Thursday, October 17, 2013

October Lab Update

It has been a busy few weeks in the lab.  It seems as though the month of October is flying by very quickly.

So, here's what we have been up to:


Early in the month, Dr. Robin Verble highlighted lab research on the West Texas Ag Life radio show.  Of particular focus were the prescribed burning program and horned lizard research.  Then, she attended the Texas Section Society for Range Management meeting last week in Fort Worth , Texas.  It was a great opportunity to meet local ranchers, researchers, and agency employees that are excited about fire use for rangeland management.  She also took home first place in the wildlife photo contest with this photo of a Texas horned lizard near Sonora, Texas:

(C) Robin M. Verble-Pearson 2013

Dr. Verble was also recently appointed as the director of the Texas Tech Center for Fire Ecology.  Expect more on this soon, as plans for the Center develop.

Anna Meyer has been studying epiphytes in the British Virgin Islands as part of her Tropical Ecology course, and Nick Goforth is rapidly wrapping up his field season in the Jemez Mountains of New Mexico.

Rachel Granberg presented a poster to the GIS in the Rockies conference in Denver, Colorado.  This poster highlighted her work with horned lizard home ranges and habitat suitability mapping.


Rachel's poster (C) Verble Fire Ecology Lab 2013

Rachel in Denver

The rest of the month promises to be just as eventful, so we will keep you posted!



Tuesday, October 1, 2013

Guest Blog-- Anna Meyer

My graduate students have all been hard at work on their thesis projects this summer.  To highlight their work, I have asked them to participate as guest bloggers and tell us a little bit about their work.  Today's guest blogger is Anna Meyer.  Anna is working on an M.S. in Natural Resources Management at Texas Tech University.  Her project examines ant abundance and density, particularly in the context of horned lizard declines.  Below, she shares some of his recent field experiences.  


            “I haven’t seen a horny toad in a dog’s years!” –Probably one of the top five phrases I’ve heard this summer (I would say ‘watch out for snakes!” won by a slim margin).  I’m not entirely sure how many years this means as it doesn’t seem to be a standardized measure, nor am I sure how dog years translate to lizard years, but the point is fairly clear: “I haven’t seen a horned lizard in a long time”.

Fig.1-An Interpretation of ‘Lizard Years’, an image from the short film “Where did the Horny Toad Go?”, by ‘Jar of Grasshoppers’ (to see more visit http://jarofgrasshoppers.com/category/horny-toad/)

I spent this summer at three properties in Central Texas tracking Texas horned lizards (Phrynosoma cornutum) and surveying ants.  My surveys focus on harvester ants and red imported fire ants (RIFA), two types of ants implicated in the continuing decline of the Texas horned lizard (THL).  I have been attempting to estimate, roughly, how many colonies of these ants are at each site.  Of the many factors that are implicated in the decline of the THL, the RIFA invasion is a very popular one.  I’ve had many people tell me: “The horned lizards are decreasing because of the fire ants.  We didn’t used to have those around here.”


Fig.2-The general range of the RIFA or ‘around here’.  (Image from ars.usda.gov)
 These blissful RIFA-free days were likely before my time.  RIFA (Solenopsis invicta) have been spreading across the Southeast United States since they were introduced in the early 1900s.   Finding themselves in a new ecosystem without predators, they quickly took advantage of the opportunity and were off, starting in Alabama and following Manifest Destiny westward.  These tiny pioneers are now occupying Central Texas, and are populating our field sites, to great consternation.  Despite the controversy surrounding RIFA, I found them less interesting than the other ant group I was studying: red harvester ants.
        
Fig.3-The red harvester ant, Pogonomyrmex barbatus. (C) Anna Meyer 2013
  Red harvester ants are a distinctive ant that are a primary component of the horned lizard diet, and I had great fun collecting these and mark-recapturing them.  Aside from the lizard tracking, this was probably the best part of my summer.  One of my tasks was to capture harvester ants and mark them with tiny dots of bright nail polish.  They showed little distress after being marked (although they displayed great rage during the marking process), and it was amusing to see 100 harvesters with silver gasters going about collecting seeds, determined to carry out their work.  After this eventful summer, I am back at school and I too am going about carrying out my work.  At the moment I’m prepping samples so that I have even more data about these charismatic ants and their importance to the ecosystem, before departing for another interesting field season next summer.


Fig.4-Red harvester ants while ‘marks’ are drying.  (C) Anna Meyer 2013 
Fig.5-Juvenile THL at Blue Mountain Peak Ranch (C) Anna Meyer 2013
 I end here with some pictures from a lively field season: Our field sites were amazing and I was very grateful for the opportunity to use them.  Along with ants and lizards, the sites sheltered a variety of wildlife: painted buntings, vermillion flycatchers, scissor-tailed flycatchers, great blue herons, vultures, bobwhite quail (and supposedly Montezuma quail), foxes, mountain lions, axis and white tailed deer, and many many more birds, plants, animals, and insects.  And most importantly of all (to us), at least one site had several THL!


Fig 6-- Juvenile THL during measuring process (C) Anna Meyer 2013

Fig 7- Juvenile male THL who grazed from the harvester ants I was observing and stayed in my plot for roughly two hours. (C) Anna Meyer 2013

Fig 8-- Unidentified scarab beetle at Camp Bowie (C) Anna Meyer 2013

Fig 9-- Dung rollers at BMPR (C) Anna Meyer 2013

Fig 10-- Female THL with radio transmitter who buried herself in the late morning as temperatures increased. (C) Anna Meyer 2013 


Fig 11-- Tarantula hawk (Pepsi spp.) at a ranch (C) Anna Meyer 2013

Fig 12-Tarantula (Aphonopelma spp.?) at BMR (C) Anna Meyer 2013