Results 21 to 30 of about 34,424 (118)

Trophic discrimination of amino acid ‐specific nitrogen stable isotopes in raptor nestlings: implications for estimating trophic position

Journal of Zoology, Volume 327, Issue 3, Page 236-247, November 2025.
We used high‐precision diet estimates from nest cameras to estimate amino acid‐specific trophic discrimination factors (TDFs) for gyrfalcon nestlings and compared these against TDFs for other taxa from the literature. TDFs for trophic amino acids in gyrfalcon were lower than values that have typically been used to estimate trophic position.
A. Bautista, D. L. Johnson, M. T. Henderson, D. L. Anderson, T. L. Booms, C. T. Williams   +5 more
wiley   +1 more source

Absence of negative effect of GPS‐tags on survival and breeding success in a long‐lived territorial raptor

Ibis, Volume 167, Issue 4, Page 1053-1064, October 2025.
GPS tracking has enabled significant advances in the study of animal movements such as migration and habitat use. However, GPS devices can affect the behaviour of tagged individuals, especially for flying animals such as birds, and may ultimately impair their reproduction and/or survival.
Lise Viollat, Roger Pradel, Cécile Ponchon, Alain Ravayrol, Alexandre Millon, Aurélien Besnard   +5 more
wiley   +1 more source

Intermittent Gliding in the Hunting Flight of the Kestrel, Falco tinnunculus L. [PDF]

, 1983
The hunting flight of the kestrel (Falco tinnunculus) consists of short bouts of flight at wind speed against the wind with the eyes in a fixed position relative to the ground, and of short flights from one such position to the next.
Weihs, D., Videler, J.J., Weihs, D.,, Daan, S., Videler, J.J.,, Daan, S.,   +5 more
core   +1 more source

Southern Extension to the Breeding Range of the Gyrfalcon, Falco Rusticolus, in Eastern North America [PDF]

, 1995
We report the observation of four gyrfalcon (Falco rusticolus) nests and several adults south of the previously recognized southern limit of the species\u27 breeding distribution in eastern North America.
DesGranges, J.-L., Morneau, F., Décarie, R., Negro, J., Brodeur, S.   +4 more
core  

Evaluating the demographic history of the Seychelles kestrel (Falco araea): genetic evidence for recovery from a population bottleneck following minimal conservation management. [PDF]

, 2009
An important requirement for biologists conserving vulnerable species of wildlife and managing genetic problems associated with small population size is to evaluate existing evidence regarding what is known of a species’ recent population history.
Groombridge, Jim J., de L. Brooke, Michael, Prys-Jones, Robert P., Dawson, Deborah A., Shah, Nirmal J., Burke, Terry   +5 more
core   +1 more source

Climatic variation affects seasonal survival of an alpine bird species

Wildlife Biology, Volume 2025, Issue 4, July 2025.
Mountains are particularly exposed to climate change, and empirical studies have shown that montane bird species are highly sensitive to the ongoing changes. Modelling mortality risks under climatic variation will give insight into species‐specific sensitivity. Willow ptarmigan Lagopus l.
Lasse Frost Eriksen, Thor Harald Ringsby, Markus F. Israelsen, Pål F. Moa, Vidar Grøtan, Erlend B. Nilsen   +5 more
wiley   +1 more source

Ann De Falco [PDF]

, 2019
Ann De Falco worked on staff in the Birnbaum Library at Pace University from 1998 to 2019.https://digitalcommons.pace.edu/oralhistory/1001/thumbnail ...
De Falco, Ann
core   +1 more source

No support for solar radiation as a major evolutionary driver of malar stripes in falcons

Journal of Avian Biology, Volume 2025, Issue 3, May 2025.
The malar stripes of falcons (Falco spp.) are often hypothesised to function by reducing the amount of solar glare reflected into the falcon's eyes while hunting, thereby aiding foraging efficiency in bright conditions. This ‘solar glare hypothesis' is supported by intraspecific trends in peregrine falcons Falco peregrinus, in which populations ...
Michelle Vrettos, Chevonne Reynolds, Arjun Amar   +2 more
wiley   +1 more source

Migration, Habitat and Hunting Style Do Not Affect the Malar Stripe of Different Falcon Species

Ecology and Evolution, Volume 15, Issue 4, April 2025.
Migratory strategy, habitat and hunting style do not markedly influence the size and intensity of malar stripes across falcon species, suggesting that other mechanisms, such as thermoregulation or camouflage, also play a role. ABSTRACT The solar glare hypothesis suggests that the malar stripe of a falcon decreases the sun's glare in the eye, possibly ...
Celeste Polak, Jente Ottenburghs
wiley   +1 more source

A Picky Predator and Its Prey: How Snow Conditions and Ptarmigan Abundance Impact Gyrfalcon Feeding Behaviour and Breeding Success

Ecology and Evolution, Volume 15, Issue 4, April 2025.
This study was conducted in the alpine areas of central Norway, and focused on the gyrfalcon (Falco rusticolus) and two ptarmigan species (Lagopus lagopus, Lagopus muta). We provide a detailed description of gyrfalcon diet throughout the nestling period, describe how this, reproductive success and territory occupancy relate to local ptarmigan densities,
Annabel Josien Slettenhaar, Jan Eivind Østnes, Børje Cato Moen, Rolf Terje Kroglund, Torgeir Nygård, Erlend Birkeland Nilsen   +5 more
wiley   +1 more source