In Mexico, the area from the delta of the Colorado River to southern Colima (ca. 2,000 km) is a transition zone from the most arid deserts of North America to tropical rainforests. Data for temperature and precipitation from 254 meteorological stations, along with field data, were used to analyze relationships between climate and vegetation. Several bioclimatic classification schemes were contrasted to explain distribution of the main types of vegetation. Vegetation follows a spatial arrangement associated with a north-south rainfall gradient, i.e., hyperarid and arid shrub deserts in a tropical-desert bioclimate, semiarid thornscrubs or thornforests and dry summer-green deciduous forests in a tropical-xeric bioclimate, and semi-evergreen rainforests in a tropical-pluviseasonal bioclimate. This main gradient is strongly related to two moisture-defined zones: the northern subtropical high-pressure cell, which controls the zone of lesser rainfall with a tropical-desert bioclimate, and the trade wind belt, which causes most rainfall in rainier zones. This zonal pattern can, however, be substantially modified by local factors, mainly mountain rainshadows.

This study characterized loss in body mass by the cave myotis, Myotis velifer, in 7 hibernation seasons (October–March 1979–1986) in western Oklahoma. Average mass entering hibernation was 14.4 g for males and 15.4 g for females. At the end of hibernation, average mass of males and females was 11.5 and 12.0 g, respectively. Males lost an average of 2.9 g (20.1%) and females lost 3.4 g (22.1%). During hibernation, males and females lost 0.021 and 0.024 g/day, respectively. We detected no difference in rate of loss of mass between the first and second halves of hibernation for either sex. Males and females lost 3.8 and 4.1 g, respectively, during 2005–2006, when only two visits were made to the cave (October and March). These values for loss in mass were slightly more than losses recorded for males and females when bats were sampled each month during hibernation.

We analyzed temporal variation in abundance of hibernating bats from long-term records (1965–2004) in gypsum caves of the Red Hills of Kansas and Oklahoma, a region lying at peripheries of geographic ranges of four species of bats. Nonparametric correlation analyses were used to evaluate variation in abundances of five species among 12 hibernacula. Townsend's big-eared bat (Corynorhinus townsendii) showed no significant change in abundance among most of its hibernacula, but exhibited one increase and one decrease in abundance in two hibernacula. The cave myotis (Myotis velifer) displayed increasing abundance in some hibernacula (27% of hibernacula, n  =  3) and one decrease (9% of hibernacula, n  =  1). The tri-colored bat (Perimyotis subflavus) exhibited increasing abundance in 60% (n  =  6) of its hibernacula. The pallid bat (Antrozous pallidus) and big brown bat (Eptesicus fuscus) exhibited no statistically significant change in size of population in any hibernaculum, although the pallid bat occurred infrequently and in low numbers (≤11 individuals) in the hibernaculum where it was detected. The changes in abundance we detected may reflect range expansions of some species (e.g., tri-colored bat) or changes in qualities of hibernacula or other aspects of habitats, but underlying mechanisms are unknown.

Analizamos la variación temporal en abundancia de murciélagos en invernaderos por medio de registros de largo plazo (1965–2004) en cavernas de yeso de las Red Hills de Kansas y Oklahoma, una región que se encuentra en los límites de las distribuciones geográficas de cuatro especies de murciélagos. Se usó el análisis de correlación no paramétrica para evaluar la variación en abundancia de cinco especies entre 12 invernaderos. El murciélago orejas de mula (Corynorhinus townsendii) no mostró cambios significativos en abundancia en la mayoría de sus invernaderos, pero exhibió un aumento y una reducción en abundancia en dos invernaderos. El murciélago de la cueva (Myotis velifer) mostró aumento en algunos invernaderos (27% de los invernaderos, n  =  3) y en un sitio una reducción (9% de los invernaderos, n  =  1). El murciélago Perimyotis subflavus exhibió un aumento en abundancia en 60% (n  =  6) en sus invernaderos. El murciélago pálido (Antrozous pallidus) y el gran murciélago marrón (Eptesicus fuscus) no exhibieron cambios significativos con respecto al tamaño poblacional en ningún invernadero, aunque el murciélago pálido apareció en baja frecuencia y en bajos números (≤11 individuos) en el invernadero donde fue detectado. Los cambios en abundancia que detectamos pueden reflejar expansiones en la distribución geográfica de algunas especies (por ejemplo, el murciélago P. subflavus) o cambios en la calidad de invernadero u otros aspectos de hábitat, pero se desconocen los mecanismos subyacentes.

We analyzed fecal pellets from 59 Nyctinomops femorosaccus and 54 Tadarida brasiliensis to assess dietary overlap in an area of sympatry. Lepidoptera, Hemiptera, and Coleoptera were the most abundant orders of insects. Niche-breadth indices were narrow overall and highest in June for both species. Indices of overlap indicated nearly complete overlap in use of resources. There does not appear to be resource partitioning of diet at the taxonomic level examined in these species during summer when sources of food are expected to be more abundant. There was a dietary shift from predominantly Lepidoptera to Hemiptera in March for N. femorosaccus, but not for T. brasiliensis. Resources other than food may impose a greater limitation on size of these populations.

An updated list of the bats of northwestern Durango, based on recent collections and literature records, is presented. A total of 43 species were recorded, five for the first time in the state (Balantiopteryx plicata, Artibeus hirsutus, Artibeus intermedius, Chiroderma salvini, and Myotis carteri). Comparisons with other intensively sampled localities across Mexico indicate that species richness in the Sierra Madre Occidental of northwestern Durango is comparable to that of Mexican rainforests, resulting from high diversity of habitats in relatively small areas. Species composition in this region is dominated by vespertilionid and molossid bats, whereas phyllostomids dominate tropical rainforests; thus, species assemblages are considerably different. Moreover, anthropogenic pressure is comparatively lower than in most of the humid tropics of Mexico. Nonetheless, no protected area exists that includes the complete spectrum of habitats of the region. An immediate conservation strategy is urgently needed if this largely unknown region of Mexico is to be preserved.

We used standard mark-recapture techniques to investigate ecological characteristics of populations of Peromyscus leucopus (white-footed deermice) inhabiting two locations within a site contaminated by heavy metals, Tar Creek Superfund Site, and reference sites, Lake Carl Blackwell and Oologah Wildlife Management Area, in northeastern Oklahoma. Basic demographic parameters such as size of population, rate of survival, rate of recapture, mean minimum longevity, number of reproductively active females, reproductive success, and incidence of infestation by botflies (Cuterebra fontinella) were not significantly different between contaminated and reference sites. However, adult, non-reproductive P. leucopus inhabiting contaminated sites had, on average, a larger body mass than those from reference sites. Other indicators of overall individual health, dental condition and prevalence of botfly infestations were significantly different among populations. Instances of extensive mottling of the upper and lower incisors, a reliable indicator of exposure to contamination by heavy metals, were only noted in individuals inhabiting contaminated sites. Unfortunately, no direct link between contamination and alterations to some population parameters could be established.

I studied ecological relationships of 10 bobcats (Lynx rufus; 4 males, 6 females) from an unexploited population in the Chihuahuan Desert of southern New Mexico during 2004–2008. Using the 95% adaptive-kernel method, I estimated annual size of home ranges to be 12,887 ha for males and 2,847 ha for females. Average activity during nighttime and daytime was 80.6 and 18.8%, respectively. Desert cottontails (Sylvilagus audubonii) were the most common prey in scats. Annual rate of survival was 0.875 for males and 0.917 for females. Average weight of males and females was 12.6 and 9.0 kg, respectively. Two bobcats tested positive for toxoplasmosis. Compared to other areas, bobcats in my study area were heavier, there was more contrast between daytime and nighttime levels of activity, and males had larger home ranges. Rate of survival was similar to other unexploited populations.

During 2006–2007, we studied movements of native bluehead suckers (Catostomus discobolus) and flannelmouth suckers (C. latipinnis), and non-native white suckers (C. commersonii) and longnose suckers (C. catostomus) in the Big Sandy River, Wyoming. Radiotransmitters were surgically implanted into 20–22 fish of each species in September and October 2006. Movements of all four species in autumn and winter were short with most fish remaining ≤2 km from locations where they were captured initially. Bluehead suckers and flannelmouth suckers began movements downstream in mid-to-late April and returned upstream to locations ≤2 km from their original locations by early summer. White suckers did not make substantial movements during spring, whereas longnose suckers made movements upstream during mid-June and returned downstream by early July. During their estimated spawning periods, longnose suckers used upstream portions, bluehead suckers and white suckers used middle portions, and flannelmouth suckers used downstream portions of the study area.

During June–September 2007, we searched bird nests for evidence of parasitism by brown-headed cowbirds (Molothrus ater) and we tested response of the avian community to taxidermy mounts of a brown-headed cowbird in a tropical deciduous forest in the Chamela-Cuixmala Biosphere Reserve in western Mexico. Of 46 nests found (black-capped gnatcatcher Polioptila nigriceps, 2; red-breasted chat Granatellus venustus, 1; blue bunting Cyanocompsa parellina, 1; orange-breasted bunting Passerina leclancherii, 1; rufous-backed thrush Turdus rufopalliatus, 1; yellow-green vireo Vireo flavoviridis, 39), only one was parasitized (nest of a black-capped gnatcatcher). Experimental responses to taxidermy mounts suggested that yellow-green vireos may have had previous contact with cowbirds. We conclude that in the Chamela-Cuixmala Biosphere Reserve, parasitism by brown-headed and bronzed cowbirds (Molothrus aeneus) remains low, or even absent for some species, as on the yellow-green vireo, but this situation could change in the near future because significant developments for the tourism industry are planned adjacent to the reserve; that could create new habitat and sources of food for cowbirds.

Geographic range of the jaguar (Panthera onca) in Mexico has decreased due to illegal hunting, loss of prey, and loss of habitat. No survey of jaguars has been conducted in San Luis Potosí since 1953, despite potentially suitable habitat in the Sierra Madre Oriental. During May 2006–March 2008, we conducted 22 field surveys, including interviews of local officials, residents, landowners, and hunters from 42 communities, and searched for tracks near each location where jaguars were reported in the Huasteca Region of the Sierra Madre Oriental of San Luis Potosí. We obtained 34 records of jaguars, 28 considered as recent records comprising ≥12 individuals and 6 historic records. Jaguars were recorded in oak forest (31.1% of records), tropical deciduous forest (28.1%), cloud forest (12.5%), tropical forest (12.5%), piedmont scrub (9.4%), pine-oak forest (3.1%), and along a border between a sugar cane plantation and tropical forest (3.1%). Locations were 150–2,400 m in elevation. We documented presence of diverse prey and four other species of felids. We generated a distribution map for jaguars and estimated loss of forests for 1970–2000. Geographical distribution of jaguars in San Luis Potosí extends north (22°30′N) to the municipality of El Naranjo, south (21°24′N) to the municipality of Xilitla, east (98°54′W) to the municipality of Ciudad Valles, and west (99°34′W) to the municipality of Rayón. The distribution comprises the subprovince of the Gran Sierra Plegada, Carso Huasteco, and Sierra del Abra Tanchipa of the Sierra Madre Oriental. Given the number of records and quality of remaining habitat, the Sierra Madre Oriental in San Luis Potosí should be considered as a high priority for long-term conservation of jaguars in Mexico.

The general paradigm associated with overland movements of semi-aquatic turtles between aquatic habitats predicts that males move more frequently and for greater distances than females and juveniles, and that larger individuals move more frequently than smaller individuals. We used capture-mark-recapture techniques to examine interpond movement patterns of western painted turtles (Chrysemys picta) among a complex of eight ponds in east-central Kansas in 2007. We assessed the broad applicability of predictions of the general paradigm by testing the following hypotheses: 1) males make interpond movements more frequently than females, 2) larger adult-sized individuals make interpond movements more frequently than juveniles, 3) propensity for pond-to-pond movement varies as a function of size within categories (i.e., males, females, and juveniles), and 4) mean minimum distance traveled between ponds is greatest for males. The proportion of males that moved between ponds was not significantly different from that of females, and we did not observe a significant difference in proportion of adults and juveniles categorized as movers. Mean length of plastron of individuals classified as movers and non-movers was not significantly different within either females or juveniles. Males categorized as non-movers were significantly larger than those that made interpond movements. Mean minimum distance traveled between ponds was not significantly different among males, females, and juveniles. Thus, our results were not consistent with any of the predictions of the general paradigm. Costs and benefits associated with overland movements of turtles are likely to vary both spatially and temporally. We suggest that as cost-benefit ratios vary, so should predictions about the propensity for interpond movements among turtles of different sexes, sizes, and ontogenetic stages.

We analyzed data from studies of cougars (Puma concolor) completed during 1982–1997 in Big Bend, Carlsbad Caverns, and Guadalupe Mountains national parks, and Big Bend Ranch State Park. We estimated annual and seasonal (hunting and non-hunting periods) rates of survival and rates of cause-specific mortality for 31 males and 29 females. In the three studies, annual rates of survival for females were higher than those for males. Seasonal rates of survival were variable between sexes and among studies; however, pooling males and females revealed that rates of survival at Carlsbad Caverns and Guadalupe Mountains national parks and Big Bend Ranch State Park were lower during hunting periods (1 September–31 March) compared to non-hunting periods (1 April–31 August). However, pooled rates of survival for males and females at Big Bend National Park were equal during hunting and non-hunting periods. Trapping was the greatest annual source of cause-specific mortality in all study areas. Shooting and unknown sources were the next greatest sources of mortality. Mortalities from intraspecific strife and natural causes were documented only in Big Bend National Park. Rates of survival for cougars in Texas and the Guadalupe Mountains of New Mexico are among the lowest in the United States. Low rate of survival should be considered when developing management plans; however, we caution against extrapolating results from limited study areas to the entire region.

We report on Aspidoscelis sexlineata (six-lined racerunner) from the four known sites of occurrence in Mexico, one being a southward range extension of 74.3 km for the species. These sites are situated in the extreme eastern part of the municipality of Matamoros, Tamaulipas, and are nearest to records for the species in the United States for Brazos Island-South Padre Island, Cameron County, Texas. In both regions, A. sexlineata occurs a short distance from the seashore in habitats formed and influenced by perturbations of hurricanes and the maritime climate of the Gulf of Mexico (e.g., sand dunes devoid of congeners with openings in halophytic vegetation). Samples of A. sexlineata from Tamaulipas are statistically similar to those from South Padre Island in two meristic characters, one ratio, and snout–vent length, but significantly different in one meristic character and one ratio involving color pattern. Because similarities among specimens from the plains of southern Texas, South Padre Island, and Tamaulipas are strongly indicated, it is reasonable to allocate the three groups to A. sexlineata stephensae, Texas yellow-headed racerunner.

From the 259 species of legumes recorded, the distribution of 242 wild species of legumes over 224 locations within 12 plant communities was examined in northeastern Mexico. Objectives were: (1) to determine diversity of legumes in the mountains and plains of northeastern Mexico and (2) to elucidate distributional patterns of legumes in this region. The subfamily Papilionoideae had the largest number of wild genera (47) and species (167), followed by Mimosoideae (13 and 44) and Caesalpinioideae (10 and 31). Genera with the largest number of native species were Dalea (28), Desmodium (16), Astragalus (13), Senna (13), Acacia (11), Phaseolus (10), Crotalaria (9), and Lupinus (8). Of wild legumes, 24 genera had ≥3 species each and 21 species were endemic to this area; most were Lupinus (5 species), Astragalus (4), and Dalea (4). Almost all of the 21 endemic species were >1,500 m in elevation in oak-pine forests (7), oak forests (5), and coniferous forests (5). Only one endemic species occurred <1,400 m in elevation. Of the endemic species, 90.5% were in the subfamily Papilionoideae. There were 17 cultivated legumes, most of them in Caesalpinioideae. Similarity and dissimilarity matrixes using the Sørensen index were assessed using minimum-variance clustering. Using diversity of legumes, three assemblages of plant communities were recognized. Oak, oak-pine, mesic-conifer, and cool-temperate coniferous forests harbored the highest diversity of legumes, while rosetophyllous and xeric scrublands and halophytic communities contained the lowest diversity.

In the understory of many Juniperus woodlands, herbaceous cover and biomass are reduced or eliminated compared to interstitial grasslands. However, there are some exceptions. Carex planostachys (cedar sedge) is a widespread herbaceous species associated with J. ashei and occurs in the understory of these woodlands in central Texas. The purpose of this paper was to compare cover and biomass of herbaceous vegetation along a gradient from below the canopy of J. ashei into an associated intercanopy patch or grassland. Levels of light are reduced below the canopy, whereas litter and moisture in the soil are higher. Cover and biomass of C. planostachys were higher below the J. ashei canopy and canopy edge. Total cover and biomass of grasses were higher in the intercanopy at elevated levels of light, reduced litter, and lower soil moisture. Spatial distribution of C. planostachys below the canopy suggests that this species is tolerant of shade and may require a woodland canopy for growth and development.

Velvet ants (Hymenoptera: Mutillidae) are a conspicuous component of the fauna of Nearctic deserts, but little is known about their natural history. We observed a nocturnal aggregation of female velvet ants on the dune-restricted plant Croton californicus var. mohavensis (Euphorbiaceae). We collected 44 female velvet ants on or directly beneath a group of male and female plants during 2 nights. Some individuals were on flowers drinking nectar. The discovery of nocturnal velvet ants on C. californicus marks the first record of nectaring in nocturnal female velvet ants.

Intraspecific variation in blackbrush (Coleogyne ramosissima) seed imbibition was investigated using seeds collected at elevations of 1,100 and 1,700 m in the Spring Mountains, Clark County, Nevada. Under experimental conditions in the laboratory, seeds of C. ramosissima collected from a high-elevation site imbibed more water than seeds collected from a low-elevation site. Amount of water in seeds at full imbibition was not affected by mode of wetting and age of seed. Thickness of testa, a possible source of regulation of imbibition, also did not differ between collection sites. These results suggest that imbibition potential of seeds of C. ramosissima may differ as a function of elevation, a trait with potential adaptive importance for this dominant aridland shrub.

Two photographs of the ocelot (Leopardus pardalis) were obtained on Sierra Fría, Aguascalientes, Mexico. These records extend the known geographic range of the species ca. 270 km east of Nayarit and 300 km northwest of Guanajuato.

The Bayou Bodcau crayfish, Bouchardina robisoni, is a rare endemic decapod that is considered critically imperiled (S1) in Arkansas by The Nature Conservancy. Few collections of this species have been made since 1977, with specimens previously known only from four counties of western and southwestern Arkansas. Herein, we provide two new distributional records in addition to documenting all known specimens and collection sites. We suggest updating the conservation status to threatened.

We report first records of the Guatemalan beaded lizard (Heloderma horridum charlesbogerti) from the Pacific versant of Guatemala. The presence of this lizard in the region further substantiates the notion that this species gained access into the region through a Pacific corridor.

During a survey of small mammals in the municipality of Santa Maria Chimalapa in eastern Oaxaca, Mexico, we obtained the first record of Thomas' shaggy bat (Centronycteris centralis, Vespertilionidae) and the funnel-eared bat (Natalus lanatus, Natalidae), as well as the second record of the false vampire bat (Vampyrum spectrum, Phyllostomidae) for the state. With these new records, the list of bats for Oaxaca increased to 86 species, confirming Oaxaca as the Mexican state with the greatest number of species of terrestrial mammals and, in particular, the Chimalapas region as one of the most diverse regions in the country.

The objective of this study was to investigate effectiveness of a common drift-fence trap, the single-funnel trap, in comparison with a new one-way double-funnel design. We expected this new design to decrease escapes over standard trapping techniques and, therefore, increase efficiency of sampling using drift fences. Five 15-m, linear, drift-fence arrays with three 15-m, Y-shaped arrays were placed at two field sites in central Texas and a single 15-m, linear array was placed at a field site at Seabrook Island, South Carolina. Each array contained an equal number of the single-funnel and double-funnel traps. One-way double-funnel traps caught and retained significantly more reptiles, total herpetofauna, and total vertebrates than did single-funnel traps. Our results indicated that double-funnel traps offer an improved trapping technique when compared with the typical single-funnel trap.

Tornados can influence forests by increasing openness of canopies and decreasing the frequency of large trees. These changes may indirectly influence the avian community; therefore, we monitored birds in a Cross Timbers community that had recently experienced an F3 tornado. We surveyed the avian community 6 times during summer of 2 years. We performed surveys along three transects in the impacted site, a nearby non-impacted site, and a grassland. Species richness and composition were significantly different among habitats, but these differences were not related primarily to damage by the tornado. A partial canonical-correspondence analysis suggested that differences among habitats were due to species segregating between habitats with trees (impacted and non-impacted forests) and those without trees (grassland). It appeared that the avian community did not respond strongly to impact of the tornado. We suggest that avian communities in relatively open and patchy forests, such as the Cross Timbers, will not respond as strongly to localized disturbance from wind as will communities in more mesic, closed-canopy forests. Open woodlands lack adequate habitat for species that occupy interiors of forests; these species are expected to segregate the strongest between impacted and non-impacted sites.

We assessed use of habitat by the semiaquatic lizard Norops aquaticus along the Río Java at the Las Cruces Biological Station, Costa Rica. We surveyed the river for lizards and determined characteristics of their perches relative to edge of the water. Individuals preferentially positioned themselves near eddies. Demographic classes differed in height of perches above the river, with adult males using the highest perches. Males were most likely to perch directly above water. In addition, males and juveniles tended to be in exposed areas, whereas females selected cover. Behavior of N. aquaticus on land is dependent on characteristics of rivers.