Panama alone, seven of these similar species occur. The
Great Kiskadee (Pitangus sulphuratus; plate 8- 29) and the
Boat- billed Flycatcher (Megarynchus pitangua; plate 8- 31)
are both large and similar in body size (23 cm/9 in), but the
latter has a wider, more flattened bill. The Lesser Kiskadee
(Pitangus lictor; plate 8- 30) looks like a small version of
the Great Kiskadee and differs from the very similarly
sized Rusty- margined Flycatcher (Myiozetetes cayanensis)
in having a somewhat longer bill. The other three species
are similar: the Yellow- throated Flycatcher (Conopias
parvus) and the Social Flycatcher (Myiozetetes similis),
which differ only in minor facial characteristics, and the
Gray- capped Flycatcher (Myiozetetes granadensis), whose
gray cap helps distinguish it from the others.
Other tyrant flycatchers also have distinctively shaped
bills, and some of these species are very small in body size.
The Northern and Southern Bentbills (Oncostoma spp.;
plate 8- 32), both only 9 cm (3.5 in) long, have short but
distinctly down- curved bills. The tiny spadebills (genus
Platyrinchus), also only 9 cm long, have extremely wide,
flattened bills. The Black- capped Pygmy- Tyrant (Myiornis
atricapillus; plate 8- 33), an inhabitant of lowland and
foothill humid forests in Ecuador and Colombia,
measures a mere 6.5 cm (2.5 in) in length. It has a small,
straight bill adapted for taking tiny arthropod prey. The
widespread Common Tody-flycatcher (Todirostrum
cinereum; plate 8- 34), which occurs in forest edges and
disturbed areas, has a long, flattened bill. These present
but a small sampling of the range of beak diversity evident
in the tyrant flycatchers.
Some flycatchers switch their diets regularly, and others
are basically opportunistic, switching according to thePlate 8- 32. The small (10 cm/4 in) Southern Bentbill
(Oncostoma olivaceum) has a distinctly down- curved bill. It is a
bird of the shaded forest understory. Photo by John Kricher.
Plate 8- 33. The tiny Black- capped Pygmy- Tyrant, here holding
nesting material, is found along humid forest borders in
foothills and lowlands of western Colombia and northwestern
Ecuador. Photo by Edison Buenaño.Plate 8- 34. The small (10 cm/4 in) Common Tody- flycatcher is
found throughout much of the Neotropics and is commonly
encountered in brushy areas and forest edges. Photo by John
Kricher.
Plate 8- 35. The Eastern Kingbird is a fiercely territorial migratory
species nesting in eastern and central North America. It
feeds on arthropods during its breeding season but switches
primarily to fruit when wintering in parts of Amazonia. It loses
its aggression toward conspecifics during migration and forms
large flocks that migrate together. Photo by John Kricher.126 chapter 8 evolutionary cornucopia