Coyote Biology

Coyote Biology

Appearance

Often compared to a German-Shepherd, the coyote is a medium-size candid with large, erect ears, a narrow muzzle, long legs, and a bushy tail held at a 45-degree angle when moving. Coat color varies from reddish-brown, with blacks and grays intermixed, to all-black individuals.

During the cold season coyotes’ longer winter coats make them appear larger than they are. This is one reason many people misjudge the actual size of a coyote they have seen.

Weight

Narragansett Coyote

Narragansett Coyote

Coyote weights and sizes vary based on where they live and where you obtain your information. For example, the Tennessee Wildlife Resource Agency (TWRA) reports that coyotes average 20-40 pounds in Tennessee while Alabama A&M and Auburn Universities report weights averaging 20-50 pounds in Alabama.

There have been reports of coyotes weighing more than 50 pounds, but these animals are said to be rare. The largest coyote on record, according to the U.S. Fish and Wildlife Service, was in Wyoming and weighed in at 74 pounds.

Generally, eastern coyotes are considered to be slightly larger than their western cousins. There are several theories why this may be. These theories include.

  1. Interbreeding with domestic dogs
  2. Interbreeding with wolves
  3. A phenotypic (physical) response to increase prey size

Let’s look at these.

The CoyDog

You may have heard someone claim that coyotes are interbreeding with domestic dogs, resulting in larger animals.  This is not a new claim.  In 1905 Stanley Young wrote in The Clever Coyote that, according to a work by MacFarlane on wild animals in northern Canada, “Indians knew of instances of their dogs interbreeding with coyotes and wolves.

How often coydogs appear has been a debate for decades.  In most studies the occurrence of these hybrids has been minimal.  For example, in the mid-1970s a study that Penn State University conducted found that only 9 out of 76 wild canids collected in Pennsylvania were probable coyote and dog hybrids.  This suggests, as most scientists still do today, that although coyote and dog hybrids are possible, they are rare.

Further studies on coydogs have offered reasons for this rarity. First, coyote and domestic dog breeding cycles do not match up. As a result, hybrid litters are born earlier, at a time when survival is less likely.  Pure coyote litters are synchronized with environmental factors that promote increased survivability. Studies have shown that hybrid litters are born earlier in the season (i.e., midwinter) when resources are fewer and weather may be more extreme.

Second, unlike coyotes, male domestic dogs are said to be unlikely to assist in caring for the pups, which further decreases chances of survival. As noted in Pack Life, male coyotes assist in pup-rearing ways such as bringing food back to the den for nursing females.

Many scientists believe that coyote and domestic dog hybrids may have been more common in the Southeast when coyotes were first colonizing east of the Mississippi River (1960s). They theorize that early colonizing coyotes were less likely to find a mate of their own species and had to choose between breeding with domestic dogs and not breeding at all.

This is very possible, as happened with the Red Wolf. As their populations dropped due to persecution and habitat degradation, red wolves began breeding with the more common coyote, resulting in hybrid canids. A major study by national and international scientists found that, “Midwestern and Southeastern coyotes were genetically 90% coyotes, with an average 7.5% dog and 2.5% wolf.”

Coywolves

Northeastern Coywolf

Northeastern Coywolf

As the name hints, coywolves are hybrid canids with mixed wolf and coyote ancestry. Larger than pure coyotes but smaller than gray wolves, this animal has been documented, at least in some areas of the U.S., to weigh an average of 30-45 pounds.

As with changes in physical characteristics, behavioral changes are evident as well. Coywolves are described as having the wolf’s pack hunting mentality and the coyote’s amazing ability to live alongside heavily developed areas.

Coupled with their pack-hunting mentality, these animals are more efficient predators of larger prey (e.g., white-tailed deer), suggesting that they have at least partially filled the wolf’s niche.

When researching coywolves, you will find that most information comes from the northeastern U.S., where these animals seem to be more prevalent, though some sources suggest that the coyotes in the southeastern U.S. are larger than those in the Northeast. As mentioned in the Coydog section, coyotes in the Northeast and Southeast were found to have a mixed genetic heritage.  Genetically, coyotes in the Northeast were found to be 82% coyote, 9% dog, and 9% wolf.  Coyotes in the Southeast were 90% coyote, with an average of 7.5% dog and 2.5% wolf.

Diet

White Coyote

White Coyote

Coyotes are omnivorous with a seasonally and spatially varying diet. The majority of their diet consists of small mammals (e.g., rodents and lagomorphs—rabbits), but they also feed on fawns, fruits, pet food, domestic pets, livestock, nuts, insects, amphibians, reptiles, etc. What appears to cause the most concern for anyone living around coyotes is the threat to domestic pets. It is very common to hear and read about suspected coyote predation on domestic cats and dogs. Interestingly, studies on urban coyote diet show the occurrence of domestic pets to be consistently low. Nevertheless, researchers suggest that the low percentage of pets in diet studies may indicate that coyotes do not always consume pets after killing them. Furthermore, this also suggests that coyotes view dogs and cats as competition for resources. Humans can have major effects on coyote populations and spatial structure by eliminating what Dr. Numi Mitchell (Narragansett Bay Coyote Study) refers to as “subsidized feeding,” that is, intentionally or unintentionally supplying coyotes with a food source. Her study found that coyote population density increased due to subsidized feeding by humans. Subsidized feeding led to increases in pack size (i.e., number of coyotes per pack) and number of packs per unit area. In contrast, her research has shown that when changes were made to promote unsubsidized coyotes, the population density decreased. This shows that humans can have a major effect on coyote population densities. By eliminating subsidized feeding, we can directly decrease human-coyote conflicts.