The Blue-crowned Motmot

Abstract

My father (a dentist) does not now remember exactly why, but, when I was four or five, on two successive evenings, he read to me, by the light from a ten-gallon fish tank in an otherwise darkened room, the entire children's edition of Birds of the World, with Arthur Singer's wonderful pictures. I don't imagine he foresaw the professional results. At any rate, the most vivid of several graphic impressions from those two nights was my introduction to the motmot. One reason, of course, was the gloriously ridiculous name (which happens to mean "socks" in my mother's Cantonese). On the other hand, there was the Motmot's marvelous tail.

Racket-shaped feathers arc one of those attributes that give tropical birds so exotic an aura. They are possessed by no birds in Europe or North America. The African Standardwinged Nightjar (Macrodipteryx longipennis) bears one on each wing. They sprout from the heads of the four Six-plumed Birds of Paradise of the genus Parotia. Otherwise, rackets adorn the tails of certain birds; the Racket-tailed Parrots (Prioniturus), the Little King and Magnificent Birds of Paradise, various hummingbirds, Tyrant Flycatchers and Drongos, the Queen Whydah,and six of the eight species of motmots.

The eight motmot species are classified in six genera, comprising the family Momotidae. That so many genera in so small a family are recognized by ornithologists should imply that this family is ancient, and the birds now living are the genetically isolated remnants of what was once a much larger group. A similar conclusion may be drawn from the order Coraciformes, the "roller-like birds;' to which this family belongs. This order's other families are wonderfully distinct from each other: the 91 kingfishers, found world-wide; the five tiny todies, confined to the Caribbean; the 25 bee-eaters and 16 rollers, two graceful Old World families; the peculiar Madagascar Cuckooroller; the beautiful crested Common Hoopoe, its various subspecies found in Eurasia, Africa and Madagascar; the seven crestless African Woodhoopoes; and the 51 grotesque hornbills of the Old World Tropics.

While the center of distribution and diversity of most tropical American families of birds is the South American continent, all eight motmot species occur in Central America and only four of these extend their ranges to South America. On the other hand, six can be found in Mexico (Peterson & Chalif, 1973).

The two smallest motmots, of the genera Asp ath a and Hylomanes, have no rackets. The two central tail feathers of the other species initially look fairly normal, if somewhat broadened at the tips. The barbs along a lower portion of the shaft, however, are only weakly attached, and are soon lost. Though this is usually stated in books to be the result of '' normal preening,'' Alexander Skutch (1983), in ail his extensive observations of five motmot species, never observed such behavior and thinks it just as likely a result of wear and tear, or the barbs falling off by themselves.

The Emerald Forest Bird Gardens received a Blue-crowned Motmot (Momotus momota) on May 2, 1991, which arrived with a damaged tail, due to shipping, both rackets having been broken off. I noticed, in the last week of July, that new central tail feathers had grown in. About three days later, one of the feathers had assumed its typical racket shape. I believe it is usual for one feather to assume its typical shape ahead of the other, briefly giving the tail an asymetrical appearance.

The most wide-ranging of all the motmots is the Blue-crowned Motmot (Momotus momota). Its 20 subspecies are distributed from the states of Nuevo Leon and Tamaulipas, in the northeastern corner of Mexico, to northwestern Argentina (Peters, 1945). These subspecies exhibit a great deal of variation, some so...