Life Sciences Commons^™

An Investigation Of The Host Specificity Of The Brown-Headed Cowbird, Brian D. Peer

Masters Theses

We attempted to determine the factors associated with the lack of parasitism of the Common Grackle (Quiscalus quiscula) by the Brown-headed Cowbird (Molothrus ater). We investigated the breeding phenology of the two species, the responses of colonial- and noncolonial-nesting grackles to female cowbird models, the frequency of artificial egg rejection by grackles, incubation success of cowbird eggs transferred into grackle nests, and the survival rates of cowbirds cross-fostered into grackle nests.

By the time cowbirds began egg-laying at our study sites, 88.5 % of all grackle nests were beyond the point of successful parasitism. Grackles responded …

Biotic, Abiotic, And Behavioral Patterns Associated With The Nocturnal Movements Of Shrews, Patrick T. Sullivan

Masters Theses

Thirteen trails left by shrews coated with fluorescent powder were examined for microhabitat documentation. Thirteen data parameters were collected from each trail, two of which differed significantly between Blarina brevicauda and Sorex longirostris. The small soricid Sorex longirostris was captured in areas with higher grass content, and lower wooded content, than the larger Blarina brevicauda. The difference in microhabitat use may be a key mechanism in reducing competition between these two species.

Phylogenetic Relationships Within The Batagur Complex (Testudines: Emydidae: Batagurinae), Jean M. Capler

Masters Theses

Relationships between 10 species of the batagurine genera Batagur, Callagur, Kachuga, Hardella, and Morenia are discussed based on a cladistic analysis of 35 morphological characters. Ocadia sinensis (Emydidae: Batagurinae) was used as the outgroup species. Four cladograms were produced with a length of 59.0 steps and a 0.75 consistency index. In contrast with previous studies, Hardella and Morenia do not appear as a monophyletic clade. Instead, Hardella is included with the remaining ingroup taxa (exclusive of Morenia) based on five synapomorphies. The present genus Kachuga was determined to be paraphyletic, having excluded the present genera Batagur and Callagur. The pangshura …

Growth And Survival Of Larval Fishes: The Role Of Zooplankton Abundance And Competition, Michael T. Welker

Masters Theses

Interactions among larval gizzard shad, bluegill and zooplankton prey were examined via a controlled mesocosm experiment and field sampling in Lake Shelbyville, Illinois. In the mesocosm experiment gizzard shad growth and survival were negatively correlated with shad density and positively correlated with macrozooplankton prey. Bluegill growth was also positively correlated with prey availability, but survival was uniformly high despite differences in zooplankton abundance and fish density. Declines in macrozooplankton and copepod biomass were related to fish density. In Lake Shelbyville limnetic overlap of larval gizzard shad and bluegill was limited to a three week period, with the interval of greatest …

Ecology Of The State Endangered Yellow Mud Turtle, Kinosternon Flavescens In Henry Co., Illinois, Michael W. Tuma

Masters Theses

Illinois populations of the state endangered yellow mud turtle (Kinosternon flavescens) persist in scattered locations on sand prairies. The largest population occurs on a remnant sand prairie of the former Green River Marsh in Henry Co. A study was conducted during 1992 to determine important criteria for preserve design. These criteria included extent of turtle movements within the site and habitat use. Turtles were captured by aquatic hoop traps, drift fence, and by hand from May 11 to August 31. A total of 16 adults, four juveniles, and eight hatchlings were captured. Population size was estimated at 44.80 adults using …

The Effects Of Nest-Box Visibility And Proximity On The Frequency Of Brood Parasitism In Wood Ducks, Roger W. Jansen

Masters Theses

I studied the effects of nest box visibility and clustering on the rate of intraspecific brood parasitism (IBP) in Wood Ducks (Aix sponsa) at Lake Shelbyville Fish and Wildlife Area in Moultrie County, IL from 2 March 1992 to 22 June 1992. Sixty-eight percent of the nest boxes sampled were used and 33% of the nests were destroyed by predators. Mean clutch sizes of unparasitized (x = 9.2) and parasitized (x = 15.2) nests were significantly different. The parasitism rate in Wood Duck nests was 54%. More visible boxes had a tendency to be parasitized at a higher rate than …