Identifying malaysian or hodgson hawk cuckoo

by mamuin Wed Mar 21, 2012 4:23 pm

Hi all,
Just wanna share an article bout the identification of malaysian and hodgson hawk cuckoo. It was sent to me by Sifu Dave Bakewell. Originally in Nature in Singapore journal.

Hodgson’s Hawk Cuckoo: a Birder’s Headache
Yong Ding Li
Introduction
Taxonomic revisions have always been the bane of the birdwatcher, though it often offers
a whole new perspective for world bird listers. Species get split, lumped, chugged into
‘dumping ground families’, thrown into totally new families or struck off original family
groupings. Classic cases of taxonomically confusing oriental birds include the Malaysian
Rail-Babbler, White-bellied Yuhina and the Mountain Tailorbird complex. In terms of
taxonomy, Southeast Asia is still relatively poorly known and every year new revisions
come into place. The Hodgson’s Hawk Cuckoo Hierococcyx (Cuculus) fugax,
unfortunately fell victim to taxonomic splitting, kicking off splitting headaches for many
regional birders. These taxa, taxonomy aside, has also been of interest to naturalists for
its close resemblance to Accipiter hawks, suggesting a case for avian mimicry (Payne,
1997; King, 2002).
The Hodgson’s Hawk Cuckoo Problem
The case of the Hodgson’s Hawk Cuckoo is nonetheless confusing because it was
originally described as four separate species, re-lumped and finally evaluated and re-split
by King (2002). Distributed throughout much of tropical and temperate east Asia, the
original Hodgson’s Hawk Cuckoo Hierococcyx fugax is now split into four distinct
species, Northern Hawk-Cuckoo Hierococcyx hyperythus, Philippine Hawk-Cuckoo
Hierococcyx pectoralis, Hodgson’s Hawk-Cuckoo Hierococcyx nisicolor and Malaysian
Hawk-Cuckoo Hierococcyx fugax (King, 2002). In Singapore, the situation is particularly
tricky because two very similar-looking species occur here, the migratory Hodgson’s
Hawk-Cuckoo H. nisicolor of subtropical Asia (wintering in Malay Peninsula, Sumatra,
Borneo and Java) and the probably resident Malaysian Hawk-Cuckoo H. fugax (Lim,
2007). Malaysian Hawk-Cuckoos are aptly named, being resident and confined largely to
the Malay Peninsula, Sumatra, Borneo and some islands in-between (King, 2002).
Both species can be distinguished by subtle differences in songs, plumage and
morphometrics. The problem lies therein that the average birdwatcher in the field is not
going to spot that 3 mm of difference in the culmen length or the 2-3 mm of difference
between their longest primary feathers (King, 2002). Neither would he be able to tell
them by call because most of these migratory Hodgson’s Hawk Cuckoo would be as
taciturn as it gets. The last piece of clue will lie in their plumage patterns, naturally.
Adults of both species are easy to tell apart. The adult Hodgson’s Hawk-Cuckoo has an
orangy rufous wash on its breast when compared to the heavy streaking on the adult
Malaysian. The problem arises in distinguishing the adult or immature Malaysian Hawk-
Cuckoo forms with the immature Hodgson’s Hawk-Cuckoo forms.

Identification in the Field
When confronted with this threefold problem, there are two subtle identification hints to
look out for. Malaysian Hawk-Cuckoo immatures tend to have a small white patch near
the nape. This feature is generally noticeable and consistent, especially if seen from the
back or the profiles. Another feature to look out for, in the event that the white nape patch
is inconspicuous are the whitish to faint fringes to the feathers on the lower mantle and
wing coverts. Robson (2005) also noted the pale innermost tertial feather of the immature
Hodgson’s Hawk Cuckoo and its generally warmer plumages (Robson, 2005) when
compared to the darker plumages of the Malaysian Hawk Cuckoo juveniles. On the bright
side, thanks to sometimes intermediate forms and often poor viewing conditions, even
experts may be misled and King (2002) acknowledges the difficulty in identification of
the immature forms (King, 2002). The table below should hopefully address some of the
identification pointers encountered in the field.
TABLE 1. A Summary of some of the visible differences between the Malaysian Hawk-
Cuckoo H. fugax and the Hodgson’s Hawk-Cuckoo H. nisicolor.

Immature Features Malaysian Hawk-Cuckoo Hodsgons’s Hawk Cuckoo
White nape patch Present Absent
Wing linings/fringes Pale whitish, sometimesfaint Buffy to rusty buff
Innermost tertial feather Less pale (more brownish) Paler (often very faint)
Bands on underside of primaries Generally broader Comparatively less broad
Underparts Generally whiter and cleaner Often has a slight rufous orangy wash
General plumage
coloration Generally darker brown Generally lighter, and richer brown

References
1. King, B.F. (2002). The Hierococcyx fugax, Hodgson’s Hawk Cuckoo, complex.
Bulletin of the British Ornithologist’s Club, 2002. Vol. 122, No. 1: 74 – 80.
2. Lim, K.S. (2007). Pocket Checklist of the Birds of the Republic of Singapore.
2nd Edition. Nature Society (Singapore).
3. Payne, R.B. (1997). Cuckoos. Cuculidae. In Handbook of the Birds of the World.
Vol.4. (del Hoyo, J., Elliott, A. & Sargatal, J. eds). Lynx Edicions.
4. Robson, C. (2005). Birds of Southeast Asia. Princeton University Press, New
Jersey.[table]