Yellowstone Cougar Project

Yellowstone Cougar Project

Why this work matters

The Yellowstone Cougar Project monitors Yellowstone’s top feline predator — the elusive cougar — by integrating year-round field work with cutting-edge tools. This project documents population trends, predation patterns, habitat selection, and behavior using tools like GPS accelerometer collars, remote cameras, and noninvasive genetic surveys. This knowledge helps answer questions regarding the role cougars play in predator-prey dynamics, competition with wolves and bears, and how Yellowstone’s predator diversity influences the Park’s ecology.

This information serves the park’s mission to understand and preserve native species and ecological processes, and helps inform many stakeholders’ conservation efforts in the Greater Yellowstone Ecosystem.

What needs to be done

There are few places left to truly understand how carnivores coexist, compete, interact, and impact their ecosystem. To continue this vital project, the Yellowstone Cougar Project uses the following methods:

  • Satellite GPS Accelerometer collars
  • Predation studies
  • Remote camera surveys
  • Snow tracking and noninvasive genetic surveys
  • Population modeling for cougar abundance, density, and population growth
  • Genetic and disease testing
  • Analyses of habitat selection and multi-species interactions from GPS collar data

The Yellowstone Cougar Project relies on donations from Yellowstone Forever’s members and corporate partners to supply the technology and support the skilled field staff needed to complete this crucial research and fund the project.

What we’ve accomplished

Cougars, along with wolves, were killed throughout the U.S. as part of predator removal campaigns in the early 1900s. Cougars were eliminated from the park around the same time wolves were in the 1930s, but the species overall survived in the West. Working in their favor were the large cat’s secretive nature and preference for rugged terrain where they are difficult to detect.

Cougars reestablished a viable, year-round population in northern Yellowstone during the 1980s. This natural reestablishment occurred during a period of high elk abundance and wolf absence, resulting in relatively rapid population growth. Following wolf restoration in the mid-1990s, cougar population growth continued to increase through 2001 when up to 42 cougars inhabited northern Yellowstone.

From 2001 to 2004, population growth slowed due in part to competition with wolves and bears over a declining elk population. Importantly, Yellowstone returned to being an intact ecosystem with all of its native large carnivores back on the landscape. Following a gap in population monitoring between 2006 and 2013, monitoring resumed in 2014 with the help of Yellowstone Forever.

Previous cougar research required radio-collaring a large number of individuals to estimate population size and predation patterns – an intensive and costly effort. However in 2014, Yellowstone began a new study to estimate population abundance using noninvasive genetic surveys. Through weekly snow-tracking surveys in winter, cougar project staff are able to integrate DNA samples (collected from hair, scat, and blood left by cougars) with recently developed statistical modeling techniques to produce population estimates. By conducting these surveys in consecutive winters, biologists estimated up to 45 cougars inhabited northern Yellowstone from 2014-2017. This work determined a healthy population still exists in numbers comparable to those from a decade ago.

The project has also established a remote camera survey network throughout northern Yellowstone to aid in population estimation. These field methods—coupled with camera detection data from recognizable GPS-collared cougars and future snow tracking and genetic surveys—will continue to provide periodic population estimates for Yellowstone.

Last January, one of Yellowstone’s marked mountain lions went missing. Scientists traveled deep into the park to investigate. And that journey? It wasn’t as straightforward as they thought it would be. Listen to the Telemetry podcast.

In addition to population monitoring, the Yellowstone Cougar Project conducts seasonal predation studies that integrate and overlap with the Yellowstone Wolf Project’s similar efforts. By capturing and fitting individual cougars with satellite GPS collars each winter, project staff are able to identify and search hundreds of clustered cougar locations annually to detect prey remains.

Since 2015, this work has demonstrated that elk make up nearly half of cougars’ diets in Yellowstone, with deer a close second. In addition, cougars prey on pronghorn, bighorn sheep, mountain goats, and smaller mammals like marmots, red foxes, and coyotes.

These GPS collars also have built-in accelerometers that allow biologists to measure fine-scale behaviors such as hunting, feeding, and traveling, as well as the ability to measure energetic expenditures of cougars.

GPS data from collared cougars is also being used in conjunction with GPS data from other carnivores and ungulates to evaluate how prey respond to predation risk, and how carnivores compete and coexist on the Yellowstone landscape. This work has only been possible through the generous donations to Yellowstone Forever.