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Full-Text Articles in Biology

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 …


Comparative Leaf Anatomy And Systematics In Dendrobium, Sections Aporum And Rhizobium (Orchidaceae), Barbara S. Carlsward, William Lois Stern, Walter S. Judd, Terence W. Lucansky Jan 1997

Comparative Leaf Anatomy And Systematics In Dendrobium, Sections Aporum And Rhizobium (Orchidaceae), Barbara S. Carlsward, William Lois Stern, Walter S. Judd, Terence W. Lucansky

Barbara S. Carlsward

The specialized leaf anatomy for species of Dendrobium within section Aporum is similar to that of species in section Rhizobium. In both sections leaves are characterized by a unifacial or nearly unifacial surface where the exposed surface is abaxial. However, leaves in section Rhizobium also feature a lacuna submerged in the mesophyll and surrounded by an adaxial epidermis. In contrast, leaves in section Aporum merely present an internal suture that divides the leaf into bilateral halves. These two sections of Dendrobium are hypothesized to be sister taxa because of synapomorphies in their foliar anatomy. A cladistic analysis performed with various …


Selective Predation On The Seeds Of Woody Plants, Scott J. Meiners, Edmund W. Stiles Jan 1997

Selective Predation On The Seeds Of Woody Plants, Scott J. Meiners, Edmund W. Stiles

Scott J. Meiners

Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the …


Comparative Leaf Anatomy And Systematics In Dendrobium, Sections Aporum And Rhizobium (Orchidaceae), Barbara S. Carlsward, William Lois Stern, Walter S. Judd, Terence W. Lucansky Jan 1997

Comparative Leaf Anatomy And Systematics In Dendrobium, Sections Aporum And Rhizobium (Orchidaceae), Barbara S. Carlsward, William Lois Stern, Walter S. Judd, Terence W. Lucansky

Faculty Research & Creative Activity

The specialized leaf anatomy for species of Dendrobium within section Aporum is similar to that of species in section Rhizobium. In both sections leaves are characterized by a unifacial or nearly unifacial surface where the exposed surface is abaxial. However, leaves in section Rhizobium also feature a lacuna submerged in the mesophyll and surrounded by an adaxial epidermis. In contrast, leaves in section Aporum merely present an internal suture that divides the leaf into bilateral halves. These two sections of Dendrobium are hypothesized to be sister taxa because of synapomorphies in their foliar anatomy. A cladistic analysis performed with various …


Comparative Leaf Anatomy And Systematics In Dendrobium, Sections Aporum And Rhizobium (Orchidaceae), Barbara Carlsward, William Stern, Walter Judd, Terence Lucansky Jan 1997

Comparative Leaf Anatomy And Systematics In Dendrobium, Sections Aporum And Rhizobium (Orchidaceae), Barbara Carlsward, William Stern, Walter Judd, Terence Lucansky

Faculty Research & Creative Activity

The specialized leaf anatomy for species of Dendrobium within section Aporum is similar to that of species in section Rhizobium. In both sections leaves are characterized by a unifacial or nearly unifacial surface where the exposed surface is abaxial. However, leaves in section Rhizobium also feature a lacuna submerged in the mesophyll and surrounded by an adaxial epidermis. In contrast, leaves in section Aporum merely present an internal suture that divides the leaf into bilateral halves. These two sections of Dendrobium are hypothesized to be sister taxa because of synapomorphies in their foliar anatomy. A cladistic analysis performed with various …


Selective Predation On The Seeds Of Woody Plants, Scott J. Meiners, Edmund W. Stiles Jan 1997

Selective Predation On The Seeds Of Woody Plants, Scott J. Meiners, Edmund W. Stiles

Faculty Research & Creative Activity

Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the …


Selective Predation On The Seeds Of Woody Plants, Scott Meiners, Edmund Stiles Jan 1997

Selective Predation On The Seeds Of Woody Plants, Scott Meiners, Edmund Stiles

Faculty Research & Creative Activity

Selective predation on the seeds of woody plants. J. Torrey Bot. Soc. 124: 67-70). 1997.-Seed predation may be an important factor influencing the structure of successional plant communities. We used a cafeteria-style experiment, placed in an old field and an early successional forest, to determine predator preferences for seeds of nine species of woody plants. Intensity of seed predation was equivalent in both sites. Seed predators preferred Acer saccharum, flex vertic illata, and Viburnum dentatum, but this was not related to seed mass. Predation intensity was more variable in the old field than in the forest, possibly related to the …


Life History Characteristics Of Daphnia Lumholtzi And Its Susceptibility To An Invertebrate Predator, Eden L. Rawski Jan 1997

Life History Characteristics Of Daphnia Lumholtzi And Its Susceptibility To An Invertebrate Predator, Eden L. Rawski

Masters Theses

No abstract provided.