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.

TPWD Receives White-nose Syndrome Grant Funding

Today Texas Parks and Wildlife received a federal grant for $21,618 to continue our research on bats and white-nose syndrome (WNS). U.S. Fish and Wildlife split nearly a million dollars across 35 states for similar research.

WNS has not been found in Texas, but it is knocking at our door. Since its discovery in New York state in 2006, it has moved toward Texas at an average speed of 200 miles a year. During it’s spread across the eastern states, an estimated 6 million bats have succumbed to the disease. TPWD will be focusing our efforts on early detection of WNS in susceptible areas.

White-nose syndrome is a serious issue and it is heartening to see such a large scale effort to combat it. Time to get to work!

See https://www.whitenosesyndrome.org for more info on WNS.

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.

Science with a Sledgehammer

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TPWD biologist Benjamin Hutchins hammers part of a Bou-Rouch pump into cobbles on the Frio River.

Flip over a rock in a stream and you may reveal some interesting aquatic invertebrates. Dig deeper into the gravel below and adjacent to the stream and you may find groundwater organisms more akin to cave-adapted species than stream dwellers. This habitat, called the hyporheic zone, is a transition between surface water and deeper groundwater. It can contain rare and unusual, blind and albino organisms like those found in springs, wells, and caves. However, because of its’ inaccessibility, little is known about the habitat or the organisms found there. Sampling requires hammering a metal spike several feet into the cobbles. This spike is hollow and perforated at the bottom. When a hand pump is mounted to the spike, water, and the organisms that live in it, can be pumped out. Although biologists have been using this instrument, called a Bou-Rouch pump, in Europe for decades, research in the United States and most other countries has been rare. In Texas, the hyporheic zone has only been sampled a handful of times, in a handful of places. Even with this limited-effort, biologists have collected rare and undescribed groundwater organisms.

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TPWD biologist Benjamin Hutchins and researcher Aaron Swink, from the Edwards Aquifer Research and Data Center at Texas State University, pump hyporheic water from the Frio River to measure water chemistry and sample for rare invertebrates.

For the first time, biologists from Texas Parks and Wildlife and Texas State University are taking a closer look at this habitat in Texas. In addition to surveying the organisms present, biologists are also measuring a suite of physical and chemical parameters to better characterize the habitat. It may turn out that some of the residents of the hyporheic zone are not as rare as previously thought: just that no one has looked closely for them. These organisms may also reveal important information about the health of our beautiful Texas springs. Because this research is just beginning, it is far too early to make any conclusions, but keep an eye on Frontiers in Texas Biodiversity for future updates.

The Texas Arachno-Challenge III

For the last two weeks, we have been working through the world’s 11 orders of living arachnids, all of which occur in Texas, the only U.S. state with such arachnid diversity. From common garden spiders to enigmatic microwhipscorpions, we’ve seen that these arachnids have a variety of unusual forms. However, we have to yet to be introduced to two of Texas’ most elusive arachnid orders, found in the Lower Rio Grande Valley.

Undetermined short-tailed whipscorpion. Photo by Dr. Jean Krejca, Zara Environmental LLC.
Undetermined short-tailed whipscorpion. Photo by Dr. Jean Krejca, Zara Environmental LLC.

The short-tailed whipscorpions (Schizomida) appear similar to vinegaroons and micro-whipscorpions, but lack a long “tail” or a “pipe cleaner”. These ant-sized arachnids are typically found, like micro-whipscorpions, in leaf litter or under rocks and logs. Aside from a single record of an undescribed species in Val Verde County, Texas short-tailed whipscorpions have only been recorded from near Edinburg and Rio Grande City. Most short-tailed whipscorpions are found in tropical regions around the world, and a few scattered records exist from southern states and as far north as Sequoia National Park in California.

So far, we’ve covered 10 orders, which means that we’ve come to the end at last. So what’s our 11th and final order that sets Texas apart from all other states? The hooded tick spiders (Ricinulei) are the smallest order of arachnids and they look a bit like a fuzzy tick with no head. Of course, they do have a head, but the mouthparts are hidden by a strange plate that hangs down where you would expect a face (hence the name ‘hooded’). Like its cousins, the hooded tick spider is found in leaf litter and soil and under rocks and wood.

Undetermined hooded tick spider. Photo by Dr. Jean Krejca, Zara Environmental LLC.
Undetermined hooded tick spider. Photo by Dr. Jean Krejca, Zara Environmental LLC.

Because these strange animals are primarily tropical, you might expect the U.S. to be out of luck for hooded tick spiders. But wait! In 1939 a single species was described from Edinburg, Texas, representing the only hooded tick spider known from the United States. But don’t think that finding one is as easy as a trip to Edinburg. “The curious, enigmatic arachnids of the Order Ricinulei are regarded as the rarest of all arthropods.” So begins the description of our Texas species, which also happens to be one of the smallest, at about 1/8 inch in length. Not only are these creatures rare, the original sampling location for Texas’ hooded tick spider, Pseudocellus dorothae, has been destroyed by urban development, and to my knowledge, the species hasn’t been seen since, meaning that if you find one, you’ll be the first person to do so in three-quarters of a century (if you see one, take a picture and please let us know!).

And with the hooded tick spider, the Texas Arachno-Challenge comes to an end. It will take you from woodlands of east Texas to the semi-tropical Lower Rio Grande Valley and west to the deserts of the Trans-Pecos. You’ll see tiny pseudoscoropions and giant vinegaroons, and if you succeed, you’ll be a true explorer of Texas biodiversity.

The Texas Arachno-Challenge II

Vinegaroon, Mastigoproctus gigantea. Photo by Cullen Hanks.
Vinegaroon, Mastigoproctus gigantea. Photo by Cullen Hanks.

Last week, we learned that all 11 of the world’s arachnid orders can be found without ever leaving the boundaries of Texas. We were introduced to several of the more common orders, but left off heading to the Trans-Pecos for some of the largest of Texas’ arachnids.

Most people that live in central and west Texas, are familiar with vinegaroons (Thelyphonida). Our one species, which also occurs in other southwestern states and large parts of Mexico, can grow over three inches in length with a formidable looking pair of pinchers (technically called chelicerae) and a whip-like tail. Generally harmless, they can pinch and excrete acetic acid (a major component of vinegar, hence the name). Vinegaroons burrow under rocks and are active at night.

Undetermined windscorpion. Photo by Cullen Hanks.
Undetermined windscorpion. Photo by Cullen Hanks.

While you’re out taking a night hike looking for vinegaroons, keep an eye out for what, at first glance, looks like a medium to large size spider, quickly scurrying about, searching for prey on open ground or under the desert bushes. On closer inspection, windscorpions (Solifugae), also known as camel spiders or sun spiders, can easily be distinguished from true spiders by their segmented abdomen, disconcertingly large, paired mandibles (again, chelicerae), and what appears to be five pairs of legs (the 5th pair are actually modified mouthparts called pedipalps). Windscorpions occur throughout most of the western United States.

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Undetermined tailless whipscorpion. Photo by Jason Butler.

Less common in the U.S., our eighth order, (Amblypygi) can be very abundant in the tropics, but are rarely encountered in Florida and Southwestern states including Texas. Like a flat, segmented spider, tailless whipscorpions look formidable with huge mandibles and creepishly long legs (particularly the 2nd pair that are used like antennas). However, if you are lucky enough to find one, your biggest challenge will be snapping a picture before it scuttles off at rapid speed. The single species in Texas, Phyrnus operculatus, has been recorded from the Big Bend region and a few caves in the southwestern edge of the Edwards Plateaus. Look under tree bark (where you can find a tree) and under stones, particularly in areas with large boulders and extensive limestone exposures that provide crackes and crevices in which the quarter-sized tailless whipscoprion can hide.

Microwhipscorpion, Eukoenenia spelaea. Photo from Smrz, Kovac, Mikes, and Lukesova, 2013. doi: 10.1371/journal.pone.0075989.g001.
Microwhipscorpion, Eukoenenia spelaea. Photo from Smrž, Kováč, Mikeš, and Lukešová, 2013. doi: 10.1371/journal.pone.0075989.g001.

Perhaps the strangest of the arachnids, the microwhipscorpions (Palpigradi) are also rarely seen. In fact, of the 11 arachnid orders, this is the only one still on the bucket list for yours truly. In appearance, a microwhipscorpion looks a bit like a tiny, eyeless vinegaroon that has had its ‘tail’ replaced by… a pipe cleaner. Like I said, they’re strange.

In Texas, species have been described from northeast Texas, near the Red River and from Austin, Texas. Like the pseudoscorpions, these tiny animals, though visible with the naked eye, will probably require magnification to locate. They have been recorded from under stones, in association with silverfish. Though you may be able to locate one by visually searching, there are also numerous contraptions that you can build to extract tiny animals from soil samples (I’m busy building one now to check off that bucket list). Although microwhipscorpions probably occur through much of the U.S., there is very little data on these enigmatic creatures.

Our final two orders will require travel to the Lower Rio Grande Valley, and they’ll be your biggest challenges. But to find out what they are, you’ll have to wait until next week, for the Texas Arachno-Challenge III.