Abundance, impacts and resident perceptions of non-native common pheasants (Phasianus colchicus) in Jersey, UK Channel Islands.

Few species are able to establish themselves in a non-native range and expand their population to

become a wide-ranging invasive. However, for those that are able to, their negative environmental

impacts include widespread predation of native flora and fauna, competition and spread of

parasites and disease. The common pheasant (Phasianus colchicus), a native of central Asia, has

been the subject of introductions for recreational hunting across the globe for hundreds of years.

Today, millions of birds are released annually and rural habitats managed to better accommodate

them. These mass introductions have prompted much research regarding the effects of pheasant

populations in areas where they are released at high densities. However, little is known about the

effects of naturalised populations of pheasants in areas where they are neither released nor their

habitat managed. To fill this knowledge gap and to aid management, this study seeks to investigate

the naturalised population of common pheasants on the Bailiwick of Jersey, UK Channel Islands.

Through an extensive programme of field surveys, this research enables a better understanding of

the impacts of this non-native species on native wildlife and agriculture. Distance sampling was

used to provide density and abundance estimates of Jersey's pheasant population and Breeding

Bird Survey data, provided by the British Trust for Ornithology, were also used to investigate

population trends over time. Summer habitat preferences were also investigated and, to

complement these findings and further inform management, an online questionnaire to analyse

local perceptions of pheasants and their impacts was conducted. Pheasant density estimates ranged from 9.5 to 16.6 pheasants per km2, with a total island-wide population of 1011-1780

pheasants. Highest concentrations were seen in the southeast (St. Clement) and northwest (St.

Ouen) of the island and the lowest concentrations in the southwest (St. Brelade), with pheasants

showing a preference for fields that contained shoots, mustard and bare ground. The long-term

data revealed an overall decreasing but oscillating population trend since 2002. Residents of Jersey

perceive pheasants as having negative impacts on farmland birds, herpetofauna and crops, with

some respondents witnessing predation of reptiles and amphibians, all of which are protected

species. Despite this, pheasants are generally well received by residents with the majority 'agreeing'

or 'strongly agreeing' that pheasants add to the appeal of the countryside and that they enjoy

having pheasants in Jersey. Pheasants are also considered to have a positive impact on birds of prey

and are credited for the rise in marsh harrier (Circus aeruginosus) and buzzard (Buteo buteo)

numbers. Arable farmers displayed the most adverse opinions of pheasants and were significantly

more likely to view pheasants as negative for arable crops. The percentages of residents who

believe pheasants should be protected by legislation and those who do not are almost equal.

Specifically, arable farmers were generally in favour of removing pheasant protection, whereas

game shooters polarise this view. The successful management of any invasive species or their

impacts relies on monitoring populations, examining their trends, and understanding their habitat

use. To this end, this study provides the baseline data required for future decisions on pheasant

management by policy makers in Jersey.