https://phys.org/news/2019-03-coyotes-north-america-doom-deer.html

Effects on white‐tailed deer following eastern coyote colonization...........

The recent spread of coyotes across North America did not doom deer populations

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REGARDING COYOTES NOT LIMITING DEER

POPULATIONS---https://youtu.be/2XCbHhDlU_k

March 20, 2019, North Carolina Museum of Natural Science

Coyotes eat deer, but not enough to limit the deer population at a large scale. A new study of deer numbers across the eastern United States has found that the arrival and establishment of coyote predators has not caused the number of deer harvested by hunters to decline.

A coyote captured on camera trap preying on a deer fawn. Credit: Dr. Aimee P. Rockhill (Western Carolina University) and Dr. Christopher S. DePerno (North Carolina State University)

With wolves and cougars extinct in most of the eastern U.S., white-tailed deer have become abundant, sometimes overabundant," says Roland Kays, wildlife biologist at the North Carolina Museum of Natural Sciences and North Carolina State University, and co-author of a paper describing this research. "Coyotes moved in as the new top predator of the east, but they aren't nearly as effective deer hunters as wolves, so there's been a lot of controversy about whether these medium-sized predators can really limit deer populations at large scales."

Coyote colonization and white‐tailed deer harvest in 1930–2016 (Hody and Kays 2018). In each of 6 states, we plotted male deer harvest in a randomly chosen county as an example. Red arrows in Delaware, New York; Camden, New Jersey; and Granville, North Carolina, show the time of coyote arrival. In Wood, Ohio; Greenville, South Carolina; and Calhoun, Florida, coyote arrived before the first deer harvest data were available. Bottom right inset shows male deer harvest in each state.

Previous studies of how coyotes might be affecting deer populations have produced inconsistent results. Some experimental removals of coyotes found that fawn survival increases following coyote removal, but others have shown no effect. Kays and a team of researchers led by Eugenia Bragina from NC State, surveyed deer population trends from 1981 to 2014 using data from 384 counties across six eastern states. "Our study is unique because it's the first to link coyote presence to changes in deer population at a large scale," Bragina says. "Getting the big-picture of the interactions between these species helps inform the management practices of these species by hunting agencies."

Coyotes harvested by trappers in 20 eastern United States from 1970 to 2015 showing a consistent increase across the region. We include 2 examples of western states for comparison. The red lines highlight smoothed relationship through annual harvest numbers (black dots). Scale of y‐axis varies across states. Data for Maryland, Delaware, and Florida were incomplete and are not shown (U.S. Furbearer Conservation Technical Working Group of the Association of Fish and Wildlife Agencies, unpublished data).

The researchers collected county-by-county data on coyote arrival by assessing museum collections, and deer population numbers by tracking hunting records from state wildlife agencies. They evaluated these data for changes in the number of deer harvested after coyote arrival and establishment in an area, while accounting for environmental differences like climate and landscape. They found that the number of harvested deer in all states generally increased over time, and that there was no consistent crash in harvest numbers following coyote arrival. They concluded that coyotes are not controlling deer populations at a large region-wide scale in the eastern North America.

"We see direct evidence of coyote predation on deer when looking at coyote scat or even spotting them with camera traps carrying off deer fawns," says Chris Deperno, a co-author on the study from NC State. "Though coyotes are known to kill adult deer, predation is focused primarily on vulnerable individuals that are sick, injured or in late stage pregnancy. Predation of healthy adults is uncommon.

Coyotes definitely kill deer fawns in their initial first weeks
after being born in the Spring,,,,,,,,,,,,but those kills do not
dampen Deer herd numbers

The researchers caution that this species interaction could potentially change as coyote numbers are still on the rise across the eastern U.S. It is unknown whether coyote populations will increase in number or density enough to influence deer populations in the future. Human-induced changes in habitat quality or landcover may also influence how these species interact.

Management efforts to increase deer population sizes involving coyote removal, the researchers advised, are unlikely to be effective at large scales or over long periods of time. "Coyote removal as a method of increasing deer abundance is expensive and labor-intensive," Bragina says. "We hope that this research leads to more acceptance of this carnivore by people. Coyotes are here to stay."

Sometimes the tables get turned and Deer chase the Coyotes

The paper, "No region-wide effects on white-tailed deer following eastern coyote colonization," is published in the Journal of Wildlife Management and Wildlife Monographs. Allison Hody, Christopher Moorman and Christopher Deperno from NC State, as well as L. Scott Mills from University of Montana, co-authored the research.

Explore further: Research indicates coyote predation on deer in East manageable

More information: "No Region-Wide Effects on White-Tailed Deer Following Eastern Coyote Colonization" DOI: 10.1002/jwmg.21651