Observations on Fecal Sac Consumption and Near-ground Foraging Behavior in the Olive-sided Flycatcher (Contopus cooperi)

Abstract

We present details on parental care and foraging behavior of Olive-sided Flycatchers (Contopus cooperi) in central Alaska. We document the first evidence of fecal sac consumption in this species. Both sexes exhibited this behavior while tending chicks less than one week old. Adults with older nestlings (1.5–2 weeks) removed fecal sacs only. The general pattern of reduced fecal sac consumption with chick age is consistent with other passerines and may supplement parental nutrition. Near-ground foraging behavior in C. cooperi is rarely reported, as birds typically sally for aerial insects near or above the canopy. Two breeding females fed multiple times from 1–3 m perches, hovering over, flying directly above or disappearing into low vegetation (<0.5 m) for up to 15 secs. Low stumps and saplings in a wood cutting area and in undisturbed forest provided access to patches of flowering vegetation that appeared to concentrate pollinator prey during cool or inclement weather. Given the conservation concerns for this species, its low productivity, dietary specialization, and hypothesized early-season reliance on insect prey, flowering vegetation presents a testable visual stimulus that may govern settlement behavior of breeding adults.