 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).
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| 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: 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.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.TOP |
