 With
400 tyrannids in 98 genera, the Tyrant Flycatchers are one of the largest
bird families in the world. This is just a short overview. Tyrant Flycatchers
are entirely New World birds ranging throughout most habitats in North
and South America. The center of distribution is South America but most
species are rather limited in distribution. An exception is the lovely
Vermilion
Flycatcher (left), a species which nests from the southwestern
United States all the way to southern South America. It is a vagrant, however,
to Monterey County (where I live) and this photo of a first-fall male documents
one of very few records from northern California. The vast majority of
tyrant flycatchers eat insects or arthropods, and many of them sit on perches
from which they sally forth to catch insects in flight. Vermilion Flycatcher
is one of those type of flycatchers. There are various other birds called
"flycatchers" in the Old World, divided among several familites, but none
of them are closely related to the tyrant flycatchers in the New World. |
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| Most North American species, like this Gray Flycatcher (below left), are migratory and move south to milder climates in the winter. Conversely, many flycatchers in southern South America move north toward the equator in the austral winter. Most of the tropical tyrannids are resident. Flycatchers are quite variable is size and color. A good many, like the Gray Flycatcher, are small and dull but there are numerous examples of big and bright birds like the Great Kiskadee (below right), captured here in a nice Texas shot by Greg Lasley. The Great Kiskadee has a huge range in the tropics -- running from the southern tip of Texas through Central America down to northern Argentina -- but many of these flycatchers have small or isolated ranges. Both the Gray Flycatcher and Great Kiskadee are related to similar species than can cause birders field identification problems. Indeed, sorting out the identification of New World flycatchers is amongst the more complex problems confronting the field observer. | ||||
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 The
majority of tyrant flycatchers are birds of wooded habitats, often hunting
by "flycatching" out from perches to chase flying insects. Such birds are
called by English names like "flycatcher" and "tyrant" or "tyrannulet."
But there are a host of ground-dwelling flycatchers in South America using
barren deserts or tree-less alpine meadows with names like "ground-tyrant"
and "field-tyrant" or Spanish words like "monjita" or "negrito." The Plain-capped
Ground-Tyrant (below) of páramo grasslands in the high Andes
from Colombia to Bolivia is just one of these.
In my visits to South America, I think the ground-dwelling flycatcher that impressed me the most was the Southern Antpipit Corythopis delalandi. In the Chapadas dos Guimairés of southwestern Brazil, Paulo Boute took Rita and I to a small patch of deciduous woods and found the bird by its distinctive vocalization. Lured in by a taped playback, we watched the Antpipit bobbing its way along the forest floor like a waterthrush or forest pipit; the convergent evolution behavior was astonishing. And its up-scale, down-scale vocals were comical: "do-WE-do, Rrrrrabbbitt?" |
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Vocalizations are indeed important in sorting through the Tyrannidae. In
some groups it is by far the best field identification character. One such
group are the pewees (Contopus), a genus with 14 species scattered from
North America to South America (a good number of which are migratory) and
across the Caribbean islands. All are rather drab birds with wingbars,
like this Western Wood-Pewee (left) photographed on its nest in
the California mountains. Separating these species visually from their
closest relatives can be next-to-impossible; vocalizations are an absolute
key. [Even some calls approach those of sibling species closely and out-of-range
claims can be controversial. Eastern Wood-Pewees to the west and Western
Wood-Pewees to the east, or the separation of the two on wintering grounds
in the tropics, remain among the more difficult field problems absent characteristic
songs.] |
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 Another
group of tyrannids in which vocalizations are critical are the flycatchers
in the genus Myiarchus. Our current understanding of species limits
in this reasonably large group (22 species) comes from the work of ornithologists
who considered calls as well as more traditional museum methods (e.g.,
Lanyon 1967, 1978). Numerous good species had previously been masked by
plumage similarities until a study of vocalizations showed their distinctiveness.
But yet another cool things about the Myiarchus is that some
species are migratory and therefore provide vagrants in the "wrong" direction.
The Dusky-capped Flycatcher (right) ranges from southeastern Arizona
down through South America but at least northern populations are migratory.
Beginning about 25 years ago, California birders have located one or two
of these annually in late fall or winter. The bird photographed at right
was one of two found in December 1992 in my own home town of Pacific Grove,
California, and I discovered one of them in my back yard! I'm fortunate
to have a variety of vagrants from my backyard but the wrong-way Dusky-capped
Flycatcher is surely the best of the lot. Perhaps the most unexpected flycatcher
to reach California is the Fork-tailed Flycatcher (below).
As I'm writing this page in January 2001, yet another wayward Myiarchus as turned up in southern California: a Nutting's Flycatcher M. nuttingi, a first for California and only the third for the United States. I have posted some photos of the bird and the event HERE. It is not possible to show the range of diversity among the New World flycatchers on this page but below are a selection of rarely photographed species (yeah, I know these are fairly marginal shots). This selection does represent a wide diversity in habitat and geography. Left to right, these are a Grenada Flycatcher in thorn scrub on the Lesser Antillean island of Grenada (it is restricted to this island and nearby St. Vincent), an Unstreaked Tit-Tyrant in Polylepis woods at very high elevation in Peru (this species is endemic to central Peru), a Many-colored Rush-Tyrant in a coastal Peruvian marsh (perhaps the most colorful among a wide variety of species restricted to marshes and stream edges), and a Rufous-breasted Chat-Tyrant in Peruvian cloud forest (a wide-ranging Andean species from Venezuela to Bolivia). The latter three shots were all during a Peruvian in 1987 and near the spot where the chat-tyrant was photographed I found an Ochre-faced Tody-Flycatcher Todirostrum plumbeiceps in an unexpected range extension/vagrant (published by Roberson 1996). |
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 Yet
all this diversity omits the undergrowth specialists that must be close
to impossible to photograph in the wild, and certainly impossible without
time and lighting equipment. These are birds like the Golden-crowned
Spadebill (right), a species I have yet to see, netted by the Smithsonian
Institute's research project from the undergrowth on Barro Colorado I.
in the middle of the Panama Canal, Panama. These tiny birds with their
huge broad bills are quite wonderful as are the equally outrageous flatbills
(genera Rhynchocyclus and Ramphotrigon), some of which are
restricted to dense thickets of lowland tropical bamboo. And speaking of
bamboo, I would rate the dapper White-cheeked Tody-Tyrant Poecilotriccus
albifacies very high among tyrannid highlights. It is restricted to
patches of bamboo in lowland rain forest of southeastern Peru and is certainly
one of the prime species at Explorer's Inn on the Madre de Dios.
This commentary has been rambling over the spectrum of habitats and plethora of adaptations by this family. Even Ridgely & Tudor (1994) note that tyrant flycatchers are "exceptionally diverse in form, so much so that generalizations are difficult" but it is basically true that the vast majority are mostly or entirely insectivorous. These insectivores have evolved and radiated until they fill every neotropical niche. Perhaps because these niches and so many and complex, many aspects of taxonomy remains controversial. Yes, the Tyrannidae include a huge chunk of the bird world, from the colorful (and fascinating) to the drab (and fascinating). And on that note, here's Greg Lasley's idea of a flycatcher (Vermilion Flycatcher, below left in another great shot by Greg) and my idea of a flycatcher (Northern Scrub-Flycatcher, below right). |
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| Photos: The first-fall male Vermilion
Flycatcher Pyrocephalus rubinus was photographed at Moss
Landing, Monterey Co., California, on 10 Oct 2004. The Gray
Flycatcher Empidonax wrightii was photographed east of Salinas,
California, on 19 April 1986 and just happened to be the first record for
Monterey County. The
Great Kiskadee P.
coronata was in Starr Co., Texas, 3 Sep 1995. The Plain-capped
Ground-Tyrant
Muscisaxicola alpina was above treeline at
Urpicancha, Dept. Cusco, Peru, on 13 Jan 1987. The nesting Western
Wood-Pewee Contopus sordidulus was in the Greenhorn Mountains
of Kern Co., California, on 10 July 1999. The Dusky-capped
Flycatcher Myiarchus tuberculifer was a great vagrant
in Pacific Grove, Monterey Co., California, on 30 Dec 1992, and so was
the Fork-tailed Flycatcher Tyrannus savana
near Jenner, Sonoma Co., California, 5 Sep 1992. The Grenada
Flycatcher Myiarchus nugator was on Grenada on 22 Mar 2000;
the Unstreaked Tit-Tyrant Uromyias agraphia
was at Abre Malaga, Dept. Cusco, Peru, 15 June 1987; the Many-colored
Rush-Tyrant Tachuris rubrigastra was at the Chilca marshes,
Dept. Ica, Peru, 11 June 1987; and the Rufous-breasted
Chat-Tyrant Ochrhoeca rufipectoralis was at Abre Malaga that
same Peruvian trip on 14 June 1987. Robin Welch loaned me the mist-netted
Golden-crowned
Spadebill Platyrinchus coronatus that was taken on Barro
Colorado I. in Panama in the early 1980s. Greg Lasley took the adult male
Vermilion
Flycatcher Pyrocephalus rubinus in Starr Co., Texas, on 14
February 1999, and I took the Northern Scrub-Flycatcher
Sublegatus arenarum on Bonaire I. in the Netherlands Antilles on 13
Aug 1985.
All photos are © 2001 Don Roberson, except
those attributed to other photographers. Three shots (all labeled) are
© 2001 Greg W. Lasley (used with permission); all rights reserved.
Family Book: There is no "family book" per se but the South American
species are well covered in Ridgely & Tudor (1994) with a fine selection
of species illustrated in color. Beyond that I certainly look forward to
the Handbook of the Birds of the World chapter.
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Other literature cited:
Lanyon, S. M. 1985. Molecular perspective on higher-level relationships in the Tyrannidae (Aves). Syst. Zool. 34: 404-418. |
