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Collars make a comeback

Eastern collared lizards rebound with partner-assisted intentional forest management

Tracy Farley
Office of Communication
August 14, 2023

What is green and gold, sports a collar, has four legs but runs on two? It’s not a riddle. Some have called it a “mountain boomer,” but it is actually an eastern collared lizard.

Thanks to intentional forest management, they are becoming a more common sight dotting rocky outcrops in the Ozark Mountains of Arkansas and Missouri, most especially on the Sylamore Ranger District of the Ozark-St. Francis National Forests in northern Arkansas.

Forest fashion icon

An eastern collared lizard on a person's hand.
Researcher Casey Brewster catches an Eastern collared lizard. (Photo by Casey Brewster-University of Arkansas)

The eastern collared lizard (Crotaphytus collaris) is a unique and striking species, with its vibrant blue-green body and contrasting black and white “collar.” It is also one of the largest lizards in the Ozark region and can run on its hind legs, which is quite interesting to watch.

The Eastern collared lizard was once prevalent across the Ozarks 40-50 years ago. Now, it’s a rare treat to see these iconic lizards because the population has dwindled. In Arkansas they are considered a species of greatest conservation need.

“It’s listed so high because somewhere between 70-80% of our populations have disappeared in the past 40-50 years,” said Casey Brewster, a research affiliate with the University of Arkansas. Brewster has been studying this lizard for several years, even for his Masters of Science and Ph.D. degrees.

“The reason for that really goes back to a lack of fire – prescribed fires or burns and even some wildfires to a certain extent,” said Brewster.

Fewer fires meant fewer lizards

A lack of fire on this landscape caused the habitat to go through successional changes, from rocky with little soil, to mosses and lower plants, to prairie, to savannah, and finally woodland.

“If you don’t have fire, then everything goes toward that late succession mature forest,” said Brewster. “The biggest thing we can do in Arkansas and Missouri is prescribed fire to restore the habitat where the Eastern collared lizard can thrive.”

Firefighters use prescribed fire to restore this glade habitat on the Sylamore Ranger District, Ozark-St. Francis National Forests in Arkansas.
Firefighters use prescribed fire to restore this glade habitat on the Sylamore Ranger District, Ozark-St. Francis National Forests in Arkansas. (USDA Forest Service photo by Idun Guenther)

“It needs to be thinned and then burned every two to three years,” said Brewster. “It will typically take at least three or four burns before you get the habitat back to a decent level. When the habitat is restored, the next part of my project is to release lizards to that site so they can recolonize it.”

Restoring historic habitat

Forest Service Zone Wildlife biologist Idun Guenther on the Sylamore and St. Francis Ranger Districts agreed. She explained that historical records indicate that there were as many as two-million acres of naturally open grassland habitat in Arkansas in the early 1800s. These open habitats have been generically referred to as “prairies” in the past. Many were true tallgrass prairies, but others are contemporarily classified as glades or barrens.

Glade restoration efforts on the district began around 2013.

“We are restoring glades on the Sylamore District where they historically existed to help the collared lizard. Glades are present across the district – among the many different types of glades, ours include limestone and sandstone glades,” said Guenther.

“The process to restore the glades includes removing cedar trees that have encroached into the glades for many decades due to fire suppression. Once the trees are cut, we introduce prescribed fire on a rotational basis depending upon the site conditions. Follow-up mechanical or invasive plant treatments are often required as well.”

Partners make it happen.

A large group of people standing on top of a solid rock mountain top.
The Nature Conservancy participated with forest personnel in providing an educational tour of the glade restoration project to Representative French Hill (R-2-AR) and his staff. (USDA Forest Service photo by Idun Guenther)

Guenther and other Forest Service employees are working in collaboration with The Nature Conservancy, Arkansas Game and Fish Commission and universities (such as University of Arkansas). The Nature Conservancy and Arkansas Game and Fish Commission have forest-wide agreements or grants that provide personnel and funding to assist with restoration efforts, including contract development for cedar removal, prescribed fire operations, outreach, field days and long-term effects monitoring. Research projects on different glade species are conducted by students at universities.

Eastern collared lizard on a rock, basking in the sun.
Eastern collared lizards love basking in the sun. This individual is searching for a good location at a rock quarry, where restoration work is underway. (USDA Forest Service photo by Idun Guenther)

Making more lizards

“Once we have a glade restored, we have to plan two to three years ahead on where am I going to get those stock animals from. We don’t have a giant population in the state,” said Brewster.

The Little Rock Zoo stepped up to help.

“The Little Rock Zoo partnered with us three to four years ago wanting to get involved with conservation,” said Brewster. “Essentially, they are breeding Collared lizards that came from Arkansas. These are Arkansas Collared lizards – not that they are a different species, but they may be genetically different in small ways than other species.”

The Little Rock Zoo’s ability to breed and raise young collared lizards gives the reintroduction program a big boost. Partnering with the Little Rock Zoo provides a lot of yearlings that can be introduced back into restored glade ecosystems.

See the change for yourself

Wildflowers blooming from restored glades in spring.
Spring erupts with beautiful wildflowers emerging from the restored glades. (USDA Forest Service photo by Idun Guenther)

“A glade functioning like it’s supposed to is one of the prettiest places to sit and view wildlife and take pictures,” said Brewster.

On the restored Sylamore district, visitors see the vegetative response to the restoration efforts. Mechanical thinning and prescribed burning return sunlight to the glades so native flowering forbs and grasses can sprout and bloom again. Although early in the habitat restoration, it appears quail, turkey, and other migratory birds are returning in greater numbers.

“It is exciting to me to see the changes on the landscape and know that we’re making a positive difference,” said Guenther.