The Depths We Go… to Study Bats

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Bat Conservation International, TPWD Nongame and Rare Species Program, and Texas A&M University biologists and volunteers during bat surveys in the Texas Panhandle.

Texas bats are in danger. White-nose syndrome (WNS), a devastating fungal disease, is almost here. The disease is caused by a fungus that thrives in the cold environments where bats hibernate. Hibernating bats with WNS often display white fungus on their noses and other hairless parts of their bodies, including their wings.The fungus isn’t always visible to the naked eye, however, and usually is not seen on bats found flying or dead outside of their hibernacula or at their summer roosts.

White-nosed syndrome kills bats during hibernation by agitating their skin which causes them to wake up and preen. This expends their extremely limited energy reserves needed to sustain them for the entire winter and can eventually lead to starvation.

White-nosed syndrome was first discovered in New York in 2006 and has since spread westward towards Texas at a rate of about 200 miles a year. The disease is responsible for the deaths of nearly six million bats across North America. It is now just 170 miles from the Texas border in Arkansas and was just recently found in eastern Oklahoma. White-nosed syndrome does not affect humans.wns_map_20160216.jpg

Texas hosts 32 species of bats, more than any other U.S. state. Three species of Texas bats are known to be impacted by WNS and five others have been found with the fungus but exhibit no disease symptoms. The effects of WNS on the remaining 25 bat species in Texas are not known.

Many bats can live for 20 years or more and are very slow to reproduce. Stressors, such as introduced diseases like WNS, can result in significant population declines and push species towards regional extirpations or even extinction. The loss of bats due to WNS could have wide-ranging impacts to the ecosystem services provided by these night-flying, insectivorous mammals. From a human perspective, bats provide billions of dollars in pest control to agriculture annually through their insect feeding activities. Loss of bat populations would likely raise agricultural costs and increase pesticide applications.

Fortunately, the Mexican free-tailed bats, which roost in the millions in Bracken Bat Cave, Old Tunnel State Park, and the Congress Avenue Bridge in Austin, migrate instead of hibernate during the winter months. While this will likely shield them from the worst effects of the disease, Mexican free-tailed bats could still spread the fungus to more susceptible species across the western U.S.

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Biologist examines a bat in a Texas Panhandle cave.

The Nongame and Rare Species Program at Texas Parks and Wildlife Department is partnering with Bat Conservation International and Texas A&M University to monitor bat populations and the spread of WNS. In early February 2016, biologists from both groups, along with some dedicated volunteers, met in the Texas Panhandle (Childress County) to test bats in several caves for WNS. Caves in this region of Texas are thought to contain environmental conditions (cold, humid) conducive to WNS infection.

Biologists searched caves for bats and when found, counted and swabbed individuals to test for WNS infection. The biologists are currently looking for additional caves in northern Texas to sample for the disease. This work is being supported by a grant through the U.S. Fish and Wildlife Service’s White-nose Syndrome Grants to States and the Pittman-Roberson Grants Programs. For more information about this disease visit White-nose Syndrome.org.

 

Texas Kangaroo Rat: Getting Ahead of the Curve

Credit: painting by Elizabeth McClelland from Kays and Wilson's Mammals of North America, © Princeton University Press (2002)
Credit: painting by Elizabeth McClelland from Kays and Wilson’s Mammals of North America, © Princeton University Press (2002)

Did you know that Texas has a kangaroo rat with its name-sake? Texas kangaroo rat is a fitting name as this is the largest of the five kangaroo rat species found in the state. The Texas kangaroo rat is the only species found in its historic range with a long, thick, white-tipped tail. Kangaroo rats are unusual for rats when it comes to their appearance (furry tail) and movement patterns. They hop on their back feet like kangaroos, and when males battle each other they jump at their opponents with their back feet using their back toes as weapons.

The Texas kangaroo rat (Dipodomys elator) is only known to occur in a relatively small region historically, where the Great Plains prairie meets the Rolling Plains. Its historic habitat is encompassed by a 15-county area in north-central Texas starting at the base of the panhandle and extending east along the Red River, including a small area of southern Oklahoma. The Texas kangaroo rat is considered to be the only mammal endemic to this region.

Credit: Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy — Migratory Bird Program, Conservation International — CABS, World Wildlife Fund — US, and Environment Canada — WILDSPACE.
Credit: Data provided by NatureServe in collaboration with Bruce Patterson, Wes Sechrest, Marcelo Tognelli, Gerardo Ceballos, The Nature Conservancy — Migratory Bird Program, Conservation International — CABS, World Wildlife Fund — US, and Environment Canada — WILDSPACE. Image provided by Smithsonian Institute.

Because so little is known about this species, and the data we do have indicates a decline in population, the Texas kangaroo rat is considered a Species of Greatest Conservation Need in the Texas Conservation Action Plan and is listed as a state threatened species by Texas Parks and Wildlife Department (TPWD). Research surveys conducted in 2002 documented their occurrence in only five of 15 counties. When those five counties were surveyed again in 2011, none were found (note: that was a year of exceptional drought). In 2009, Wild Earth Guardians petitioned the species for listing under the U.S. Endangered Species Act (ESA). U.S. Fish and Wildlife Service (USFWS) is in the process of conducting a 12-month review and will examine all available data (best available science) to determine whether the need to list this species as threatened or endangered is warranted.

In order to gain much-needed information about the current status, distribution and habitat needs, Texas Parks and Wildlife Department (TPWD) is funding a research project with Texas State University that will begin this fall. The Texas Comptroller’s Office is also funding a research project that Texas Tech University is currently conducting which includes examining genetic health and population status. In addition to these two research projects, a researcher from Tarleton State University received Section 6 funds through TPWD last year to evaluate the genetic structure of this species from museum specimens that is currently ongoing.  The combined results of these three research projects will provide a better understanding of the current status, habitat needs and reasons for its decline, and will help identify management actions needed to protect and enhance populations of this unique Texas species. The data yielded from these three studies will provide the most current data to be included with historical research data as “best available science” for USFWS to consider, along with consideration of any and all conservation efforts in place to protect this species, before a final listing determination is made.

In September 2015, researchers from Texas State University met with TPWD Wildlife Division staff and Natural Resource Conservation Service (NRCS) agents who work directly with landowners in the counties within the Texas kangaroo rat’s current and historic range to discuss research needs. The goals of that meeting was to help prepare TPWD biologists and other natural resource professionals to inform landowners about funded-research efforts, explain what providing access to private lands for research would entail, explain the role landowners can play to help reduce the need for listing the species, and to explain what it could mean to the landowner if this species is listed in the future.

TPWD and NRCS staff meet with Texas State University researchers at Caprock Canyons State Park in September, 2015.
TPWD and NRCS staff meet with Texas State University researchers at Copper Breaks State Park in September, 2015.

Working with private landowners is the key to success in conservation and protecting this and many other rare species in Texas. Our best chance at reducing the need for federal protection of rare species is through developing partnerships with landowners willing to provide access to private property for field investigations and willing to voluntarily implement best management practices to benefit this species. The lesser prairie chicken and dune sage brush lizard are two examples of rare species in Texas that have realized the benefits of partnering with landowners through conservation agreements. Such partnerships and agreements successfully influenced USFWS listing decisions through the voluntary protections provided to those species occurring on private lands, and thus reduced the need for federal oversight. Let’s continue to work together proactively to protect the biodiversity of Texas that we value so greatly.

Porcupines in Texas are Moving East

Have you seen a porcupine lately? If you live in central Texas, the chances are you’ve noticed one in a tree or on the road. If you haven’t seen one yet, keep your eyes out, because they’re expanding into new territory.

In the past few years, Texas Parks and Wildlife Department (TPWD) has been contacted by numerous people reporting porcupines in central Texas. Porcupines are known to occur primarily in northern and western Texas, but not so much in the central portion of the state. The map below shows the generally accepted distribution of porcupines in Texas.

Previously known range of porcupines in Texas. From "The Mammals of Texas - Online Edition".
Previously known range of porcupines in Texas. From “The Mammals of Texas – Online Edition”.

While receiving all these porcupine reports was interesting, they were also anecdotal and difficult to interpret. However, now a new tool called iNaturalist has enabled members of the public to record and share wildlife observations. iNaturalist uses photos, GPS locations, and community identifications to improve the reliability of the data and it is quickly becoming a powerful tool for biologists and researchers to learn about wildlife from the public.

Currently, iNaturalist has 73 porcupine reports for Texas since 2012. The map of these observations supports the reports we received from the public. While we shouldn’t confuse an abundance of observations with the abundance of porcupines (the number of observations is also influenced by the number of people making observations), these data clearly demonstrate a shift in our understanding of the distribution of porcupines in Texas.

Texas porcupine observations in iNaturalist from 2012 – 2015.
Porcupine observations in iNaturalist from 2012 – 2015.

It’s exciting to see how much we can learn in a few short years when people combine their efforts and share their knowledge. Check out the Mammals of Texas iNaturalist Project to start learning about other mammals in the state.

So keep your eyes peeled for porcupines! They are fascinating animals and if you live in Austin or San Antonio, they may be headed your way.