Cranial lesions caused by helminth parasites and morphological traits in the European polecat Mustela putorius

We investigated the occurrence of cranial lesions caused by helminth parasites in the European polecat Mustela putorius in a museum collection in Slovakia. Selected traits of polecat body morphology and condition were studied with respect to the prevalence of the parasites, and number and extent of helminth-caused lesions in crania of 183 adult polecats. The trematode Troglotrema acutum was identified as the parasitic agent (prevalence 62.6 %), with a strong relationship between number of lesions and extent of cranial damage (surface of cranium). Prevalence of infection did not differ significantly between sexes (68.9 % in females, 51.1 % in males). Females with lesions by Troglotrema acutum have significantly greater braincase breadth than uninfected ones. Among males, infected individuals were generally significantly heavier and larger than uninfected individuals. Therefore, contrary to assumptions, it seems that parasites did not influence significantly body measurements of the animals, and differences are probably rather a result of an intra-sample age variation among infected polecats (older individuals are bigger, more probably infected and damage is more pronounced).