Park Lake were both correlated with numbers of midge larvae. 38 Distributions of the two species overlapped extensively. Siegfried (1976) described a similar relationship between canvasback and scaup. He suggested that since canvasbacks feed primarily on plant material while scaup feed on free swimming invertebrates, it follows that food habits dif- ferences must separate the species. Such a relationship could also separate scaup and redhead because, like canvas- back, redhead feed more on plant material than do scaup (Bellrose 1976). Ring-necked duck use was correlated with a different set of habitat variables than described red- head and scaup use. Niche overlaps of ring-necks with scaup and redheads were variable. This indicates that ring- necked duck are seldom.found in the same areas with redhead and scaup because they use different resources. Alexander and Hair (1979) found that ring-necked duck were aggressive and dominated redhead and scaup. Perhaps ring-necked duck aggressively exclude redhead and scaup from use-areas. American coot distributions were related to waterstar mudplantain density on both Lake Lansing and Park Lake. Pirnie (1935) also described a relationship between coot use and mudplantain on Lake Lansing. He indicated that coot feed heavily upon this plant. LITERATURE CITED LITERATURE CITED Alexander, W. C. and J. D. Hair. 1979. Winter foraging behavior and aggression of diving ducks in South Carolina. Proc. Annu. Conf. Southeast. Assoc. Fish. Wildl. Agencies 31: 226-232. Bellrose, F. C. 1976. Ducks, geese and swans of North America. Wildlife Management Institute. Stackpole Co., Harrisburg, Pa. 544 pp. Goodman, D.C. and H. I. Fisher. 1962. Functional anatomy of the feeding apparatus in waterfowl (Aves:Anatidae). Southern Illinois University Press, Carbondale. 193 pp. Humphrys, C. R. and R. F. Green. 1962a. Ingham County. Michigan Lake Inventory Bulletin 33. Dept. Resource Development, Michigan State University. East Lansing. l p. , 1962b. Clinton County. Michigan Lake Inventory Bulletin 19. Dept. Resource Development, Michigan State University. East Lansing. l p. Hurlbert, S. H. 1978. The measurement of niche overlap and some relatives. Ecology 59: 67-77. , and J. 0. Keith. 1979. Distribution and spatial patterning of flamingos in the Andean altiplano. Auk 96: 328-342. Lerg, J. M. 1975. Birds of Rose Lake. Wildlife Division Report No. 2698, Michigan Dept. Nat. Res., Lansing.101pp. Kim, Jae-On and F. J. Kohout. 1975. Multiple regression analysis: subprogram regression. p. 320-367 in Nie, N. H., C. H. Hull, J. G. Jenkins, K. SteifiErenner, and D. H. Bent (Eds.), Statistical Package for the Social Sciences. 2nd ed. MCGraw-Hill BoOk Co., new York. 675 pp. McWhirter, D. W. and D. L. Beaver. 1977. Birds of the capital call count area of Michigan. Publications of the MuseumpMichigan State University Biological Series 5(5): 357-441. 39 40 Michigan Conservation Dept. 1938a. Lake Inventory Map: Lake Lansing. Institute for Fisheries Research, Mich. Cons. Dept., Lansing. A , 1938b. Lake Inventory Map: Park Lake. Institute far Fisheries Research, Mich. Cons. Dept., Lansing. Petraitis, P. S. 1979. Likelihood measures of niche breadth and overlap. Ecology 60: 703-710. Pirnie, M. D. 1935. Michigan waterfowl management. Mich. Dept. Cons., Lansing. 328 pp. Sangster, M. E. 1977. Spring waterfowl migration in the Uinta Basin of northeastern Utah. Great Basin Nat. 37: 274-279. Scott, T. G. and C. H. Wasser. 1980. Checklist of North American plants for wildlife biologists. The Wild- life Society, Washington, D.C. 58 pp. Siami, M. 1979. The abundance and distribution of benthic macro-invertebrates in Lake Lansing . M. S . Thesis . Michigan State Univ., East Lansing. 107 pp. Siegfried, W. R. 1976. Segregation in feeding behavior of four diving ducks in southern Manitoba. Can. J. Zool. 54: 730-736. Thornburg, D. D. 1973. Diving duck movements on Keokuk Pool, Mississippi River. J. Wildl. Manage. 37: 382- 389. Wilson, M. M. 1980. Phytoplankton and macrophyte chloro- phyll a of two lakes. M.S. Thesis. Michigan State Univ.,_East Lansing. 59 pp. APPENDIX 41 2 5 7. 1 _ 6 o'A 9 a 0 meters 200 Figure A-l. Location of transects on Lake Lansing. 42 0 meters mo L ii .4 Figure A-2. Location of transects on Lake O'Hills. 43 0 meters 100 L n I Figure A-3. Location of transects on Park Lake.