Brown Thrashers and Carolina Wrens were both less detectable during winter, and one observer was less likely to detect Carolina Wrens.
Brown Thrashers were likely to colonize areas characterized as successional scrub-other--which consist mostly of wildlife openings in our study site--in the winter (Fig.
Occupancy of non-migratory Northern Cardinals and Carolina Wrens decreased or remained static between summer and winter, whereas occupancy of partially migratory Brown Thrashers and Eastern Towhees increased.
A high rate of turnover indicates that sites managed for breeding habitat, or preserved because they contain breeding individuals, are not likely to be used by wintering Brown Thrashers or Eastern Towhees.
For instance, Northern Cardinals and Brown Thrashers were too ubiquitous and too sparse, respectively, to be associated with any particular type of cover during the breeding season.
Fifteen territorial mockingbird subjects were each presented with four different treatments: (1) Northern Mockingbird song types in a standardized mockingbird repetition pattern (NM/NM), (2) mockingbird song types in a standardized Brown Thrasher repetition pattern (NM/BT), (3) thrasher song types in a standardized mockingbird repetition pattern (BT/NM), and (4) thrasher song types in a standardized thrasher repetition pattern (BT/ BT).
2A) revealed significantly different responses to mockingbird song types in a mockingbird repetition pattern (NM/NM) than to Brown Thrasher song types with either repetition pattern (one-way ANOVA with Tukey's HSD post hoc, n = 15, [F.
Mockingbirds generally responded more strongly to playback of conspecific song types than to Brown Thrasher song types, comparing individual response measures among treatments (Fig.
Brown Thrasher songs included both significantly lower frequencies (P = 0.
Subjects responded strongly to playback of mockingbird song types in a standardized mockingbird repetition pattern, but responded relatively little to Brown Thrasher song types even when these sounds were played in exactly the same pattern of five repetitions/bout.
Brown Thrashers respond more strongly to Brown Thrasher songs in the normal repetition pattern than to thrasher songs in a mockingbird pattern, suggesting that repetition pattern is important for species recognition in thrashers.
How our mockingbird subjects were able to distinguish mockingbird song types from Brown Thrasher song types with the same repetition pattern is not clear.
The relatively low rate of nesting success among American Robins and Brown Thrashers was due to extremely high levels of nest predation during 1999 (which was not observed in 2000).
Among the shrub/savanna species, nests of Mourning Doves (Zenaida macroura), Willow Flycatchers (Empidonax traillii), American Robins (Turdus migratorius), and Brown Thrashers (Toxostoma rufum) were found most frequently (Table 1).
Among shrub/savanna species, Mourning Doves, Willow Flycatchers, and Yellow Warblers experienced relatively high rates of DNS, whereas American Robins and Brown Thrashers experienced relatively low rates of DNS.