European Herring Gull (Larus argentatus) Science Article 11 abstract Flock composition and interspecific dominance were studied in Black-headed Gulls and Herring Gulls wintering at an inland refuse dump in Germany. Herring Gulls were the dominant species and forced the much more numerous Black-headed Gulls to forage close to operating bulldozers. This supports the hypothesis that […]
Nitrite poisoning in herring gulls (Larus argentatus) and ring-billed gulls (Larus delawarensis)
European Herring Gull (Larus argentatus) Science Article 2 abstract Landfill disposal of a fertilizer manufacturing waste product was associated with a die-off of gulls in New Hanover County, North Carolina. An estimated 250 herring and ring-billed gulls were found dead at the site following the initial disposal of this material. Chemical analyses revealed that the […]
Helping at the nest in European Bee-eaters: Who helps and why?
European Bee-eater (Merops apiaster) Science Article 6 abstract Avian cooperative breeding has been regarded as an ideal system in which to investigate the role of kin selection in the evolution of altruistic behaviour (Brown 1987). However, many studies of helping at the nest have been carried out on communally breeding species in which the costs […]
A Case of Bigamy in the European Bee-eater (Merops apiaster)
European Bee-eater (Merops apiaster) Science Article 1 abstract This example of bigamy is interesting, because it does not fit with current hypotheses about the adaptive value of polygyny. Orians (1969) argued that females may sometimes gain by being the second female on a good territory rather than a lone female on a poor territory, and […]
Response to typical, mixed and shortened song versions in Eurasian treecreepers, Certhia familiaris
Eurasian Treecreeper (Certhia familiaris) Science Article 1 abstract Eurasian treecreepers, Certhia familiaris, exhibit an extremely low song variation, with particular males singing only a few variants of basically the same song type. However, males of this species are known to sing shortened and mixed song versions, which contain notes typical for the sibling short-toed treecreeper, […]
Reproductive decisions of boreal three-toed woodpeckers (Picoides tridactylus) in a warming world: from local responses to global population dynamics
Eurasian Three-toed Woodpecker (Picoides tridactylus) Science Article 1 abstract Here, I examine whether both nestling prey abundance and profitability affect the timing of reproduction and hence the number of fledglings of three-toed woodpeckers, Picoides tridactylus. Individuals living in eastern Finland reproduced earlier and reared larger broods in habitat patches where the bark-beetle community developed earlier […]
Breeding performance, natal dispersal, and nest site fidelity of the three-toed woodpecker in the German Alps
Eurasian Three-toed Woodpecker (Picoides tridactylus) Science Article 2 abstract I studied the breeding biology of the three-toed woodpecker Picoides tridactylus in order to determine factors that influence annual and seasonal variations. Data from 37 pairs showed that 79% of nests produced at least one fledgling. The median laying date was not affected by elevation, and […]
Dispersal and migration in Eurasian Spoonbills Platalea leucorodia
Eurasian Spoonbill (Platalea leucorodia) Science Article 2 abstract Sightings of Eurasian Spoonbills marked at the Odiel marshes, SW. Spain, were analysed to determine the extent of philopatry, sites of dispersal and the temporal and spatial patterns of migration in this population. Odiel Spoonbills winter in the Senegal delta (2500 km south of the Odiel). However, […]
Microverontreinigingen in lepelaarkuikens uit het Zwanenwater
Eurasian Spoonbill (Platalea leucorodia) Science Article 1 abstract De broedkolonies van de lepelaar (Platalea leucorodia) behoren tot de meest noordelijke in het verspreidingsgebied van de soort. Sinds het begin van de zestiger jaren heeft de soort sterk onder druk gestaan, met een dramatisch dieptepunt van minder dan 200 broedparen eind jaren zestig. Naast verstoring, habitatverlies, […]
Influence of snow cover on food hoarding in Pygmy Owls Glaucidium passerinum
Eurasian Pygmy Owl (Glaucidium passerinum) Science Article 2 abstract Voles are the most preferred prey of Pygmy Owls (Glaucidium passerinum) in Northern Europe, where the extensive snow cover may decrease the availability of voles. Snow covermay thus cause changes in the diet fromwhat is expected on the basis of prey abundance alone. Food hoarding behaviour […]