The influence of Syngamus trachea on pheasant populations

Abstract

The common pheasant, Phasianus colchicus, is arguably the most common and important game bird species within Europe. Its importance as a game species means that in order to maintain adequate population levels, up to 20 million pen-reared birds are released every summer within the UK. Despite the supplementation of natural populations with pen-reared birds, the breeding success of released pheasants is poor compared with natural populations. The cause behind the poor breeding success of released pheasants is currently unclear, however many factors such as increased parasitic worm infections are believed to be major factors. Syngamus trachea is a parasitic nematode belonging to family Syngamidae and the super family Strongylodiea, and is a common parasite of Galliformes and Passeriformes. Infection with S. trachea can occur either directly by the ingestion of eggs or third stage larvae, or indirectly, by the ingestion of an infected invertebrate paratenic host, most commonly the earthworm (Lumbricus terretsris and Eisenia foetida). Infection with S. trachea can lead to decreased body condition, poor reproductive success and even death in heavily infected birds. The confinement of large populations of birds within release pens means the likelihood of infection is extremely high. The aim of the present study is to model disease dynamics within release pens with the aim to enable the spatial manipulation of disease.

Description

Temporal and spatial modelling of disease dynamics.