Pantex Blog
Wild Pantex – Partnering in Prairie Dog Research
Article by Jim Ray, Pantex Wildlife Biologist/Scientist
A lot of data has been gathered on black-tailed prairie dogs and associated species at Pantex. This has involved Pantex Natural Resources staff, Texas Tech University’s Natural Resources Management Department, U. S. Geological Survey’s Texas Cooperative Fish and Wildlife Research Unit at Texas Tech, and the Texas Parks and Wildlife Department. As with the burrowing owl work (previously discussed), resources contributed through those external entities allowed inclusion of study sites from across the Southern High Plains of Texas for some of the objectives.
Upon examining aerial photographs, and following-up with ground-truthing, we found that the slopes above playa wetlands were very important to black-tailed prairie dogs in our region. Plain and simple, these slopes often escape plowing and thus hold remnant patches of prairie for prairie dogs and other wildlife species.
Estimates of black-tailed prairie dogs derived from procedures published by the Rocky Mountain National Arsenal were made in prairie dog colonies by Pantex staff, annually, during 2000-2003. Concurrently, Texas Tech conducted counts, while developing a model that considered date, time, temperature, and the number of prairie dogs observed. While, population estimates were very similar between the original method and the outcome of the new model, the model allows collection of the necessary data in far less time. This reduces the amount of time that busy biologists have to spend in the field conducting counts.
Through the use of grids of live traps we found that abundance of small mammals was similar between grasslands not occupied by prairie dogs, areas where prairie dogs were recently eradicated, and in active prairie dog colonies. However, in looking at individual species, two different graduate students found that the northern grasshopper mouse (Onychomys leucogaster) was more abundant in prairie dog colonies than at sites without prairie dogs. One of the graduate students found that the hispid pocket mouse (Chaetodipus hispidus) and harvest mouse (Reithrodontomys spp.) were more abundant on sites not occupied by prairie dogs.
Among birds, and certainly expected, western burrowing owls (Athene cunicuaria) were most abundant in study plots within active prairie dog colonies. However, the diversity of bird species was similar in areas with and without prairie dogs. One graduate student found that our summer resident bird species were most abundant in active prairie dog colonies, while migrant species were more abundant in plots without prairie dogs. Cassin’s sparrows (Aimophila cassinnii) and lark buntings (Calamospiza melanocorus) were most abundant on active colonies, while abundances of red-winged blackbirds (Agelaius phoenicerus), horned larks (Eremophila alpestris), chipping sparrows (Spizella passerina), and foraging barn swallows (Hirundo rustica) were higher on non-colonized sites.
Our data indicate that ground-dwelling insects were more abundant in active prairie dog colonies than in shortgrass prairie not occupied by prairie dogs. Although the abundance of amphibians did not differ statistically between active colonies and unoccupied grassland, the number captured in active colonies was three times higher than what was found in the absence of prairie dogs.
The collaboration on prairie dogs with Tech has involved several students and resulted in two M.S. theses (McCaffrey 2001, Pruett 2004). To date, four peer-reviewed scientific publications (prairie vole, small mammals/invertebrates, prairie dogs, small mammals) have resulted from the work. Eight presentations on the work have been made at state, national, and international conferences, and even more at meetings characterized as less technical in nature.
Mapping of prairie dog colonies at Pantex is an annual management activity. In fact, mapping of the colonies dates back to at least 1996, making it perhaps the longest-running colony monitoring program for the species in the region.
Photo: This is a herp array, which are used to sample amphibians, reptiles and ground-dwelling insects. These creatures fall into buckets that are buried at the end of each "wing," including the center.
Wild Pantex – A Tribute to the Eastside Girl
Article by Jim Ray, Pantex Wildlife Biologist/Scientist
Normally, I would not write what looks like an obituary for one of my study animals. Having worked in this profession for more than 24 years I have seen study animals come and go and have worked die-offs, where victims number into the thousands. Nor do I normally name animals, unless it is a band number, or perhaps an ear tag color-combination. Like many of my colleagues, I’m more of a “populations” kind of guy, than becoming focused on individuals.
However, I am going to pay tribute to the Pantex Eastside Female bobcat for two reasons. First off, in our minds she had become the wildlife matriarch of Pantex, of sorts – our mascot. Secondly, several people have asked me to send her off in style in this public blog. So here goes…
On Sunday, January 20, a power-outage led to the discovery that our original female bobcat had been electrocuted after, evidently, climbing to the top of a power pole. There is no telling why she climbed the pole – perhaps to avoid a coyote or harassment from a male bobcat. I can only guess.
Eastside Girl showed up in 2006 as the first bobcat ever documented at Pantex. Because her home range comprised the developed area of the Plant, and she was somewhat comfortable with on-lookers, she and her annual litters became popular with Pantex employees. She was a beautiful cat and many of her litters spent considerable time just outside the backdoor of one of our main buildings. When we began our bobcat project with West Texas A&M University in 2009, we caught her on the very first night of trapping! Her red and yellow ear tags differentiated her from the dozens of other cats that we would catch and mark over the years. Once I got a feel for her home range, I coined the nickname, the Eastside Girl.
When people would call me about her, most guessed her weight to be around 40 pounds. However, having captured her three times, I know that she officially weighed in at 20, 20, and 21 pounds - a big, healthy Southern Great Plains' female bobcat!
I have two great memories of the Eastside Girl – well two that don’t involve her captures. And there were many neat observations of her with her kittens. One memory involves watching her go over a tall chain link fence. She would just jump up to the top, sometimes briefly connecting with the middle of the fence on the way up. Then, she would back down the other side like a bear backing down a tree.
The other happens to have involved kittens. I was radio-tracking Eastside Girl and when I came across her, I turned the engine off so that I could initiate a download of her GPS collar’s data. I can do that with my laptop computer.
I soon noticed that I had parked between her and her two kittens. I could tell the kittens wanted to join mama; they were coming towards me, but suddenly Eastside Girl let out a loud bird-like “coo.” This was a sound I would have never guessed to have come from a cat if I hadn’t been right there watching. Immediately, the two kittens stopped their progress and laid down flat on the ground. Mama’s words of “stay put” or “hide” meant business and the kittens complied.
According to Lena Thurmond, the West Texas A&M graduate student who is wrapping up her thesis work on the bobcats on and around Pantex, the three GPS collars that the Eastside Girl wore over the years recorded approximately 4,486 GPS locations while delineating a home range of 24 square miles. This gal rarely crossed highways so was truly, pretty much, a Pantex bobcat.
The Eastside Girl is gone, but all indications from our work point to the rapid re-occupancy of home ranges, once vacated – there will be a replacement. Will it be one of her daughters? Time will tell.
Dignitaries Make Mark on Pantex Renewable Energy Project
U.S. Congressman Mac Thornberry joined local dignitaries and other visitors gathered at the Pantex Plant Thursday to make their mark on an important wind project at the Plant. The visitors joined NNSA Production Office and B&W Pantex leaders, as well as representatives from project contractor Siemens Government Technologies Inc., in signing one of the massive wind turbine blades that will become part of the Pantex Renewable Energy Project (PREP). When it is complete this spring, PREP will be the largest federally owned wind farm in the U.S. and will provide more than 60 percent of the annual electricity needs for the Plant.
The ceremony provided stakeholders an opportunity to receive an update on the project, as well as get a close-up look at the wind turbines that make up the project. Each blade weights 11 tons and is more than 150 feet long. When completed, the towers will stand over 400 feet tall at the blade tips.
Elected officials visiting the Plant included Thornberry, Texas State Sen. Kel Seliger, Texas State Legislator Four Price, Amarillo Mayor Paul Harpole and Carson County Judge Lewis Powers.
Wild Pantex – Partnering for Burrowing Owls
Article by Jim Ray, Pantex Wildlife Biologist/Scientist
Research on Western Burrowing Owls has been a major part of the body of wildlife research that has taken place over the last 14 years at Pantex. Much data has been produced through a collaboration that involved the Pantex Natural Resources staff, Texas Tech University’s departments of Biological Sciences and Natural Resources Management, and the U. S. Geological Survey’s Texas Cooperative Fish and Wildlife Research Unit at Texas Tech. Thanks to resources contributed through those external entities much of this work included study sites scattered across the Southern High Plains of Texas, thus increasing the value of the data through the scale of the research effort.
Initially, Burrowing Owls were counted by Pantex staff in conjunction with prairie dog population surveys derived from procedures conducted and published by the Rocky Mountain National Arsenal (2000-2003). Then, from 2003-2005 Pantex contracted with Texas Tech staff to study the ecology of these owls.
The density of breeding Burrowing Owls at Pantex was similar to other sites across the region, and the bigger the prairie dog colony and the more holes that were available, the more Burrowing Owls we found. Although sometimes observed in other burrow types in the Great Plains, during this study we found no Burrowing Owl nests in study plots that were outside prairie dog colonies.
Each owl pair at Pantex fledged just shy of three young per year during the study. Local prey availability, vegetation measurements, nor density of prairie dogs had any effect on density of owls or their ability to fledge young at a location. Most of the Burrowing Owls that we captured and banded during the breeding season migrated away from the region for the winter months.
We found that these owls can fare as well in close association with man, as in more rural settings. More vertebrate prey, like mice and amphibians, were taken as food at rural sites, whereas invertebrates, like insects, were taken in greater abundance in situations where the birds were nesting near human activity.
We also studied whether or not necklace-style radio transmitters could be safely worn by Burrowing Owls for research purposes. It was found that the necklaces should be used with caution, perhaps with further modifications and evaluations, as both wild and captive owls initially spent considerable time focused on the necklace instead of watching for potential predators. However, the owls habituated to the necklaces relatively quickly, and survival was not affected.
The collaboration on Burrowing Owls with Tech has involved several students and resulted in two M.S. theses (Teaschner 2005, Chipman 2006). To date, two peer-reviewed scientific publications (radio-necklaces, land-use) have resulted from the work, and a popular article has recently been accepted to be published in Bird Watcher's Digest. Seven presentations on the work have been made at state, national, and international conferences, and even more at meetings characterized as less technical in nature.
Today, West Texas A&M University collaborators collect bird data in plots within prairie dog colonies at Pantex in association with wind energy research, thus monitoring of Burrowing Owls continues at Pantex. Mapping of prairie dog colonies is an annual management activity, thus Burrowing Owl habitat availability is monitored.
Wild Pantex – Burrowing Owls
Article by Jim Ray, Pantex Wildlife Biologist/Scientist
This week I have a guest blogger, one that we have collaborated with on burrowing owl research. I will follow this up next week with more information on the research project itself.
Nancy McIntyre is Professor of Biological Sciences and Curator of Birds at Texas Tech University. She writes:
"Burrowing Owls are easy to overlook, especially when you’re traveling 55+ miles per hour. My first encounter with a Burrowing Owl was along a lonely prairie road in eastern Colorado, now 20 years ago. Recently transplanted from Georgia, I was traveling from point A to point B and marveling at the utter lack of trees, when a black-tailed prairie dog crossed the road in from of me. I slowed and realized that the road cut through an enormous prairie dog colony. Slowing further, I spotted a dumpy bird that flew from the ground to a fence post. I pulled abreast of the post, stopped, and beheld my first Burrowing Owl. I took a pair of binoculars from my glove compartment and focused them on the little guy's facial expression; one that was at once both cute and ornery. Yellow eyes glared at me with real menace, but given that their owner was less than nine inches tall, I couldn’t help but laugh out loud at the absurdity. Thus began my love affair with Burrowing Owls.
Burrowing Owls are among the most accessible owls in the world because they are diurnal and often live near human settlements. These traits are at odds with the typically secretive, nocturnal habits of other owls. Indeed, many Texans may see Burrowing Owls on a daily basis throughout much of the year and yet may never see another type of owl in their entire lives. However, many more Texans are unaware of the existence of owls so close by. Collaborations between Texas Tech University and Pantex have contributed to our understanding of their reproduction, behaviors, and habitat associations.
Burrowing Owls occur from Canada to the southern tip of South America, but they are not equally abundant over all of these regions. They are absent from forested areas, being birds of the wide open spaces of prairie and desert. And the owls do not occur in all portions of their range throughout the year: like most birds, they are migratory. Most Burrowing Owl individuals will migrate away from their summer breeding area to an overwintering location. For example, some owls that breed in Canada overwinter along the Texas coast. Burrowing Owls are primarily summer residents at Pantex, one of numerous breeding bird species that occur at the site. However, a few burrowing owls from points north can be found at Pantex during the winter.
Burrowing Owls rely upon other species to dig their burrows. Over much of the owls’ range, the primary burrow providers are black-tailed prairie dogs, which are too large to be owl prey. These colonial rodents live in “towns” of family groups in numerous burrows. Different burrows have different uses: some are nurseries whereas others are used as latrines. Many burrows may be unoccupied because of death or abandonment by residents. These empty burrows may be colonized by Burrowing Owls, where they raise 2-4 chicks, primarily on a diet of insects and small vertebrates like mice.
Listed as endangered in Canada and threatened in Mexico, the Burrowing Owl is a species of concern in the U.S. Burrowing Owls are disappearing from areas where they once occurred and are declining in most areas where they remain, primarily due to conversion of habitat for agriculture and urbanization, and especially to declines in prairie dog numbers. Construction of artificial burrows, protection of nesting sites during reproduction, and promoting appreciation of prairies and deserts and all their inhabitants will hopefully prevent our grandchildren from learning about Burrowing Owls in the same breath as the Dodo or Carolina Parakeet. These two species are no longer with us."
Photo: Dr. Nancy McIntyre and a burrowing owl.