Iguana b&w text Physiology and Sociality: Why Banded Geckos Band Aggregation may have important repro- ductive, ecological, and fitness implica- tions. Although studies of aggregating behavior have been conducted for many species, few have measured the benefits of lizard aggregation. LANCASTER ET AL. (2006. Animal Behaviour 72:199–207) conducted a study to determine the ben- efit of aggregation in the desert-dwelling Banded Gecko (Coleonyx variegatus). Geckos from Borrego Springs, San Diego County, California were housed in groups of five and offered a surplus of retreats in an effort to test the hypothesis that geckos benefit from grouping by lowering rates of evaporative water loss. The authors also tested effects of humid- ity and scents of conspecifics and preda- tors. Geckos avoided predator-scented areas, supporting past work on other species, but did not band together to avoid predators. Nor did lizards use con- specific scents to choose retreat sites, and no social or mating benefits were found. Instead, the study showed that Banded Geckos benefit from aggregation by low- ering rates of evaporative water loss. Thus, aggregation provides physiological but no evident social benefits for Coleonyx variegatus. Foraging Ecology of Tokay Geckos Although individuals exhibited varied foraging behavior, AOWPHOL ET AL. (2006. Amphibia-Reptilia 27:491–503) found no significant differences in forag- ing parameters (foraging period, time spent moving, foraging attempts, forag- ing success, prey size consumed, and for- aging distance) among male, female, or juvenile Tokay Geckos (Gekko gecko) in Thailand. Foraging occurred from 1800–0900 h, peak emergence was from 1800–2000 h, and peak retreat time from 0400–0700 h. Food items were insects, most in the orders Lepidoptera, Orthoptera, and Coleoptera. The lack of size differences in prey taken by geckos of different sizes reflected no prey size selec- tion, possibly attributable to low insect availability. Geckos mostly used a sit- and-wait strategy, but foraged more widely when prey was relatively abun- dant. Are Snakes with Narrow Distributions More Specialized? The Italian Aesculapian Snake (Zamenis lineatus) has a narrow distribution in southern Italy and on Sicily. CAPULA ET AL. (2006. Amphibia-Reptilia 27:531– 537) examined the diet of this snake to test the hypothesis that species with nar- row distributions will be more ecologi- cally specialized than wide-ranging rela- tives. The diet of adult Z. lineatus consisted of small mammals and birds, whereas that of juveniles was composed mainly of lizards. Diets of males and females did not differ. The authors con- cluded that the feeding ecology of Z. lineatus was very similar to that of the widespread ecological generalist, Z. longissimus, indicating that the assump- 56 IGUANA • VOLUME 14, NUMBER 1 • MARCH 2007 NATURAL HISTORY RESEARCH REPORTS N A T U R A L H I S T O R Y R E S E A R C H R E P O R T S Desert-dwelling Banded Geckos (Coleonyx variegatus) benefit from aggregating in groups because that lowers rates of evaporative water loss. JE FF L EM M Tokay Geckos (Gekko gecko) are native to southeastern Asia, but have been widely introduced in tropical and subtropical areas. A study in Thailand indicated that adults of both sexes and juve- niles were active at comparable times, used essentially similar foraging strategies, and ate the same types of prey. JE FF L EM M The feeding ecology of the Italian Aesculapian Snake (Zamenis lineatus) was very similar to that of the widespread ecolog- ical generalist, Z. longissimus, indicating that narrowly distributed Mediterranean snakes are not more specialized than their widely distributed counterparts. ST EF A N M O EL LE R , W W W .E LA PH E. IN FO Iguana 14.1 b&w text.QX6 2/25/07 10:46 PM Page 56 IGUANA • VOLUME 14, NUMBER 1 • MARCH 2007 57NATURAL HISTORY RESEARCH REPORTS tion that narrowly distributed Mediterranean snakes are more special- ized than their widely distributed coun- terparts does not apply to the dietary ecology of these snakes. Jump Dispersal in Introduced Mediterranean Geckos From 1962–1997, Mediterranean Geckos (Hemidactylus turcicus) were intentionally introduced multiple times into a science building at the University of Central Oklahoma in Edmond. In 2005, LOCEY AND STONE (2006. Journal of Herpetology 40:526–530) recorded 365 captures of 305 individuals and estimated the population size to be 1005 geckos with at density of 478 lizards/ha. The population had dispersed a maximum of 200 m from the point of introduction, a diffusion dispersal rate of 20 m/yr. The wide distribution of this species across the southern United States since their intro- duction in Key West, Florida was recorded in 1910 suggests that expansion of the species’ range occurred as a conse- quence of multiple jump dispersal events instead of slow diffusion dispersal. Population Structure and Density of Leopard Tortoises Leopard Tortoises (Geochelone pardalis) are the largest tortoises in southern Africa, where they are widely distributed in a variety of habitats. MCMASTER AND DOWNS (2006. Journal of Herpetology 40: 495–502) studied Leopard Tortoises in semi-arid farmland in Nama-Karoo, cen- tral South Africa. The sex ratio of 92 tor- toises did not differ significantly from 1:1. Adult females were larger than adult males, and adults were larger than con- specifics studied in more mesic habitats. A population estimate of 57.6 ± 4.0 tor- toises translated to a very low density of 0.017 tortoises/ha, much lower than in more mesic situations. Slow rates of diffusion dispersal in introduced Mediterranean Geckos (Hemidactylus turcicus) suggest that the wide distribution of this species across the southern United States is a conse- quence of multiple jump dispersal events. D A W SO N /W IK IP ED IA .O R G The population density of Leopard Tortoises (Geochelone pardalis) was lower in dry South African habitat than in more mesic situa- tions, but adults were larger. A N D ER S G .J . R H O D IN , C H EL O N IA N R ES EA R C H F O U N D A TI O N Butler’s Garter Snake Will Remain on Protected List A legislative committee in Wisconsin that this summer had threatened to remove Butler’s Garter Snake (Thamnophis butleri) from a protected list that stops developers from killing it, reversed course and decided to allow the snake to remain on a list of threatened species. The decision was praised by state Department of Natural Resources execu- tive assistant Mary Schlaefer, who said protecting the endangered snake was vital to the overall health of the environment. Critical steps need to be taken when there is a species like this snake that is in danger of disappearing, she said. With their habitat shrinking, the reptiles were placed on the threatened list in 1997 by the DNR, meaning that in most cases the snakes cannot be killed. The protected area encompasses about 405,000 acres in southeastern Wisconsin. Known for its colorful yellow stripes, the 1- to 2-foot-long snake is generally found in marshes, prairies and fields, as well as in roadside grassy areas and in vacant lots. In addition to southeastern Wisconsin, it can be found in Ohio, Indiana, Michigan, and in southern Canada. The Republican-controlled Joint Committee for Review of Administrative Rules decided in July to remove the snake from the DNR’s threatened list if the agency didn’t soften its regulations. The agency on Tuesday outlined a num- ber of changes it had made and was in the process of implementing, including reducing the time of review of proposed projects from 27 to seven days and com- ing up with more funding to reduce costs for homeowners to get needed surveys. Those surveys can cost up to $10,000, said Andy Galvin, a consultation special- ist in the DNR’s bureau of endangered resources. The agency also reduced the number of acres in the protected area by 500. It is working to identify as many as 65 protected sites for the snake. Once those are established and stabilized, regu- lations on private landowners can be ended more quickly, Schlaefer said. “Our goal is to manage based on science, but in a way that minimizes impact on homeowners,” she said. The committee voted 7-2 not to take the snake off the protected list. One of the two no votes, state Rep. Debi Towns, R-Janesville, said she was con- cerned that the DNR was not setting a N E W S B R I E F S A legislative committee in Wisconsin that this summer had threatened to remove Butler’s Garter Snake (Thamnophis butleri) from a protected list that stops developers from killing it, reversed course and decided to allow the snake to remain on a list of threatened species. G A R Y C A SP ER Iguana 14.1 b&w text.QX6 2/25/07 10:46 PM Page 57