Strategic Communications and Marketing News Bureau

Camera trap study reveals the hidden lives of island carnivores

Illinois Natural History Survey wildlife ecologist Max Allen and his colleagues used camera traps to determine which carnivores were living on the Apostle Islands in Lake Superior, Wisconsin. Here, Allen is reading the heart rate of an adult mountain lion captured in Mendocino National Forest on another study of carnivores.

Photos courtesy Max Allen

Delete

Edit embedded media in the Files Tab and re-insert as needed.

CHAMPAIGN, Ill. — Researchers placed 160 cameras on 19 of the 22 Apostle Islands in northern Wisconsin to see which carnivores were living there. After taking more than 200,000 photos over a period of three years, the team discovered that several carnivores are living on various islands in this remote archipelago in Lake Superior.

A bobcat on Oak Island, Wisconsin, in 2015.

A bobcat on Oak Island, Wisconsin, in 2015.

Reported in the journal Community Ecology, the study reveals a thriving community of carnivores, with some doing better than others on islands that differ in size and proximity to the mainland.

The researchers put motion-activated cameras on each of the islands studied, at a density of one camera per square kilometer. Over time, the camera traps recorded 10 of 12 Wisconsin land carnivores, including American martens, black bears, bobcats, coyotes, fishers, gray foxes, gray wolves, raccoons, red foxes and weasels. The cameras also captured images of semiaquatic carnivores mink and river otters, as well as raptors, small rodents, squirrels, songbirds and waterfowl.

“This is one of the first studies to focus on the carnivore community in an island system,” said Illinois Natural History Survey wildlife ecologist Max Allen, who led the new research with Morgan Farmer and Tim Van Deelen at the University of Wisconsin, and Erik Olson from Northland College. “The area is remote and difficult to access, with rough water in summer and variable ice conditions in winter, so the carnivore community had never been studied.”

The INHS is a division of the Prairie Research Institute at the University of Illinois at Urbana-Champaign.

The research offers new insights into a phenomenon known as island biogeography, which describes the distribution and diversity of species in territories with distinct boundaries that can act as obstacles to inward and outward migration.

“Most research on island biogeography has been conducted in tropical marine systems that have innately high levels of biodiversity and few carnivores,” Allen said. The new study is unique in that it examines carnivores in a remote island system in a temperate locale, he said.

A bobcat on Oak Island, Wisconsin, in 2015.

A bobcat on Oak Island, Wisconsin, in 2015.

“We were surprised to find an intact carnivore community – including gray wolves and American martens – on these islands,” Allen said. “We found more carnivore species on islands that were larger and/or closer to the mainland.”

A red fox on Stockton Island, Wisconsin, in 2015

Photo courtesy Max Allen/Erik Olson/Tim Van Deelen

Delete

Edit embedded media in the Files Tab and re-insert as needed.

Black bears were found on 13 of the islands examined. They appeared to prefer bigger islands that were closer to other islands. Gray wolves, however, were seen only on one of the 19 islands studied. These differences may have to do with the animals’ diets and habits. Bears tend to be solitary and eat a variety of foods, while wolves are social, with more specialized diets. The latter tend to prey on ungulates like deer.

The researchers were surprised to find that some smaller carnivores, such as weasels and American martens, appeared to prefer life on islands further from the mainland.

A pair of American martens on Stockton Island, Wisconsin, in 2014.

A pair of American martens on Stockton Island, Wisconsin, in 2014.

The carnivores may swim from island to island or use ice bridges that form in winter between the islands. Documented declines in the duration of lake ice as a result of climate change may hinder the movement of carnivores between islands and to and from the mainland, Allen said.

“The study offers a first glimpse of the top predators making a living on the Apostle Islands,” Allen said. “It’s pretty exciting to be the first to document species in an area, especially a wild and remote piece of land in the National Park Service.”

Editor’s notes:

To reach Max Allen, email maxallen@illinois.edu.  

The paper “Is there anybody out there? Occupancy of the carnivore guild in a temperate archipelago” is available to members of the media from the U. of I. News Bureau.

Read Next

Uncategorized Portrait photos of, from left, Carl Bernacchi, Stephen Long and Donald Ort

Review: Heat-resilient crops are within reach — given enough time and money

CHAMPAIGN, Ill. — Laboratory and field experiments have repeatedly shown that modifying the process of photosynthesis or the physical characteristics of plants can make crops more resilient to hotter temperatures. Scientists can now alter the abundance or orientation of leaves, change leaf chemistry to improve heat tolerance and adjust key steps in the process of […]

Arts Diptych image of the book cover of "Natural Attachments" and a portrait of Pollyanna Rhee standing in front of greenery.

Book explores how ‘domestication’ of environmentalism limits who it protects

CHAMPAIGN, Ill. — The response to a 1969 oil spill off the coast of Santa Barbara, California, reveals how the modern environmental movement has been used to protect the interests of private homeowners, said a University of Illinois Urbana-Champaign researcher. Landscape architecture professor Pollyanna Rhee chronicled how affluent homeowners use what she calls “ownership environmentalism” […]

Agriculture Graduate student Andrea Jimena Valdés-Alvarado, left, and food science professor Elvira Gonzalez de Mejia standing in the Edward R. Madigan Laboratory holding samples of the legume pulses they used in the study.

Fermenting legume pulses boosts their antidiabetic, antioxidant properties

CHAMPAIGN, Ill. — Food scientists at the University of Illinois Urbana-Champaign identified the optimal fermentation conditions for pulses ― the dried edible seeds of legumes ― that increased their antioxidant and antidiabetic properties and their soluble protein content. Using the bacteria Lactiplantibacillus plantarum 299v as the microorganism, the team fermented pulses obtained from varying concentrations […]

Strategic Communications and Marketing News Bureau

507 E. Green St
MC-426
Champaign, IL 61820

Email: stratcom@illinois.edu

Phone (217) 333-5010