SWCHR BULLETINVolume 2, Issue 4 Winter 2012

Conservation - Preservation - Education - Public InformationResearch - Field Studies - Captive Propagation

ISSN 2330-6025

OFFICERS 2010-2012

PRESIDENTTom Lott

VICE PRESIDENTTodd Hughes

INTERIM SECRETARYSara Lott

EXECUTIVE DIRECTORGerald Keown

BOARD MEMBERSToby Brock, Hans Koenig

BULLETIN EDITORChris McMartin

ABOUT SWCHR

Originally founded by Gerald Keown in 2007, SWCHR is a 501(c)(3) non-profit association, governed by a board of directors and dedicated to promoting education of the Association’s members and the general public relating to the natural history, biology, tax-onomy, conservation and preservation needs, field studies, and captive propagation of the herpetofauna indigenous to the Ameri-can Southwest.

THE SWCHR LOGO

There are several versions of the SWCHR logo, all featuring the Gray-Banded Kingsnake (Lampropeltis alterna), a widely-recognized reptile native to the Trans-Pecos region of Texas as well as adjacent Mexico and New Mexico.

ON THE COVER: Speckled Kingsnake, Lampropeltis getula holbrooki, Brazoria County, TX (Matt Hollanders). This photograph was voted the winner of the 2011 SWCHR Award for Excellence in Herpetological Photography.

BACKGROUND IMAGE: Elephant Tusk, Big Bend National Park, TX (Chris McMartin)

COMMITTEE CHAIRS

COMMITTEE ON COMMON AND SCIENTIFIC NAMESTom Lott

RANGE MAP COMMITTEETom Lott

AWARDS AND GRANTS COMMITTEE(vacant)

COMMUNICATIONS COMMITEEGerald Keown

ACTIVITIES AND EVENTS COMMITTEE(vacant)

NOMINATIONS COMMITTEEGerald Keown

EDUCATION COMMITTEESara Lott

MEMBERSHIP COMMITTEEToby Brock

CONSERVATION COMMITTEE(vacant)

JOINING SWCHR

For information on becoming a member please visit the member-ship page of the SWCHR web site at

http://www.southwesternherp.com/join.html.

©2012 Southwestern Center for Herpetological Research. The SWCHR Bul-letin may not be reproduced in whole or in part on any web site or in any other publication without the prior explicit written consent of the Southwestern Center for Herpetological Research and of the respective author(s) and photographer(s).

The SWCHR BULLETIN is published quarterly by the SOUTHWESTERN CENTER FOR HERPETOLOGICAL RESEARCH

PO Box 624, Seguin TX 78156www.southwesternherp.com

email: admin@swchr.orgISSN 2330-6025

SWCHR Bulletin Winter 20121

A CALL FOR PAPERS

Are you a field herpetologist or a herpetoculturist working with species native to the American Southwest? Do you have a paper or an article you have written for which you would like to find a permanent repository? Want to be assured you will always be able to share it with the world? Submit it to the SWCHR Bulletin for possible publication. Submitted manuscripts from SWCHR members, as well as non-members, will be considered.

To be accepted for publication, submissions must deal with herpetological species native to the American Southwest. Such topics as field notes, county checklists, range extensions, taxonomy, reproduction and breeding, diseases, snake bite and venom research, captive breeding and maintenance, conservation issues, legal issues, etc. are all acceptable. For assistance with formatting manuscripts, search ‘scientific journal article format’ on the internet and tailor the resultant guidance to suit.

Previously published articles or papers are acceptable, provided you still hold the copyright to the work and have the right to re-publish it. If we accept your paper or article for publication, you will still continue to be the copyright holder. If your submission has been previously published, please provide the name of the publication in which it appeared along with the date of publication. All submissions should be manually proofed in addition to being spell checked and should be submitted by email as either Microsoft Word or text documents.

Send submissions to swchrbulletin@swchr.org.

TABLE OF CONTENTS

A Message from the President, Tom Lott

Natural History Observations of the Anguid Lizard Gerrhonotus infernalis (Baird, 1859)in Travis County, Texas (Lacertilia: Anguidae), Philip Ralidis and Edward Acuna

Feeding Observations of Captive Regal Ringneck Snakes, Diadophis punctatus regalis (Serpentes: Colubridae), Andy O’Connor

Notes on Natural History and Captive Maintenance of the Texas Horned Lizard, Phrynosoma cornutum (Lacertilia: Phrynosomatidae), Lou Hamby

Book Review: A Field Guide to Oklahoma’s Amphibians and Reptiles, Chris McMartin

2

3

6

8

11

SWCHR Bulletin Winter 20122

A Message from the President

All in all 2012 was a good year for SWCHR. In only our fifth year of existence we have gradually gained in prominence and stature, becoming an accepted and respected resource for all things herpetological in the southwestern region. Our participation in the Sanderson “Snake Days” event in June as well as the first ever National Reptile and Amphibian Law Symposium in Houston in September are but examples of the kind of involvement we hope to expand upon in the coming years. I extend my personal thanks, as well as those of the membership, to those who made our participation in these events possible.

The SWCHR Bulletin also, with this issue completing only its second year, has become the kind of publication many of us feel is needed in the avocation, filling the virtually-unoccupied niche between the sometimes excessively technical (and dry) national herp journals and the frequently too chatty and cliquish local herp society publications. Despite sluggish and even desultory submission rates, our Editor, Chris McMartin, has managed to shepherd this journal into a respectable contribution to the herpetological literature, publishing unique, pertinent articles that would be largely unavailable elsewhere. I extend our collective thanks to Chris for his efforts on our behalf.

I would also thank our founder and Executive Director, Gerald Keown, for all of the herculean efforts he puts forth to keep the organization running smoothly from day to day, serving as the public face of SWCHR, as well as wearing many different hats throughout the year.

And finally, I would like to thank our membership for its continued financial and moral support and, once again, to encourage all of you to become active participants by posting on the forums, volunteering to serve on committees, submitting articles for publication in the Bulletin, submitting photos for the species accounts , etc.

I hope everyone enjoys a great Holiday Season and that 2013 is an even better year!

Happy herping,

SWCHR Bulletin Winter 20123

Natural History Observations of the Anguid Lizard Gerrhonotus infernalis (Baird ,1859) inTravis County, Texas (Lacertilia: Anguidae)

by Philip Ralidis and Edward Acuna

Abstract: Observations of the Texas alligator lizard over a nine year period in Travis County have revealed strong seasonal patterns of arboreal and saxicolous behavior. Extreme crypsis may account for a markedly attenuated flight response. Utilization of arboreal pathways between limestone karst retreats and favored basking sites presumably reduces exposure to terrestrial predators, and preference for dense understory a reduction in avian predation. Although common in suitable habitat in the study area, these attributes account for relatively infrequent sightings even by experienced field personnel, and allow persistence of stable populations in a rapidly expanding urban area.

The Texas alligator lizard, Gerrhonotus infernalis, is the northernmost representative in this genus of five species (Good, 1994). It is the second largest native saurian in Texas, with the maximum recorded standard length (snout-vent) of 8 inches (20 cm) exceeded only by the anguid Ophisaurus attenuatus. Despite its large size and distinctive patterning, it can be a frustrating species to find with any regularity; most anecdotal reports from local herpetologists and enthusiasts describe sporadic, even accidental, encounters despite significant time in habitat. Our observations between the years 2002 - 2010 at two study sites in the Barton Creek greenbelt of Austin, Texas belie presumptions of essentially terrestrial behavior that hold true for Elgaria of the western United States. Average annual records of 25 lizards combined with multiple sightings of individuals in any given season has resulted in more than 400 separate encounters during the study period.

Texas Alligator Lizard, Gerrhonotus infernalis, from Travis County, TX. Photo by John Williams.

As initially fortuitous encounters with Gerrhonotus evolved into an increasingly intimate knowledge of its habits and predictable activity patterns, the unique adaptation of their physiologic, morphologic, and behavioral attributes to the specific habitat parameters of the Travis County greenbelt became more apparent. Conversations

with colleagues studying this species in other parts of their range, and comparisons with published and anecdotal accounts in more xeric localities lead us to suspect that some of the behavioral patterns seen in our populations may be particular to mesic Hill Country habitats.

These cumulative observations focus on three aspects of Gerrhonotus biology: extensive arboreality, extreme cryptosis with marked attenuation of flight response, and survival in the rapidly expanding metropolis of Austin. Our perception of stable study site populations despite increasing human protrusion into habitat supports this species’ at least temporary success in meeting these challenges. Study Sites

Gerrhonotus infernalis inhabits a variety of habitats in an arc-like distribution from the comparatively mesic juniper and oak dominated Hill Country region of Travis County at the easternmost extension of its range (Fayette County contains populations within an isolated Hill Country geological and floral community some 60 miles east) to xeric Chihuahuan Desert in Val Verde and Terrell Counties, the Chisos Mountains of Big Bend National Park, and southward in Mexico to San Luis Potosi. Our two study sites reside in the Barton Creek greenbelt within Austin, Texas city limits. Barton Creek is semi-permanent and runs 41 miles before emptying into the Colorado River. Austin is c.620 feet above sea level, receives an average annual rainfall of 33 inches, and is situated on the Edwards Aquifer, a huge porous limestone reservoir at the easternmost edge of the Edwards Plateau that runs south to San Antonio. Considerable seasonal and cyclical variation in precipitation for any particular month in successive years may result in a completely dry creek bed, or one so inundated as to support rafting.

Our two study sites inside the Barton Creek greenbelt are within several miles of each other. Gerrhonotus reside in favorable habitat along much of the contiguous trail, but certain stretches contain much higher lizard densities affording consistent observation. Our initial perception of overabundant habitat became attuned to specific microhabitat features correlated with frequent sightings. Nonetheless, we believe our bias towards favored observation sites has precluded more extensive exploration of other greenbelt sections that are probably just as supportive.

Niche Tree communities are dominated by various species of oak (Quercus sp.) and the ubiquitous juniper (Juniperus sp.), known locally as cedar. We have very few observations of Gerrhonotus on cedar, and suspect the oils and resins it contains to be noxious to them. The abundance of herbaceous undergrowth (Nandina and Legustrum sp.) allows these lizards to bask in preferred dappled sunlight, where their cryptic coloration makes them difficult to detect. The proximity of extensive limestone karst outcrops with innumerable fissures, and the relatively undisturbed microhabitat combine to make these study sites especially productive. The typically gentle downslope of extensive rock outcrops to the adjoining trail allows

SWCHR Bulletin Winter 20124

for adequate soil drainage; Gerrhonotus is not a riparian species.

Gerrhonotus displays a definite bimodal seasonal activity pattern in Travis County, with peak activity occurring during late September through mid November, followed closely by March through late May.

The fall peak correlates with breeding, and pairs are sometimes found in close proximity at this time (we have witnessed apparent courting behavior, but not actual copulation). Gravid females can be found with some regularity in late March/early April; their body girth contrasts with the thin habitus of emergent nongravid females (repeated observations of individuals over several months affirm their gravida status). We suspect brooding females utilize limestone fissures and hollow trees, as persistent searches under surface objects during late spring have not revealed nests. Consistent observations of long term captives maintained under natural daylight cycles confirm their fall breeding and spring gestation patterns.

Hatchlings are rarely found, most likely due to utilization of the leaf litter microhabitat that allows their tan and dark brown cross-banding to render them nearly invisible. We have occasionally uncovered them under rocks with fairly moist substrate, as well as perched on leafy stalks of various undergrowth. We once observed three newly hatched specimens together on a vine covered oak stump adjacent to a limestone outcrop, suggesting the nest (and brooding female) were in the immediate vicinity.

Gerrhonotus are observed every month of the year under suitable conditions. They can be seen with some regularity on mild winter days when ambient temperatures approach 60 degrees Fahrenheit. At such times, they are invariably seen in limestone hibernacula with head and foreparts partially exposed to sunlight; we have never seen an individual fully exposed during winter months. As consistently warmer temperatures allow for effective thermoregulation, the lizards can be found fully exposed on rock faces and the trees and brush immediately adjacent to them. They appear to be not completely reliant upon these hibernacula as very few individuals were observed in thick brush piles without nearby rocky outcrops. The vast majority of winter and early spring observations, however, occur among the karstic fissures.

The onset of summer in Austin heralds a marked decline in field observations. Gerrhonotus are not particularly heat tolerant, and are rarely found when ambient temperatures exceed 85 degrees Fahrenheit. During the often prolonged droughts common to the Hill Country, even early morning or late evening searches are unproductive. However, individuals will sometimes emerge after a significant summer rain. These respites afford an opportunity to assess an animal’s overall condition and potential for fall breeding.

Territorial ranges for these lizards are unknown, but presumed small given their overall sedentary nature. One particular adult female was found on three consecutive Fridays in early spring: the first and third observations were in her hibernaculum crevice, and the second when discovered on the ground approximately 125 m from that site. This lizard was readily identifiable by her short regenerated tail and body markings, and conceivably covered at least

250 m in that time span. The strong arboreal tendencies of this species might allow for considerably greater territorial wanderings, however, and would by their very nature make direct observation extremely difficult.

The elongated body and tail, along with the variegated pattern of subdued browns and grays, makes these lizards exceedingly difficult to detect amongst their favored microhabitat: the extensive network of horizontal and obliquely oriented small branches of live and dead trees and brush, often arranged in a visually challenging orientation of repeating patterns that allow the lizard to virtually blend in with its background.

Gerrhonotus infernalis, Austin Greenbelt, Travis County, TX. Though not typically found on the ground, the coloration helps them blend in with the leaf litter. Photo by John Williams.

Despite our hard-earned ability to detect these lizards when other persons not familiar with them cannot, we are repeatedly humbled by the specimens we miss when the searched bush or vine tangle is viewed from a different angle. The efficacy of cryptosis in Gerrhonotus cannot be overstated.

We have only once observed feeding in the field, when a large male was found partially suspended in a vine tangle while maneuvering to grasp a large unidentified insect. Another observation of a female found seven feet above ground on an oak branch (several days after discovery in a nearby crevice) afforded us the opportunity to test feeding response in the field. We introduced a small roach onto the branch, and despite our immediate proximity (the lizard had maintained eye contact with us since discovery), it rapidly grasped and consumed its prey with apparent disregard for us.

In captivity Gerrhonotus readily consume a wide variety of invertebrates, especially large orthopterans and arachnids. One captive female had no apparent difficulty in consuming two 4-5 inch Scolopendra simultaneously, despite the frantic writhing and biting exhibited by these formidable arthropods. They eagerly consume small lizards and snakes (Anolis, Sceloporus, Scincella, Tantilla, Virginia), and we suspect they are important predators of bird eggs and hatchlings. Adult specimens are not infrequently found coiled in

SWCHR Bulletin Winter 20125

close proximity to the nests of the wren (Thyrothorus sp.). Although we have not observed field predation upon Gerrhonotus, numerous ophidian species that inhabit the same microhabitat probably do so regularly. An event related to us by a person well versed in local natural history described a Salvadora attempting to predate a lizard that had grasped its own tail in its effort to thwart the snake. The predilection of these lizards to utilize concealed understory brush would appear to minimize predation from local raptors and other birds; however, the extensive use of these same sites by the squirrels (Sciurus sp.) make these potentially important predators.

Gerrhonotus are essentially diurnal, yet we know of anecdotal reports of crepuscular activity in the more xeric portions of their range. We have found individuals abroad at dusk during late spring and early summer, and suspect these animals spend the night on their brush perches. Study of their behavioral adaptations to more extreme xeric conditions, such as in the Chihauhuan desert of Val Verde County, might be quite revealing.

Arboreality

Over 95% of our seasonally active Gerrhonotus observations have been above ground, ranging in height from several inches to more than 20 feet. The majority of adult and subadult sightings are between 3-5 feet elevation, usually on horizontal or obliquely oriented branches of less than 3 cm diameter. Subadults seem to favor the deeper recesses of thick bushes such as Nandina, while adults frequently utilize comparatively more open sites. They especially favor situations with numerous similar sized branches, so as to further aid their formidable crypsis.

The elongated body is accentuated by an effectively prehensile tail. When picked up in the field, most specimens attempt to wrap their tail (if not significantly shortened) around one’s fingers. Field and captive observations support a strong role in arboreal maneuverability. Unlike other lizards, Gerrhonotus are not inclined to self autotomize (under gentle handling, we have never witnessed it in the field); even the liberal feces-smearing and biting behavior of Elgaria appears greatly attenuated in this species. Our field records suggest an overall tail regeneration rate in adults of approximately 60%. Significant tail shortening does not appear to negatively affect climbing, however, as such specimens have often been found at great heights. The contributing role of specialized foot and digit scalation is currently under study (Greene, pers. communication).

It is our belief that Gerrhonotus in our area rely on an extensive arboreal network that provides mobility in herbaceous structures with seasonally plentiful prey base in the form of insects, other lizards, bird eggs and nestlings, but are also supremely suited to maximize their elongated body form for effective camouflage. So well suited are these lizards to this particular microhabitat, that we have many observations of individuals in branches directly overlying the very busy greenbelt trail despite heavy pedestrian, cyclist, and pet (canine) traffic. The animals always appeared alert yet at ease, with none of the typical skittish behavior of their Sceloporus congeners sometimes found only a few feet away. In this regard they appear similar in niche to the Mexican Abronia. Personal observations of colleagues studying these lizards in the Chipinqua Mountains of Nuevo Leon, at a much higher elevation, seem to support a much

more terrestrial pattern for Gerrhonotus.

Of interest are the observed springtime arboreal behaviors of Thamnophis cyrtopsis and T. proximans, both predominantly terrestrial serpents. They are found regularly in branches several feet above ground during our search for Gerrhonotus, but only during spring. These snakes probably share a minimal common prey base with Gerrhonotus, and might predate juvenile and subadult lizards. More likely, however, they are afforded the same benefits of concealed basking and predator evasion upon emergence from brumation.

Crypsis

Gerrhonotus are truly cryptic masters in their rocky woodland habitat. It is truly humbling and at the same time frustrating to look directly into a brush pile and strain to see the lizard spotted by your field partner only a few feet away! Occasionally it is the glint of sunlight reflecting a reddish hue on the animal’s tail amongst a tangle of vines that gives it away; other times the faintest disruption of a silhouetted tree branch that turns almost miraculously into the elongated form of a large adult that was only moments ago completely invisible. In every instance, however, the lizard sees

In situ photograph from the Austin Greenbelt, Travis County, TX of a G. infernalis demonstrating crypsis. Photo by John Williams.

you first, as evidenced by the direct eye contact one makes with an already observant animal. Clearly, the lizard has already seen you when you begin to approach it, and yet very rarely does the animal move at this point. Instead, a typical encounter allows such close approach as to be almost completely upon it before a response (if any) is elicited. In most instances this is so extreme as to allow gentle grasping of the lizard—no sudden lunging or maneuvering as is required for most other native saurians. This passive response is so strongly ingrained that it is the rule, rather than the exception, that specimens discovered in rock crevices that have merely to recede a few inches to evade capture usually allow manipulation of a stick behind them to force expulsion into the open. How then can an animal so seemingly impervious to the visual cues of an approaching potential predator survive?

SWCHR Bulletin Winter 20126

Gerrhonotus are infrequently found on the ground in our study area, despite our initial attempts to extrapolate field success with Elgaria by searching exclusively under ground cover. As in their arboreal niche, their cryptic coloration serves them well amongst the dead oak leaves and other debris of the forest floor. When discovered in the open, most specimens typically freeze—it is often only the perceived gentle movement at one’s feet that alerts the observer to the lizard’s presence. When motivated, these animals engage in a serpentine evasive maneuver that can be quite effective in evading capture. In contrast, lizards found elevated in trees or brush have extremely attenuated flight response, suggesting that their behavioral response is strongly influenced by these specific physical parameters. Specimens captured from karstic fissures seem to rely upon crypsis instead of receding to evade capture.

Further observations would seem to equate discovery and gentle handling with an effective predation event. Lizards were frequently handled in the early years of our research to document gender, overall health, and gravidity. It became increasingly apparent that, over time, these individuals would no longer be easily found at their preferred basking sites. In contrast, animals that were observed in a comparatively unobtrusive manner (i.e., from several yards instead of just feet away) would often remain at that site on subsequent visits. There appears to be some distance parameter, short of actual physical contact, that defines a disturbance to the animal’s sense of nondetection.

Urbanization adaptability

Gerrhonotus are famous in the Austin area for their seemingly random occurrence in suburban backyards, back roads, even parking lots with surrounding woods. Most reported sightings appear in the fall, in keeping with the peak activity we have noted in the field. Sometimes specimens turn up in numbers where previously unsuspected, as in the case of five individuals found one week in October on a small wooded road bordered by major traffic routes.

The Barton Creek greenbelt receives hundreds of thousands of visitors yearly, drawn to the trails that support hiking, bicycling, pet exercising, and other sundry recreational uses. Because of its generally favorable climate, a substantial transient population resides in Austin, and a significant number of these persons reside (at least temporarily) in the greenbelt. Defacement of rock, trash deposition, random wood cutting and gathering have all affected the greenbelt at various times. An apparent city-driven effort to remove brush from some sections of the greenbelt has negatively affected Gerrhonotus habitat to some degree. For the most part, however, Austin residents seem to take pride in this natural heritage that helps define the city. Greenbelt trail users appear genuinely interested in our response to queries regarding deliberate searching of trees and brush along the trailside.

The amount of potential Gerrhonotus habitat in the greenbelt is quite overwhelming. It would take a concerted effort by a great many field workers well versed in this species particular habits to fully expand our knowledge of nocturnal activity, territorial ranges, detailed elevational parameters, brooding sites, intra- and interspecific interactions, and potential antifungal/antibacterial

roles of lizard saliva in egg brooding females. Given the formidable armamentarium of phenotypic and behavioral attributes Gerrhonotus displays, we feel confident it will grace the Texas Hill Country for a long time to come.

Works Cited

Good, D.A. 1994. Species limits in the genus Gerrhonotus (Squamata: Anguidae). Herpetological Monographs 8: 180-202.

Feeding Observations of Captive Regal Ringneck Snakes, Diadophis punctatus regalis

(Serpentes: Colubridae)

by Andy O’Connor

I maintained two regal ringneck snakes in captivity, each approximately 23.5 inches long and of unknown weight. In the 6 and a half months I had these snakes in my possession, their diet consisted of mostly lizards including 1 desert night lizard (Xantusia vigilis), neonate and adult western banded geckos (Coleonyx variegatus), 1 neonate northern alligator lizard (Elgaria coerulea), 2 neonate and 2 subadult side blotched lizards (Uta stansburiana), 1 subadult sagebrush lizard (Sceloporus graciosus), 10 neonate western fence lizards (Sceloporus occidentalis), and 1 non-native long tailed grass lizard (Takydromus sexlineatus). Snakes offered included neonate northwestern garter snakes (Thamnophis ordinoides), common garter snakes (Thamnophis sirtalis), live and dead-on-road (DOR) frozen/thawed great basin gopher snakes (Pituophis catenifer), 1 DOR frozen/thawed northern pacific rattlesnake (Crotalus oreganus), 1 DOR frozen/thawed western racer (Coluber constrictor), and various-sized live and DOR frozen/thawed night snakes (Hypsiglena torquata). One stillborn frozen/thawed night snake was consumed, which was the only snake consumed by either ringneck.

Regal ringneck snake, Diadophis punctatus regalis, envenomating a western banded gecko, Coleonyx variegatus. Photo by Andy O’Connor.

SWCHR Bulletin Winter 20127

There was a clear and obvious predatory reaction to most lizards. Most snakes received little, if any, interest except an occasional tongue flick, one or two twitches of the head, and following the potential prey item around for a few minutes.

The regal ringnecks were most active in the late evening hours, although daytime activity was common, including climbing, basking, and exploring the enclosures. These behaviors, along with their dietary preference, differ from most other reports of these snakes in captivity. I believe a parasite load may have had some effect on their behavior and diet, although I also strongly believe that the locale from which they were collected may happen to be a lizard-eating population, as opposed to ophiophagous as the species is well documented to be. Perhaps smaller sympatric species may have been consumed more readily such as smaller night snakes, ground snakes (Sonora semiannulata), shovelnose snakes (Chionactis occipitalis), and blackhead snakes (Tantilla sp.), although a small-enough live night snake received little if any reaction from both snakes.

Venom reaction during feeding

Most of the lizards consumed were fairly small prey items, and while it is possible that blunt force played a part in death, there seemed to be reactions to venom most of the time. The most-witnessed feedings occurred with the fence lizards and banded geckos—many of the other prey items were eaten overnight. The fence lizards were usually grasped by a back leg or the flank in between the front and hind legs and appeared to die within 10 minutes, appearing to simply fall asleep. The neonate banded geckos experienced similar fates, although one gecko was bitten on the hind leg and then released a few minutes later when the snake was spooked by me moving in my chair while observing. The gecko was still alive, although it appeared paralyzed at the hips, as it was dragging itself with its front legs. At this point the snake grabbed the gecko by the head and started consuming it before the gecko appeared to have succumbed to the venom.

Once the lizard was sufficiently immobilized, the snake began swallowing the gecko headfirst. Photo by Andy O’Connor.

The most thoroughly documented feeding I have with video is on an adult banded gecko. As the video shows, from the first bite to the gecko being fully swallowed took over an hour and 15 minutes. The original bite occurred on a hind leg, and the snake actually “swallowed” the entire leg to the hip almost immediately. The gecko appeared to struggle at full strength only for a minute or two. The next half hour was a pattern of 3-5 minutes of resting followed by struggling attempts to escape that seemed weaker each time. After the first half hour, the gecko was no longer able to attempt to walk, but seemed to have labored breathing and would occasionally gape its mouth as if trying to take a deep breath. After approximately 40 minutes, the gecko was dead, and the snake held on for an additional 7-10 minutes before trying to swallow the snake from its current grip at the back leg. After about 10 minutes the snake gave up, backed off the gecko’s leg, and searched for its head for the next few minutes. The snake seemed slowed down; perhaps the hunt and holding the gecko in place expended a lot of energy, and the swallowing process took almost 30 minutes.

At this point, the snake has nearly completely swallowed the gecko. Photo by Andy O’Connor.

The snake that ate more often appeared healthy, although slightly underweight, and the other snake which only ate for me on 4 occasions in 6 months was very underweight and had what I would describe as lumps under the skin that I believe indicated parasitism. It had 2 small lumps when originally captured, and by the time the snake died it had 8 or 9 and one was elongated, nearly an inch long (roughly 4% of the animal’s total length). Strangely, the healthier, more consistent snake died first, 5 days after eating the adult banded gecko. The thinner snake died 3 days later. I believe their husbandry was not perfect, but was not the cause of their deaths and that parasites either directly or indirectly (by loss of appetite and energy) were the cause. I wish it would have been feasible to make a veterinary visit, but with the species being uncommon in captivity, and their seemingly delicate build, I am not sure what the local reptile vet could have done beyond general lab work.

I am not currently working with regal ringnecks but enjoyed this brief opportunity to observe their feeding habits. Although the behaviors exhibited occurred in a captive environment and should

SWCHR Bulletin Winter 20128

be considered in context, they are outside of the commonly observed behaviors for this species of snake and are an indication that more studies on the diet and activity patterns could reveal new information.

Notes on Natural History and Captive Maintenance of the Texas Horned Lizard,

Phrynosoma cornutum(Lacertilia: Phrynosomatidae)

by Lou Hamby

Most horned lizard species are well represented in the fossil record from the Pleistocene epoch onward. The Texas horned lizard, Phryonosoma cornutum, is found slightly earlier, starting in the upper Pliocene 3 million years ago (Pianka and Hodges).

Horned lizards generally measure between 60 and 109mm. The largest Texas horned lizard on record measured just over 7 inches (184mm) from tip of snout to tip of tail (Brown and Lucchino 1972).

Horned lizard coloration varies from yellow, brown, light tan, or red and variations depending on the substrate on which they are found. The male Texas horned lizard below was captured, photographed as a voucher for the Texas Parks and Wildlife Department (TPWD), and subsequently released.

Male Texas horned lizard, La Salle County, TX. The “eyed” pattern on the back is typical, but this individual is of exceptional color. Photo by Lou Hamby.

Habitat

Texas horned lizards are found in many different types of habitat and prefer rocky, sandy or loamy soils. They prefer scant vegetation and generally flat topography. These are strictly diurnal lizards. On many occasions I have found horned lizards in blackbrush (Coleogyne sp.) and small brush off the ground as a place to spend the night. They also climb into brush to escape the searing surface heat from the midday sun. I have found them most active in the morning and late afternoon, usually seeking a sheltered cool or shady spot during the heat of the day. Most of my observations have been on Texas county roads composed of dirt or caliche.

Habits

One does not mention Texas horned lizards without bringing up their infamous ability to eject blood out of their eyes. This is a defensive function, and often when captured the horned lizard will eject blood. These lizards also depend on their ability to blend in with their background and instead of running, will often crouch and flatten out and blend with the background. They are difficult to see when flattened out. Their “crown” of horns is useful if picked up by a predator. In my opinion one of the worst enemies of the Texas horned lizard is the roadrunner (Geococcyx californianus). I have seen roadrunners with horned lizards in their bills many times.

Harvester ant (Pogonomyrmex sp.) mound. Photo by Keith Birkemeyer, Probest.com.

Diet

Harvester ants (Pogonomyrmex sp.) are one of the more prevalent food requirements for the Texas horned lizard. These ants are responsible for the familiar large “ant piles” with all plants removed from around their nests, resulting in a large bare spot. It is thought by biologists that the decline in the harvester ant population may be a contributor to the Texas horned lizard’s diminishing numbers. Some beetles, insects, and other small spiders and moths are also taken. There have also been observations of some horned lizards eating small amounts of vegetation. I have personally observed this with Coast horned lizards (Phrynosoma coronatum), but I suspect Texas horned lizards also take in small amounts, and this may be a way of utilizing leafy vegetation to meet hydration requirements. Horned

SWCHR Bulletin Winter 20129

lizards are not as active as other lizards at lower temperatures, and they usually require higher temperatures before they eat compared to other lizards. My personal “sweet spot” for horned lizard observation is ambient temperatures around 85-88 degrees Fahrenheit.

Below are the results of a study conducted on ant requirements of various horned lizards. The diet of the Texas horned lizard (3rd on the list) is 61% ants by volume.

Ant requirements of horned lizards by species. Table courtesy Phrynosoma.org.

Hydration

Texas horned lizards require water. Horned lizards in the wild use their whole body as a collection surface in rain, or when dew forms on their body. They tip their bodies in such a way that they are able to translate the droplets to their mouths to get the much-needed liquid. This is known as “rain harvesting,” a term coined by horned lizard enthusiast and author Wade Sherbrooke.

Hibernation

Hibernation usually takes place in late September and October. Usually only babies are observed active in September. Certainly this is predicated on the temperature drop we get in Texas. Emergence of adults is usually in April to May. I personally have seen my first horned lizard of the year in Medina County on or about April 15th for several years in a row (though not the last two years). More northern areas of Texas may experience a later emergence due to cooler temperatures during the same time period. Determining Sex

Sexing horned lizards is generally easiest when they are older (at least 3-5 months old). With males, there is a row of enlarged femoral pores lining the underside of each leg. Sometimes, especially with the older males, there may be a waxy substance secreted from the pores. There is a wide hemipenal bulge on both sides of the base of the male’s tail. In addition, males have two enlarged postanal scales aft of the vent opening. Female horned lizards lack the hemipenal

bulge and have a more slender, evenly contoured tail all the way to the tip, without the widened bulge on the sides. Their femoral pores are smaller and less noticeable.

Breeding

After emergence from hibernation, males began to seek out females. Males may be aggressive towards one another, especially when two males are trying to court one female. Mark Brock from Phrynosoma.org captured this aggression on video and posted it to the following link:http://www.youtube.com/watch?feature=player_detailpage&v=oWac0BV5-WY

By late May or early June one often will observe gravid females. Eggs are deposited in shallow cavities in front of burrows, or under rocks. This usually coincides with moisture from spring rains. The eggs are covered up by the female and usually hatch within 50 days.

Captive Care Information

Texas horned lizards are protected in Texas. No one should keep these as captives unless for scientific study and after securing permission from TPWD. The following is captive information for those who may be involved with a study or possibly will be in the future.

Feeding

60-70% of the diet for captives needs to be ants. I have been involved with horned lizards as far back as the early 1970s and I can assure you that horned lizards need ants for their health and longevity. As a contributor to Phrynosoma.org, I have interfaced with many of the experts in captive care of horned lizard species, and using crickets (Acheta domestica and similar species) and other insects exclusively for horned lizards (instead of ants) is almost always going to cause serious problems with respect to the overall health and vitality of a horned lizard. Wax worms (Galleria mellonella) and ¼-inch crickets can be included sparingly. Also, using a Zoomed “Bug Napper,” a device put out at night, allows for wild caught moths and other wild insects to be incorporated into their diet. But for the most part, one must provide ants. If you are not willing to do this, please don’t ever consider keeping a horned lizard no matter your level of experience.

I suggest if you are involved in a program you should contact some of the experts at TWPD, or the Horned Lizard Conservation Society, or Phrynosoma.org. As a member of SWCHR I am also available.

This is an absolute must for anyone who keeps horned lizards. It is a homemade apparatus consisting of a vacuum cleaner (Dirt Devil) on a PVC pipe for collecting ants. Photo by Lou Hamby.

SWCHR Bulletin Winter 201210

The next photograph is an ant feeder that anyone who is serious about horned lizards should acquire or make. Note the ants are put in the bottom of a bowl-like arrangement and they climb up the stick in the middle but can’t get out of the bowl. This way they don’t threaten the horned lizards by overwhelming them numerically and the horned lizards graze on the ants as they pop up and down the stick. It is a very slick way of feeding horned lizards; much better than throwing a large number of ants into the enclosure at one time. It is also wise to refrigerate the ants for 10 or 15 minutes before feeding, as they move slower and are less threatening.

An example of an ant feeder for more regimented dispensation of ants to horned lizards. Photo by Jeff Judd.

Enclosure

The best choice is an outside enclosure designed to be off the ground where fire ants cannot get in. If you must have a horned lizard in house, a 50 gallon tank would be the minimum for two or three lizards. I prefer a ZooMed 10.0 UVB fluorescent over some of the stronger UVB spot or basking bulbs. I usually have my fluorescent set about 16-17” off the substrate. For heat, I use regular spot bulbs from the hardware store; usually a 100-watt and a 50-watt arranged roughly side by side, with no light on the cool half side of the cage. Horned lizards can bask and thermoregulate their body temperatures in a well-designed enclosure, even when temperatures are 100 degrees Fahrenheit or more on the hot side. During the summer I usually run the light cycle for 12 hours. Be careful if you are in a warm climate and for some reason keep your lizard in a garage; it will certainly cook!

Hardware store “play sand” has always been a cheap and adequate substrate for indoor caging. I recommend at least 4 to 6 inches of sand.

In captivity horned lizards will readily take water from a dropper, spray on the rocks in their cage, or even from a bowl. The photograph below shows a bowl arrangement I came up with years ago and use for nearly all my lizards. They are not threatened by the water but

stick their noses down through the mesh to get the water they need. I have used this bowl arrangement with several species of horned lizards.

A custom mesh insert for water dishes allows horned lizards to drink without falling in. Photo by Lou Hamby.

I usually hydrate horned lizards twice a week. This includes using the bowl previously mentioned and/or an eye dropper if they will take it, or spraying water on the rocks. If one of the rocks has some divots in it, they seem to find those little moisture spots quickly. Do not, I repeat do not give them regular tap water if your water has fluoride or other chemicals in it!

If you have an indoor-housed Texas horned lizard, it is imperative you have a sun cage aside from the indoor cage so the lizard can get regular sunlight occasionally. Even short stints in regular sunlight are important to overall health. Covering half the cage with special animal-proof shade cloth is a good idea—you get semi-shade on a hot day and the lizards often use that side of the cage. If you have an outside enclosure, be sure it is “varmint” proof. I personally like my outside cages on wheels. I wheel them into the garage at night, and wheel them out in the morning. Whatever you do, be cognizant of the sun and the location of your cage. I use the mountain laurel on the side of my driveway to give shade, especially around 2 or 3 o’clock in the afternoon when it really warms up!

Homemade cage on casters to facilitate movement between sun and shade. Photo by Lou Hamby.

SWCHR Bulletin Winter 201211

Texas Horned Lizard (or Other Reptile Species) Rescue

If you should ever need to surrender a horned lizard, I know of no one more qualified to take a rescue than my good friend Mike Comella. He has been practicing reptile rescue medicine and rehabalitation for a long time, and a quick overnight shipment to his Wichita Falls rescue facility will certainly save the animal’s life. Frankly, most general-practice veterinarians do not have much experience or have a very good track record when it comes to reptiles, let alone horned lizards. I support the idea of permitting adoptions of endangered reptiles such as Texas horned lizards which were taken out of the wild and should not be put back. Often some well-meaning person will capture a horned lizard and bring it home, not feed it correctly or have any idea how to take care of it. They also don’t realize horned lizards are protected in Texas and other states where they occur. TPWD would also do well to contact Mike if they need to adopt out a horned lizard taken from the wild in such situations.

I hope that in this brief musing I have pointed out, above all else, the difficulty in keeping these lizards. Even experts who deal with lizards on a regular basis have found great trouble with providing proper husbandry. They are best left in nature where they belong!

Study of a Texas horned lizard head highlighting scalation. Photo by Lou Hamby.

Works Cited

Brown, T.L. & R. V. Lucchino. “A record sized specimen of the Texas Horned Lizards (Phrynosoma cornutum).” Texas Journal of Science XXIV(3): 353-354, 1972.

Pianka, Eric R. and Wendy L. Hodges. “Horned Lizards.” Reptiles 6(6): 48-63, 1998.

Sherbrooke, Wade C. “Rain-Harvesting in a Lizard, Phrynosoma cornutum: Behavior and Integumental Morphology.” Journal of Herpetology 24:302-308, 1990.

Book Review: A Field Guide to Oklahoma’s Amphibians and Reptiles, 3d ed.

by Greg and Lynnette SievertOklahoma Department of Wildlife Conservation:

Oklahoma City, 2011. Softcover, spiral-bound.211 pp. $25. ISBN 978-0-615-42788-1

Review by Chris McMartin

Oklahoma is an often-overlooked herping opportunity, featuring 58 amphibian and 99 reptile species and subspecies based on current taxonomy. However, growing up in the state, I never had a really good state-specific field guide. I spent countless hours studying Robert Webb’s seminal Reptiles of Oklahoma published by the University of Oklahoma in 1970. Much of that book consists of dichotomous keys (nothing against those, but I’ve always viewed those as more suited to museum-specimen study) and lists of voucher specimens, along with some enlightening discussion on contemporary history of field herpetology and descriptions of type specimens collected in Oklahoma (and the difficulties in ascertaining locality based on now-defunct place names). While I find such information fascinating, it doesn’t exactly make for a field guide in the practical sense. On the other hand, after I had moved from the state, several attempts at field guides hit the market, but they largely seemed to be at the opposite end of the spectrum—a few pictures of the most commonly-encountered species, but not enough information in species accounts to satiate those with more than a casual interest in the state’s herpetofauna.

You can imagine my excitement when earlier this year, while passing through the state, I serendipitously discovered the Sieverts’ recent endeavor to fill this gap between overly-technical and natural-history-deficient guides to Oklahoma amphibians and reptiles. Granted, the guide has existed in two previous editions dating back to 1996, but I had little knowledge of them, nor had any need to seek them out, having not herped extensively in the state since leaving home many years ago. From clues peppered throughout the text, changes in this edition include the elimination of certain species from the state’s herpetofaunal roster and inclusion of species described since publication of the previous editions. In another happy circumstance, I currently live in Kansas where the Sieverts also reside, offering the opportunity to discuss this guide with them briefly during the most recent annual meeting of the Kansas Herpetological Society.

Let me first describe what catches one’s eye upon first beholding this book. In a welcome departure from standard paperback guides,

SWCHR Bulletin Winter 201212A Field Guide to Oklahoma’s Amphibians and Reptiles is spiral-bound. While the casual observer viewing this book on a museum gift-shop’s shelf might initially foresee difficulty in aligning the book with other volumes in their personal library, it is clear indication this book is not meant to languish on a shelf—it is designed for practical field use. The spiral binding allows the book to lay flat, with the pages of interest readily accessible. Anyone who has attempted to use a field guide in one hand to identify a squirming specimen in the other hand can surely appreciate this feature. The pages are glossy which is common to many field guides and helps resist (to an extent) stains potentially encountered in field use.

Less apparent, the background image on the cover is of what appears to be rattlesnake skin—and it is textured in mild relief such that you can feel the keeled scales. While not of practical use in the field, it adds a unique touch of style to the cover.

The inside front cover features a ruler in both inches and centimeters, almost a given for inclusion in a field guide. Both inside covers display an outline map of the state with all counties labeled. This is handy, but I would have preferred one cover to show the county map and the other cover to display different information, such as a simplified depiction of the state’s ecoregions similar to the habitat-type map found on page vi, or perhaps a quick-reference list of state threatened species/species of special concern.

The book opens with a brief introduction including discussion on Oklahoma’s confluence of several habitat types, followed by an explanation of how the range maps were derived. The maps err on the side of caution, in the sense that while county records exist for some species, if they have not been found since the first instance or no recent records exist, that county is no longer considered within a species’ range—hence, the maps presented are often much more conservative than previous guides’ efforts. This is helpful for field herpers who wish to explore locales with higher probability of success in finding target species. Those who are interested in finding new county records, or confirming old ones, will probably be conducting more extensive research and will discover relevant historical vouchers on their own (such as through Webb’s book, in the case of reptiles).

Additionally, there is a brief discussion of laws pertaining to Oklahoma amphibians and reptiles in the opening pages. However, the text says Species of Special Concern “should not” be taken from the wild, yet in the applicable individual species accounts it is more proscriptive, saying they “may not” be taken. This may be a simple editorial oversight but can confuse readers, especially those wishing to work with such species (though the authors do recommend checking with the Oklahoma Department of Wildlife Conservation for the latest regulations). A better approach would be to expand the section covering legal concerns and omit it from the individual accounts.

The final section before acknowledgments and the species accounts deals with scientific and common names as well as some background on taxonomic changes and the ensuing debate. The authors explain their rationale for sticking with more “traditional” names, both scientific and common.

Of course, the meat of the book consists of the individual species accounts. Each species is dedicated at least one page, which includes a couple of photographs, a range map, and textual description of

size, appearance, similar species, food, habitat, and general notes. Some species are afforded a two-page spread, with the additional space used for additional photographs highlighting ontogenetic and/or population color variation or field marks for the species. Each order of herpetofauna gets a brief introduction covering general characteristics of the order. In addition, each order is identified in the book with color-coded tabs, making it easier to flip quickly to the appropriate section of the book.

For some species, a brief explanation of what the scientific names mean is given, which is nice, but in some cases there are discrepancies which may be artifacts missed during edition updates (e.g. the explanation for “crepitans” is given under accounts for both cricket frog species, Acris crepitans and A. blanchardi). There is also some redundancy in the accounts for closely-related species, often verbatim notes within the accounts. An avid reader such as me may have wished the redundant info to have been replaced with diagnostic text, more in-depth natural history notes, or additional photographs. However, conferring with the authors reminded me that many people do not read field guides cover-to-cover and may not read all species accounts, so the information is repeated to ensure important species attributes are not missed.

Speaking of photographs, they are generally good. With few exceptions, they appear to be standard, posed “field guide” type shots, not that this is problematic. New for this edition are the inclusion of tadpole photographs where those species are distinct in their larval form. No credits are listed for individual photos, but Greg Sievert (the senior author) took all photographs for the guide, including the cover shots. It took him many years to do so—locating and photographing all extant species in the state was no small feat!

The range maps depict county lines which are extremely helpful in narrowing down both the likely identification of a species in hand, or determining which species are likely to be found if conducting a survey of a particular county. The only complaint I have for the range maps is that they use a single color for a species, with no breakout of subspecies; the reader is left to infer from the text where individual subspecies may be encountered. This was a conscious decision at the Oklahoma Department of Wildlife Conservation level, as they assumed the average reader would probably not be concerned with subspecies. This may be remedied in the next edition of the guide.

Rounding out the book are a short glossary and bibliography. No index is included, but would be of little use anyway given the simple layout of the book.

All told, the concerns mentioned here are very minor. This guide is not only a great addition for any state/regionally specific library, but the utility of the spiral binding ensures it stands out in its genre as being extremely functional in actual field herping conditions. I recently learned a fourth edition is in the works, which will correct some of the errors noted as well as add new county records; no anticipated date of publication has been set but it promises to build upon this successful lineage of Oklahoma guides. For news on the fourth edition and where to buy the current edition, and to submit updates such as errors in need of correction or new county records, the Sieverts have posted a page to their site at Emporia State University, http://academic.emporia.edu/sievertg/book.htm.

SWCHR CODE OF ETHICS

As a member of the Southwestern Center for Herpetological Research, I subscribe to the Association’s Code of Ethics.

Field activities should limit the impact on natural habitats, replacing all cover objects, not tearing apart rocks or logs and refraining from the use of gasoline or other toxic materials.

Catch and release coupled with photography and the limited take of non-protected species for personal study or breeding use is permitted. The commercial take and sale of wild-caught animals is not acceptable.

Collecting practices should respect landowner rights, including but not limited to securing permission for land entry and the packing out of all personal trash.

Captive-breeding efforts are recognized as a valid means of potentially reducing collection pressures on wild populations and are encouraged.

The release of captive animals including captive-bred animals into the wild is discouraged except under the supervision of trained professionals and in accordance with an accepted species preservation or restocking plan.

The disclosure of exact locality information on public internet forums is discouraged in most circumstances. Locality information posted on public internet forums usually should be restricted to providing the name of the county where the animal was found. When specific locality data is provided ot one in confidence, it should be kept in confidence and should not be abused or shared with others without explicit permission.

Other members of the Association are always to be treated cordially and in a respectful manner.

SWCHRPO BOX 624SEGUIN TX 78156