作者单位:Dept. of Ecol. and Evol., Univ. of Lausanne, 1015 Lausanne-Dorigny, Switzerland[1]IPHC CNRS ULP, 23 rue Becquerel, 67087 Strasbourg Cedex 2, France[2]Ornithol. Group, Div. of Ecol. and Evol. Biol., Faculty of Biomed. and Life Sci., Graham Kerr Building, Univ. of Glasgow, Glasgow G12 8QQ, UK[3]Institute of Comp. Med., Univ. of Glasgow, Faculty of Vet. Med., Bearsden Road, Glasgow G61 1QH, UK[4]