Dusky Antbirds were marked with unique color band
combinations in Parque National Soberania, GamboaPanama Province, Republic of Panama during the nonbreeding
(dry) season from 1991 through 1995, and
during the breeding season in 1993 and 1994. Dusky
Antbirds were common in second-growth habitat,
reaching densities of 3 per hectare (Morton et al., unpubl.
data). Observations and playbacks of Dusky Antbird
song were used to establish the identities of territorial
occupants (see Morton and Derrickson 1996 for
more details on field methods). Once we established
that a pair occupied a territory, the area was systematically
searched for nests. Many empty nests were
found, possibly because of prior predation. We found
that Dusky Antbirds, like most tropical passerine species,
have complete clutch sizes of two or fewer eggs.