woodpeckers is an example of evolutionary convergence
brought about by similar foraging ecologies. All
woodcreepers have become bark- probing specialists,
but their feeding behavior is different from that of
woodpeckers. A woodcreeper moves methodically up
and around a trunk, probing into crevices, poking its bill
into epiphytes, and generally removing insects, spiders,
and even an occasional tree frog. Woodcreepers rarely
peck into the trunk, instead using their long bills as
forceps to pick off prey. They may also join mixed flocks
that follow army ant swarms.
Like other furnariids, woodcreepers are soft shades
of brown and rufous. Many have various amounts of
yellowish- white streaking on the breast, head, and back.
Overall body size, bill size and shape, and streaking
patterns vary with species. The smallest is the 14 cm
(5.5 in) Wedge- billed Woodcreeper (Glyphorynchus
spirurus; plate 15- 105), which has a very short but
sharply pointed bill. Several species reach about 30 cm
(just over 12 in) in length, and the largest, the Long-
billed Woodcreeper (Nasica longirostris; plate 9- 14),
a sensational- looking inhabitant of várzea forests,
reaches just over 35 cm (14 in). Among the oddest
of the group are the five species of scythebills (genus
Campylorhamphus; plate 15- 106), whose extremely
long, downward curving bills are used to probe deeply
into bromeliads and other epiphytes.
Many woodcreepers are ant followers, joining
antbirds and other species to feed on insects and other
animals disturbed by oncoming army ants. Because
they have differing body sizes and bill shapes, several
species of woodcreepers coexist and feed with little or
no apparent competition. At one army ant swarm in
Belize, I observed six woodcreeper species. Two were
large, three were medium- size, and one was small.
Woodcreepers are common not only in rain forests
but also along forest edges, disturbed jungle, and dry
forests (plate 15- 107). Although they are suboscines,
many species have songs consisting of pleasant, if
simple, melodious, whistled trills.
Antbirds, Antthrushes, and Antpittas (Some
of Which Do Follow Ant Swarms, Most of
Which Do Not)
The families Thamnophilidae, Formicariidae, and
Grallariidae (order Passeriformes) include the antbirds,
antshrikes, antwrens (plates 15- 108– 110), antvireos,
antthrushes, and antpittas— all generally referred to as
Plate 15- 108. The Dot- winged Antwren (Microrhopias
quixensis) is one of the most widespread and commonly
encountered typical antbirds, ranging from southeastern
Mexico through Central America to Amazonian Ecuador,
Brazil, and Bolivia. Photo by Andrew Whittaker.Plates 15- 109 and 15- 110. The 9.5 cm (3.75 in) Amazonian
Streaked Antwren (Myrmotherula multostriata) is a typical
antbird; it is not an ant follower. It is found along the edges of
lakes and streams throughout Amazonia. A male (15- 109) and
female (15- 110) are shown. Most typical antbird species are
sexually dimorphic. Photos by Sean Williams.Plates 15- 109.Plates 15- 110.300 chapter 15 neotropical birds: the bustling crowd