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Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas R. Wood, Eric K. Bollinger Nov 1997

Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas R. Wood, Eric K. Bollinger

Eric K. Bollinger

Brown-headed Cowbirds (Molothrus ater) often remove host eggs, usually to the detriment of the host's reproductive success. We tested the hypothesis that host egg size and number influence the incubation efficiency of a parasitic egg. A single House Sparrow (Passer domesticus) or Brown-headed Cowbird egg was placed in each host nest (addition), and in some nests a host egg was removed as well (addition/removal). Hatching success and incubation length were measured to determine whether host-egg removal conferred an advantage in incubation efficiency compared to simple addition of a parasitic egg. Redwinged Blackbirds (Agelaius phoeniceus) and Chipping Sparrows (Spizella passerina) served …


Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas R. Wood, Eric K. Bollinger Nov 1997

Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas R. Wood, Eric K. Bollinger

Faculty Research & Creative Activity

Brown-headed Cowbirds (Molothrus ater) often remove host eggs, usually to the detriment of the host's reproductive success. We tested the hypothesis that host egg size and number influence the incubation efficiency of a parasitic egg. A single House Sparrow (Passer domesticus) or Brown-headed Cowbird egg was placed in each host nest (addition), and in some nests a host egg was removed as well (addition/removal). Hatching success and incubation length were measured to determine whether host-egg removal conferred an advantage in incubation efficiency compared to simple addition of a parasitic egg. Redwinged Blackbirds (Agelaius phoeniceus) and Chipping Sparrows (Spizella passerina) served …


Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas Wood, Eric Bollinger Nov 1997

Egg Removal By Brown-Headed Cowbirds: A Field Test Of The Host Incubation Efficiency Hypothesis, Douglas Wood, Eric Bollinger

Faculty Research & Creative Activity

Brown-headed Cowbirds (Molothrus ater) often remove host eggs, usually to the detriment of the host's reproductive success. We tested the hypothesis that host egg size and number influence the incubation efficiency of a parasitic egg. A single House Sparrow (Passer domesticus) or Brown-headed Cowbird egg was placed in each host nest (addition), and in some nests a host egg was removed as well (addition/removal). Hatching success and incubation length were measured to determine whether host-egg removal conferred an advantage in incubation efficiency compared to simple addition of a parasitic egg. Redwinged Blackbirds (Agelaius phoeniceus) and Chipping Sparrows (Spizella passerina) served …


Explanations For The Infrequent Cowbird Parasitism On Common Grackles, Brian D. Peer, Eric K. Bollinger Feb 1997

Explanations For The Infrequent Cowbird Parasitism On Common Grackles, Brian D. Peer, Eric K. Bollinger

Eric K. Bollinger

We determined the factors responsible for the lack of parasitism on Common Grackles (Quiscalus quiscula) by Brown-headed Cowbirds (Molothrus ater). We found no evidence of parasitism on the 401 grackle nests we monitored in east-central Illinois. By the time cowbirds began laying eggs, 88.5% of all grackle nests were beyond the point of successful parasitism. Grackles rejected cowbird eggs more frequently during the prelaying stage of the nesting cycle (38.2%) compared to later stages (12.3%). Thirty-three cowbird eggs and nestlings were cross-fostered into grackle nests. Data were collected on 15 cowbird nestlings, of which three fledged. The cross-fostered cowbird eggs …


Explanations For The Infrequent Cowbird Parasitism On Common Grackles, Brian Peer, Eric Bollinger Feb 1997

Explanations For The Infrequent Cowbird Parasitism On Common Grackles, Brian Peer, Eric Bollinger

Faculty Research & Creative Activity

We determined the factors responsible for the lack of parasitism on Common Grackles (Quiscalus quiscula) by Brown-headed Cowbirds (Molothrus ater). We found no evidence of parasitism on the 401 grackle nests we monitored in east-central Illinois. By the time cowbirds began laying eggs, 88.5% of all grackle nests were beyond the point of successful parasitism. Grackles rejected cowbird eggs more frequently during the prelaying stage of the nesting cycle (38.2%) compared to later stages (12.3%). Thirty-three cowbird eggs and nestlings were cross-fostered into grackle nests. Data were collected on 15 cowbird nestlings, of which three fledged. The cross-fostered cowbird eggs …


Explanations For The Infrequent Cowbird Parasitism On Common Grackles, Brian D. Peer, Eric K. Bollinger Feb 1997

Explanations For The Infrequent Cowbird Parasitism On Common Grackles, Brian D. Peer, Eric K. Bollinger

Faculty Research & Creative Activity

We determined the factors responsible for the lack of parasitism on Common Grackles (Quiscalus quiscula) by Brown-headed Cowbirds (Molothrus ater). We found no evidence of parasitism on the 401 grackle nests we monitored in east-central Illinois. By the time cowbirds began laying eggs, 88.5% of all grackle nests were beyond the point of successful parasitism. Grackles rejected cowbird eggs more frequently during the prelaying stage of the nesting cycle (38.2%) compared to later stages (12.3%). Thirty-three cowbird eggs and nestlings were cross-fostered into grackle nests. Data were collected on 15 cowbird nestlings, of which three fledged. The cross-fostered cowbird eggs …


Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel A. Cristol, Paul V. Switzer, K L. Johnson, L S. Walke Jan 1997

Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel A. Cristol, Paul V. Switzer, K L. Johnson, L S. Walke

Paul V. Switzer

No abstract provided.


Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel A. Cristol, Paul V. Switzer, K L. Johnson, L S. Walke Jan 1997

Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel A. Cristol, Paul V. Switzer, K L. Johnson, L S. Walke

Faculty Research & Creative Activity

No abstract provided.


Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel Cristol, Paul Switzer, K Johnson, L Walke Jan 1997

Crows Do Not Use Automobiles As Nutcrackers: Putting An Oft-Repeated Anecdote To The Test, Daniel Cristol, Paul Switzer, K Johnson, L Walke

Faculty Research & Creative Activity

No abstract provided.


Comparisons Of Genetic Variance And Physiological Responses In Two Populations Of Western Mosquitofish, Gambusia Affinis, Brett Egger Jan 1997

Comparisons Of Genetic Variance And Physiological Responses In Two Populations Of Western Mosquitofish, Gambusia Affinis, Brett Egger

Masters Theses

The study was conducted to determine the effects of lowered genetic variance in the Western mosquitofish (Gambusia affinis) on the physiological parameters of critical thermal maximum and minimum pH. Mosquitofish were obtained from two small central Illinois ponds, Lost Pond and Shadow Pond, by seines and dip nets. Once caught, fish were returned to the laboratory and acclimated for a minimum of five days at a temperature of 27°C and a pH of 8.25. At the beginning of each experimental run, fish were subjected to the physiological experiments for determination of critical thermal maximum and minimum pH, and then measured …


Adaptive Significance Of Re-Nesting Following Nest Abandonment In The Blue-Gray Gnatcatcher (Polioptila Caerulea), Melissa Nicole Helton Jan 1997

Adaptive Significance Of Re-Nesting Following Nest Abandonment In The Blue-Gray Gnatcatcher (Polioptila Caerulea), Melissa Nicole Helton

Masters Theses

We studied the adaptive significance of nest abandonment and re-nesting in the Blue-gray Gnatcatcher (Polioptila caerulea) in east-central Illinois from 1995 through 1997. This Neotropical migrant is widely distributed and highly persistent in re-nesting following nest abandonment. Nest abandonment may be a response to brood parasitism, predation or other nest disturbances. We studied the nesting behavior of gnatcatchers and investigated the cues which may elicit nest abandonment. We monitored 57 pairs of gnatcatchers which built a total of 98 nests. Twenty pairs successfully fledged a total of 63 young and overall nest success was only 8.5%. Daily mortality rates for …


The Effects Of Habitat Fragmentation And Factors Influencing Nest Box Use On The Southern Flying Squirrel (Glaucomys Volans) In Southern Illinois, Catherine J. Woodworth Jan 1997

The Effects Of Habitat Fragmentation And Factors Influencing Nest Box Use On The Southern Flying Squirrel (Glaucomys Volans) In Southern Illinois, Catherine J. Woodworth

Masters Theses

I studied the effects of habitat :fragmentation on the southern flying squirrel (Glaucomys volans) in 30 forest fragments in southern Illinois. The fragments ranged in size from 6 ha to 5264 ha, and had varying degrees of isolation. I placed 10 nest boxes in each habitat fragment and checked them monthly. I captured southern flying squirrels in 24 of the 30 fragments, and found evidence of squirrels (i.e., nests and feeding stations) in 4 additional fragments. Thus, only 2 fragments did not show any evidence of squirrel use suggesting that the southern flying squirrel may not be particularly …


Transfer Of Immunity Against Hymenolepis Diminuta Parasites In Mice, Jerome F. Atta-Fynn Jan 1997

Transfer Of Immunity Against Hymenolepis Diminuta Parasites In Mice, Jerome F. Atta-Fynn

Masters Theses

The potential transfer of resistance against the rat tapeworm, Hymenolepis diminuta, from adult BALB/c mice to their young, was tested by comparing the worm burdens of 24 experimentally infected pups from previously infected females to 14 experimentally infected pups from uninfected females. The mean number of worms recovered, mean weight of recovered worms and frequency of mice pups with eggs of the parasite in their feces were significantly lower in infected pups from infected mothers than in infected pups from uninfected mothers. The lower worm burden observed in the infected pups from infected mothers suggested that the resistance to …


Roost Site Selection Of The Red Bat (Lasiurus Borealis), Kenneth J. Mager Jan 1997

Roost Site Selection Of The Red Bat (Lasiurus Borealis), Kenneth J. Mager

Masters Theses

I monitored the roosting activity and evaluated roost site selection of red bats (Lasiurus borealis) at study sites in Coles County during the summer of 1996. Red bats were mist-netted and radio transmitters were affixed to 12 individuals. A total of 105 transmitter-days were recorded with 75 roost locations identified. The roost types consisted of eight different species of trees, prairie grass, and residential structures but the vast majority of roosts (92%) were in large, deciduous trees. The height of the roosts ranged from 0.5 to 21.4 m, but 54.7% were between 5-10 m. Movement between consecutive roosts ranged from …