DUTCH
BIRDINGVOLUME 42 • NO 4 • 2020 Identification of Oriental Cuckoo and Common Cuckoo based on primary pattern
Petteri Lehikoinen & Roni Väisänen
dentification of Oriental Cuckoo Cuculus opta- tour feathers between the two but the information Itus has always been a topic of lively discussions is slightly contradicting. Payne (2005) describes among birders in Europe. As an extremely rare va- juvenile Himalayan as having broader white fring- grant to Europe (outside Russia), the species has es on crown, back, and wing-coverts and tips of gained an almost mythical reputation. The cur- inner secondaries than Oriental, whereas Erritzøe rently known plumage differences between Orien et al (2012) report these being buffish in juvenile tal and Common Cuckoo C canorus overlap con- Himalayan and white in juvenile Oriental. A he- siderably and are difficult to assess in the field patic morph occurs in both Oriental and Hima (Cramp 1985). The lack of reliable identification layan (Erritzøe et al 2012). The songs of these two features for Oriental, besides vocalisation, is sur- species differ from each other, which is the most prising. This lack of knowledge might result in a important feature to identify the two (Lindholm & vagrant Oriental being overlooked in Europe, es- Lindén 2007, Xia et al 2016). pecially during migration periods when records The precise distribution ranges of Oriental are more probable. During migration, birds usu- Cuckoo and Himalayan Cuckoo in China are un- ally remain silent, unlike in the breeding season clear (Payne 2005, Xia et al 2016). Based on song when they are actively advertising territory through differences, Himalayan occurs north to Shanxi vocalizations. and north-east to Hebei and Oriental south to The aim of this paper is to shed some light on Liaoning (Xia et al 2016). According to Payne the plumage features of Oriental Cuckoo and on (2005) and Erritzøe et al (2012), birds in Taiwan separating it from the different subspecies of belong to Himalayan based on their small size. Common Cuckoo by studying museum specimes. However, Xia et al (2016) found that their song is Nowadays, a substantial proportion of birders are more like Oriental. equipped with cameras, and the features present- Common Cuckoo is more widespread than ed in this paper can be interpreted even from Oriental Cuckoo and most authors recognize four flight photographs of lower quality. subspecies: C c canorus (hereafter nominate ca norus), C c bangsi (hereafter bangsi), C c subtele Range and geographical variation phonus (hereafter subtelephonus) and C c bakeri Oriental Cuckoo has a more eastern breeding (hereafter bakeri) (eg, Payne 2005, Erritzøe et al range than Common Cuckoo. Oriental breeds in 2012, Gill et al 2020). Nominate canorus breeds Russia from west of the Ural mountains all the in Europe and across Russia, Kazakhstan, Mon way east to Kamchatka and winters south from golia and northern China, as far east as Kamchatka south-eastern Asia to Australia (figure 1). The re- (figure 1). The breeding range of bangsi is restrict- lated more southern species Himalayan Cuckoo ed to the Iberian peninsula and extreme north- C saturatus was formerly considered conspecific western parts of the Maghreb. Bakeri breeds from with Oriental (Erritzøe et al 2012) but is nowadays north-eastern India, Bhutan and northern Vietnam often treated as a full species (eg, Dickinson & to south-eastern China. Subtelephonus has a Remsen 2013, Gill et al 2020). Himalayan is breeding range from the southern Caspian Sea to widely distributed in south-eastern Asia and a southern Mongolia and the extreme north-west- shorter-distance migrant than Oriental, wintering ern parts of China. Bangsi and most nominate south to New Guinea. It is remarkably smaller in canorus winter in Africa, south of the Sahara. size than Oriental (Erritzøe et al 2012), although Subtelephonus winters in India and eastern parts there is some overlap (Payne 2005). Oriental and of Africa, whereas bakeri and eastern populations Himalayan are very similar in plumage. Literature of nominate canorus winter in south-eastern Asia presents differences in the fringes of juvenile con- (Cramp 1985, Erritzøe et al 2012). However, there
[Dutch Birding 42: 229-247, 2020] 229 Identification of Oriental Cuckoo and Common Cuckoo based on primary pattern