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Effect Of Feathers As Nest Insulation On Incubation Behavior And Reproductive Performance Of Tree Swallows (Tachycineta Bicolor), Michael Lombardo, Ruth Bosman, Christine Faro, Stephen Houtteman, Timothy Kluisza
Effect Of Feathers As Nest Insulation On Incubation Behavior And Reproductive Performance Of Tree Swallows (Tachycineta Bicolor), Michael Lombardo, Ruth Bosman, Christine Faro, Stephen Houtteman, Timothy Kluisza
Michael P Lombardo
Many species of birds line their nests with feathers, presumably because of the insulative qualities of feathers and because feathers may act as a barrier between nest parasites and nestlings. In 1993, we experimentally examined the role of feathers as nest insulation on the incubation behavior, nestling growth, and reproductive performance of Tree Swallows (Tachycineta bicolor) nesting in boxes in western Michigan. There were no significant differences between the incubation rhythms of females with experimental nests (i.e. no feathers) and females with control nests (i.e. with feathers). Nestlings that were reared in control nests had significantly longer right tarsi and …
Repeated Sampling Affects Tree Swallow Semen Characteristics, Michael Lombardo, M.L. Green, P.A. Thorpe, M.R. Czarnowski, H.W. Power
Repeated Sampling Affects Tree Swallow Semen Characteristics, Michael Lombardo, M.L. Green, P.A. Thorpe, M.R. Czarnowski, H.W. Power
Michael P Lombardo
Male Tree Swallows (Tachycineta bicolor) face intense sperm competition because mated pairs copulate frequently, extra-pair copulations are common, and females store sperm. We examined the effects of repeated sampling on the characteristics of Tree Swallow semen by manually expressing semen from 15 males immediately after capture (T0) and then hourly for 4 h (T1-T4). The semen characteristics of individual males varied in response to repeated sampling. The total number of sperm cells we obtained from each male over the 4-h sampling period varied from 104-107. Semen samples lacking …
Individual, Temporal, And Seasonal Variation In Sperm Concentration In Tree Swallows, Michael Lombardo, Armetris Forman, Matthew Czarnowski, Patrick Thorpe
Individual, Temporal, And Seasonal Variation In Sperm Concentration In Tree Swallows, Michael Lombardo, Armetris Forman, Matthew Czarnowski, Patrick Thorpe
Michael P Lombardo
We determined sperm concentrations in Tree Swallows (Tachycineta bicolor) by manually expressing semen samples from males during prelaying, egg-laying, incubation, and nestling periods. Sperm concentrations varied by orders of magnitude (0-109 sperm mL-1) among males. Sperm concentrations were highest during the incubation period and lowest during the prelaying period. None of the samples collected during the prelaying, egg-laying, and incubation periods were devoid of sperm. In contrast, 45% of samples collected during the nestling period lacked sperm. Sperm concentrations (1) did not vary over the course of the morning during prelaying, egg-laying, and incubation periods but significantly increased during the …
Microbial Colonization Of The Cloacae Of Nestling Tree Swallows, Tamara Mills, Michael Lombardo, Patrick Thorpe
Microbial Colonization Of The Cloacae Of Nestling Tree Swallows, Tamara Mills, Michael Lombardo, Patrick Thorpe
Michael P Lombardo
Microbes have the potential to be important selective forces in many aspects of avian biology. Microbes can affect fitness as a result of either their pathogenic or beneficial effects on host health. Little is known about the chronology of microbial colonization of nestlings or the effects of microbes on fledgling condition. We set out to (1) characterize the time course of microbial colonization of the cloacae of nestling Tree Swallows (Tachycineta bicolor), (2) examine the relationship between cloacal microbes and fledgling condition, and (3) determine if nest mates had similar assemblages of cloacal microbes. We repeatedly measured nestlings and sampled …
Within-Pair Copulations: Are Female Tree Swallows Feathering Their Own Nests?, Michael Lombardo
Within-Pair Copulations: Are Female Tree Swallows Feathering Their Own Nests?, Michael Lombardo
Michael P Lombardo
A variety of hypotheses has been proposed to explain why socially monogamous birds copulate repeatedly with their mates when only a single copulation is necessary to fertilize an entire clutch (Birkhead and Møller 1992, Petrie 1992, Hunter et al. 1993). Petrie (1992) hypothesized that a female should copulate frequently with her mate so as to reduce her mate’s involvement in extrapair copulations. By reducing her mate’s involvement in extrapair copulations, a female may: (1) avoid the transmission of parasites and sexually transmitted diseases (Hamilton 1990); (2) may avoid sperm depletion by her mate; and (3) may monopolize her mate’s paternal …