2006/03/01 by Ana de León, Eduardo Mínguez, Paul Harvey +3 · 3 citations
Environmental Science · Immunology and Microbiology · Agricultural and Biological Sciences · #Animal Ecology and Behavior Studies #Bird parasitology and diseases #Insect and Pesticide Research
paper · doi:10.1080/00063650609461417
openalex publication_date 2006/03/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Capsule The main factors are past and present human activities, especially the introduction of rats to islands. Aims To assess factors that influence breeding distribution and abundance of Storm-petrel. Methods We used a database for 142 islands in Shetland and Orkney. Breeding status of Storm-petrel was related to data for each island on introduced and indigenous predators, other human-related features, and aspects of island geography. Results Although 92% of the total land area of the archipelagos comprised islands with rats present, Storm-petrel colonies were almost totally restricted to rat-free islands. They also occurred more frequently on islands with cliffs, far from neighbouring islands with humans, and on islands with a low rate of human visits. Colony size was smaller on the smallest occupied islands. Breeding numbers of Great Skuas Stercorarius skua, Great Black-backed Gulls Larus marinus, and Storm-petrels all correlated, as each increased with island size. Conclusions The presence or absence of rats is the single most important influence on Storm-petrel breeding distribution in Orkney and Shetland. However, geographical and human-related effects, such as the presence of cliffs or the occurrence of human visits, also appear to influence the distribution of Storm-petrels, whereas avian predators appear to have had little effect until now.