Table 2.

Maternal behavior of Peromyscus mice reared by biological (control) or foster parents

	Retrieving pups	Nest building	Components of the HNGI score
			huddling	nursing	grooming	in nest
White-footed mice
Control	3.4±1.6	24.0±9.3a	562.9±149.6b	511.9±154.7b	11.2±3.5b	589.1±154.1b
In-fostered	5.8±4.0	59.2±49.3a	610.5±142.9b	502.8±150.3b	21.5±10.0b	622.8±131.6b
Cross-fostered	5.7±1.7	63.1±44.3a	358.1±78.7b	293.8±76.3b	32.1±15.5b	429.1 ±67.3b
California mice
Control	6.4±3.3	10.0±5.8c	592.7±57.7d	558.4±62.3d	71.8±11.3d	561.3±56.4d
In-fostered	15.3±8.4	5.5±3.8c	530.9±58.0d	501.1±55.5d	98.5±14.6d	596.2±66.6d
Cross-fostered	4.1±2.3	4.7±3.4c	647.3±95.9d	566.3±81.9d	95.8±15.0d	655.5±82.5d

All data are presented in seconds. The HNGI score is divided into its four component variables. Data are presented as raw means ± SE. Comparisons were made between cross-fostered and in-fostered animals and between in-fostered and control animals. Despite species differences in the HNGI score (labeled with superscripts b and d; U = 181, Z = 2.33, p = 0.02) and nest building (labeled with superscripts a and c; U = 164, Z = −2.67, p = 0.008), cross-fostering did not affect maternal behavior.