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Friday, August 14, 2015

Surveying for legless lizards on Tejon Ranch to determine the conservation status of newly described species, By Dr. James Parham, California State University, Fullerton

Closeup of a California Legless Lizard, in this case one of the newly described species from the San Joaquin Valley (Anniella grinnelli). Photo by James Parham.

I first learned about Tejon Ranch in the context of being an important site for early California naturalists (such as John Xántus, See blog post here) and a still large, contiguous, undeveloped property within our beautiful, but crowded, state. At that time, access to Tejon Ranch was limited, which added to mystery to its appeal. For all of these reasons, I consider myself fortunate to be starting (since last year) a research project on Tejon Ranch to study the distribution of California Legless Lizards.

Legless lizards are slow-moving, worm-like reptiles that are rarely encountered by people. In fact, I know many field herpetologists in California have never seen a legless lizard in nature. This is because, unlike other lizards in California, legless lizards are fossorial (burrowing). Therefore, you either have to be lucky, or else actively search for them in order to find one. Perhaps because they are relatively hard to find, they remain one of the more poorly studied reptiles in North America.

Example of a California Legless Lizard, in this case one of the newly described species from the San Joaquin Valley (Anniella grinnelli). Photo by Alex Krohn.

 The story of my involvement with studying legless lizards started in 2000, when I collaborated with Ted Papenfuss of the Museum of Vertebrate Zoology, UC Berkeley, to study their genetics. At that time, the California legless lizard was a single wide-ranging species (Anniella pulchra), known from south of the Sacramento River Delta to Baja California. With another species, the Baja California Legless Lizard (Anniella geronimensis) restricted to sand dunes in Baja California.

The known distribution of Anniella species prior to
  the description of four new species in 2013. 
Source: IUCN Red List.
At that time, studies of the genetics and morphology of other Californian small vertebrates were showing that species as wide ranging as Anniella pulchra were actually made up of multiple species. Because California Legless Lizards are fossorial it means they are restricted to certain habitats (e.g., sandy soils, leaf litter), it seemed highly likely that they would be very susceptible to whatever physical processes and barriers were driving speciation in other small vertebrates. The initial idea for the project was simple, get samples from different parts of the range and compare their morphology and genetics. So we set out to collect new samples, and also put out the word to our colleagues throughout the state. We figured that there was probably a new species of Anniella to be described, and that maybe we would end up dividing A. pulchra into two species.

In the process of collecting samples, Dr. David Germano (Cal State Bakersfield) alerted us to some funny-looking Anniella from the San Joaquin Valley (SJV). These specimens lacked the typical yellow belly, and instead had silvery or purplish bellies. Anniella bellies do have some amount of variation, the yellow can be faint giving the belly a silvery or pinkish hue and juveniles in particular can be washed out. But in these specimens the purple or silver color was very pronounced in adults, and consistent upon further sampling of specimens in the same area. Then, in an exciting development, our genetic investigations showed a direct correspondence between these color variations and the deep genetic differences. The more data we collected, counting scales under a microscope and bones from x-rays, the more consistent differences were reinforced for the weird-colored samples from the SJV. We were also able to show that yellow-bellied samples from the Southern Sierra Nevada and Southern California were also genetically distinct, although with less obvious or even non-observable coloration differences. After years of collecting, we published two papers, a genetic study (Parham and Papenfuss, 2009) and then the description of four new species (Papenfuss and Parham, 2013; See press release here, see Anderson Cooper’s snarky comments here).

This image shows the characteristic belly coloration of three of the four new species. Top (purple, Bakersfield Legless Lizard). Middle (gray, Temblor Legless Lizard). Bottom (yellow, Southern California Legless Lizard). Note that the yellow coloration is also characteristic of the Southern Sierra and Northern California Legless Lizards. Modified from Papenfuss and Parham (2013, Fig. 3)
But the description of new species is just the beginning of their scientific history, and over the past few years we have been working to answer the next questions. For example, If we expand our genetic data with more DNA from more samples, does it support our findings? (the answer is yes, these species are well supported). The most pressing questions include: Can we better determine the geographic distributions of the new species? Which species occur in protected areas (such as Tejon Ranch and other ecological reserves)? The fact that some of the new species have such restricted ranges raises important questions about their conservation status. In particular, the ranges of the two distinctly colored species are almost entirely restricted to the SJV, an area that is highly modified by agricultural development and home to other rare and threatened plants and animals such as the Bakersfield Cactus and the San Joaquin Kit Fox. A telling comparison is that these both species are found within a fraction of the range of the Endangered Blunt-Nosed Leopard Lizard (Gambelia sila).

Map showing the distribution of two of the four new legless lizard species are entirely within the historic range of the Endangered Blunt-Nosed Leopard Lizard (Gambelia sila). Purple: Bakersfield Legless Lizard. White: Temblor Legless Lizard. Gambelia photo by Sarah Rieboldt.
In an effort to better understand where different species of legless lizards species occur in the SJV, we focus our search efforts to areas where no specimens have been previously collected, or where there are no genetic samples. Which begs the question, how does one find a legless lizard? One of the main ways that people encounter them is when they are gardening, i.e., moving soil and debris, and it is possible in some parts of California to find them by raking under leaf litter. Some people also find them under objects, such as boards or even garbage that can maintain a moist microclimate. Using the second observation, we have been successful using a system of cover objects (“Anniella boards”) for the past 15 years. Anniella boards can be made of wood, fashioned cardboard (broken down boxes, taped and glued), or roofing material. We establish a site by placing 10-50 (usually 10-20) of these boards in areas where we think Anniella may occur. At the present time, we have over 1,000 Anniella boards in central California, especially in the San Joaquin Valley. We usually establish sites in the summer and fall so they can be seasoned by rain in the winter and then checked in the spring. It can take years to get an Anniella. In fact one site that we established in 2004 gave up its first Anniella this year- two individuals under one board -which means we checked it unsuccessfully, every year, for 10 years.

Mike White (Tejon Ranch Conservancy Science Director) helps install an Anniella board near Tejon Creek in 2014. Photo by James Parham

Screen capture of GoogleEarth map showing tracks for some of the fieldwork we did in Central California in 2014 and 2015.

Image of the San Joaquin valley. Source: Public Domain.
Which brings us to the significance of Tejon Ranch for our study. Tejon Ranch occupies a central position within the Southern SJV, equidistant from all known sites of legless lizards. In other words, this large contiguous property of undeveloped land is in the middle of our gap in understanding. By studying what species occur where on Tejon Ranch, we can fill some of the largest gaps in our knowledge about the distribution and potential contact zones of up to four of the five species. The SJV is highly modified by extensive agriculture that has destroyed most Anniella habitat within the SJV. Urban development is also an issue, and some areas where legless lizards were once known have been turned into housing developments.

Known range of California Legless Lizards Right: Detailed map of Central California showing the uncertain distribution of the new species, especially in the southern San Joaquin Valley. Modified and updated from Papenfuss and Parham (2013, Fig. 1).

Isaac Magallanes (Cal State Fullerton student) surveys for a good place to put
 Anniella boards on Tejon Ranch near Tejon Creek in March of tis year. Photo by James Parham.
In 2014 and 2015, funded by small internal grants and startup funds from my position as an assistant professor at Cal State Fullerton, my students, colleagues, and I have intensified our efforts within Kern County, including setting up five sites within Tejon Ranch in 2014. Checking these sites in 2015 yielded one juvenile specimen of uncertain identity (the young can have washed out belly color) that we still need to test genetically. That sample is from Tejon Creek, near the center of Tejon Ranch in the foothills of the Tehachapi. On the eastern side of Tejon Ranch we have sites in the Caliente Creek, a drainage that we already know has three different species of Anniella at different elevations, and our best chance for finding an area where two species may contact. We have two within four miles of each other, which is the closest we have samples of two different species anywhere in California.

Anniella habitat on Tejon Ranch near Caliente Creek. This drainage is important because our research has shown that this drainage includes three different species of Anniella at different elevations, and our best chance for finding an area where two species may contact. Photo by James Parham.
With boards in place and and predicted end of the drought, we feel confident that over the next few years we will be able to learn a lot about what species live in what parts of Tejon Ranch and other sites within the SJV. Our work will be enhanced by a recently announced State Wildlife Grant, that has been awarded to our newly expanded working group including myself (Cal State Fullerton), Erin Tennant (California Department of Fish and Wildlife Region 4 Lands Program), and Brian Simison (Center for Comparative Genomics, California Academy of Sciences) as Co-Pis, along with collaborators Ted Papenfuss (UC Berkeley), Michael Westphal (Bureau of Land Management, Hollister), and Amy Kurtisubo (Bureau of Land Management, Bakersfield). And also including many others including Mike White (Conservation Science Director, Tejon Ranch Conservancy) and numerous land and property owners/managers.

Erin Tennant (California Department of Fish and Wildlife) with an Anniella pulchra at 
the Yaudanchi Ecological Reserve, Tulare County. Photo by James Parham.
The purpose of the State Wildlife Grant is to perform fieldwork and genetic analyses to further define the distribution and conservation status of the four newly discovered species of Anniella. New distributional data discovered as part of this project will be combined with those from museum records to provide a range-wide analysis of the species’ status and occurrence on protected lands, such as ecological reserves managed by the California Department of Fish and Wildlife, Tejon Ranch, and others. Given the modest ideas for this project early on, it is amazing to see how it has grown in size and scope. In 2000, I could not have imagined that 15 years later I would still be studying Anniella and visiting Tejon Ranch. I am looking forward to the next field season.

Literature Cited

Papenfuss, T.J., and J.F. Parham. 2013. Four new species of California legless lizards (Anniella). Breviora 536:1-7.

Parham, J.F., and T.J. Papenfuss. 2009. Evidence for high genetic diversity among fossorial lizard populations (Anniella pulchra) in a rapidly developing landscape (Central California). Conservation Genetics 10(1):169-176.