Rook (Corvus frugilegus) Science Article 1 abstract Jarenlange vervolging en een daaruit volgende afname brachtende broedpopulatie van de Roek vijftig jaar geleden op een dieptepunt.Verminderd gebruik van gifstoffen en een wettelijke beschermingleidden in de jaren zeventig van de vorige eeuw inveel voormalige broedgebieden een spectaculair herstel in.Inmiddels lijkt de populatiegroei te stagneren. Tegelijk neemt hetaantal …
Tag Archive: all of Corvus
Dec 27 2011
Investigating Physical Cognitionin Rooks, Corvus frugilegus
Rook (Corvus frugilegus) Science Article 3 abstract Although animals (particularly tool-users) are capable of solving physical tasks in the laboratory, the degree to which they understand them in terms of their underlying physical forces is a matter of contention. Here, using a new paradigm, the two-trap tube task, we report the performance of non-tool-using rooks. …
Dec 27 2011
Non-tool-using rooks, Corvus frugilegus, solve the trap-tube problem
Rook (Corvus frugilegus) Science Article 4 abstract The trap-tube problem is used to assess whether an individual is able to foresee the outcome of its actions. To solve the task, an animal must use a tool to push a piece of food out of a tube, which has a trap along its length. An animal …
Dec 27 2011
Habitat preferences of foraging Rooks Corvus frugilegus during the breeding period in the agricultural landscape of eastern Poland
Rook (Corvus frugilegus) Science Article 2 abstract The study was carried out in 2000-2002 around 6 rookeries. Rooks foraged in numbers from 1 to 132 birds (n = 417); flocks of less than 10 individuals were dominant. The type of crop influenced the size of a foraging flock. Most of the rooks were recorded within …
Dec 27 2011
Rock climbing and Raven Corvus corax ocurrence depress breeding success of cliff-nesting Peregrines Falco peregrinus
Raven (Corvus corax) Science Article 3 abstract Aims: To assess the significance of rock climbing-induced disturbance and Raven Corvus corax occurrence on the breeding output of a cliff-nesting Peregrine Falco peregrinus population.Location: Northern Italy- southern Switzerland.Methods: Breeding success, productivity and fledgling rate of 29 Peregrine pairs were analysed in relation to the occurrence of rock …
Dec 27 2011
Effect of raven Corvus coraxscavenging on the kill rates of wolf Canis lupuspacks.
Raven (Corvus corax) Science Article 4 abstract During late winter 1991 and 1992, we investigated the influence of raven Corvus coraxscavenging on the predation rate by different-sized wolf Canis lupuspacks on moose Alces alcesin the Yukon Territory, Canada. To assess the magnitude of scavenging, we presented 10 ungulate carcasses, pre-warmed to simulate the flesh temperature …
Dec 27 2011
Effect of prior nesting success on future nest occupation in raven Corvus corax
Raven (Corvus corax) Science Article 6 abstract Based on the fate of 48 nests of Raven Corvus corax we tested the hypothesis that low return rates of Raven were caused by unsuccessful nesting attempts in previous seasons. Ravens nested on electrical power pylons in 1996-1998 in an intensively managed farmland (W Poland). The studied nesting …
Dec 27 2011
Interactive behaviour between Bearded Vultures Gyp tus barbatus and Common Ravens Corvus corax in the nesting sites: predation risk and kleptoparasitism
Raven (Corvus corax) Science Article 2 abstract Aims: Aggressive interactions between the Bearded Vulture Gyp tus barbatus and the Common Raven Corvus corax are frequent in the Pyrenean nesting sectors shared by both species. The Bearded Vulture’s nesting sectors are vulnerable to kleptoparasitism (food is stored in a visible and predictable manner in nests, perching …
Dec 27 2011
Evidence for cryptic northern refugiaamong high- and temperate-latitude species in Beringia
Raven (Corvus corax) Science Article 9 abstract Stewart and Dalen (2008) argue that only temperate species were locked incryptic northern refugia during Pleistocene glacial cycles, while species presently found athigh latitudes had much wider distributions during glaciations. Christin L. Pruett & Kevin Winker, Climatic Change, 2007 Download article download full text (pdf)
Dec 27 2011
Use of the bait-marking method to estimate the territory size of scavenging birds: a case study on ravens Corvus corax
Raven (Corvus corax) Science Article 5 abstract We tested the applicability of the bait-marking method in ravens Corvus corax to estimate their territory size during the breeding season in Bia
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