Factors affecting breeding distribution of Storm-petrels Hydrobates pelagicus in Orkney and Shetland Capsule The main factors are past and present human activities, especially the introduction of rats to islands

De León, A., Mínguez, E., Harvey, P., Meek, E., Crane, J.E. and Furness, R.W. (2006) Factors affecting breeding distribution of Storm-petrels Hydrobates pelagicus in Orkney and Shetland Capsule The main factors are past and present human activities, especially the introduction of rats to islands. Bird Study, 53(1), pp. 64-72.

Abstract

<i>Aims</i>: To assess factors that influence breeding distribution and abundance of Storm-petrel. <i>Methods</i>: 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. <i>Results</i>: 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<i> Stercorarius skua</i>, Great Black-backed Gulls <i>Larus marinus</i>, and Storm-petrels all correlated, as each increased with island size. <i>Conclusions</i> 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.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Furness, Professor Robert
• Authors: De León, A., Mínguez, E., Harvey, P., Meek, E., Crane, J.E., and Furness, R.W.
• Subjects: Q Science > QL Zoology; G Geography. Anthropology. Recreation > GE Environmental Sciences
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Bird Study
• ISSN: 0006-3657