Table 1.

Regression categorization by SD treatment group (18 males/group).

Group	Complete Regression	Intermediate Regression	Weak Regression and Nonregression	Delayed Development
6-MSD	4	3	9	2
3-MSD	9	1	5	3
SD-gest	12	3	3	0
SD-birth	12	3	3	0
SD-4wk	12	3	3	0

NOTE: Number of males in each group that exhibited complete regression, intermediate regression, weak or nonregression, or were classified as delayed developers. Rows sum across to 18 males per treatment group. The number of intermediate and weak regressors did not vary with treatment group, but the number of complete regressors increased with decreasing exposure to SDs (p < 0.005, logistic regression) and the number of delayed developers decreased with decreasing exposure to SDs (p < 0.05, logistic regression). LD = long day length; SD = short day length; 6-MSD and 3-MSD = dams transferred to SDs 6 and 3 weeks before mating; SD-gest = LD-housed females transferred to SDs on the day after mating; SD-birth = LD-housed females transferred to SDs on the day of parturition; SD-4wk = LD-gestated offspring transferred to SDs 4 weeks after birth.