Caldwell Hahn, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 33
Experimental West Nile virus infection in Eastern Screech Owls (Megascops asio)
This study evaluated the potential effects of different concentrations of bleached/unbleached kraft mill effluent (B/UKME) on several reproductive endpoints in adult largemouth bass (Micropterus salmoides). The kraft mill studied produces a 50/50 mix of bleached/unbleached market pulp with an estimated release of 36 million gal of effluent/day. Bleaching sequences were C90d10EopHDp and CEHD for so
Authors
Nicole M Nemeth, D. Caldwell Hahn, D. H. Gould, R. A. Bowen
Parasitic Cowbirds have increased immunity to West Nile and other mosquitoborne encephalitis viruses
The rapid geographic spread of West Nile Virus [WNV, Flaviviridae, Flavivirus] across the United States has stimulated interest in comparative host infection studies of avian species to delineate competent reservoir hosts critical for viral amplification. Striking taxonomic differences in avian susceptibility have been noted, offering the opportunity to strategically select species on the basis o
Authors
W.K. Reisen, D.C. Hahn
Passive West Nile virus antibody transfer from maternal Eastern Screech-Owls (Megascops asio) to progeny
Transovarial antibody transfer in owls has not been demonstrated for West Nile virus (WNV). We sampled chicks from captive adult WNV-antibody-positive Eastern Screech-Owls (Megascops asio) to evaluate the prevalence of transovarial maternal antibody transfer, as well as titers and duration of maternal antibodies. Twenty-four owlets aged 1 to 27 days old circulated detectable antibodies with neut
Authors
D.C. Hahn, N.M. Nemeth, E. Edwards, P.R. Bright, N. Komar
Auditory brainstem responses in the Eastern Screech Owl: An estimate of auditory thresholds
The auditory brainstem response (ABR), a measure of neural synchrony, was used to estimate auditory sensitivity in the eastern screech owl (Megascops asio). The typical screech owl ABR waveform showed two to three prominent peaks occurring within 5 ms of stimulus onset. As sound pressure levels increased, the ABR peak amplitude increased and latency decreased. With an increasing stimulus prese
Authors
E.F. Brittan-Powell, B. Lohr, D.C. Hahn, R.J. Dooling
Inter-species variation in yolk steroid levels and a cowbird-host comparison
We examined variability in yolk hormone levels among songbird species and the role of yolk steroids as a mechanism for enhanced exploitation of hosts by the parasitic Brown-headed Cowbird Molothrus ater. Within-clutch variation in yolk steroids has been found in several avian species in single species studies, but few comparisons have been made among species. We found a large range of differences
Authors
D. Caldwell Hahn, Jeffrey S. Hatfield, Mahmoud A. Abdelnabi, Julie M. Wu, Lawrence D. Igl, Mary A. Ottinger
Geographic variation in cowbird distribution, abundance, and parasitism
We evaluated geographical patterns in the abundance and distribution of Brown-headed Cowbirds (Molothrus ater), and in the frequency of cowbird parasitism, across North America in relation to habitat fragmentation. We found no distinctive parasitism patterns at the national or even regional scales, but the species is most abundant in the Great Plains, the heart of their original range, and least
Authors
M.L. Morrison, D.C. Hahn
Contrasting determinants of abundance in ancestral and colonized ranges of an invasive brood parasite
Avian species distributions are typically regarded as constrained by spatially extensive variables such as climate, habitat, spatial patchiness, and microhabitat attributes. We hypothesized that the distribution of a brood parasite depends as strongly on host distribution patterns as on biophysical factors and examined this hypothesis with respect to the national distribution of the Brown-headed
Authors
D.C. Hahn, R.J. O'Connor
Tetranucleotide microsatellite markers for the Brown-headed Cowbird Molothrus ater
No abstract available.
Authors
Jonathan L. Longmire, J.L. Roach, M. Maltbie, P.S. White, O.L. Tatum, K.D. Makova, D.C. Hahn
Host selection in the forest interior: cowbirds target ground-nesting species
We investigated patterns of cowbird host selection in a large (1300 ha), unfragmented forest in eastern New York in 1992-3 to determine whether cowbird parasitism rates can be attributed to species-specific traits or to other features associated with nest sites. Nest height was significantly associated with parasitism (P = 0.003) in this community of 23 species (n = 430 nests, 23% parasitized).
Authors
D.C. Hahn, J. S. Hatfield
Use of lice to identify cowbird hosts
The host specificity of avian lice (Phthiraptera) may be utilized by biologists to investigate the brood parasitism patterns of Brown-headed Cowbirds (Molothrus ater). As nestlings, brood parasites have a unique opportunity to encounter lice that are typically host specific. Lice are permanent hemimetabolic ectoparasites, a group found strictly on the body of the host, and they are transferred alm
Authors
D.C. Hahn, R.D. Price, P.C. Osenton
Introduction
No abstract available.
Authors
M.L. Morrison, L.S. Hall, S.K. Robinson, S.I. Rothstein, D.C. Hahn, T.D. Rich
Science and Products
Filter Total Items: 33
Experimental West Nile virus infection in Eastern Screech Owls (Megascops asio)
This study evaluated the potential effects of different concentrations of bleached/unbleached kraft mill effluent (B/UKME) on several reproductive endpoints in adult largemouth bass (Micropterus salmoides). The kraft mill studied produces a 50/50 mix of bleached/unbleached market pulp with an estimated release of 36 million gal of effluent/day. Bleaching sequences were C90d10EopHDp and CEHD for so
Authors
Nicole M Nemeth, D. Caldwell Hahn, D. H. Gould, R. A. Bowen
Parasitic Cowbirds have increased immunity to West Nile and other mosquitoborne encephalitis viruses
The rapid geographic spread of West Nile Virus [WNV, Flaviviridae, Flavivirus] across the United States has stimulated interest in comparative host infection studies of avian species to delineate competent reservoir hosts critical for viral amplification. Striking taxonomic differences in avian susceptibility have been noted, offering the opportunity to strategically select species on the basis o
Authors
W.K. Reisen, D.C. Hahn
Passive West Nile virus antibody transfer from maternal Eastern Screech-Owls (Megascops asio) to progeny
Transovarial antibody transfer in owls has not been demonstrated for West Nile virus (WNV). We sampled chicks from captive adult WNV-antibody-positive Eastern Screech-Owls (Megascops asio) to evaluate the prevalence of transovarial maternal antibody transfer, as well as titers and duration of maternal antibodies. Twenty-four owlets aged 1 to 27 days old circulated detectable antibodies with neut
Authors
D.C. Hahn, N.M. Nemeth, E. Edwards, P.R. Bright, N. Komar
Auditory brainstem responses in the Eastern Screech Owl: An estimate of auditory thresholds
The auditory brainstem response (ABR), a measure of neural synchrony, was used to estimate auditory sensitivity in the eastern screech owl (Megascops asio). The typical screech owl ABR waveform showed two to three prominent peaks occurring within 5 ms of stimulus onset. As sound pressure levels increased, the ABR peak amplitude increased and latency decreased. With an increasing stimulus prese
Authors
E.F. Brittan-Powell, B. Lohr, D.C. Hahn, R.J. Dooling
Inter-species variation in yolk steroid levels and a cowbird-host comparison
We examined variability in yolk hormone levels among songbird species and the role of yolk steroids as a mechanism for enhanced exploitation of hosts by the parasitic Brown-headed Cowbird Molothrus ater. Within-clutch variation in yolk steroids has been found in several avian species in single species studies, but few comparisons have been made among species. We found a large range of differences
Authors
D. Caldwell Hahn, Jeffrey S. Hatfield, Mahmoud A. Abdelnabi, Julie M. Wu, Lawrence D. Igl, Mary A. Ottinger
Geographic variation in cowbird distribution, abundance, and parasitism
We evaluated geographical patterns in the abundance and distribution of Brown-headed Cowbirds (Molothrus ater), and in the frequency of cowbird parasitism, across North America in relation to habitat fragmentation. We found no distinctive parasitism patterns at the national or even regional scales, but the species is most abundant in the Great Plains, the heart of their original range, and least
Authors
M.L. Morrison, D.C. Hahn
Contrasting determinants of abundance in ancestral and colonized ranges of an invasive brood parasite
Avian species distributions are typically regarded as constrained by spatially extensive variables such as climate, habitat, spatial patchiness, and microhabitat attributes. We hypothesized that the distribution of a brood parasite depends as strongly on host distribution patterns as on biophysical factors and examined this hypothesis with respect to the national distribution of the Brown-headed
Authors
D.C. Hahn, R.J. O'Connor
Tetranucleotide microsatellite markers for the Brown-headed Cowbird Molothrus ater
No abstract available.
Authors
Jonathan L. Longmire, J.L. Roach, M. Maltbie, P.S. White, O.L. Tatum, K.D. Makova, D.C. Hahn
Host selection in the forest interior: cowbirds target ground-nesting species
We investigated patterns of cowbird host selection in a large (1300 ha), unfragmented forest in eastern New York in 1992-3 to determine whether cowbird parasitism rates can be attributed to species-specific traits or to other features associated with nest sites. Nest height was significantly associated with parasitism (P = 0.003) in this community of 23 species (n = 430 nests, 23% parasitized).
Authors
D.C. Hahn, J. S. Hatfield
Use of lice to identify cowbird hosts
The host specificity of avian lice (Phthiraptera) may be utilized by biologists to investigate the brood parasitism patterns of Brown-headed Cowbirds (Molothrus ater). As nestlings, brood parasites have a unique opportunity to encounter lice that are typically host specific. Lice are permanent hemimetabolic ectoparasites, a group found strictly on the body of the host, and they are transferred alm
Authors
D.C. Hahn, R.D. Price, P.C. Osenton
Introduction
No abstract available.
Authors
M.L. Morrison, L.S. Hall, S.K. Robinson, S.I. Rothstein, D.C. Hahn, T.D. Rich