Predators and their prey – why we need them both, Conservation Northwest
Predation and Deer Population, PA Game Commission
- Predators kill most deer during their first summer (birth to approximately 12 weeks of age). We reported this in our own study during the summers of 2000 and 2001 when we radio-tagged over 200 fawns and monitored them closely to measure cause-specific mortality. Of the fawns killed by predators in our study, 84 percent were killed prior to 9 weeks of age. Coyotes and bears killed similar numbers of fawns. In the South Carolina study, 100 percent of fawns killed by predators were killed within 9 weeks of birth. Despite predation and other mortality causes, 57 to 72 percent of fawns were still alive in Pennsylvania at 9 weeks of age. Predators have less effect on older deer.
Coyotes Are Colonizing Cities. Step Forward the Urban Hunter., NYTimes, Dec 26, 2017
- The growing popularity of urban hunting is igniting a fierce debate over the perils and benefits coyotes pose in populated areas, and whether city dwellers ought to adapt to living alongside a cunning predator that has thrived since one of its top adversaries, the gray wolf, has been all but wiped out in much of the continent.
With higher deer population, Minn. wolf numbers jump 25 percent Bemidji Pioneer, Sept 25, 2017
Top Down-Bottom Up Ecosystems, Columbia Daily Tribune, June 7, 2017
- So the sun and plants are absolutely essential to the ecosystem. But so are the big guys. Removing them from an ecosystem disturbs many other parts of the ecosystem. This is called trophic cascades — the trouble cascades down the rest of the ecosystem. Here is yet another example of how complex the natural world is.
See also: Coyotes, Wolves, Cougar, Lynx, Feral Hogs
Michigan coyotes more visible than usual, DNR warns, Free Press, March 2, 2017
State, hunters stepping up efforts to control Michigan’s “resilient” coyote population, Michigan Radio, Feb 23, 2017
- The move to bring the Eurasian lynx into Kielder Forest, Northumberland, is designed to reinvigorate the habitat and help control the deer population. But the idea has divided locals, with farmers worried the six animals, due to be imported from Sweden, will kill sheep. The wild cats, which need to eat around 4.5lb of meat a day, were last seen across Britain in 700AD.
A Natural Cure for Lyme Disease, New York Times, Aug 20, 2016 The return of the lynx, BBC News, March 28, 2016
If humans have inadvertently increased the chances of contracting Lyme disease, the good news is that there’s a potential fix: allow large predators, particularly wolves and cougars, to return. They would help keep down the number of deer, which, although they don’t carry the Lyme-causing bacterium, probably encourage its transmission.
O’Donoghue, though, thinks the threat to British sheep is minimal. He describes the lynx as a “deer specialist” – it can be used to control excessive numbers of roe and muntjac deer – and a “forest ambush predator”.
The return of the lynx, BBC News, March 28, 2016
- Maine coyotes getting bigger, more wolflike, Portland Press Herald, May 7,2017
Scientists say there’s a reason for that: With 8% wolf DNA, the coyote species that prowls the Northeast is an evolving hybrid that’s becoming a more effective predator of deer.
- Are coyotes affecting local fawn recruitment?, Sandusky Register, Jan 22, 2017
An Illinois Natural History Survey study found that coyotes killed 20-to-80 percent of the fawns at different study sites near Chicago. Clearly, as coyote populations continue to grow and hunt fawns all spring and summer, we can expect to have fewer deer. Hunters need to try harder to eradicate enough coyotes to keep up with their population growth. Of course, the anti-hunting crowd prefers to let nature take its course and is content to allow the coyotes to be left alone — until they begin eating their pet cats or attacking their dogs.
- Two coyotes crash through window of suburban Detroit home, MLive, Jan 18, 2017
While there have been suspicions that coyotes might be responsible for a couple outdoor cats that have come up missing, Couch said there was never any proof. Macomb County Animal Control Chief Jeff Randazzo said there is typically an uptick in coyote sightings this time of year. January through March is mating season and a time when they’re more active.
- Coyotes In Chicago Have It Good, Experts Say In Urging City To Ignore Them, DNAInfo Chicago, May 12, 2016
Urban coyotes keep the city’s rat and goose populations down, but pose little threat to Chicagoans, experts testified before a City Council committee Thursday. Gehrt testified coyotes were a natural drag on the number of white-tailed deer, serving to minimize the number of deer collisions with cars.
- Wily coyotes continue to thrive in the Southeast at the expense of deer populations, US DeptAgriculture, Nov 22, 2016
- The purpose of Kilgo’s research is to better understand the abundance, population dynamics, and ecology of coyotes in the Southeast, as well as the magnitude of coyote predation on deer fawns and the potential for this predation to affect deer population size.
- Coyote hunting season now year-round in Michigan, MLive, April 26, 2016
The coyote population in Michigan is at an historic all-time high, and the Department of Natural Resources has said expanding the season to year-round will give landowners more tools to control local populations. An impact on the population at a larger level is not expected, however.
- Coyotes help manage deer populations, study finds, Times Freepress, Oct 29, 2015
Kilgo said the role of coyotes in deer management is something that can no longer be ignored as coyotes have become a force in the Southeast. His research is expected to help natural resource managers maintain deer populations at levels beneficial to ecosystem health and deer hunting — an economically important activity in the Southeast.
- Coyotes Create Dangers and Divisions in New York Suburbs, New York Times, June 23, 2015
In New Castle, N.Y., residents are warring over what to do about the animals, which attacked and killed a number of small dogs in the town this past year. In Saddle River, N.J., a man was bitten by a rabid coyote in April as he worked in his yard. And in Stamford, Conn., dozens of cats have gone missing, and coyotes have started attacking larger dogs, even German shepherds and golden retrievers.
“Ten years ago, it was rare to see coyotes, but they have really exploded on the scene here,” said Capt. Richard Conkin of the Stamford Police Department. He said that starting in March, the animals seemed to become more aggressive.
- 10 fascinating facts about urban coyotes, The Natural History of the Urban Coyote, April 5, 2015
Coyotes are opportunistic omnivores and will eat fruits and vegetables along with animal prey. A study by Urban Coyote Research Program analyzed over 1,400 scats and found that “the most common food items were small rodents (42%), fruit (23%), deer (22%), and rabbit (18%).” Only about 2 percent of the scats had human garbage and just 1.3 percent showed evidence of cats. “Apparently, the majority of coyotes in our study area do not, in fact, rely on pets or garbage for their diets,” say the researchers.
- Do Coyote Have An Impact On Michigan’s Deer Herd?, Woods and Water News, March 1, 2015
Michigan’s coyote population is at an all-time high following a severe deer epidemic of Epizootic Hemorrhagic Disease (EHD) which is a viral hemorrhagic disease causing extensive hemorrhaging in Michigan deer. EHD is viral and caused by biting midges and our deer herd was devastated in 2012. This means there was suddenly an abundance of dazed, sick and dying deer available for coyotes to eat. In most of the state they responded to the increase in food by having more pups [up to 19]. In some counties they double pupped and out of nowhere the coyote population skyrocketed to meet the demand for more predators to eat the sick and dying deer. The following year the deer numbers were drastically reduced, the EHD epidemic was over and less sick deer were available to feed coyotes. So Michigan’s coyote population is super strong and the deer herd is low and stumbling from the massive die off and cold winter of 2014. This means the remaining healthy deer are constantly harassed by roaming packs of coyote.
- White-tailed deer population dynamics and adult female survival in the presence of a novel predator, Journal of Wildlife Management, Volume 79, Issue 2, pages 211–219, February 2015
Our data indicate that for low-density deer populations with heavy predation pressure on neonates, protecting adult females from harvest may not completely offset population declines. Coyote removal might be a necessary strategy because it could possibly increase very low fawn survival, which appears to be the most important vital rate influencing λ in our study.
- Study to examine predators’ effect on deer populations, Lehigh Valley Live, Jan 18, 2015
The study, which will take place in the Susquehannock, Bald Eagle and Rothrock state forests, will be the first major look at the impact of predation in the state since 2001, when the agency determined that more than half of fawns born each year made to the hunting seasons. However, of those that died, 22 percent of the deaths were attributable to predators such as coyotes, bears, bobcats and fishers.
- WHITE-TAILED DEER ON KIAWAH, Wildlife on Kiawah Island, 2014?
Beginning in 2002, the Town of Kiawah, in partnership with the University of Georgia, conducted a Fawn Mortality Study. The goals of the fawn mortality study were to determine the recruitment ratio (the percentage of fawns which survive to adulthood) in the population, and to determine the primary factors of fawn mortality, specifically the role of bobcats. This 4-year study ended in 2005 and determined that bobcat predation is the major factor influencing fawn mortality (bobcats killed 55% of 129 deer fawns collared during the study), and that bobcats along with other mortality factors are able to maintain the deer population at current levels.
- Wildlife: Besides hunters, deer have few predator, Pittsburgh Post Gazette, Nov 23, 2013
Coyotes are the top natural deer predator in the East. Some studies have shown that coyotes are responsible for up to 80 percent of fawn mortality, and small packs of coyotes chase and kill some adult deer. In fact, most deer killed by predators are fawns, sickly or aged adults, or deer exhausted from slogging through deep snow. Only mountain lions and wolves routinely take healthy adult deer, and even they prefer the young, sick or weak.
- Deer Management: Are Predators Eating Your Fawns?, Outdoor Life, May 10, 2013
In one such study, researchers in South Carolina captured and monitored 60 newborn fawns. Coyotes killed over 50% before fall. Fawns are particularly vulnerable immediately after birth as 66% of the kills occurred within the first 3 weeks of life.
- Urban Coyote Ecology and Management, Cook County, IL
- Coyote (Canis latrans), Michigan Department of Natural Resources
- The Effect of Coyotes on Deer Populations, Game and Garden, 2013
- Do Coyotes Cause Deer Declines?, Emammal, 2013
- Lansing-area residents say wolf-like creature prowls neighborhood; Michigan DNR says it’s a coyote, MLive Nov 29, 2012
- Experts surprised by which predator is No. 1 killer of deer in Michigan’s Upper Peninsula, MLive, April 2, 2012
- Coyote packs are on the rise in West Michigan, MLive, Jan 7, 2011
- It’s a Coyote Eat Deer Feed Tick World: A Deterministic Model of Predator-Prey Interaction in the Northeast, Kathy Li and Orianna DeMasi, Snapshots in Research, Spring 2009
In conclusion, we proposed the following plan: Cull deer at high rates for a short time period, say five years, and then at more modest rates to maintain healthy populations.
- 2012 MICHIGAN FURBEARER HARVEST SURVEY, MICHIGAN DEPARTMENT OF NATURAL RESOURCES. Wildlife Division Report No. 3578, October 2013
- Harvest of red fox, bobcat, and fisher in 2012 were near the low end of their historical ranges (Figures 6-8). In contrast, harvest of coyote was near the high end of their historical ranges.
Study Concludes Coyotes Help Manage Deer Population in Southeast U.S., US Forest Service Research, Oct 7, 2015
- Isle Royale may add 20-30 wolves to keep pack from disappearing, Detroit Free Press, Dec 16, 2016
Researchers – especially those at Michigan Technological University in Houghton who have kept alive an annual report on the wolves and moose of Isle Royale and their interactions since the late 1950s – have been warning that the wolf pack was on the decline, largely due to inbreeding and genetic deficiencies.
Those researchers and others called for a reintroduction of wolves to bolster the herd, arguing that the annual study – which has produced insights into topics from arthritis to air pollution – is too valuable to lose and that a moose herd that isn’t threatened will do great ecological damage before dying out themselves.
- Wolves And The Environment, WGRZ, May 15, 2016
Steve Hall is Co-Founder of the Adirondack Wildlife Refuge in Wilmington NY, “There was a time in American history where if you saw a predator, the reaction was something everyone agreed on, you shot him, you got rid of him. The problem is, it took us another couple of hundred years to understand that wolves are the ones that control the deer population, the moose population, the elk population. This is one of the reasons why we’ve had this explosion of deer over the Eastern part of the country.”
- Isle Royale’s inbred 2-wolf pack ‘headed for extinction,’ researchers say, MLive, April 19, 2016
The National Park Service on Monday announced the findings of the Michigan Tech University study that outlines observations and projections for the ill-fated wolves. The population is down from three wolves last year. In contrast, the island’s moose, which are only preyed upon by wolves, continue to increase. The two remaining wolves are father and daughter as well as half-siblings, researchers say. They were born two years apart from the same mother and are estimated to be 6 and 8 years old.
- A Royale concern returns, Ann Arbor News, April 18. 2016
In January 2011, about 433 moose were living in the western Upper Peninsula. By last year, the DNR estimated that number had fallen to 323.
The 1930s concern about a large number of moose stripping Isle Royale’s vegetation mirrors what some feel could happen again, now that its resident wolf population appears to have fallen to just two. In recent decades, this predator-prey relationship has see-sawed. The changes have been documented in a continuing study by researchers from Michigan Tech University. The National Park Service is studying options. One of the island’s leading researchers has said wolves need to be imported to Isle Royale to restore the predator-prey balance as soon as possible.
- Biologists conducting U.P. wolf survey, MI DNR Bulletin, March 9, 2016
In August 2014, prior to the fall elections, the Michigan Legislature passed a citizens’ ballot initiative called the Scientific Fish and Wildlife Conservation Act. The initiative – advanced by numerous sporting groups – granted, among other provisions, sole authority to the NRC to designate game species.
- Predator-Prey Study: Wolves not threat to deer you may think, MLive, Jan 31, 2016
In the snowy woods of the western Upper Peninsula, wildlife researchers are learning a thing or two about deer survival: what preys on adult whitetails and fawns — and what else contributes to their deaths.
Some in the hunting community presume the answer is wolves. Many know harsh winters take a toll. Both are true, according to recent research, but a lot depends on other factors, such as the availability of young forests and food, predator density, and what other prey are available. The study, started in 2009 by Mississippi State University and the Michigan Department of Natural Resources, has turned up some surprises.
- Study delays difficult decision on Isle Royale wolves, Detroit Free Press, Nov 15, 2015
Over the past few years, varied proposals have been floated and considered for saving the Isle Royale wolves: from taking no action and letting nature decide, to adding wolves to prevent inbreeding that can produce unhealthy pups, or culling a burgeoning moose herd — growing because of the steep drop in predator wolves — without adding wolves.
Wolf Hunting Law Ruled Unconstitutional by Michigan Court of Appeals, Encyclopedia Britannica, Dec 16, 2016
Cougar, Lynx, Bob Cats
- Too Many Deer on the Road? Let Cougars Return, Study Says, New York Times, July 18, 2016
Laura R. Prugh, a wildlife scientist at the University of Washington; Sophie L. Gilbert, a wildlife ecologist at the University of Idaho; and several colleagues argue in the journal Conservation Letters that if eastern cougars returned to their historic range, they could prevent 155 human deaths and 21,400 human injuries, and save $2.3 billion, over the course of 30 years.
- Resurgent Bobcats Prompt State To Study Habitat, Population, Hartford Courrant, Sept 27, 2015
Once hunted almost to extinction in Connecticut, bobcats have made a comeback over the past 40 years. Wildlife experts say bobcats have been reported in every city and town in the state, and some estimates put their numbers in the thousands. Bobcats tend to be reclusive and usually hunt smaller game such as rabbits, woodchucks, mice and birds. But they are opportunistic hunters, according to state researchers, and will go after larger game like deer if they can take the animal by surprise or if it’s weakened by illness or hunger. The apparent resurgence of the bobcat may also help explain reported sightings in recent years of mountain lions. The only confirmed record of a mountain lion or cougar in Connecticut was one that was killed on the Wilbur Cross Parkway in June 2011. Wildlife experts determined that the big cat had wandered there all the way from South Dakota.
- How cougars would keep deer from killing people, Futurity, July 15, 2016
Using cougars and their value in reducing deer-vehicle collisions as a case study, researchers find that within 30 years of cougars recolonizing the Eastern US, large cats could thin deer populations and reduce vehicle collisions by 22 percent—each year preventing five human fatalities, 680 injuries, and avoiding costs of $50 million.
- Cougars could save lives by lowering vehicle collisions with deer, Science Daily, July 14, 2016
A team of researchers has for the first time begun to quantify the economic and social impact of bringing back large carnivores. Using cougars and their value in reducing deer-vehicle collisions as a case study, the researchers found that within 30 years of cougars recolonizing the Eastern U.S., large cats could thin deer populations and reduce vehicle collisions by 22 percent — each year preventing five human fatalities, 680 injuries and avoiding costs of $50 million.
- Deer hunters face unwanted competition as feral hog explosion thins herds, Fox News, March 31, 2016
The explosion of feral hogs across the U.S. is threatening the deer population — spreading disease, dominating the food chain and even, on occasion, killing and eating fawns. In Louisiana, where there are an estimated 700,000 wild hogs, hunters and wildlife officials say they are taking a toll on the whitetail deer herd.