Birdfinding.info ⇒ The Thai endemic form of Chestnut-headed Partridge is confined to a region of forested hills about 25 miles long and 5 miles wide. Its entire known range is within Khao Khitchakut National Park and Khao Soi Dao Wildlife Refuge. It can be found in the vicinity of the Buddha Footprint, a revered pilgrimage destination at the top of Khao Khitchakut, reached by a 4-km trail from Wat Phluang.
“Siamese Partridge”
Arborophila cambodiana diversa
Endemic to the Soi Dao Mountains of southeastern Thailand, where it reportedly inhabits evergreen forests between about 500 and 1,000 m elevation.
Identification
Medium-brown overall, with a mostly pale, tan-brown head, darker brown crown, blackish eyestripe, blackish beard on its lower throat and foreneck, and a necklace of whitish spots on the chest.
The back is subtly barred with black, and the wings have a complex pattern of pale-gray, black, and rufous.
The sides and flanks are boldly patterned with black-and-white chevrons, and the belly is pale and bordered with white spots and streaks.
“Siamese Partridge,” A. c. diversa. (Phra Phutthabat Pluang – Pha Daeng, Khao Khitchakut National Park, Chanthaburi, Thailand; March 14, 2020.) © Wich’yanan (Jay) Limparungpatthanakij
“Siamese Partridge,” A. c. diversa. (Phra Phutthabat Pluang – Pha Daeng, Khao Khitchakut National Park, Chanthaburi, Thailand; March 14, 2020.) © Wich’yanan (Jay) Limparungpatthanakij
“Siamese Partridge,” A. c. diversa, lateral view. (Kao Sa Bap, Chanthaburi, Thailand; January 8, 1930.) National Museum of Natural History, Smithsonian Institution
“Siamese Partridge,” A. c. diversa, dorsal view. (Kao Sa Bap, Chanthaburi, Thailand; January 8, 1930.) National Museum of Natural History, Smithsonian Institution
“Siamese Partridge,” A. c. diversa, ventral view. (Kao Sa Bap, Chanthaburi, Thailand; January 8, 1930.) National Museum of Natural History, Smithsonian Institution
Voice. Recordings attributed to this form are of three basic types—which occur together in the same recording. One is a liquid, metallic note monotonously repeated at a rate of about two per second: Khao Soi Dao Tai, Chanthaburi, Thailand; January 10, 2005. © P.D. Round.
Another is the same note uttered in pairs. The third—likely the female in duet—is a deeper, three-note phrase repeated at intervals of about two-thirds of a second (i.e., three times in two seconds). All can be heard in this recording: Phra Phutthabat Pluang – Pha Daeng, Khao Khitchakut National Park, Chanthaburi, Thailand; March 14, 2020. © Wich’yanan (Jay) Limparungpatthanakij.
Cf. “Cambodian Partridge”. The “Cambodian” (cambodiana) and “Siamese” (diversa) forms of Chestnut-headed Partridge share approximately the same overall pattern but differ dramatically in coloration. “Siamese” is mostly warm-brown whereas “Cambodian” is mostly rufous on its head and breast, black on its crown, and boldly barred with black throughout its upperparts. “Siamese” also differs in having a prominent blackish beard, which is either subtle or lacking on “Cambodian.” A third subspecies, chandamonyi, is reportedly intermediate between the others, but there appear to be no published images of it available to evaluate.
Notes
Monotypic form that was formerly considered a separate species but was reclassified as a subspecies of Chestnut-headed Partridge (A. cambodiana). The reason for the reclassification was the discovery of a population (A. c. chandamonyi) with features intermediate between cambodiana and diversa.
References
BirdLife International. 2016. Arborophila cambodiana. The IUCN Red List of Threatened Species 2016: e.T22679057A92801643. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22679057A92801643.en. (Accessed March 19, 2020.)
eBird. 2020. eBird: An online database of bird distribution and abundance. Cornell Lab of Ornithology, Ithaca, N.Y. http://www.ebird.org. (Accessed March 19, 2020.)
Madge, S., and P.J.K. McGowan. 2002. Pheasants, Partridges, and Grouse: A Guide to the Pheasants, Partridges, Quails, Grouse, Guineafowl, Buttonquails, and Sandgrouse of the World. Princeton University Press, Princeton, N.J.
McGowan, P.J.K., G.M. Kirwan, and P. Boesman. 2020. Chestnut-headed Partridge (Arborophila cambodiana). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. https://www.hbw.com/node/53460. (Accessed March 19, 2020.)
Poole, C.M. 1999. Little known Oriental bird: Chestnut-headed Partridge. Oriental Bird Club Bulletin 30. https://www.orientalbirdclub.org/chestnut-h-partridge.
Robson, C. 2002. Birds of Thailand. Princeton University Press, Princeton, N.J.