Previous phylogeographic studies of the great tit (Parus major) and the willow tit (Parus montanus) found a general absence of phylogeographic structure for both species and suggested that each species underwent range contraction during the last Ice Age and survived in relatively low numbers, P. major in southern Europe and P. montanus in southeastern Asia. However, prior studies did not sample the entire range of either species. We analyzed sequence data for the complete mitochondrial ND2 gene from 87 P. major and 139 P. montanus from 15 new Eurasian localities, both to test prior conclusions and to provide better coverage of each species' range. Our analyses confirmed the absence of phylogeographic structure in P. major and P. montanus and supported the prior refuge hypothesis for P. major. For P. montanus, we concluded that besides surviving the Ice Age in southeastern Asia, as previously hypothesized, it apparently sustained a relatively large population in northern Eurasian riverine thickets and then expanded eastward. Genetic diversity was low in P. major (π = 0.0012, h = 0.64) and moderate in P. montanus (π = 0.0021, h = 0.88), suggesting higher long-term effective population sizes and the older ages of populations in P. montanus. If molecular substitution rates are similar, P. montanus colonized its current Eurasian range earlier than P. major. Differences between prior studies and ours likely result from sampling gaps in earlier studies.
Bibliographical noteFunding Information:
We are grateful to B. Eddy, H. Furguson, and to the late G. Eddy for funding fieldwork. Additional support came from the National Science Foundation (DEB 9707496 and DEB 0212832) and the Dayton-Wilkie Natural History fund. Tissue samples were provided by Burke Museum of Natural History and Culture, University of Washington; Moscow State University Zoological Museum, Moscow, Russia; and the Bell Museum of Natural History, University of Minnesota. We thank the Burke Museum for curatorial assistance and M. Westberg for laboratory assistance. We also thank A. Andreev, V. Andreev, Yu. Lohman, D. Banin, I. Karagodin, Ya. Red’kin, B. Schmidt, V. Rohwer, C. S. Wood, X. Pu, V. Masterov, R. Faucett, G. Voelker, V. Sotnikov, S. Birks, B. Barber, I. Fadeev, E. Nesterov, E. Koblik, and A. Jones for logistical help with expeditions and collecting.