HABITAT FRAGMENTATION AND PATERNITY IN LEAST FLYCATCHERS

We examined the effect of habitat fragmentation, as well as breeding density and synchrony, on realized reproductive success of male Least Flycatchers (Empidonax minimus). Both breeding density and synchrony were similar in both continuous (6.75 males/ha, 3.40; respectively) and fragmented (4.04 males/ha, 2.11: respectively) habitats, and no morphological or territorial variables differed between males in either habitat. The number of nests containing extra-pair offspring was lower in fragmented habitat (11%) compared to the continuous habitat (50%). Males in fragmented habitat attracted secondary mates significantly more often than males in continuous habitat (44%, 0%; respectively) resulting in similar estimates of realized reproductive success in either habitat. Although habitat fragmentation does not appear to affect realized reproductive success of male Least Flycatchers, we suggest that males of this species demonstrate a facultative shift in reproductive tactics. Received 21 April 2008. Accepted 17 September 2008.