Breeding biology of two wagtail subspecies on Ulleung Island, Korea: Amur Wagtails, Motacilla alba leucopsis and Black-backed Wagtails, M. a. lugens

Woo-Yuel Kim,Jin-Young Park,Ji-Young Lee,Incheol Kim,Ha-Cheol Sung

doi:10.1080/19768354.2018.1496949

Abstract

ABSTRACTThere is much controversy over the species and subspecies status of the white wagtail complex, which is further compounded by interbreeding between two subspecies, the Amur Wagtail (Motacilla alba leucopsis) and the Black-backed Wagtail (M. a. lugens). This study presents preliminary information on the breeding biology of both subspecies on Ulleung Island, Korea, over two breeding seasons (2012–2013). Mixed pairs of the two subspecies were common on this island, with almost 50% of all pairs being heterotypic or intermediate pairs; however, assortative mating was still present. Females of both subspecies were more likely to be paired with Amur wagtail males, whereas intermediate females were more likely to be paired with Black-backed Wagtail males. Clutch size, egg size and mass, and reproductive parameters (such as hatching success and nest success) did not significantly differ from each other. However, the mean values were low in intermediate pairs. Our results indicate no reproductive barrier between the two subspecies, but that some post-isolating mechanisms are still in progress.

Highlights

The white wagtail (Motacilla alba) has a widespread breeding distribution, expanding across most of Eurasia, including western Alaska and southeastern Greenland
To elucidate the breeding biology of Amur Wagtails and Black-backed Wagtails, we examined the proportions of breeding pairs and their reproductive performance on Ulleung Island
We documented a total of 33 breeding pairs of wagtails (12 pairs in 2012; 21 pairs in 2013) over the two survey years, of which we captured and banded 25 individuals (11 individuals in 2012; 14 individuals in 2013)

Summary

Introduction

The white wagtail (Motacilla alba) has a widespread breeding distribution, expanding across most of Eurasia, including western Alaska and southeastern Greenland Over this range, nine to 13 subspecies have been recognized, based on extensive geographic variation in morphological and genetic characteristics (Cramp 1988; Snow and Perrins 1998; Alström et al 2003; Pavlova et al 2005). Based on the genetic relationships of mitochondrial and/or nuclear DNA sequences, these two subspecies have been, again, classified as the same group (Pavlova et al 2005) and classified as different group (Ödeen and Alström 2001; Alström et al 2003) These results show lack of congruence with respect to the morphological and genetic patterns for the taxonomic status of the two subspecies

Methods

Results

Conclusion