Food resources and quality for the introduced Cretan wild goat or agrimi Capra aegagrus cretica on Atalandi Island, Greece, and implications for ecosystem management

Abstract

A study of seasonal food availability and quality for Cretan wild goat or agrimi Capra aegagrus cretica introduced on Atalandi Island, Greece, was conducted during 1988–1989. The major portion of available forage consisted of Olea europaea var. sylvestris, Pistacia lentiscus and Cistus spp. The first two species are the main food resources in late summer and early autumn, the critical period for agrimi nutrition, and the only species with crude protein (CP) content exceeding maintenance requirements of agrimi. Grasses contained the highest level of neutral detergent fibre (NDF) and acid detergent fibre (ADF) among all plant categories in all seasons. Herbaceous species had the lowest level of lignin and shrubs the highest. In vitro organic matter digestibility (IVOMD) of herbaceous species was > 50% only in spring. During summer only Olea europaea produced sufficient forage with digestibility c. 50%. Future management must be directed toward maintaining a balance between vegetation productivity and grazing pressure. Maintaining the agrimi population at grazing capacity would allow an increase of productivity of palatable species. The seeding of palatable native herbs would provide nutritious feed for the agrimi and reduce the grazing impact. Continuous monitoring of the agrimi population, vegetation and soil trends is considered indispensable.