Results 171 to 180 of about 7,869 (211)

Ecological constraints on digestive physiology in carnivorous and piscivorous birds

Journal of Experimental Zoology, 1999
Digestion strategies of meat- and fish-eating birds have received little attention, and the assumption has generally been made that there is rather little variation in digestion parameters between species in these guilds. We show that there is significant though small variation between species in apparent absorption efficiency.
G.M. Hilton, D.C. Houston, N.W.H. Barton, R.W. Furness, G.D. Ruxton   +4 more
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Asymmetric impact of piscivorous birds on size-structured fish populations

Canadian Journal of Zoology, 2006
Fish are frequently considered the top predator in freshwater food web models despite evidence that predatory birds can impact fish populations. In this study, we quantified bird predation rates on experimental populations of rainbow trout ( Oncorhynchus mykiss (Walbaum, 1792)) created by stocking nine small lakes in British Columbia, Canada ...
Christa Beckmann, Peter A. Biro, John R. Post   +2 more
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FACTORS INFLUENCING THE ABUNDANCE OF PISCIVOROUS BIRDS ON LAKE KYLE, ZIMBABWE

Ostrich, 1987
Summary Junor, F. J. R. & Marshall, B. E. 1987. Factors influencing the abundance of piscivorous birds on Lake Kyle, Zimbabwe. Ostrich 58:168-175. A five-year census of fish-eating birds on Lake Kyle, Zimbabwe, revealed that eight species were present in significant numbers with the Reed Cormorant being the most abundant.
F. J. R. Junor, B. E. Marshall
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Estimating Mercury Exposure of Piscivorous Birds and Sport Fish Using Prey Fish Monitoring

Environmental Science & Technology, 2015
Methylmercury is a global pollutant of aquatic ecosystems, and monitoring programs need tools to predict mercury exposure of wildlife. We developed equations to estimate methylmercury exposure of piscivorous birds and sport fish using mercury concentrations in prey fish. We collected original data on western grebes (Aechmophorus occidentalis) and Clark'
Joshua T, Ackerman, C Alex, Hartman, Collin A, Eagles-Smith, Mark P, Herzog, Jay, Davis, Gary, Ichikawa, Autumn, Bonnema   +6 more
openaire   +2 more sources

Piscivorous birds as top predators and fishery competitors in the lagoon ecosystem

Hydrobiologia, 2008
Piscivorous birds have received much attention with respect to competition with fisheries for resources. The majority of studies have been focused on cormorants Phalacrocoracidae, while predation by other piscivorous bird species has often been overlooked. This study was designed to supplement sociological research (Bell, 2004), which revealed that the
R. Žydelis, A. Kontautas
openaire   +1 more source

Liver and Breast Feather Mercury in Piscivorous Birds of the Caspian Sea: Monitoring Changes

Bulletin of Environmental Contamination and Toxicology, 2011
Mercury in the liver and breast feathers of the Common Cormorant, and in three species of Grebes from the southern coast of the Caspian Sea, were determined. The Common Cormorant had significantly more mercury in its tissues (liver: 8.5 ± 1.5; feather 8 ± 1 mg/kg dry weight) than Grebes (Great Crested Grebe: 3 ± 0.5, 8 ± 1.5; Black-necked Grebe: 3 ± 0 ...
F, Rajaei, A, Esmaili Sari, M, Savabieasfahani, N, Bahramifar, M, Ghasempouri   +4 more
openaire   +2 more sources

Selecting Piscivorous Bird Species for Monitoring Environmental Change in the Banc d'Arguin, Mauritania

Ardea, 2018
This study aims to select piscivorous bird species to be used as indicators to monitor changes in fish diversity at the Banc d'Arguin, Mauritania. Such species should have a high diet diversity, low dietary overlap and data should be easy to collect. We compared the diets of five colony nesting bird species at the Banc d'Arguin: the Slender-billed Gull
Jan Veen, Hanneke Dallmeijer, Thor Veen
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Recovery of infectious pancreatic necrosis virus from the faeces of wild piscivorous birds

Aquaculture, 1992
Abstract Faecal samples were collected from wild birds frequenting salmonid fish hatcheries to determine if birds excrete infectious pancreatic necrosis (IPN) virus in their faeces. Samples were collected from early June through early September. IPN virus was detected in faeces from herons, mallards, and other birds at titres similar to the titres ...
P.E. McAllister, W.J. Owens
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Killing of piscivorous birds at Scottish fin fish farms, 1984–1987

Biological Conservation, 1994
Abstract In recent years there has been growing concern about the environmental consequences of the rapidly expanding Scottish fish farm industry. One such concern is the control of fish predators. A questionnaire survey (covering 78% of all Scottish fin fish farms) in 1985 showed that many farmers thought piscivorous birds were a problem and that ...
openaire   +1 more source

THE ABUNDANCE AND FOOD CONSUMPTION OF PISCIVOROUS BIRDS ON LAKE KARIBA, ZIMBABWE-ZAMBIA

Ostrich, 1996
Summary Hustler, K. & Marshall, B.E. 1996. The abundance and food consumption of piscivorous birds on Lake Kariba, Zimbabwe-Zambia. Ostrich 67:23-32. About 40 species of piscivorous birds have been recorded on Lake Kariba (Zimbabwe-Zambia) but only 26 were observed during this study, carried out in 1986–87.
K. Hustler, B. E. Marshall
openaire   +1 more source