Gad Perry

The densest terrestrial vertebrate

An understanding of the abundance of organisms is central to understanding ecology, but many population density estimates are unrepresentative because they were obtained from study areas chosen for the high abundance of the target species. For example, from a pool of 1072 lizard density estimates that we compiled from the literature, we sampled 303 estimates and scored each for its assessment of the degree to which the study site was representative. Less than half (45%) indicated that the study area was chosen to be representative of the population or habitat. An additional 15% reported that individual plots or transects were chosen randomly, but this often indicated only that the sample points were located randomly within a study area chosen for its high abundance of the target species. The remainder of the studies either gave no information or specified that the study area was chosen because the focal species was locally abundant. In many environments, lizards form important elements of the food web. In many cases, they have been used as model organisms with which to examine

Toe Clipping of Amphibians and Reptiles: Science, Ethics, and the Law 1

Abstract Public concern for the humane treatment of animals in research has led to specific guidelines for appropriate treatment of study organisms. Field research poses special challenges that Institutional Animal Care and Use Committees find difficult to address based on existing guidelines. Toe clipping is a common but contentious example whose use has been called barbaric and whose efficacy has been questioned. We provide a brief review of the ethical bases for such positions, the legal framework they have engendered, and the scientific evidence regarding the impacts of the practice. Leading philosophical views vary but tend to focus on the suffering or distress of individual animals, primarily vertebrates. The law has adopted this individual-centered view. Biologists, in contrast, tend to more wholistic views that focus on populations and ecosystems. Scientific studies of the impacts of toe clipping, most of them relatively recent, have become increasingly sophisticated statistically. Most show little impact of toe clipping on study animals, the exception being the likelihood of recapture of toe-clipped individuals in some frogs. If unaccounted for, effects of methodology can bias scientific findings. The few studies focusing on physiological indicators of distress show no increase resulting from toe-clipping. Thus, toe clipping of reptiles and amphibians meets legal and ethical expectations and should remain acceptable where it meets study needs. Biologists have long been concerned about the possible ethical implications of their methods. Philosophical inquiry has been beneficial in improving our understanding of these methods, but the need of biologists for better philosophical elaboration of ecological ethics has only partially been addressed.

Thermoregulation in a nocturnal, tropical, arboreal snake

Abstract Few studies have focused on the thermal biology of tropical or nocturnal snakes. We recorded preferred body temperatures (Tb) of seven Brown Treesnakes (Boiga irregularis) in the laboratory and compared these to operative temperatures obtained with copper models and Tbs obtained by radiotelemetry from 11 free-ranging snakes on Guam. Operative temperatures on Guam did not vary across refuge types, unless the site received direct solar radiation. In a thermal gradient and on Guam, Brown Treesnakes thermoregulated around two distinct temperature ranges (21.3–24.9°C; 28.1–31.3°C). In the gradient, brown treesnakes exhibited elevated Tb into the higher range only in the evening. On Guam, snakes achieved Tbs in the high range only when direct solar radiation was available during the afternoon, a period when snakes were inactive. Higher mean Tbs on sunny days corresponded with observations of basking behavior.

Conservation of amphibians and reptiles in the British Virgin Islands: Status and patterns

The British Virgin Islands (BVI) forms part of the Puerto Rican Bank and its fauna is closely related to that of the US Virgin Islands and Puerto Rico. Humans have inhabited the region for several thousand years and their impacts have continuously included habitat modification, hunting, and introduction of invasive species. Those are the three main causes of concern for the present-day herpetofauna of the BVI, which contains 34 amphibian and reptile species. Of these, five (15%) are common, three (9%) are at risk, eight (23%) are endangered, ten (29%) are data deficient, two (6%) are extinct, and six (18%) are introduced or cryptogenic. Several endemic species are only found on tiny islets where stochastic events can easily lead to their extinction. The native iguana, Cyclura pinguis , and the sea turtles found in the region are in an especially sensitive condition. Habitat destruction and fragmentation are ongoing and likely to accelerate. Invasive species are still arriving, establishing, and spreading. Thus, although the short-term conservation status of the BVI herpetofauna appears unlikely to change, we are more concerned about the mid-term outlook. We recommend some specific remedies intended to offset these pressures and provide long-term protection to the biota of the BVI.

Changes in Intestinal Morphology Following Feeding in the Brown Treesnake, Boiga irregularis

(Anura: Ranidae) in an unpredictable and patchy environments. Oecologia 109:184-199. STUMPEL, A. H. P., AND H. VAN DER VOET. 1998. Characterizing the suitability of new ponds for amphibians. Amphibia-Reptilia 19:125-142. Vos, C. C., AND A. H. P. STUMPEL. 1995. Comparison of habitat isolation parameters in relation to fragmented distribution patterns in the tree frog (Hyla arborea). Landscape Ecol. 11:203-214. WELLS, K. D. 1977. The social behaviour of anuran amphibians. Anim. Behav. 25:666-693. WILBUR, H. M., 1997. Experimental ecology of food webs: complex systems in temporary ponds. Ecology 78:2279-2302. , AND R. A. ALFORD. 1985. Priority effects in experimental pond communities: responses of Hyla to Bufo and Rana. Ecology 66:1106-1114. YANOVIAK, S. P. 1999. Effects of leaf litter species on macroinvertebrate community properties and mosquito yield in Neotropical tree hole microcosms. Oecologia 120:147-155.

The Three Rs of Animal Research: What they Mean for the Institutional Animal Care and Use Committee and Why

The Institutional Animal Care and Use Committee (IACUC) is entrusted with assessing the ethics of proposed projects prior to approval of animal research. The role of the IACUC is detailed in legislation and binding rules, which are in turn inspired by the Three Rs: the principles of Replacement, Reduction, and Refinement. However, these principles are poorly defined. Although this provides the IACUC leeway in assessing a proposed project, it also affords little guidance. Our goal is to provide procedural and philosophical clarity to the IACUC without mandating a particular outcome. To do this, we analyze the underlying logic of the Three Rs and conclude that the Three Rs accord animals moral standing, though not necessarily “rights” in the philosophical sense. We suggest that the Rs are hierarchical, such that Replacement, which can totally eliminate harm, should be considered prior to Reduction, which decreases the number of animals harmed, with Refinement being considered last. We also identify the need for a hitherto implicit fourth R: Reject, which allows the IACUC to refuse permission for a project which does not promise sufficient benefit to offset the pain and distress likely to be caused by the proposed research.

Reducing the Risk of Biological Invasion by Creating Incentives for Pet Sellers and Owners to Do the Right Thing1,2

Abstract Invasive species are a major threat to biodiversity and economic interests, with many introductions resulting from actions of people involved in pet and ornamental plant businesses. Invasive species eventually end up in the care of the general public, with most costs born by society rather than businesses or owners: a classic economic externality. Although standard economic instruments used to address externalities are useful, they require considerable extension in this case. Simple taxation of the trade has been suggested and can reduce the volume of trade, but taxes do little to discipline the riskiest actors in the market. Using reptiles and amphibians as our focus, we provide an outline for a mechanism addressing invasive species issues, focusing primarily on the local level. We propose to collect funds from the trade and apply them specifically to support (1) a national resource center offering information and training; (2) programs to professionalize local education and response teams, focusing on pet store owners, hobbyist organizations, and first responders; (3) an incentive program to encourage pet stores to take back unwanted animals; (4) a tracking system for identifying and penalizing owners of newly released animals; and (5) a rapid-response system to address newly reported invasives. Participation by local entities helps them avoid uniform policies from the national level that are typically both more onerous and less effective. To provide an additional incentive for the industry at large to participate in the process, the level of taxation could decrease as problems diminish.

Short-term effects of prescribed fire on lizards in mesquite-Ashe juniper vegetation in central Texas

Prescribed fire is a common land management tool used to reduce undesirable shrubs, improve forage quality, and enhance wildlife habitat for game species. However, it also has impacts on nongame species. We examined whether a prescribed fire would affect the abundance of lizards and invertebrates in central Texas. In February 2004, four sites were treated with low-intensity prescribed fires; four adjacent non-burned sites served as controls. Vegetation structure (litter depth, percent canopy cover, visual obstruction) and foliar cover were recorded prior to and seasonally following the burn. Lizards and potential invertebrate prey were collected from all plots between March and August 2004 (152 traps, 5908 trap nights). Lizard numbers were not significantly (P > 0.312) affected by the fire, nor were their potential prey or habitat greatly affected. Burning reduced numbers of Homoptera (P 0.25 for all measures); however, foliar cover of Texas wintergrass was lower in burned plots in March but recovered to non-burned levels by May. Our results suggest that small-scale, low-intensity fires have minimal impact on central Texas lizards, the vegetation structure of their habitat, or the invertebrates of their diet.

The red-eared slider, Trachemys scripta elegans , in the British Virgin Islands

Gad Perry1,2, Jennifer L. Owen1, Clive Petrovic3, James Lazell4, Jim Egelhoff5 1 Department of Natural Resource Management, Texas Tech University, Box 42125, Lubbock, Texas 79409-2125, USA 2 Corresponding author; e-mail: Gad.Perry@TTU.edu 3 H. Lavity Stoutt Community College, Tortola, British Virgin Islands 4 The Conservation Agency, 6 Swinburne St., Jamestown, Rhode Island 02835, USA 5 BVI Pest Control, P.O. Box 1109, Virgin Gorda, BVI

Surface water mitigates the anti-metamorphic effects of perchlorate in New Mexico spadefoot toads (Spea multiplicata) and African clawed frogs (Xenopus laevis)

UNLABELLED Spea multiplicata (New Mexico spadefoot toad) larvae were exposed to 60, 110, and 1000 microg L(-1) perchlorate dissolved in natural surface water to determine risks associated with perchlorate exposure in desert-adapted anurans. Hind- and forelimb development and tail resorption were measured to identify effects of perchlorate exposure. No perchlorate-related effects on snout-vent length, hindlimb length, and proportion metamorphosed were observed in the highest treatment group (positive control; 1000 microg L(-1)) suggesting that either S.multiplicata are not sensitive to the effects of perchlorate at the concentrations tested or that unidentified constituents of natural surface water mitigated perchlorate toxicity. To identify whether surface water mitigated perchlorate toxicity, Xenopuslaevis were exposed to 20 and 60 microg L(-1) perchlorate in surface water and synthetic laboratory prepared water (i.e., FETAX media). X.laevis exposed to perchlorate dissolved in surface water exhibited no perchlorate-related anti-metamorphic effects, whereas X.laevis exposed to perchlorate in FETAX media experienced changes in percent metamorphosing (p<0.001), time to metamorphosis (p<0.001), snout-vent length (p<0.001), and hindlimb length (p<0.001) as compared to FETAX controls. These results suggest that natural surface water can mediate perchlorate effects at concentrations up to 60 microg L(-1) for X.laevis and greater than 1 mg L(-1) for S.multiplicata, potentially due to physicochemical properties of surface water. CAPSULE This manuscript discusses the effects of perchlorate in natural surface water to S.multiplicata and X.laevis.