Editor’s note: The image above shows Crow-billed Drongo (left) and Black Drongo. The former was noted in Shanghai on Tues. 11 Oct. 2016, a first for the city. The latter is a common passage migrant in Shanghai. In this post, I show you how to separate the two species.
On Tues. 11 Oct. 2016 at Nanhui, Shanghai’s major birding spot on the East China Sea, Shanghai Birding member kaca found a first-winter Crow-billed Drongo Dicrurus annectans. kaca’s record was the first for Crow-billed Drongo in Shanghai.
Is kaca’s historic discovery a one-off, or is it the result of more birders with greater skills more thoroughly covering Shanghai’s hot spots and communicating more readily with one another? If the answer is the latter, then there may be a Crow-billed Drongo in your future! To sift out Crow-billed from the many Black Drongo in our area, note the following:
— All drongos have a strong, black bill. Crow-billed (Panel 2a, above) may have the stoutest, as deep at its base as it is wide.
The swollen look of its bill may be Crow-billed’s most striking feature. The bill of Black Drongo Dicrurus macrocercus cathoecus is broad and short but noticeably less thick-based than that of Crow-billed. Compare bills of the two species in the image at the top of this post. (Race cathoecus is the form of Black Drongo birders are most likely to see in Shanghai.)
— The iris in kaca’s first-winter Crow-billed is reddish-brown (2a). Adult Crow-billed has a blood-red iris.
Compare brown iris of adult Black at top of post.
— Black Drongo often shows white spot at gape, never present in Crow-billed.
Note again the photo leading off this post.
— First-winter Crow-billed shows white spotting from breast to undertail coverts (2b, 3).
First-winter Black, by contrast, shows more patchily white underparts (panels 1a, 1b in photo below).
— The tail of Crow-billed shows a less shallow fork than the tail of Black. On average, the tail of Black is forked about twice as deeply as that of Crow-billed.
Compare Panel 4 in photo above to Panel 2 in photo below. Adult Crow-billed and Black have deeper forks, but the proportions are the same as in the sub-adults. In addition, the outer rectrices of Crow-billed’s tail are more likely to curl upward.
BACKGROUND ON THE SPECIES
A monotypic species, Crow-billed Drongo Dicrurus annectans breeds from the Himalayan foothills in India east to Hainan. In winter some birds go as far south as Sumatra and Java. Shenzhen-based French birder Jonathan Martinez, an expert on southeast China birds, reports breeding populations of Crow-billed in northern Guangdong and southwest Hunan. There are coastal records, most likely of migrants, from Hong Kong and Guangxi. Shanghai Birding member Paul Holt writes that Crow-billed is “undoubtedly overlooked” in southern China and “is probably quite rare or at least very localized.” Martinez agrees, calling Crow-billed “scarce” even at the Guangdong and Hunan sites.
ALSO TUESDAY …
On Tuesday I arrived in Nanhui too late to see Crow-billed Drongo. My partners Kai Pflug and Elaine Du and I made the fateful decision to cover Hengsha Island in the morning. The alluvial island at the mouth of the Yangtze was decidedly humdrum, with Far Eastern Curlew out on the mud along with 2 Sanderling and a Ruddy Turnstone. The huge new tree plantation on the island failed to deliver any forest birds beyond a single Asian Brown Flycatcher. There was a good count (17) of Richard’s Pipit.
We arrived in Nanhui and found kaca, who mentioned an unusual drongo he had seen that morning. We kept our eyes peeled for dark drongos, finding none. Our Nanhui harvest was limited to expected October birds such as Grey-backed Thrush (6) and Eyebrowed Thrush (2). Asian Brown Flycatcher (26) seemed to be on every tree.
All of Shanghai’s Big 5 Leaf Warblers were present: Pallas’s Leaf Warbler (1), Yellow-browed Warbler (1), Arctic-type Warbler (2), Pale-legged/Sakhalin Leaf Warbler (7), and Eastern Crowned Warbler (2).
We had 3 Japanese Paradise Flycatcher, Elaine’s and my season’s first Daurian Redstart, Asian Stubtail, and Rufous-tailed Robin.
I’m trying to get over missing the Crow-billed Drongo. I tell myself, “That’s birding,” but those words can’t fully dispel the empty feeling.
I am however happy for kaca, and I am encouraged, because the growing fluidity in reporting is leading to ever more astounding new bird records for Shanghai.
List 1 of 2 for Tues. 11 Oct. 2016 (29 species)
Birds noted on Hengsha Island (Héngshā Dǎo [横沙岛]), a small alluvial island at mouth of Yangtze River in Shanghai, China. S gate to reclaimed area at 31.297333, 121.859434. Partly cloudy. Low 17° C, high 19° C. Humidity 64%. Visibility: large buildings visible from distance of 38 km. Wind NE 18 km/h. PM2.5 AQI: 42 (good). Sunrise 05:55, sunset 17:25. TUE 11 OCT 2016 07:15-10:15. Craig Brelsford, Elaine Du, & Kai Pflug.
Little Grebe Tachybaptus ruficollis 18
Great Crested Grebe Podiceps cristatus 7
Grey Heron Ardea cinerea 9
Great Egret A. alba 2
Intermediate Egret A. intermedia 1
Little Egret Egretta garzetta 18
Eastern Cattle Egret Bubulcus coromandus 2
Eurasian Coot Fulica atra 40
Lesser Sand Plover Charadrius mongolus 15
Kentish Plover C. alexandrinus ca. 500
Far Eastern Curlew Numenius madagascariensis 1
Ruddy Turnstone Arenaria interpres 1
Red-necked Stint Calidris ruficollis 12
Sanderling C. alba 2
Dunlin C. alpina 310
Spotted Redshank Tringa erythropus 1
Common Greenshank T. nebularia 50
Wood Sandpiper T. glareola 1
Common Kestrel Falco tinnunculus 1
Long-tailed Shrike Lanius schach 6
Eurasian/Oriental Skylark Alauda arvensis/gulgula 25
Barn Swallow Hirundo rustica 40
Plain Prinia Prinia inornata 5
Asian Brown Flycatcher Muscicapa dauurica 1
Eurasian Tree Sparrow Passer montanus ca. 50
Eastern Yellow Wagtail Motacilla tschutschensis 50
White Wagtail M. alba 2
Richard’s Pipit Anthus richardi 17
Olive-backed Pipit A. hodgsoni 1
List 2 of 2 for Tues. 11 Oct. 2016 (35 species)
Birds noted around Pudong Nanhui Dongtan Wetland (Pǔdōng Nánhuì Dōngtān Shīdì [浦东南汇东滩湿地]; 30.920507, 121.973159), Pudong, Shanghai, China. Partly cloudy. Low 17° C, high 19° C. Humidity 64%. Visibility: large buildings visible from distance of 38 km. Wind NE 18 km/h. PM2.5 AQI: 42 (good). Sunrise 05:55, sunset 17:25. TUE 11 OCT 2016 13:00-18:05. Craig Brelsford, Elaine Du, & Kai Pflug.
Garganey Spatula querquedula 9
Northern Shoveler S. clypeata 7
Eurasian Wigeon Mareca penelope 15
Little Grebe Tachybaptus ruficollis 30
Grey Heron Ardea cinerea 3
Little Egret Egretta garzetta 42
Black-crowned Night Heron Nycticorax nycticorax 3
Eurasian Coot Fulica atra 20
Spotted Redshank Tringa erythropus 1
Common Greenshank T. nebularia 8
Feral Pigeon (Rock Dove) Columba livia 6
Spotted Dove Streptopelia chinensis 7
Long-tailed Shrike Lanius schach 20
Japanese Paradise Flycatcher Terpsiphone atrocaudata 3
Barn Swallow Hirundo rustica 2
Light-vented Bulbul Pycnonotus sinensis 1
Asian Stubtail Urosphena squameiceps 1
Pallas’s Leaf Warbler Phylloscopus proregulus 1
Yellow-browed Warbler P. inornatus 1
Arctic/Kamchatka Leaf/Japanese Leaf Warbler P. borealis/examinandus/xanthodryas 2
Pale-legged/Sakhalin Leaf Warbler P. tenellipes/borealoides 7
Eastern Crowned Warbler P. coronatus 2
Plain Prinia Prinia inornata 7
Dark-sided Flycatcher Muscicapa sibirica 2
Asian Brown Flycatcher M. dauurica 26
Blue-and-white Flycatcher Cyanoptila cyanomelana 8
Rufous-tailed Robin Larvivora sibilans 1
Mugimaki Flycatcher Ficedula mugimaki 3
Taiga Flycatcher F. albicilla 1
Daurian Redstart Phoenicurus auroreus 2
White’s Thrush Zoothera aurea 8
Grey-backed Thrush Turdus hortulorum 6
Chinese Blackbird T. mandarinus 1
Eyebrowed Thrush T. obscurus 2
White Wagtail Motacilla alba 11
Brelsford, Craig, moderator. Shanghai Birding, a WeChat chat group. Quotations in post from Paul Holt and Jonathan Martinez taken from this chat group. News about kaca’s discovery of Crow-billed Drongo was first disseminated in this chat group. To join Shanghai Birding, fill out the form on our Sightings page.
del Hoyo, Josep, et al., eds. The Handbook of the Birds of the World. Lynx Edicions. Vol. 14, “Bush-shrikes to Old World Sparrows.” Highly detailed species accounts for Crow-billed Drongo (p. 212) and Black Drongo (p. 222) written by G.J. Rocamora and D. Yeatman-Berthelot.
MacKinnon, John & Karen Phillipps. A Field Guide to the Birds of China. Oxford University Press. Entry on Crow-billed Drongo, p. 282.
Message, Stephen & Don Taylor. Waders of Europe, Asia and North America. Refreshed my memory on basic points separating Lesser Sand Plover from Greater Sand Plover.
Robson, Craig. Birds of Southeast Asia. Princeton University Press. Crow-billed Drongo and Black Drongo, p. 176.