Habitat selection of Black-headed gulls breeding in the Dutch Wadden Sea

Habitat selection is of great importance in the fate of individuals, the structure and dynamics of ecosystems, and also the evolution and diversity of life. The research species in this study is a most wildly seen opportunistic gull species in the Netherlands, the black-headed gull. In this study, GPS- UHF tracking collar was used for remote detection of the positions of 11 individuals, including 4 males and 7 females who failed in their breeding during the breeding season in 2019 on Griend, the Netherlands. We want to mainly figure out (1) if the tidal cycle can affect the habitat selection of the black-headed gulls in the Wadden Sea, and (2) if they show different habitat selection behavior between two different breeding statuses, which is before and after breeding failure. Hypotheses were made that it shows a regular habitat selection in response to the daily tidal cycle and that difference can be shown between two different breeding statuses. We used the random selection function (RSF) fitting with integrated nested Laplace approximations (INLA) to analyze their preference value for different habitats. The result shows that this species prefers to go to the emerged areas in response to the daily tidal cycle, and the regularity can be more distinctly shown in the intertidal area. The selection preference for most habitats remain similar between before and after breeding failure, however, a difference can be shown in several habitats during the high tide.