Does nest defense behavior vary with differences in landscape features in four species of shrub-nesting birds?

This study focused on if landscape features around the nest affect levels of anti-predator behavior in different shrub-land birds. Adult behavior was recorded on day 7 post-hatch, when chicks were remover as part of another study. The species studied are American Robins (AMRO), Gray Catbirds (GRCA), Northern Cardinals (NOCA) and Brown Thrashers (BRTH). The behavior between the different landscapes of AMROs and GRCAs was not significantly different. This shows that the energy difference is not significant enough to deter protective behavior. However, the NOCAs in less developed areas had a significantly more aggressive behavior. Also, the BRTHs had a significantly higher behavior score in lower percent grassland/shrub-land areas. This may be due to predation risk and perceived quality of the habitat. Variation in their habitat influenced their behavior.Ope