Illegal Immigration? Coyotes Move North, East, and South

Illegal Immigration? Coyotes Move North, East, and South

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Study review by Kip Hansen

 

coyoteThis essay is about coyotes!

One of the odd things about this blog — WUWT — is the broad range of interests of the readers here.  Perhaps I shouldn’t be surprised by this as readers here tend to be better-than-average educated, well read, interested in all things Science, concerned about the environment and tend to have more open minds.

At least three times in the last couple of years, I have written about some topic, only to have the comments section overwhelmed by discussions of coyotes — their habitat, range and behaviors — with lots of interesting stories of personal sightings and experiences.

We hear and read so much news about the threat of species extinction and shrinking ranges of species that I though a modern success story was in order.

The publishing of a brand new study about North American coyotes and their historic ranges has presented this opportunity to write about coyotes and allow readers to share their stories — this time on topic!

The new study comes to us from James W. Hody (North Carolina State University) and Roland Kays (North Carolina Museum of Natural Sciences) in a paper published in the open-access journal ZooKeys, titled Mapping the expansion of coyotes (Canis latrans) across North and Central America.

 The paper is a major effort exploring this statement:

“The geographic distribution of coyotes (Canis latrans) has dramatically expanded since 1900, spread­ing across much of North America in a period when most other mammal species have been declining. Although this considerable expansion has been well documented at the state/provincial scale, continent-wide descriptions of coyote spread have portrayed conflicting distributions for coyotes prior to the 1900s, with popularly referenced anecdotal accounts showing them restricted to the great plains, and more ob­scure, but data-rich accounts suggesting they ranged across the arid west.”

Hody and Kays dug into biological history using “archaeological and fossil records, museum specimens, peer-reviewed reports, and records from wildlife management agencies” to determine the true historical range of the coyote as far back as 10,000 years before the present.  What they found was that “coyotes have been present in the arid west and California throughout the Holocene, well before European colonization. Their range in the late 1800s was undistinguishable from earlier periods, and matched the distribution of non-forest habitat in the region.”   Here’s the primary map they offer:

Fig_1_and_2

While we see that there are a few outliers, it is clear that, historically, coyotes have been mainly found in grasslands and arid lands of the North American west. The authors conclude:

“These data indicate that that coyotes’ range in the late-1800s reflected a longstanding geographic distribution that formed well before the 1700s, not a recent westward ex­pansion. This contradicts widely-cited descriptions of the historical distribution of coy­otes (Figure 1), which suggest that California and the Rocky Mountains as areas that were colonized by coyotes as recently as the 19th and 20th centuries ….. Instead, the historical distribution of coyotes matches areas where non-forested habitats (e.g., grassland, prairie, desert) dominate the climax vegetation, more closely corresponding to earlier range descriptions by Nowak … and Young and Jackson …. The Holocene distribution of coyotes in Mesoamerica remains unclear due to the relatively small number of published histori­cal specimens available from this area.”

Using contemporary reports from the literature and various state wildlife agencies, Hody and Kays construct the following map of the expansion of the coyote’s range in North America to occupy all of the contiguous United States,  all of Mexico as well was expansion into much of Canada, Alaska and Central America as far south as the Panama Canal.

coyote_expansion

This extensive colonization of new territory is hypothesized to have been facilitated by a variety of circumstances:

  1. The extirpation of other apex-level predators throughout North America, mainly the wolf and the cougar (mountain lion) in Eastern North America and the cougar and jaguar in Central America reducing predation of coyotes by these species and increasing available prey for the coyotes.
  1. The conversion of forested landscapes into agricultural landscapes opening up familiar ecosystems (similar to grasslands) to the coyotes and offering new prey — farm animals such as lambs, goats, chickens etc.  This is believed to be the case in North America and in Central America.
  1. “Hybridization of coyotes with wolves and domestic dogs in eastern North America introduced new genotypes that may have promoted colonization and survival in eastern habitats” (see the story of the “Red Wolf”). In the southeastern United States and in Central America,  hybridization is primarily with domestic dog breeds.  (Oddly, hybridization with wolves and dogs does not appear to be happening on the northwestern front of the coyote’s expansion.)

All-in-all, this mid-level predator is gaining territory (and genetic content) through its incredible adaptability to modern conditions and the environmental changes being made by the continued and changing human influences on landscapes.

Darien_GapThe paper’s authors express fears of what effects the coyote may have on South American ecosystems when the coyote manages to cross the barrier currently presented by the Panama Canal and the dense forests of the Darién Gap in southern Panama and northwestern Columbia. “If coyotes reach South America, it is likely that the grassland and agricultural habitats in Colombia and Venezuela could support viable populations, unless competition with native carnivores restricts them….. its potential effects on native wildlife is entirely unknown.”

The paper is available in pdf format from the publisher.

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Author’s Comment Policy:

North American native cultures commonly contain myths and stories revolving around the coyote, where it is often portrayed as “The Trickster”.   For the Navajo, “coyote is an irresponsible and trouble-making character and he is one of the most important and revered characters in Navajo mythology.”

I currently live at the foot of the Catskill Mountains in Central Hudson Valley of New York State.  The Catskills comprise 1,120 square miles (716,800 acres or 290,000 hectares) of wooded hills and valleys with an average altitude of about 3,000 feet (~1000 meters).  Coyotes live and breed here and are a pest species for ranchers and farmers — one of my sons hunted them for a local farmer.  In the winter, the mountain population moves downslope into the Hudson Valley which is much more densely populated.  It is believed that the presence of coyotes keeps down the feral cat population (a plus).

Throughout New York State, there is a long tradition of scary stories being spread about “coy-dogs” and “coy-wolves”, often used as a “boogeyman” to prevent children was straying too far from home after dark.  “Don’t go too far from the house, the coy-dogs’ll get ya!”

The American coyote is the true winner in the competition for America’s Most Successful Predator (second to Man, of course).

If you want me to respond specifically to a question or comment, address it to “Kip…” so I am sure to see it.

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Superforest,Climate Change

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