Caldwell Hahn, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 33
Experimental West Nile virus infection in Eastern Screech Owls (Megascops asio) 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...
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 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...
Authors
W.K. Reisen, D.C. Hahn
Passive West Nile virus antibody transfer from maternal Eastern Screech-Owls (Megascops asio) to progeny 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...
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 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
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 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...
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 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...
Authors
M.L. Morrison, D.C. Hahn
Science and Products
Filter Total Items: 33
Experimental West Nile virus infection in Eastern Screech Owls (Megascops asio) 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...
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 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...
Authors
W.K. Reisen, D.C. Hahn
Passive West Nile virus antibody transfer from maternal Eastern Screech-Owls (Megascops asio) to progeny 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...
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 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
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 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...
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 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...
Authors
M.L. Morrison, D.C. Hahn