As most humans in the Northern Hemisphere tend to seek shelter indoors and limit activity during winter, wolves are at their most active. There are two main reasons for this higher activity period this time of year. First, gray wolves are built for cold weather, so as the chill seems to bite into human nerves, wolves do not feel the same effect. The double layer of fur in wolves seal out the cold temperatures and snow, creating a comfortable environment for wolves. On the contrary, the high temperatures of summer are oppressive to the heavily furred canines. Thus, winter is a more active time of the year for them.

The second reason wolves are more active in winter is because it's their annual breeding season. Wolves breed only once a year, during the winter months so the pups will be born in the spring, when food is plentiful and the weather less severe. The season begins in late December and proceeds until late February or early March. Most of this period is simply behavioral preparation for mating, which only occurs for a few days up to two weeks at the completion of the season.

Wolves actually begin an increase in sexual hormone production around October, but obvious breeding behaviors begin to show in December as a general increase in dominance among the hierarchy. Both alpha-male and alpha-female step up their dominance frequency and severity toward all submissive members in an effort to reaffirm their breeding rights. This increase is a major reason why the Sawtooth Pack has experienced most hierarchy changes during winter. As the season progresses, the alpha-female will then begin to solicit attention from the alpha-male, or other males. She does this by performing behaviors that appear to be playful. She will approach the alpha-male and paw at his back or head, place her head across his back, or just simply stand or walk next to him, usually touching.

In the beginning, the alpha-male usually returns a snap or growl in response to her advances. Other females may do the same behavior toward the alpha or other males, but are usually disciplined if caught by the alpha-female. Then, the females of the pack begin their estrus cycle, usually within a few days of one another. Once this occurs, the males of the pack begin to pay attention to the female advances.

The alpha-female then increases her "flirtatious" advances toward the alpha-male, plus performs the ultimate sexual solicitation behavior of pushing her rump against the alpha-male's rump or side and curling her tail to the side (exposing her genitalia). This posture only occurs during peak breeding season and an excellent indicator of the next stage of the season, actual mating. Once the alpha-male catches on to her indications, he will then begin to reciprocate the play-like behaviors of placing his head over her back and sparring with her while both are standing on their hind legs (an action that resembles dancing).

Soon after, he will then pair bond to the alpha-female, which is an act of guarding her from all other males who may attempt to mate with her. She is fertile at this stage. During this time, no other wolf is permitted within a close proximity to his chosen mate. Usually, the other pack members avoid the alpha-pair during this time and observe the two from a distance.

Mating occurs over several occasions each day for anywhere between two days to two weeks. The intercourse process is exactly the same act as domestic dogs perform. When ovulation is complete and intercourse ceases, the alpha-pair no longer exhibit solicitation behaviors toward one another and essentially all dominance and hierarchy behaviors return to normal very quickly, even overnight sometimes.

After the season is complete, all wolves seem to be exhausted and then enter into a very low energy period of the year, springtime. At the completion of the 63-day gestation period, packs with a successful breeding season welcome new pups into their family in April or May.