English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We studied prey selection of Sandwich Terns (Sterna sandvicensis) in the presence of kleptoparasitising Black-headed Gulls (Larus ridibundus) on Griend, Dutch Wadden Sea, from 1992 to 1998. Most often, gulls robbed larger sandeels rather than herring from terns. Provided that one parent attends the chick, energy intake would be too low for the chicks' survival if exclusively fed on sandeel. By provisioning an increasing proportion of herring, parent terns could theoretically overcome a potential food shortage when the chicks grow older. However, the proportion of herring did not increase with age of chicks in most years. Instead, parents increased their foraging effort with the growth of their offspring. In years with high proportions of food loss, parents left their chicks unattended at the nest more often. In that way, parents were largely able to counterbalance food shortage of offspring. In 1992 and 1996, when diet composition was unfavorable and food losses to gulls were high, parents left their chicks unattended at the nest for ∼80% of the daylight period. It is argued that the present working level of parents might be higher than in the 1960s.

Foraging Decisions of Sandwich Terns in the Presence of Kleptoparasitising Gulls