The thick-billed warbler (Phragamaticola aedon, passeriformes, Acrocephalidae) as a host species for the common cuckoo (Cuculus canorus, Cuculiformes, Cuculidae) in the middle Amur River basin

Abstract

The thick-billed warbler (Phragamaticola aedon) is known as one of the main host species for the common cuckoo (Cuculus canorus) in Primorsky Krai and the environs of Khabarovsk. The interaction of these species in the middle Amur River basin is discussed for the first time. In 2013–2014, at the Khingan Nature Reserve, four cuckoo eggs were found in the nests of thick-billed warblers. There are also unpublished data on the findings of cuckoo eggs and nestlings in the nests of the thick-billed warbler from the same area. The similarity of coloring of the parasite and host eggs confirms that the thick-billed warbler is one of the main host species for the common cuckoo in the middle Amur River basin. At the same time, our observations, as well as data from other researchers, show that, in the studied area, the thick-billed warbler usually recognizes cuckoo eggs and destroys them. A description of cuckoo eggs found in Khingan Nature Reserve is given, and the problems of interactions between the nest parasite and its host species are discussed.