Distribution and characteristics of Southwestern Willow Flycatcher breeding sites and territories: 1993 - 2001
No abstract available.
Studies in Avian Biology↗
Geology topics
Tracy McCarthey
Publications and source records attributed to Tracy McCarthey.
Nestling sex ratios in the southwestern willow flycatcher
Using molecular-genetic techniques, we determined the gender of 202 Southwestern Willow Flycatcher ( Empidonax traillii extimus ) nestlings from 95 nests sampled over a five-year period. Overall nestling sex ratio did not vary significantly from 50:50 among years, by clutch order, or by mating strategy (monogamous vs. polygamous pairings). However, we did observe significant differences among the four sites sampled, with sex ratios biased either toward males or females at the different sites. Given the small population sizes and geographic isolation of many of the endangered subspecies' breeding populations, sex-ratio differences may have localized negative impacts.
Condor↗