The Leafbirds are a small group of arboreal passerines found throughout
tropical Asia. All are in the same genus Chloropsis so they are
all closely related. Five species are fairly widespread in SE Asia/Greater
Sundas; one is endemic to Sumatra, and two are endemic to the Philippines.
Leafbirds tend to be various combinations of green, yellow, and sometimes
a little blue, but perhaps the most attractive is the Gold-fronted Leafbird
(left or above) which can sometimes be found feeding on flowers. We had
several working the bottlebrush at the Quality Inn along the Kosi River
in the w. Himalayan foothills. Leafbirds have spiked tongues adapted for
taking nectar (like the Rhabdornis
of the Philippines) and often poke into tubular flowers but, unlike Rhabdornis,
they build cup-shaped nests. For this reason, their arboreal habits, and
their whistled songs, they sort-of remind me of North American vireos.
I've
had the good fortune to see all three of the island endemic leafbirds.
One of them is the Yellow-throated Leafbird (right), found only
on Palawan I. and adjacent Balabac and Calamian islands. Leafbirds were
traditionally considered closely related to the Ioras (Aegithinidae).
Like ioras they tend to forage alone or in pair in the subcanopy, often
eating berries and fruit and well as insect prey. Even some recent literature
place the leafbirds together with the ioras in the same family (e.g., Kennedy
et al. 2000). But DNA studies (Sibley & Ahlquist 1990) showed that
leafbirds were not that closely related to ioras but were more closely
related to bushshrikes, helmetshrikes and vangas within a broad corvine
assemblage that arose in Australasia. They have fairly hefty bills for
their size (recalling a miniature cuckoo-shrike) but are short-tailed.
Once also considered related to the bulbuls (Pycnonotidae) but having some
characters of drongos (Dicruridae) or cuckoo-shrikes (Campepahagidae; Austin
& Singer 1961), Sibley & Monroe (1990) placed then next to cuckoo-shrikes
in their own family.
Leafbirds are clearly closely related to the two species of Fairy-Bluebird (genus Irena) which some place in the family Irenidae (which name takes precedence over Chloropseidae). Many recent books on Asian birds lump them together in the same family. Taxonomic relationships of these Asian families remain uncertain and controversial. The Handbook of the Birds of the World project apparently will separate the Leafbirds as a family and split off the Fairy-Bluebirds as another. This family-splitting seems odd when they haven't split up the barbets (into three) which proposal is supported by substantial biochemical evidence and other analysis. But they've adopted a more traditional approach and so I've just followed suit.
Photo: The Gold-fronted Leafbird Chloropsis aurifrons (top) was at the Quality Inn near Ramnagar, Uttar Pradesh, India, on 13 Mar 2001. The Yellow-throated Leafbird Chloropsis palawanensis (top) was photographed at Balsahan, Palawan, Philippines, on 21 Feb 1990. Photos © 2001 D. Roberson, all rights reserved.
Bibliographic note
There is no family book as yet nor much written about this group at all.
Other literature cited:
Austin, O. L., and A. Singer. 1961. Birds of the World. Edited by H. S. Zim. Golden Press, New York.TOPKennedy, R. S., P. C. Gonzales, E. C. Dickinson, H. C. Miranda, Jr., and T. H. Fisher. 2000. A Guide to the Birds of the Philippines. Oxford Univ. Press, Oxford, U.K.
Sibley, C. G., and J. E. Ahlquist. 1990. Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale Univ. Press, New Haven, CT.
Sibley, C. G., and B. L. Monroe, Jr. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT.
Page created 23 Mar 1999, revised 2-3 May 2001