Long-distance migration of Korean common cuckoos with different host specificities

Abstract

The common cuckoo Cuculus canorus is a generalist brood parasite at the species level, consisting of multiple groups of individuals specialized in the same host species (termed gens and gentes in plural). Ecological variation between different host species, including habitat type and breeding phenology often result in different behavioral, developmental and genetic profiles among cuckoo gentes. In this study, we report a long-distance migration performed by the Korean population of common cuckoos distributing allopatrically with different host specificity: the meadow bunting Emberiza cioides gens and the vinous-throated parrotbill Sinosuthora webbiana gens. Our satellite tracking of 10 common cuckoos (five of each gens) showed that Korean cuckoos performed around 22,000 km roundtrips to Southeast Africa with up to three sea-crossing, including 3000 km non-stop Arabian Sea-crossing. Cuckoos left South Korea between late August and mid-September, and arrived at the wintering area (e.g., Tanzania and Mozambique) around the end of November, staying there until March or April next year before returning to Korea in May. Their migration routes were very narrow, and similar between the outward and return journey. The major stopovers were usually located before and after sea-crossing, such as in Myanmar, India and Somalia, of which the conservation value need to be recognized. Despite these long and delicate journeys, different cuckoo gentes that we tracked exhibited very similar migration patterns, consequently being separated on the breeding ground but otherwise being mixed.

Keywords

• Brood parasite
• Common cuckoo
• Gentes
• Host specificity
• Migration
• Satellite tracking