Short notes on wintering Blue-and-white Flycatcher (Cyanoptila cyanomelena/intermedia) at Lake Toba, Sumatra, Indonesia
INTRODUCTION
In their FORKTAIL 28 (2012): 121–128 report "Zappey’s Flycatcher Cyanoptila cumatilis, a forgotten Chinese breeding endemic", PAUL J. LEADER & GEOFF J. CAREY describe the Zappey's Flycatcher (Cyanoptila cumatilis) as a recent split from the Blue-and-white Flycatcher.
Their report states that there are few findings of Zappey's Flycatcher outside it's breeding range of Central China, and it's wintering range largely unknown. It can be assumed that the species winters in similar areas of the Blue-and White Flycatcher in tropical Asia, but few observations exists.
I therefore took it upon myself to set out in late November / early December of 2015 on an expedition (fueled mostly by banana pancakes) to determine if Zappey's was wintering in north Sumatra.
In my opinion my sightings were inconclusive, but I have presented my findings here (with photos) for anyone interested in this complex species split.
MacKinnon lists the Blue-and-white Flycatcher as a rare winter visitor to Sumatra, but it is probably locally common in secondary growth/ forest edge of Lake Toba.
SPECIES IDENTIFICATION
The male's of both Blue-and-white C. cyanomelena and the subspecies C. intermedia differ slightly, while Zappey's C. cumatilis is somewhat more distinctive in the field . Although the plain brown and white plumage of the females have unique features, they appear to be slight, and are not readily distinctive in the field. Females are can probably only be identified in the hand with the aid of an assortment of bizarre measuring tools which the ornithologist adores and the birdwatcher laments.
LOCATION OF OBSERVATIONS
The Lake Toba Caldera is situated in northern Sumatra, a large island in western Indonesia. In the center of Lake Toba lies Samosir Island at an altitude of 915 M – 1600 M asl. On the eastern side of Samosir Island is the village of TukTuk which is popular with tourists and is easily reached by regular ferry from the village of Parapat. Many types of accommodation in various price ranges are available.
Just to the west of Tuktuk, there is a leisurely 4 km south-north walk through villages along a old road from the village of Tomok to Ambaritta. This walk parallels the main south-north road to the east, and the dramatic, near vertical 700m rise of vegetated cliff face on the west.
A few very tall fig trees can still be found amongst the secondary growth growth along this route. These large fig trees are reported to be planted many years ago when the villages were first founded, and it is in them that most of my observations of Blue-and-white Flycatcher's are seen. Despite lengthy observations of these flycatchers in the fruiting fig trees, I did not see them eat the fruit of these impressive trees. Of special note were the high numbers of Coppersmith Barbets, flocks comprised of over 100 individuals, which would swarm a fruiting tree.
SIGHTINGS
Here are the links to my eBird lists:
http://ebird.org/ebird/view/checklist/S26010854
http://ebird.org/ebird/view/checklist/S26079393
http://ebird.org/ebird/view/checklist/S26107627
http://ebird.org/ebird/view/checklist/S26145201
http://ebird.org/ebird/view/checklist/S26211257
http://ebird.org/ebird/view/checklist/S26178732
Notable additional wintering species observed include:
Asian Brown Flycatcher (common)
Dark-sided Flycatcher (fairly common)
Mugimaki Flycatcher (fairly common)
Ferruginous Flycatcher (Uncommon)
Korean Flycatcher (scarce)
Tiger Shrike (uncommon)
Forest Wagtail (scarce)
SOURCES
http://orientalbirdclub.org/wp-content/uploads/2013/01/Zappeys-Flycatcher.pdf, PAUL J. LEADER & GEOFF J. CAREY
eBird.org, various authors
Birds of Southeast Asia, Craig Robson 2003
Birds of Borneo, Sumatra, Java and Bali, J. MacKinnon 1993