Refuge abandonment in a formerly harvested waterbird and the consequent formation of multi-species bird colonies

The intense human persecution of wildlife in the past forced many animal populations to look for refuge in human-inaccessible habitats. With the decline of direct persecution and the changes in the attitude of modern urban societies towards wildlife during the last few decades, an ecological process of abandonment of refuge habitats has become pervasive, and many species make habitat choices deemed surprising presently, such as colonizing sites that are more accessible to humans. We tested this process in the Yellow-legged Gull (Larus michahellis) by analysing long-term time series (1976-2022) of breeding pairs in 7 colonies in southern Europe. Overall, Yellow-legged Gull numbers showed a strong pattern of decrease during the study period, due to the recent closure of open-air garbage dumps. However, while the number of pairs in colonies located in human-inaccessible sites (islets with cliffs) declined rapidly, new colonization, together with a monotonic linear population growth, was de..., , # Refuge abandonment in a formerly harvested waterbird and the consequent formation of multi-species bird colonies

Dataset DOI: [10.5061/dryad.brv15dvn3](10.5061/dryad.brv15dvn3)

## Description of the data and file structure

All supplementary material data used in this article has been uploaded. The submitted data represent long-term monitoring of breeding pairs of Yellow-legged Gulls (Larus michahellis) in different locations, which have been classified into two types (accessible and non-accessible) according to the accessibility capacity of humans (vertical rocky islets vs. sandy islets with flat dunes or flat islets). To graphically visualize the data and study non-linear relationships, we have used GAMs. Tables S1 and S2 were used for graph construction, and the statistical software R ([https://www.r-project.org/](https://www.r-project.org/)) was used.

DRYAD-DATABASE.xls content: All data used in this study are divided into pages. These are annual monitoring results, where the n...,