Control of oestrus in blue foxes by means of additional light

Valtonen, M.; Nydahl, K.

Of 74 young and 52 adult blue fox which received 4 h extra light per day from 1 Feb. to 15 Mar., 90.9 and 100% resp. mated vs. 88.7 and 100% of 72 and 53 young and adult subjected to natural daylight (controls). In the group receiving extra light, 16 and 63% of young and adult resp. had mated by 31 Mar. vs. 10 and 42% of control and the number of cubs born per mated averaged 7.25 and 9.93 vs. 6.73 and 8.74.