Wolves and high percentage hybrids do not come to sexual maturity until
about 17 to 23 months of age. They only breed once a year, normally in
the late fall to late winter months. Estrus and spermatogenesis are
normally controlled by the daylight hours of the day. However, there
are exceptions to both the age of maturity and the period of fertility.
I have a rather unorthodox breeding cycle in my controlled and housed
packs. By using a sun lamp, heat bulb in the center of each 8′ x 36′
pen, I extend the daylight hours quite a bit.
Also in the controlled pack with pairs of wolves right next door in
sequence, the rivalry of pairs stimulates each other to estrus and
spermatogenesis earlier. This factor plus the fact that they have
access to all the good nutritional food that they want, 24 hours each
day, also causes earlier fertility.
Male wolves usually are not fertile through the warm months. After
shedding in Spring (molting), one will notice that the heavy fur
covering of the males is gone, leaving the scrotum naked as a dog’s.
Thus and then no more sperm building until the Fall molt and again the
testicles are covered with a fine covering of fur.
Now the fact that a male has produced full spermatogenesis during winter
months, and has not had the opportunity to expel it during the mating
season, might cause him to remain fertile a month or two more than his
peers who had mating privileges during the rut. This sometimes leads
people to dispute my analysis of breeding periods of fertility and
infertility. Plus the incidents of a few male wolves that do remain
fertile seemingly year round, for mating with dogs whose cycle is much
different from the Wolf’s.
So one can readily see that the USUALLY as opposed to the ABSOLUTE must
be maintained in nearly all facets of Wolf breeding. As in human
societies, there are no fast and hard rules that one can go by.
As we well know, most dogs of the larger breeds gestate 59 to 61 days
before birthing. Hybrids of over 75% Wolf usually gestate 62 to 64
days. Whereby most pure bred wolves gestate 63 to 66 or even 67 days
from the date of the first coupling or tying.