Tag: all of Corvus

Neergang en herstel van de Roek als broedvogel in Nederland in de 20e eeuw

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 […]

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. […]

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 […]

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 […]

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 […]

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 […]

Proximity of raven (Corvus corax) nest modifies breeding bird community in an intensively used farmland

Raven (Corvus corax) Science Article 1 abstract In this paper I tested the hypothesis that areas around nests of raven Corvus corax built on electricity pylons in an intensively used farmland are avoided by small birds as their nest sites. Birds were counted along 13 transects (length 1000 m, width 200 m) starting from pylons […]

Behavioural phenotypes may determine whether social context facilitates or delays novel object exploration in ravens ( Corvus corax )

Raven (Corvus corax) Science Article 7 abstract Individuals consistently differ in behavioural phenotypes. Here we examine the interaction between behavioural phenotype and response to social context during novel object exploration in a neophobic corvid species, the raven (Corvus corax). The presence of conspecifics tends to encourage object exploration and learning but may also delay or […]