Partial albinism in a semi-isolated population of great reed warblers

Albinism in birds is thought to result from the expression of recessive all eles that disrupt melanin pigmentation at feather development. We have stud ied great reed warblers Acrocephalus arundinaceus in a recently founded and increasing population in Sweden during 15 years for the presence of birds with albinistic feathers. The study population was founded in 1978 and the few cases of albinism was exclusively recorded during the first five pears of our study (1985-1989). This fits to the expected pattern if albinism is governed by recessive alleles; we have previously demonstrated that the pop ulation suffered from inbreeding during the first years of our study. The a lbinistic birds experienced a similar lifetime reproductive success as norm ally coloured birds.