Iguana b&w text 264 IGUANA • VOLUME 14, NUMBER 4 • DECEMBER 2007 NATURAL HISTORY RESEARCH REPORTS Escape Behavior in Cuban Curly-tailed Lizards Several aspects of escape behavior are pre- dictable by escape theory based on expected costs due to predation risk and escaping. Although the function of pur- suit-deterrent signaling is to dissuade predators from attack, relatively little is known about relationships between spe- cific components of escape and the sig- naling behavior. COOPER (2007. Herpetologica 63: 144–150) studied effects of the risk factor distance from refuge on flight initiation distance, dis- tance fled, probability of entering refuge, and the distance between predator (an approaching human) and prey when pursuit-deterrent display begins (display distance) in the Cuban Curly-tailed Lizard (Leiocephalus carinatus). The author also investigated whether starting distance (distance between predator and prey when approach begins) affects escape behaviors. As predicted by escape theory, flight initiation distance and dis- tance fled were greater and refuge entry was less probable at greater distance from refuge, indicating that qualitative predic- tions of escape theory apply to pursuit- deterrent signalers. Starting distance did not affect escape behaviors, presumably because it did not affect perceived risk, but might do so at a faster approach speed. Display distance and flight initia- tion distance were identical in the data set analyzed, but individuals sometimes perform tail displays prior to fleeing. Native Predators May Limit Iguanas in Florida Known predators of Green Iguanas (Iguana iguana) in Florida include Raccoons (Procyon lotor), domestic dogs (Canis familiaris), Yellow-crowned Night Herons (Nyctanassa violacea), Florida Burrowing Owls (Athene cunicularia floridana), and a hawk (Buteo sp.). Smith et al. (2007. Journal of Kansas Herpetology 23: 7–8) report nest preda- tion and attempted adult predation on Green Iguanas by a Gray Fox (Urocyon cinereoargenteus) and suggest that avian and mammalian predators may poten- tially function as limiting factors on col- onization patterns of exotic iguanas in Florida. Survival of Timber Rattlesnakes (Crotalus horridus) Juvenile survival is one of the least known elements of the life history of many species, in particular snakes. BROWN ET AL. (2007. Copeia 2007: 656–671) conducted a mark-recapture study of Timber Rattlesnakes (Crotalus horridus) from 1978–2002 in northeast- ern New York near the northern limits of the species’ range. They marked 588 neonates and estimated annual age-, sex-, and morph-specific recapture and sur- vival rates. Wild-caught neonates (field- born, n = 407) and neonates produced by captive-held gravid females (lab-born, n = 181) allowed comparison of the birthplace, or lab treatment effect, in estimated survival. Recapture rates declined from about 10–20% over time while increasing from young to older age classes. Estimated survival rates (S ± 1 SE) in the first year were significantly higher among field-born (black morph: S = 0.773 ± 0.203; yellow morph: S = 0.531 ± 0.104) than among lab-born snakes (black morph: S = 0.411 ± 0.131; yellow morph: S = 0.301 ± 0.081). Lower birth weights combined with a lack of field exposure until release appar- ently contributed to the lower survival rate of lab-born snakes. Subsequent sur- vival estimates for 2–4-yr-old snakes were S = 0.845 ± 0.084 for the black morph and S = 0.999 (SE not available) for the yellow morph, and for > 5-yr-old snakes S = 0.958 ± 0.039 (black morph) and S = 0.822 ± 0.034 (yellow morph). The most parsimonious model overall Tail-curling may serve as a pursuit-deterrent signal in Cuban Curly-tailed Lizards (Leiocephalus carinatus). JO H N B IN N S A Gray Fox (Urocyon cinereoargenteus) exca- vating a Green Iguana (Iguana iguana) nest and eating the eggs at Hugh Taylor Birch State Park in Broward County, Florida. G A R Y H . B U SC H 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 For young Timber Rattlesnakes (Crotalus horridus) (ages 1 yr and 2–4 yr), survival tended to decline over the years for both “yellow” and “black” morphs, whereas for adult snakes (> 5 yr), survival was constant or even increased slightly. SU ZA N N E L. C O LL IN S, C N A H IGUANA • VOLUME 14, NUMBER 4 • DECEMBER 2007 265NATURAL HISTORY RESEARCH REPORTS contained an independent time trend for survival of each age, morph, and lab- treatment group. For snakes of the first two age groups (ages 1 yr and 2–4 yr), survival tended to decline over the years for both morphs, whereas for adult snakes (> 5 yr), survival was constant or even increased slightly. These data on survival and recapture are among the first rigorous estimates of these parame- ters in a rattlesnake and among the few available for any viperid snake. These data are useful for analyses of the life- history strategy, population dynamics, and conservation of this long-lived snake. Ringneck Snakes are Toxic to Prey Ringneck Snakes (Diadophis punctatus) are suspected of being venomous because their Duvernoy’s gland secre- tions have high levels of phospholipase activity, which is characteristic of many viperid and elapid venoms, and because anecdotal reports of feeding behavior are consistent with the use of a venom. O’Donnell et al. (2007. Toxicon 50: 810–815) tested the toxicity of Northwestern Ringneck Snake (D. p. occidentalis) oral secretions to a natural prey species, Northwestern Garter Snakes (Thamnophis ordinoides), by injecting 2–35 µl of oral secretions intraperitoneally. All doses were 100% lethal within 180 min. The dose signifi- cantly affected the time to loss of a right- ing response. Neither injection of saline nor denatured oral secretions resulted in loss of a righting response or any visible detrimental effects. The authors sug- gested that Northwestern Ringneck Snakes may have evolved venom to sub- due larger prey items than the snake would otherwise be capable of taking. Virginia Herpetological Society Publications On-line The Virginia Herpetological Society has digitized all of its publications from 1958 to 2005, providing easy access to almost 50 years worth of field notes, articles, and the history of the society. Interested herpetologists are encouraged to access this resource at fwie.fw.vt.edu/ VHS/ (or publications specifically at fwie.fw.vt.edu/VHS/vhs_history.htm). Fourth Annual Sonoran Desert Herpetological Symposium The Tucson Herpetological Society and its cosponsors are pleased to announce the fourth symposium on “Current Research on Herpetofauna of the Sonoran Desert” from 11–13 April 2008. The goals of this meeting are: (1) Presenting research on the herpetofauna of the Sonoran Desert (in the states of Arizona, Sonora, and on the Baja California Peninsula and gulf islands), and (2) Bringing the interested commu- nity together to get better acquainted. Invited speakers are Harry Greene, Ed Moll, and Cecil Schwalbe. The first three Sonoran Desert Herpetofaunal symposia were an epiphany for many. These symposia revealed the wide variety of research being conducted in the area. For more informa- tion, see: http://tucsonherpsociety.org/. N E W S B R I E F S Northwestern Ringneck Snake (Diadophis punctatus occidentalis) oral secretions are toxic to a natural prey species, Northwestern Garter Snakes (Thamnophis ordinoides). SU ZA N N E L. C O LL IN S, C N A H The Tucson Herpetological Society and cosponsors announce the fourth symposium on “Current Research on Herpetofauna of the Sonoran Desert.” TH O M A S W IE W A N D T, W IL D H O R IZ O N S