The Toucan Barbet (Semnornis ramphastinus; plate
15- 35) and its close relative the Prong- billed Barbet
(Semnornis frantzii) are now placed in their own
family (Semnornithidae). The Prong- billed Barbet is
found in montane cloud forests in Central America.
The colorful Toucan Barbet is endemic to a small area
east of the Andes in Ecuador and Colombia. Also a
montane species, it is found along forest edge where
trees are bearing fruit.
Fruit and Nectar Feeders
Because of the relatively constant availability of fruit
and nectar in tropical forests, many bird species
of several families concentrate their diets on these
resources. Throughout the tropical year there is at
least some availability of both. Though seasonality
exerts important effects on animal communities, it
is nonetheless generally true that some plants are
fruiting or flowering every month of the year. In the
temperate zone, fruits tend to be abundant only from
midsummer through autumn. Many birds, including
migrating species, switch over from predominantly
insect to fruit diets at that time. In the tropics, however,
no such dramatic switch need be made. The constant
availability of at least some nectar and fruit has made it
possible for several major bird groups to specialize and
feed on one or the other (or both). More is said about
fruit ecology in chapter 10.Hummingbirds: Nectarivores
Nectar feeders consist mostly of hummingbirds (family
Trochilidae, order Apodiformes), though many other
birds, such as flowerpiercers, tanagers, and orioles,
also devour nectar to varying degrees. At the present
time there is no agreement as to exactly how many
hummingbird species exist because, again, authorities
differ in how they lump or split species. Currently, there
are somewhere between 325 and 350 accepted species,
depending on the authority. These small, rapid fliers are
all restricted to the New World (though interestingly
enough, there are fossilized remains of a hummingbird
from the Old World). Most species are tropical, but
14 species do migrate to breed in North America
and several other species occur there as rarities. The
iridescent beauty of hummingbird plumage is reflected
in the species’ names: Berylline, Emerald- chinned,
Magnificent, Garnet- throated, Sparkling- tailed, and
Ruby- topaz Hummingbirds, for a few examples.
Among them you’ll meet jewelfronts, blossomcrowns,
trainbearers, sylphs, coronets, velvetbreasts, sapphires,
hillstars, firecrowns, sabrewings, spatuletails, topazes,
starthroats, fairies, mangos, and racket- tails.Plate 15- 36. This male Crowned Woodnymph (Thalurania
colombica) is in ideal light to bring out the brilliant coloring of
the gorget. Photo by James Adams.Plate 15- 35. The Toucan Barbet is relatively common
throughout its rather limited range in northwestern South
America. Photo by Edison Buenaño.
276 chapter 15 neotropical birds: the bustling crowd