Brood Parasitism Defense Behaviors Along an Altitudinal Gradient in the American Robin (Turdus Migratorius)

Table 3: Response times (s) (mean ± S.E.) of female American Robins to Brown-headed Cowbird and Song Sparrow models at low and high elevation sites (n_low=14 nests; n_high=11 nests) for each behavioral category. P values * P < 0.05, * P < 0.01, * P < 0.001.

	Low			High
Behavior^†	Cowbird	Sparrow	P^a	Cowbird	Sparrow	P^b	P^c
Non-Aggressive	61.4 ± 26.5	152.4 ± 36.3	*	185.3 ± 35.9	121.1 ± 35.7	NS	*
Mildly Aggressive	135.6 ± 29.7	71.9 ± 23.7	NS	96.7 ± 30.9	99.4 ± 27.0	NS	NS
Strongly Aggressive	93.5 ± 29.9	60.5 ± 30.6	NS	16.4 ± 7.4	51.3 ± 24.5	NS	*

^†Time spent performing behavior during 5-minute trials
^aComparisons between models within low elevation sites.
^bComparisons between models within high elevation sites.
^cResults of multiple comparisons among cowbird model presentations between sites.