The behavioural rhythms of organisms are thought to be under strong selection, influenced
by the rhythmicity of the environment 1 , 2 , 3 , 4 . Such behavioural rhythms are well studied …

Recent estimates of the world's swan Cygnus sp. populations indicate that there are
currently between 1.5–1.6 million birds in 8 species, including the Coscoroba Swan

Each winter~ 30% of the Northwest European Bewick’s Swan Cygnus columbianus bewickii
population feeds in Polder Wieringermeer, the Netherlands, on waste crops left after the …

Foragers tend to exploit patches to a lesser extent farther away from their central place. This
has been interpreted as a response to increased risk of predation or increased metabolic …

The extent to which animal migrations shape parasite transmission networks is critically
dependent on a migrant’s ability to tolerate infection and migrate successfully. Yet, sub-lethal …

The relative investment of females and males into parental care might depend on the
population’s adult sex-ratio. For example, all else being equal, males should be the more caring …

The north-west European population of Bewick’s Swan Cygnus columbianus bewickii declined
by 38% between 1995 and 2010 and is listed as ‘Endangered’ on the European Red List …

In this expedition from 1 to 26 February 2022 we visited the most important areas for Black-tailed
Godwits in southern Spain and Portugal during northward migration. Our aim was to …

In 2004 the University of Groningen has started a long-term demographic project on a partly
colourringed breeding population of Black-tailed Godwits Limosa limosa (hereafter: godwits) …

… Wim Tijsen and the second time for Siebe Bonthuis. In 2017 Siebe joined the team of Wim
Tijsen … and he enjoyed it that much, so this year Wim and Siebe form a team. The second team…