CALYPTOMENID BROADBILLS  Calyptomenidae
Broadbills are among the most spectacular birds on earth but most are exceptionally difficult to observe. This combination makes them perhaps my favorite of all families of birds. When you are fortunate enough to see one of them, it is an great day. But wait! New evidence (Moyle et al. 2006) shows that two major lineages of broadbills diverged from each other about 55 million years ago. After that, the Asities of Madagascar and the Sapayoa of the New World diverged from this group. To maintain Asities as an endemic family in Madagascar, one must now split the Broadbills into two families: the Calyptomenid Broadbills and the Eurylaimid Broadbills (more on this below).

The Calyptomenid Broadbills are just 6 species: three green broadbills in Asia and three lowland forest broadbills in Africa. These are all great birds. Perhaps the most impressive of all is Whitehead's Broadbill, an endemic of montane Borneo (left, in a spectacular photo © Gareth Knass). The velvet greens are as neon-vibrant in the Bornean cloud forest as the crimson-red of the male Andean Cock-of-the-Rock is in the Andean rainforest. Indeed, with its small bill and puffed-out forehead, this broadbill might pass an the Asian version of cock-of-the-rock. On top of that it has an amazing vocalizing of cackles and raucous cries.

It was those calls that permitted Rita and I to finally see the Whitehead's Broadbill on Mt. Kinabalu, when we taped in a fabulous male. In addition to its incredible selection of raucous calls, the male had an elaborate bowing and peering behavior. This photo (right © Hideo Tani) shows a vocalizing bird on Mt. Kinabalu, stretching and beginning to bow, just as ours had done.

There is another spectacular Bornean endemics: Hose's Broadbill Calyptomena hosii (below). So far I've been unable to locate any in the wild, but I eventually held a specimen at a major museum. The glistening colors explained the appropriateness of the old name for Hose's: the "Magnificent Green Broadbill." Long ago I chose it as among the "top 50 birds of the world" and continue to do so today. Back then I could find no painting of it, so I made my own (below).


The two Bornean endemics, plus Green Broadbill Calyptomena viridis  that also occurs on the mainland of southeast Asia, are primarily fruit eaters. They build elaborate, hanging, purse-shaped nests. In these Calyptomenid Broadbills, the nests are suspended close to the branch and the entrance is at the top. In this they differ from Eurylaimid Broadbills (and Asities and Sapayoa) whose nest is suspended farther from the branch, and the entrance is at the side (Prum 1993, Moyle et al. 2006).
 

The most surprising result of the new biochemical evidence of relationships and evolution in the broadbills, based on nuclear DNA (Moyle et al. 2006), is that there were multiple dispersals of early broadbills to Africa and the New World. It appears that for a short time (10 million years) the Eurylaimides evolved in isolation on India in the Indian Ocean, before India smashed into Eurasia. Northeast India made contact with the Asian continent by the Paleocene, during the warmest time in the Tertiary (crocodiles and flying lemurs north to Ellesmere Island, 78 degrees N latitude!). The Calyptomenid Broadbills dispersed east (to southeast Asia) and west (to Africa) during this time. Presumably, over time, many intermediate species became extinct with changing climate, leaving today's three green broadbills in southeast Asia, and three species isolated in the lowlands of central Africa. Several million years later the Sapayoa diverged in the New World tropics, the Asities diverged in Madagascar, and Grauer's Broadbill Pseudocalyptomena graueri  diverged from the remaining Eurylaimid Broadbills that still exist today from Indian to southeast Asia.
The three African species of Calyptomenid Broadbills [genus Smithornis] lack the dazzling colors of Asian birds, but their structure and behaviors are special. I have only a piteously poor photo of perhaps the dullest member of the family, the African Broadbill (far left), but Gareth Knass got this better shot of the central African specialty, Rufous-sided Broadbill (near left). Most of the African species sit quietly under the canopy, occasionally calling, and then dart out after prey with incredibly sharp snaps of their huge broad bills. I've seen the Rufous-sided Broadbill Smithornis rufolateralis at M'Passa Reserve in northeastern Gabon, in the heart of the Congo Basin rainforest. When finally located, the tiny broadbill seemed to be "all bill" and nothing else except for a rusty wash at the shoulder (although you don't get this impression in the photo). The spectacular behavior quite blinds one to the details of plumage.
Photos: The Whitehead's Broadbill Calyptomena whiteheadi shown at top left was photographed by Gareth Knass; the one in the center of the page is by Hideo Tani (Apr 2004), both taken on Mt. Kinabalu, Sabah, Borneo. The African Broadbill Smithornis capensis was in the Kakamega Forest, Kenya, in Nov 1981. The Rufous-sided Broadbill  Smithornis rufolateralis was photographed by Gareth Knass. All photos © Don Roberson, except those attributed to Gareth Knass and Hideo Tani, who hold those copyrights, used with permission. All rights reserved.

Bibliographic essay

Family Book
Lambert, Frank, and Martin Woodcock. 1996. Pittas, Broadbills, and Asities. Pica Press, Sussex, England.

In the standard format of recent books in the Pica Press series, color plates are found separately (with facing page captions) from the text, giving the feeling this is meant to be a field guide. The quality of the paintings is good, at least to my eye, given my minimal experience in the wild with these great birds but more experience in handling museum specimens. However, not even well-printed plates can capture the glistening colors of these wonderful birds, and the "field guide" poses are stiff and lifeless. The introductory text appears up-to-date, and the species accounts seemed well-researched. I found no obvious errors in the maps or text, but then I know comparatively little about these families. Despite giving the book high marks for apparent accuracy and attractive paintings within the limits of the genre, how I wish for a more "old-fashioned" book on these special families, with full-page spreads of each species in habitat and evocative detail of each species' discovery to science! The "field guide" approach to the art, and the plodding quality of the scientific text, just does not do justice to these marvelous creatures. Yet for what it is, the book is generally well-done and a welcome addition to the bookshelf.
    Lambert & Woodcock did not anticipate the actual relationships shown by the nuclear DNA research (Moyle et al. 2006), so this fine family book is already outdated on phylogeny and related issues.
The Handbook of the World volume covering this family (Bruce 2003) was, as expected, spectacular. However, it, too, did not anticipate the true nature of the relationships of this group.

Other literature cited:

Bruce, M. 2003. Family Eurylaimidae (Broadbills) in del Hoyo, J., A. Elliott, & D.A. Christie, eds., Handbook of the Birds of the World, Vol. 8, pp. 54-93. Lynx Edicions, Barcelona.

Moyle, R.G., R.T. Chesser, R.O. Prum, P. Schikler, and J. Cracraft. 2006. Phylogeny and evolutionary history of Old World suboscine birds (Aves: Eurylaimides). Amer. Mus. Novitates 3544: 1-22.

Prum, R. O. 1993. Phylogeny, biogeography, and evolution of the broadbills (Eurylaimidae) and asities (Philepittidae) based on morphology. Auk 110: 304-324.

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