Hunger guides mountain lions' actions to enter residential areasMarch 13, 2018
In late February, CBS News Denver reported that mountain lion sightings were on the rise in Colorado's high country. Lion attacks on people in the state and around the world are rare, but the story referenced an attack on a 5-year-old boy in 2016 by a mountain lion near Aspen.
Wildlife biologists around the world studying these big cats have had difficulty explaining why these attacks occur, even after tracking the predators with GPS collars. A study from Colorado State University and Colorado Parks and Wildlife provides new insight. Researchers found that while the animals are generally fearful of and avoid humans, hunger can dampen that fear.
The study, "Hunger mediates apex predator's risk avoidance response in wildland-urban interface," was recently published online in the Journal of Animal Ecology.
"These predators, including mountain lions, aren't 'hangry' and seeking out back yards to find food, but there comes a point when a mountain lion is hungry enough that it may use back yards to hunt for food, similar to what takes place in the wild ," said Kevin Blecha, who worked on the research in conjunction with Colorado Parks and Wildlife biologists, while pursuing a graduate degree in ecology from CSU.
Previous studies have shown that big cat predators intentionally avoid people, due to fear. Other research has found that predators prefer to spend their time in prey-rich areas.
"Unfortunately, these two explanations were not lining up in explaining large predator movements in back yards, and even contradicted each other, especially when there could actually be more prey, like deer, available near people's homes," said Blecha.
GPS tracked predator movements
In this study, researchers analyzed hunting behaviors of mountain lions on the fringes of Denver and Boulder, Colorado, through the sprawling exurbia, and into the jagged wilderness areas along the Continental Divide. The team used bio-monitoring collars with GPS location and acceleration recorders, strapped to the lions, allowing the researchers to document the predators' hunting behaviors.
Data from the GPS collar locations revealed whether the mountain lions were avoiding, attracted to, or ambivalent to houses. GPS tracked the dates and times since the mountain lion last fed on a prey animal, allowing researchers to measure the hunger level that the lions were experiencing while moving about its home range. Animals that had not eaten in more than four to seven days showed little to no avoidance of the higher housing densities.
Hunger, time of year matter in animals' actions
Blecha and the team found that predators' behavior was connected with having an emptier stomach. While a mountain lion can become hungry at any time of the year, the animals would go longer and longer periods of time between making kills as the winter progressed through late spring, a time of the year when wild prey numbers are lowest. Late spring is also when conflicts between mountain lions and humans may be the highest. Researchers concluded, too, that female mountain lions avoided houses less than male counterparts, which is likely due to females expending more energy during times when they are rearing kittens.
In addition, camera traps recorded whether the animals' prey sources were more likely encountered in the higher housing densities or in more wild, public land areas like national forestlands. These camera traps revealed that deer, raccoons and pets were less likely to be encountered in the wildland areas. Complementing this finding, the collars showed that mountain lions were more successful at finding and killing prey near houses than they were away from these structures.
Blecha said it is likely that prey such as mule deer are safer in sprawling subdivisions and exurbias, given that mountain lions, coyotes, and human hunters usually avoid these urban fringes.
"This study contributes to a growing body of evidence indicating that an animal's energetic state is very important in the decision-making process; animals will make riskier choices when hunger beckons," said Blecha. "This is likely the same for all animals, whether it is mountain lions, rabbits, birds, or even humans."
This is among the first studies to demonstrate a direct relationship between hunger and the decision-making process of a large predator.
Colorado Parks and Wildlife officials said homeowners living in the wildland-urban interface can do their part by recognizing that wild and domestic animals in their backyards are seen as prey to wild predators.
"It is important to keep pets from running loose in these areas without supervision," said Blecha.
Colorado State University
Related Predators Articles:
The size of marine invertebrate predators has increased over the past 500 million years, while the size of their prey has not, a new study reveals.
By deploying green clay caterpillar models across six continents, researchers unmasked an important global pattern.
Researchers from the University of Bristol have discovered that some fish within a shoal take on the responsibilities of leader when they are under threat from predators.
Restoring predator and prey species together helps accelerate ecosystem recovery efforts compared to pursuing restoration of one species at a time, new research concludes.
Researchers show how simultaneously restoring predators and prey is much faster and more effective than doing so one at a time.
Reducing human pressure on exploited predators and prey at the same time is the best way to help their populations recover, a new study indicates.
When it comes to predators, scientists find larger sheephead that consume bigger urchins help keep that population under control.
Scientists from the universities of Bristol and Groningen, in The Netherlands, have created a computer game style experiment which sheds new light on the reasons why starlings flock in massive swirling groups over wintering grounds.
Scientists have shown for the first time how bacteria with resistance to a viral predator can become susceptible to it after spending time in the company of other susceptible or 'sensitive' bacteria.
Tiny predators in the soil can literally sniff out their prey: soil bacteria, which communicate with each other using scent.
Related Predators Reading:
by John Seidensticker (Author), Susan Lumpkin (Author)
Track Down Predators
INsiders brings predators to life, with the most up-to-date information and state-of-the-art 3-D illustrations that practically leap off every page, stimulating minds and imaginations in a whole new way. View Details
Smart Kids: Predators: The World's Deadliest Hunters
by Roger Priddy (Author)
From the venomous box jellyfish to the vicious piranha, deadly black mamba to the great white shark, Predators is packed with astonishing photographs and information about some of the world's most efficient hunters. There are essential facts to absorb about each one, such as their habitat and preferred prey, plus a Killer Fact about each one, too – did you know that tigers have been blamed for over 16,000 human deaths in India? An inspirational read for fact-hungry kids. View Details
Predator: If It Bleeds
by Bryan Thomas Schmidt (Author), Jeremy Robinson (Author), Andrew Mayne (Author), Kevin J. Anderson (Author), Jonathan Maberry (Author), Mira Grant (Author), Larry Correia (Author), Steve Perry (Author), Dayton Ward (Author), Tim Lebbon (Author)
An anthology celebrating the 30th anniversary of the PREDATOR franchise, IF IT BLEEDS includes seventeen brand new, never before seen stories--exclusive to this collection--featuring the Predators throughout space and time. Based entirely on the original films, novels, and comics, PREDATOR: IF IT BLEEDS (a quote from the original movie) reveals the Predators stalking prey in 12th Century Japan, 9th Century Viking Norway, World War I, Vietnam, the Civil War, Hurricane Katrina, and the modern day, as well as across the far reaches of future space.DEVIL DOGS by Tim... View Details
Predator: Scarpetta (Book 14)
by Patricia Cornwell (Author)
Investigating the disappearance of two sisters in Florida, Dr. Kay Scarpetta follows clues that twist and turn, leading her into the psychopathic depths of a jailed serial killer's mind. View Details
The Predator: Hunters And Hunted Official Movie Prequel
by James A. Moore (Author)
The official prequel leading directly into THE PREDATOR, available the film and introducing key concepts that then will explode onto the screen in the movie.
The official prequel novel leads into the summer blockbuster The Predator, Shane Black's new movie set within the universe of the previous films. With a screenplay by Shane Black and Fred Dekker, the film stars Yvonne Strahovski, Boyd Holbrook, Olivia Munn, Alfie Allen, Thomas Jane, Sterling Brown, Keegan-Michael Key, Edward James Olmos, Jake Busey, and more. Author James A. Moore (Alien: Sea of Sorrows) will work... View Details
Predator: The Secret Origins of the Drone Revolution
by Richard Whittle (Author)
The untold story of the birth of the Predator drone, a wonder weapon that transformed the American military, reshaped modern warfare, and sparked a revolution in aviation
The creation of the first weapon in history whose operators can stalk and kill an enemy on the other side of the globe was far more than clever engineering. As Richard Whittle shows in Predator, it was one of the most profound developments in the history of military and aerospace technology.
Once considered fragile toys, drones were long thought to be of limited utility. The Predator itself was... View Details
Predator: Life and Death
by Dan Abnett (Author), Brian Albert Thies (Illustrator), Rain Beredo (Illustrator), Dave Palumbo (Illustrator)
Colonial Marines land on the planet Tartarus to investigate illegal prospecting by a rival corporation on a Weyland-Yutani claim. But what they find are the shell-shocked survivors of a battle with extraterrestrial hunters over the possession of a mysterious horseshoe-shaped spaceship of unknown origin.
The Weyland-Yutani rep demands the marines take the ship, and the marine captain is determined to protect her crew. But neither objective is likely when a band of Predators attacks!
Predator: Life and Death is chapter one in a new story cycle involving Predators, Aliens,... View Details
The Art and Making of The Predator
by Dominic Nolan (Author)
Official companion book to the new blockbuster sci-fi movie from Shane Black, containing stunning concept art and behind-the-scenes photography from the filming process.
Witness the return of one of the most formidable movie monsters of all time as
director Shane Black brings The Predator to the world's cinema screens.
This official companion book provides a unique look at the making of the movie,
including fascinating detail on all the major aspects of production such as stunt work,
production design, visual effects, costumes and props. Interviews with the cast... View Details