By Olivia Allison Asher
Photos from the Gotham Coyote Project's camera traps
Seasons govern the lives of coyotes. Right now, in the dark winter, it is mating season.
Coyotes mate once a year, between mid-January to mid-February, because female coyotes are monestrous, meaning they only produce eggs and are fertile once a year. Sometimes overly-hopeful male coyotes try to mate outside of mating season, but their female partners brush them off.
Coyotes are generally monogamous, and in most cases they stay in the same mating pair for life. Starting in mid-January, these mating pairs start play-wrestling and play-chasing each other more often. The pairs also groom and sniff each other and engage in more physical contact.
At the end of January and the beginning of February coyotes actively begin mating with their partners. Mating continues regularly through mid-February, when the female coyote’s fertility period ends. Then, female coyotes who become pregnant gestate for about 60-63 days and give birth to pups between March and April.
Not all female coyotes become pregnant after mating season, but it is difficult to distinguish between pregnant coyotes and non-pregnant coyotes. Why? Non-pregnant coyotes often become pseudopregnant and act like they are pregnant. One typical behavior of pregnant coyotes is begging for regurgitated food from their mates, a behavior mimicked by pseudopregnant coyotes. Pseudopregnant and pregnant coyotes even have the same levels of the hormone progesterone which prepares the uterus for pregnancy.
Other hormones associated with pregnancy and birth like relaxin, which prepares the body for labor, and prolactin, which instigates milk production, are found at different at different levels in pregnant and pseudopregnant coyotes.
Of course, pseudopregnant coyotes do not give birth to pups, so what is the purpose of a pseudopregnancy? Here are some ideas:
Pregnant behavior, like begging for regurgitated food, strengthens the bond between mating coyote pairs, even if the female isn’t actually pregnant. Since coyotes live and hunt with their mates throughout their entire life, maintaining a strong pair bond is crucial.
Pseudopregnancy helps coyotes continue their seasonal life cycle. By becoming pregnant or pseudopregnant, female coyotes signal that mating season is over. Coyotes always give birth in the spring when resources are abundant and they have plenty of time to raise their pups while the weather is warm. If mating season continued longer, it could throw off the seasonal clock and result in pups born at an inconvenient time, possibly jeopardizing the pup’s health.
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Carlson and E. M. Gese. “Integrity
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Carlson and E. M. Gese. “Reproductive Biology of the Coyote (Canis latrans): Integration of Mating Behaviors, Reproductive Hormones, and Vaginal Cytology.” Journal of Mammalogy, vol. 89, no. 3, June 2008, pp. 654-664. Jstor, www.jstor.org/stable/25145142
Hennessy, Dubach, Gehrt, and B. J. Swanson. “Long-term pair bonding and genetic evidence for monogamy among urban coyotes (Canis latrans).” Journal of Mammalogy, vol. 93, no. 3, June 2012, pp. 732-742. Jstor, www.jstor.org/stable/23259969