To Photo: Oak and Niko.

There are four stages to the canine estrus cycle (reproductive cycle)—proestrus, estrus, diestrus, and anestrus.

Proestrus is the stage where the female’s estrogen level peaks. Proestrus lasts for, on average, 9 days. Males are attracted to her but she is not receptive to them.

Estrus, which also averages 9 days, is the fertile period. Estrogen levels drop and proestrogen levels rise. More importantly, the female is receptive to males.

Diestrus lasts for about 2-3 months or until the female gives birth, if she’s become pregnant. The female is no longer receptive to males.

Anestrus is the rest of the year.

I believe we (our wolves) are in Estrus.

In the past when I’ve witnessed any of our wolf pairs mating it’s been close to the middle of February. Oak and Niko are a bit ahead of schedule.

The pair has to “tie” together in order for the female to become pregnant. Though I haven’t seen the pair tied yet, I believe they’re very close to that happening.

Our male red wolf, Niko, has had an odd look on his face lately, as he follows the female around the enclosure.
Estrus has begun.
Though attempts were made, no “tie” as of yet.

If you would like to witness any part of this behavior, I would head out to the Red Wolf Enclosure soon. Tomorrow, if you can’t do it sooner!


* From

Estrus, etymology: 1850, “frenzied passion,” from Latin oestrus “frenzy, gadfly,” from Greek oistros “gadfly; breeze; sting; anything which makes one mad, mad impulse,”…”First attested 1890 with specific meaning “rut in animals, sexual heat.”

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