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Invasive species are threatening biodiversity and ecosystem stability globally. The introduction of the California kingsnake (Lampropeltis californiae) on Gran Canaria, Canary Islands, Spain represents an emerging invasion that is already threatening endemic island species. Dead neonatal mice treated with 80-mg acetaminophen tablets are approved as a registered pesticide for control of invasive brown treesnakes (Boiga irregularis) in Guam and could potentially be used as an oral toxicant to control invasive California kingsnake populations. We sought to evaluate oral toxicity of acetaminophen and to determine the dosage necessary for lethal control of invasive California kingsnake populations. Dead mice inserted with a known acetaminophen dose (0 mg, 40 mg, 60 mg, and 80 mg) were fed to California kingsnakes from Gran Canaria. Each dose was tested in 20 male and 20 female snakes representing the size range found in Gran Canaria. After snakes ate their dead mouse, they were monitored for mortality, regurgitation, and time of death and regurgitation. Treatments of 60 mg and 80 mg had 100% mortality, while 40 mg had 87.5% mortality. No control snakes died. Time to death occurred on average 38.6 hours after consuming the dead mouse. The top two time to death models accounted for 97% of model weights and included variables dosage (mg/kg), sex, and dosage * sex or those terms plus body condition index. Out of the 116 snakes that died, 97 regurgitated the mouse that contained the acetaminophen capsule, and time to regurgitation was highly correlated with time to death. Acetaminophen is a highly effective oral toxicant for California kingsnakes. Dead mouse baits treated with acetaminophen have potential as a control method on Gran Canaria but should not solely be expected to protect native species or eradicate California kingsnakes on Gran Canaria. Future efforts should focus on preventing California kingsnakes from invading other Canary Islands.

Amphibians can be important consumers in both aquatic and terrestrial habitats and may represent an important energetic link between the two, particularly in the tropics, where amphibian species richness and abundance are high. In the past 20 years, amphibian populations have declined dramatically around the world; numbers have decreased catastrophically in protected upland sites throughout the neotropics, usually resulting in the disappearance of over 75% of amphibians at a given site, particularly those species that breed in streams. Most studies of amphibian declines have focused on identifying causes and documenting changes in adult abundance, rather than on their ecological consequences. Here, we review evidence for the potential ecological effects of catastrophic amphibian declines, focusing on neotropical highland streams, where impacts will likely be greatest. Evidence to date suggests that amphibian declines will have large-scale and lasting ecosystem-level effects, including changes in algal community structure and primary production, altered organic matter dynamics, changes in other consumers such as aquatic insects and riparian predators, and reduced energy transfers between streams and riparian habitats. Furthermore, because of habitat and functional differences between larvae and adults in most amphibians, the loss of a single species is akin to losing two species.

The diet of Eastern collared lizards (Crotaphytus collaris) from southeastern Colorado, near the northern edge of the range of this species, was described from analysis of the stomach contents of 13 lizards collected at a picnic area in the Comanche National Grassland, Baca County. The diet consisted primarily of beetles of various types and sizes, and grasshoppers, though one female collared lizard consumed two small lizards. These results agree with previously published accounts of Eastern collared lizard diets at other sites and suggests that saurophagy can occur at any site where the opportunity to prey on lizards exists.

Intraspecific chemical communication among related and unrelated conspecifics may play an important role in social organization and kin recognition within snakes. We monitored the movements of 7 adult Crotalus horridus (Timber Rattlesnake) and 22 of their neonates from May 2008 to October 2010. Our objective was to determine if neonates follow their mothers to suitable den sites in North Central Missouri. Mothers tended to move away from the rookery between parturition and ingress, but neonates stayed in the vicinity of their release site for up to a week after the dispersal of their mother. Despite the loss of radiotransmitters, we were able to follow 6 neonates to ingress: 5 overwintered in the same den as their mother and 1 overwintered in a known den of a conspecific female. Our observations support the hypothesis that Timber Rattlesnake neonates follow their mother or, at the very least, follow conspecifics to suitable den sites in the ir first year.

Field endocrine studies providing new comparisons for inference into the evolutionary and ecological factors shaping organismal physiology are important, often yielding novel physiological insights. Here, we explored factors associated with the sex steroid hormone concentrations and adrenocortical response to capture stress in Hog Island boas (Boa constrictor imperator) in the Cayos Cochinos archipelago of Honduras to generate comparative field hormone data from a tropical reptile and test the island tameness hypothesis. Baseline concentrations of testosterone, corticosterone, estradiol, and progesterone were measured during the wet and dry seasons, and an acute stressor of 1 h in a cloth bag was used to assess the stress response. Plasma steroid concentrations in these snakes were generally low in comparison to other taxa. Higher testosterone concentrations in males and higher estradiol and corticosterone concentrations in females were observed during the wet season compared to the dry season, which may be indicative of mating activities and vitellogenesis during this period. Snakes displayed a 15-fold increase in corticosterone concentrations in response to capture stress, a rise that was not impacted by whether a snake had been captured during previous years. The adrenocortical stress response was greater in males and positively related to body temperature. We suggest that this system merits future inquiries into the physiology and behavior ofB. c. imperator, particularly as a model for studying insular impacts on diverse life history characters.

The range of the parthenogenetic lizard Aspidoscelis tesselatus extends from eastern Chihuahua, Mexico, to southeastern Colorado, USA. In Colorado, pattern-class D, source of the neotype of the species, is syntopic with the more widely distributed pattern-class C only in Ninemile Valley of the Purgatoire River, beyond which, in all directions, these pattern classes are allopatric. We identify a recent northward range expansion of pattern-class C to the same northern latitude attained by pattern-class D, thereby establishing a latitudinal baseline for the species. The two northern arrays of pattern-class C, reported herein, occupied open habitats of sparsely distributed shrubs on rocky slopes, whereas the northernmost arrays of pattern-class D were using juniper woodland. Although this allopatric arrangement suggests ecological segregation of pattern classes, we provide an example of pattern-class C in juniper woodland only ca. 11 km south of the new records, which suggests that other factors could be involved.

Studies of recently isolated populations are useful because observed differences can often be attributed to current environmental variation. Two populations of the lizard Anolis lemurinus have been isolated on the islands of Cayo Menor and Cayo Mayor in the Cayos Cochinos Archipelago of Honduras for less than 15 000 y. We measured 12 morphometric and 10 habitat-use variables on 220 lizards across these islands in 2 y, 2008 and 2009. The goals of our study were (1) to explore patterns of sexual dimorphism, and (2) to test the hypothesis that differences in environment among islands may have driven divergence in morphology and habitat use despite genetic homogeneity among populations. Although we found no differences among sexes in habitat use, males had narrower pelvic girdles and longer toe pads on both islands. Between islands, males differed in morphology, but neither males nor females differed in habitat use. Our data suggest that either recent selection has operated differentially on males despite low genetic differentiation, or that they display phenotypic plasticity in response to environmental variation. We suggest that patterns may be driven by variation in intrapopulation density or differences in predator diversity among islands.

In Omar Torrijos National Park, Coclé Province, Panama, we visually located Cope's vine snakes Oxybelis brevirostris at night along trails and streams. Of 203 O. brevirostris located, we documented height of perch for 185 individuals during March 2005–March 2007. All sleeping snakes encountered were on vegetation rather than on the ground. There was no significant difference in height of perch between males (170.1 cm) and females (148.7 cm). There, however, was a significant positive relationship between snout–vent length and height of perch. Longer snakes perched on branches significantly more often than small snakes, which tended to perch on herbaceous leaves.

We examined aspects of natural history and ecology of the black-chested spiny-tailed iguana, Ctenosaura melanosterna, on Cayo Cochino Menor, Honduras, over 6 years to provide baseline data to assist in management of this critically endangered species. Size of territory is resource-dependent, and the species seems to prefer habitats with open canopy. Mating occurred between March and June, with emergence of hatchlings from June to August. Ctenosaura melanosterna is an omnivore that feeds on a variety of vegetation, invertebrates, vertebrates, and food-scraps. The threats to this population include predation by Boa constrictor, competition with an increasing population of Iguana iguana, and potential poaching of adults and eggs for food.

We examined nesting in Norops lionotus to describe nesting sites and to determine if nesting aggregations were by multiple females or repeated deposition of eggs by the same female. We also described eggs during incubation and the subsequent hatchlings. We collected eggs from nests along streams at Omar Torrijos National Park in central Panama and incubated them until they hatched. We located seven nests (six active, one inactive) containing 47 eggshells (2 depredated; 45 hatched) and 67 unhatched eggs. All nests were on the downstream side of large boulders covered by moss and herbaceous vegetation. Estimated minimum number of females using each nest was one to five, depending on assumptions of the estimate. Estimates indicated that nesting aggregations were a combination of multiple females nesting communally and repeated deposition of eggs by the same female. Hatchlings averaged 2.66 cm in snout–vent length, 4.60 cm in length of tail, and 0.42 g in mass, with no significant difference between males and females or among nests. Overall sex ratio for hatchlings was not significantly different from 1∶1.