Worcestershire Record No. 22 April 2007 p. 14

P. F. Whitehead

Polecats are now widely distributed in Worcestershire and I have known for some years that they and/or their ferret cross-breeds occur in Evesham town. Specimens found dead at Hampton during October 2005 (SP 04) and April 2007 (SP 04) showed the pale under-fur of ferret influence. Between October 2005 and April 2007 polecats or polecat-ferrets have visited town gardens in Evesham, leaving their characteristically compacted faeces available for study.

The Evesham animals exist largely independently of rabbits, and examination of their faeces confirms their animal content as being exclusively invertebrate. They are therefore making full use of the variety of niches that exist in urban and suburban gardens, and impacting significantly on their invertebrates at a time when insectivorous hedgehogs are now absent from many of their former garden haunts. The influence of ferret genes in this population has limited ecological significance, for it has established its own niche occupancy and adapted to the urban ecosystem. Pure-bred polecats also occur in or close to Evesham town, so that, in the absence of conclusive sightings, urban tolerance per se should not be regarded as evidence of ferret influence.

Whitehead (1999) showed that a pure-bred polecat on the Malvern Hills (SO74) ate earwigs and seven species of beetle. The urban polecats of Evesham are no different. Examination (following maceration in hot water) of a single faeces of 1.7 grams dry weight voided on an urban lawn on 10 April 2007 showed that it contained thousands of comminuted fragments (many <0.1mm in length) of isopods Porcellio scaber Latreille (perhaps 14 individuals) and Philoscia muscorum (Scopoli) (one individual), and that these constituted the major element of the diet at that time. Earwigs Forficula auricularia L. were represented by one individual, and the carabid beetles Nebria brevicollis (F.), Pterostichus cupreus (L.) and Amara cf. similata (Gyllenhal) by one individual in case. All of these invertebrates are characteristic of garden biotopes.

Four faeces collected on 18 April 2007 weighed 13 grams dry weight, and these were somewhat different in structure, being packed with grass foliage, and containing remains of only a few isopods P. scaber. Herbivory is not frequently cited for polecats. The sample contained the remains of four earwigs F. auricularia and two ants Myrmica sp. Only four carabid beetles were isolated, including Amara aenea (De Geer), a species of more open insolated sites, Amara sp. indet., and Amara eurynota (Panzer). This last is a localised species, only rarely occurring in gardens, but more usually on disturbed sandy sediments in lowland valleys, which might explain the presence of numerous sand-grains in these faeces. Fragments of a weevil were also isolated as the abdominal sternites only; they are believed to represent Phyllobius pyri (L.), which is widely distributed in leafy places.