Invasion of an Avian Nest Parasite, Philornis downsi, to the Galapagos Islands: Colonization History, Adaptations to Novel Ecosystems, and Conservation Challenges

Abstract

This chapter discusses the invasion of an avian nest fly, Philornis downsi, to the Galapagos Islands, its interactions with novel bird hosts, and the strategies that are being implemented to protect threatened, endemic bird species. Philornis downsi was first recorded in the Galapagos less than 60 years ago and is the first bird parasite with parasitic larval stages and non-parasitic adults to reach the islands. Since its introduction, it has successfully spread to most islands and habitats in the archipelago and is associated with a wide range of bird hosts. The consequences of its feeding habits on naive birds have been deleterious to a large number of species, many of which are in decline. An international research group, coordinated by the Charles Darwin Foundation and Galapagos National Park Directorate, is studying various aspects of the biology of P. downsi and its impacts on selected bird species with the aim of fully understanding the complex interactions between flies and birds. The ultimate aim of these investigations is the development of effective management tools.