Ozark Plateau National Wildlife Refuge

04/17/2026

Happy Bat Appreciation Day 2026! 🦇 Bats are incredible animals that play vital roles in various ecosystems. Bats save billions in agriculture by consuming vast amounts of insects, acting as natural pest control. Bats pollinate over 500 plant species, including bananas, mangoes, and cacao. Bat guano in cave ecosystems support a diverse array of unique cave fauna. Bats also are the only mammals naturally capable of true and sustained flight!

Photos Credits:
Ozark big-eared bats in hand, Jena Donnell, Oklahoma Department of Wildlife Conservation; Roosting Ozark big-eared bats, Richard Stark/USFWS

04/03/2026

The refuge is working with researchers from the University of Alabama-Huntsville, the Oklahoma Department of Wildlife Conservation, The Nature Conservancy and the San Antonio Zoo on a multiple year mark-recapture study of the rare and endemic Oklahoma cave crayfish. This species has a very limited distribution and currently is known only from a cave on Ozark Plateau NWR and three other caves on nearby private land. Traditional survey methods consist of counting individual crayfish we encounter while in the cave. This survey technique, while providing useful information, has limitations in regard to understanding population size. Cave crayfish can occur throughout the subterranean aquatic habitat in spaces that are too small for human access, so we can't find or see all of them. To improve our understanding of crayfish abundance, researchers are uniquely marking each captured crayfish by injecting a non-toxic acrylic-based polymer to specific tail segments. The polymer comes in multiple colors that fluoresce under UV light. These unique markings allow researchers to identify individuals already captured during previous survey efforts so that, overtime, we will begin to develop a much better understanding of the population size by comparing the total number captured to the number recaptured. A concurrent lab-based study of behavior and reproduction in the species has confirmed that the marking method lasts and is safe. An animal in the lab was marked four years ago. Her marks are exactly the same and she continues to thrive. She also laid eggs and those babies hatched and are healthy and growing.

02/11/2026

The Refuge currently is conducting the hibernaculum census for the endangered and rare Ozark big-eared bat. There are fewer than 2,500 Ozark big-eared bats throughout their entire known range and many hibernate in several cold limestone and sandstone caves (4° to 11°C/ 39° to 52° F) on the refuge. Ozark big-eared bats hibernate winter through early spring to conserve energy when their primary food source (moths and other insects) is unavailable. Because body temperatures of hibernating bats are influenced by substrate temperature, bats select sites with temperatures low enough to ensure their metabolic rate will not use critical
fat reserves before hibernation ends. They rely on these fat reserves, making them highly vulnerable to starvation if disturbed and forced to prematurely rouse, which burns critical energy. We are happy to report that we have seen healthy colonies and strong numbers at each site visited to date.

📷 Ozark big-eared bats hibernating deep within a cave on Ozark Plateau NWR (Richard Stark/USFWS)

02/02/2026

Excuse me...

I would like to make a special announcement:

A groundhog is a woodchuck and a woodchuck is a marmot. Thank you for your attention to this important matter.

Sincerely,
Rusty "Chuck" Burrows, the Ozarkian Whistlepig

Excuse me...

I would like to make a special announcement:

A groundhog is a woodchuck and a woodchuck is a marmot. Thank you for your attention to this important matter.

Sincerely,
Rusty "Chuck" Burrows, the Ozarkian Whistlepig

Photo:
A groundhog/woodchuck/marmot/whistlepig on Ozark Plateau NWR looking for its shadow and wondering who I am (Richard Stark/USFWS).

01/23/2026

Endangered Ozark big-eared bats tend to hibernate in the coldest places of the coldest caves, often near the entrance. This behavior predisposes them to disturbance during a very sensitive time of year when they must rely on fat reserves built up during the fall to survive. Human presence in these caves during winter can cause them to awaken, potentially wasting critical fat reserves needed to survive until spring. To protect them during these sensitive periods, bat-friendly steel gates are sometimes constructed on the entrances to prevent unauthorized entry and disturbance. Biologists can enter quietly and stay just long enough to document their presence and estimate colony size, often with the aid of photographs, in an ongoing effort to monitor population trends in this very rare species.

Photo: A colony of endangered Ozark big-eared bats hibernating in a cave on Ozark Plateau NWR on a cold winter day (Richard Stark/USFWS)

01/12/2026

Tricolored bats sometimes appear to glisten when our helmet lights first encounter them at a distance during winter bat surveys. These bats have a tendency to roost in warmer sections of caves where humidity levels are high. During hibernation, the bat's body temperature, heart rate, and metabolic rate drop significantly. The cooler body in a humid, relatively warmer environment create the perfect conditions for condensation. Water droplets that glisten in the light form on its fur because its body surface is cooler than the surrounding moist air.

📷 A tri-colored bat in deep torpor and covered in condensation in a cave during the winter hibernation season on Ozark Plateau NWR (Richard Stark/USFWS)

10/01/2025

Due to the federal government shutdown, this account is not being actively updated.
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Operations in the Absence of Appropriations

09/23/2025

Chickadees are amazing little birds. Common in eastern deciduous woodlands and at backyard feeders, chickadees are busy this time of year storing away surplus food items. When food is abundant, they cache away extra berries, seeds and insects by the thousands in a variety of locations such as tree bark crevices and clusters of dead leaves. Caching is a very important survival strategy that requires an extraordinary memory. When food becomes scarce during the lean winter months, they are able to relocate tucked away snacks that help them get through the winter. This "scatter hoarding" also makes it less likely that a competitor will find their entire stash.

Photo: A Carolina chickadee in winter (Credit: Richard Stark)

09/19/2025

While many moths and butterflies overwinter as caterpillars (in a dormant state known as diapause), the herald moth survives the winter as an adult by taking refuge in dark places with cool but stable temperatures like caves. This distinctive looking moth has scalloped, hooked forewings with white crosslines that resemble a dead leaf, and help the moth blend in with leaves while at rest in the forest. They range in color from gray to rustic brown to orange.

📷A herald moth overwintering in a cave in the Ozarks of eastern Oklahoma (Richard Stark/USFWS)

09/17/2025

Hanging from near the ceiling of a cave, this bat is out of reach of most would-be predators such as raccoons, cats, raptors, and snakes. Although tri-colored bats commonly roost in trees during the summer, during the winter, they seek the shelter of caves. Specialized locking tendons in their feet allow them to hang while truly at rest. Hanging like this also provides a safe vantage point for launching into flight.

📷 A tri-colored bat takes shelter in the quiet darkness of a cave in the Ozark Highlands (Credit: Phillip Crawford/ODOT NRP)