We used non-invasive genetic techniques to investigate the number and distribution of cougars (Puma concolor) inhabiting Guadalupe Mountains National Park, Texas. During 8 years, ≥31 resident and transient cougars were identified genetically and ≥15 individuals used the park in 2002. Based on estimates of size of home ranges of males and females, the park should support 4–6 resident adults. Genetic data suggest a high number of transients and, perhaps, an unstable population that may be the result of intense hunting pressure outside protected areas. Analysis of genetic diversity indicates restricted gene flow between the park and other populations in western Texas.

We radiotracked 23–63 adult female elk (Cervus elaphus) during 2003–2007 to determine whether condition (amount of body fat), survival of adults, or production and survival of juveniles was being impacted by habitat or other influences. Lactating females accrued relatively high levels of body fat (8.9–11.4%). Rates of survival of adult females were 0.95–1.00, rates of pregnancy were 0.87–0.96, and probability of pregnancy was most strongly related to mass, with larger females more likely to conceive. Preweaning (0.69–0.82), postweaning (0.58–0.87), and annual (0.44–0.71) rates of survival of juveniles varied among years. Excluding harvest, elk were able to achieve an annual rate of increase in size of population of 11–12%, which was limited only by survival of juveniles. Survival of juveniles was associated primarily with precipitation during gestation and parturition, indicating few constraints related to habitat.

We studied relationships between quality and quantity of habitat and conversion of land to caliche roads and well pads associated with oil and gas development. We asked how these factors affected abundance of dune-dwelling lizards, with emphasis on a habitat specialist, the dunes sagebrush lizard Sceloporus arenicolus. Open depressions in dune complexes are a critical landscape feature for S. arenicolus, and extensively used by all species; thus, size and total area of open depressions in a study site were our measures of habitat quality and quantity. There were significant differences in habitat quality among sites, and habitat quality and quantity were correlated significantly. Abundances of all lizards, including S. arenicolus, varied significantly among sites and this variation could be explained by amount of habitat at a given site. Relationships between oil and gas development, quantity and quality of habitat, and abundances of lizards likely occur on different spatial scales constraining our ability to detect direct effects of oil and gas development alone. Our research is the first to investigate effects of oil and gas development on an assemblage of dune-dwelling lizards.

We examined two co-occurring species of Malvaceae in the savanna of central Texas to determine their photosynthetic response to varying levels of light. Abutilon theophrasti had a mean (±1 SD) density of 4 ± 4 plants/m² in the open-grassland phase of the savanna, and a density of 1 ± 2 plants/m² under canopy of woody mottes. Malvaviscus arboreus var. drummondii was not in the open-grassland phase and had a density of 3 ± 6 plants/m² under canopy of woody mottes. Mean midday levels of light in the open and canopy were significantly different at 2,004 versus 192 µmol/m²/s, respectively. Maximum photosynthetic rate of A. theophrasti (34.6 ± 3.6 µM CO₂/m²/s) occurred at a photosynthetic-flux density of 2,000 ± 0.0 µM /m²/s and was significantly greater than the maximum photosynthetic rate of M. arboreus var. drummondii (14.8 ± 2.2 µM CO₂/m²/s), which occurred at a photosynthetic-flux density of 1,350 ± 173.0 µM /m²/s. Light saturation, light-compensation point, dark respiration rates, stomatal conductance, and transpiration rates for A. theophrasti were higher than rates of M. arboreus var. drummondii. These species have significant differences in most gas-exchange measurements, reflecting differences in their habitats. Based on these differences, M. arboreus var. drummondii is a sun–shade intermediate and A. theophrasti is a sun plant. However, maximum-photosynthetic-rate values and levels of light at maximum photosynthetic rate suggest that M. arboreus var. drummondii would do well in edge or partially shaded habitats.

Nichol's turk's head cactus Echinocactus horizonthalonius var. nicholii (Cactaceae) occurs in a few isolated populations in the Sonoran Desert of south-central Arizona (Pima and Pinal counties) and in one isolated population in Mexico. Populations of this variety are disjunct from the more widespread typical variety (E. h. var. horizonthalonius) that occurs in the Chihuahuan Desert of New Mexico, Texas, and Mexico. Variety nicholii occurs almost exclusively on Horquilla limestone substrate, and was federally listed as endangered in 1979. Since 1995, we have monitored study plots of this cactus in the Waterman Mountains, Pima County, Arizona, 32°20′N, 111°28′W, elevation 975 m, measuring size of plants, condition, and presence-absence of reproduction in ca. 200 individuals. Here we report data for 1995–2008. Rates of growth were slow, averaging 0.35 cm (SD ± 0.53) in height and 0.26 cm (SD ± 0.28) in diameter/year. Plants usually began flowering when they reached about 4 cm in height and 8 cm in diameter. Of 109 deaths recorded since 1995, 47% followed a visible decline in condition; the remainder of deaths were unanticipated. The study population declined from 129 individuals in 1995 to 89 in 2008.

A significantly greater proportion of brush-cleared plots had the Zapata bladderpod Physaria thamnophila than did uncleared plots. However, density of P. thamnophila, especially density of seedlings, was correlated positively with a canopy-cover index on the four sites studied. These apparently contradictory results may have been due to facilitation of seeds and seedlings of P. thamnophila by litter. Litter, normally associated with shrubs, was spread across the site by brush-clearing. Beneficial effects of brush-clearing (without disruption of soil) on P. thamnophila suggest that fire may have been part of its environment in the past. The four populations of P. thamnophila that we studied fluctuated widely in size and in rates of reproduction and establishment from year to year.

The fly Palpada mexicana is one of the many syrphids that employ hilltopping as a mating system. In central Arizona, males of P. mexicana can be found on peaktops in spring and, to a lesser extent, autumn. Year after year, the flies gather to perch or hover near certain prominent plants on the ridgeline that constitutes Usery Peak, Maricopa County. About 20% of all marked males returned on subsequent days to the landmarks where they had been captured. Although site fidelity and territoriality are apparently fairly weak in this species, the behavior of P. mexicana is similar to that of various hilltopping flies and other insects, but markedly different from those syrphids that wait or search for mates at flowers or oviposition sites.

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.

The Tibicen bifidus species complex is composed of T. b. bifidus (Davis, 1916) and T. b. simplex Davis, 1941. We analyzed biogeographical, morphological, and physiological parameters to determine if these taxa represent two species. There are significant differences in biogeography, as well as selection of host-plant and several morphological characteristics. Comparisons of their calling songs approach statistical significance. Sound-pressure level of alarm calls and thermal responses of the two taxa do not differ significantly. Our data suggest that the two taxa represent distinct species.

Seasonal variability in intensities of ectoparasites of western fence lizards (Sceloporus occidentalis) was quantified in spring, summer, and autumn 2008. Lizards were suspended over pans of water in the laboratory to enumerate replete western black-legged ticks (Ixodes pacificus) and mites. Intensity of ectoparasites was greatest in spring. On average, mites comprised the greatest proportion of ectoparasites, followed by larval and nymphal ticks, respectively. Mites were on lizards year-round. Overall intensity of ticks was greatest in spring, but low during summer and autumn. Males were more heavily parasitized by ticks than females in spring, whereas females had greater intensities of mites in autumn. There was a slight, positive relationship between size of lizard and intensity of ticks, but not with intensity of mites. We report greater intensities of ectoparasites on S. occidentalis than several other studies, which may be due to differences in habitats and methods.

During the 2006 and 2007 breeding seasons, we conducted a systematic survey for western burrowing owls (Athene cunicularia hypugaea) across the portions of California's southeastern deserts that had never been systematically surveyed for the species. We found few or no western burrowing owls in northern and eastern portions of the Mojave Desert or in the Sonoran Desert (excluding Palo Verde Valley). However, there was a substantial concentration of burrowing owls in the western Mojave Desert, which we estimated to contain ≤560 (SE  =  268) breeding pairs. We also documented 179 breeding pairs along the banks of water-conveyance structures in Palo Verde Valley in the Sonoran Desert region. These two disjunct populations comprise a significant portion of the population of burrowing owls in California.

In October 2006, months after shallow experimental ponds in the Salton Sea Basin were filled with water from the Alamo River and Salton Sea, fish were observed in several ponds, although inlets had been screened to exclude fish. During October 2007–November 2009, nine surveys were conducted using baited minnow traps to document species and relative abundance of fish. Surveys yielded 3,620 fish representing five species. Desert pupfish (Cyprinodon macularius), the only native species encountered, was the most numerous and comprised >93% of the catch. Nonnative species included western mosquitofish (Gambusia affinis, 4.1%), sailfin molly (Poecilia latipinna, 2.8%), and tilapia (a mixture of hybrid Mozambique tilapia Oreochromis mossambicus × O. urolepis and redbelly tilapia Tilapia zillii, <0.1%). Dominance by desert pupfish, which persisted over our 2 years of study, was unusual because surveys conducted in nearby agricultural drains yielded relatively few desert pupfish.

We determined the effect of three concentrations of gibberellic acid on germination and photoblastic behavior of five species of Opuntioideae from the Mapimi Biosphere Reserve, southern Chihuahuan Desert, Durango, Mexico. For Cylindropuntia imbricata, addition of high concentrations (1,500 ppm) of gibberellic acid gave a 30% germination similar to the control; for Opuntia rastrera, medium concentrations (1,000 ppm) gave <40% germination; and for O. microdasys, low concentrations (500 ppm) gave 35% germination. High concentrations restricted germination. Opuntia macrocentra and Cylindropuntia leptocaulis did not differ significantly from the control. Opuntia macrocentra required light for germination; addition of gibberellic acid did not substitute for light. For all species, light increased germination and the effect of gibberellic acid is species dependent, rarely better than the control. Species we studied did not seem to have physical dormancy and may have had physiological dormancy that was unaffected by gibberellic acid.

We report observations on feeding and nesting behavior, reproductive condition, and activity patterns of the Mexican red-bellied squirrel (Sciurus aureogaster) during 2000–2002 in an oak-pine (Quercus-Pinus) forest south of Pátzcuaro, Michoacán, Mexico. Squirrels fed heavily on seeds of pines, oaks, and dogwoods (Cornus), and rarely cached food. Squirrels used leaf nests for nesting and did not use tree cavities. Squirrels had year-round breeding activity and were more active in early morning and before sunset; however, daily activities were noticeably reduced during hot and sunny days or during strong winds. Squirrels had two color phases: gray-white and melanistic.

We conducted a survey in March 2007 of two neighborhoods in Tucson, Pima County, Arizona, where coyotes (Canis latrans) were present. The survey was conducted originally in 1992 in the same neighborhoods. We compared responses between years. Coyotes appeared habituated to humans to the point of approaching dogs on leashes; most humans did not attempt to harass nearby coyotes. Responses revealed an increase in frequency of sightings of coyotes between years. Attitudes about coyotes (e.g., nuisance, threatened) affected how humans reacted toward this predator.

We report five new records of mammals for Le Flore County, Oklahoma, and additional records of Sorex longirostris for the state. Records for 14 other species, some not reported from the county or state in decades, provide new information on distributions in southeastern Oklahoma.

Diet of Harris' hawks (Parabuteo unicinctus) was analyzed using 94 pellets and 128 remains of prey collected during autumn-winter 2006 and 2007 in Reserva Oasis la Campana, a privately protected coastal area in central Chile. Hawks consumed primarily small mammals (69.6% frequency, 88.4% biomass). Although native rodents were consumed most frequently (52.5% frequency), European rabbits (Oryctolagus cuniculus) contributed most of the biomass (56.9%) in the diet. Birds were second in importance (23.2% frequency, 10.5% biomass), and some insects and reptiles were consumed. The geometric mean mass of vertebrate prey (267.8 g) was close to that previously documented for Harris' hawks in areas near the Andes Mountains of central Chile. Composition of the diet in our study was similar to that documented for North America, and was almost identical to that in other areas of central Chile.

New distributional records are reported for millipeds of the orders Callipodida, Chordeumatida, Julida, Polydesmida, and Spirobolida. Two state records are documented for the julids, Brachyiulus lusitanus (Verhoeff) and B. pusillus (Leach) in Texas. In addition, we report 21 county records for other taxa, including the third record for Aliulus caddoensis Causey in Oklahoma.

Larvae of the phorid fly Megaselia scalaris were in eggs in a naturally incubated nest of an alligator snapping turtle (Macrochelys temminckii). It appears that these larvae contributed to failure of this nest. Infestation by phorid larvae has been reported previously for eggs and nests of multiple species of turtles, but has not been reported from M. temminckii.

Lampropeltis ruthveni is recorded for the first time from four localities in the Mexican state of Hidalgo. This expands the known range northeastward by 84.6 km (by air) from the nearest locality in the state of Querétaro.

Crematogaster sotobosque is a Neotropical ant previously known as far north as Costa Rica. We report on a collection of this species from a mixed-deciduous-conifer forest in the Santa Catalina Mountains, Pima County, Arizona. We also extend the known distribution of this species southward to Bolivia.

We report the first observation of depredation on a nest of the eastern meadowlark (Sturnella magna) by a speckled kingsnake (Lampropeltis getula holbrooki). Depredation events probably are opportunistic, but they may have an impact on local populations of eastern meadowlarks.