動物學(xué)

動物學(xué)

來源出版物：Current Zoology，2015，61（1）: 181-190聯(lián)系郵箱：Sonia KLEINDORFER，sonia.kleindorfer@flinders.edu.au

封面介紹：Image of an adult male small tree finch Camarhynchus parvulus on Floreana Island. Small tree finch males are pairing with medium tree finch C. pauper females to produce hybrid offspring. Over the past decade，the two parental species have diverged in foraging behaviour whereas hybrid birds have not. See Katharina J. PETERS and Sonia KLEINDORFER，Pp 181-190. Photo credits: Katharina J. PETERS.

Divergent foraging behavior in a hybrid zone： Darwin's tree finches（Camarhynchus spp.）on Floreana Island

Katharina J. PETERS，Sonia KLEINDORFER

Hybrid speciation is increasingly recognized as a mechanism for novel evolutionary trajectories. However，we know very little about the ecology of a contact zone that has arisen in sympatry. This study examines the foraging behavior and fitness of two species of Darwin's tree finches（Camarhynchus parvulus，C. pauper）and hybrid offspring on Floreana Island. Previous study showed that the percentage of hybrids in the tree finch population increased from 19% in 2005 to 41% in 2010，and their body and beak size increased by ～5%（parental phenotype did not change）. In 2005-2006，all three tree finch groups（two parental species and hybrid birds）used the same foraging substrate，technique，and height. By 2010-2013，the small tree finch C. parvulus had changed its foraging technique and the medium tree finch C. pauper had changed its foraging height. Both parental species had higher body condition when foraging at（divergent）mean foraging heights per species but hybrid birds did not. We discuss the implications of conserving forest to facilitate vertical niche expansion and the role of hybridization for genetic persistence.

Hybridization； Speciation； Adaptive radiation； Conservation； Scalesia； Ecological niche