Abstract |
Species richness, composition and abundance of farmland birds were compared between point counts (50, 100, and 150 m radius half circles) and territory mapping on three 40 ha plots in Quebec, Canada. Point counts of smaller radii tended to have larger density estimates than counts of larger radii. Territory mapping detected 10 more species than 150 m-radius point counts. Territory mapping at 150 m radius detected more birds per species than point counts; relative abundances however were similar. Bird density is probably optimally estimated with a 100 m-radius point count. After four visits, more than 80% of species and birds from seven visits had been detected by 150 m radius point counts. The modified point count method appears to be accurate enough to reflect the farmland avifauna characterized by more labor intensive methods such as territory mapping. |