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.

We studied the long-nosed leopard lizard, Gambelia wislizenii, in the Great Basin Desert of southeastern Oregon to identify intraspecific patterns of behavioral variation. Sex and body size played an important role in determining intraspecific behavioral differences. Males and females showed different habitat preferences, with males spending more time on hardpan and in the center of shrubs. Males made more long moves and clustered their long moves more frequently than females. Smaller lizards displayed more head turns, tongue flicks, and use of elevated perches. Smaller individuals also spent a higher proportion of time moving.

Limited information is available regarding the digestibility or germination of seeds after passage through the digestive system of northern bobwhites (Colinus virginianus), especially of plants associated with the sand sagebrush (Artemisia filifolia)–mixed prairie community. Thus, our objectives were to determine the apparent digestibility of seeds of 45 plant species associated with the sand sagebrush–mixed prairie community and the germination of seeds before and after passage through the digestion system of bobwhites. Seeds of 12 of 45 species fed to bobwhites were found to pass through the digestive system intact. The apparent seed digestion pattern of the 12 plant species with incomplete digestion of seeds was legumes > forbs > grasses > shrubs. At the end of a 7-d germination period, the digestion of seeds by bobwhites reduced seed germination of alkali sacaton (Sporobolus airoides), black-eyed Susan (Rudbeckia hirta), and western yarrow (Achillea millefolium var. occidentalis) but increased the germination of white prairie clover (Dalea candida) seeds (P ≤ 0.05). However, the germination percentage of predigestion seeds of white prairie clover exceeded that of postdigestion seeds (P < 0.05) by the end of a 21-d germination period. Averaged across species, the 21-d seed germination of postdigestion seeds was lower than predigestion seeds (P < 0.05). Viable seeds found in feces are disseminated by quail onto the landscape. Plant species that have been lost from overgrazing or the application of herbicides might be reintroduced onto landscapes through dissemination by bobwhites via food plots, feeding stations, or both if the seeds are deposited onto a suitable germination substrate with suitable seed germination conditions.

Federal land managers and ranchers often use prescribed fire as a tool to reduce invading woody plants within desert grasslands of the arid southwestern United States. Managers must evaluate the threat of the burn toward the health and survival of plants of concern including how preemptive clearing before prescribed fire might benefit these species. One example is the endangered Pima pineapple cactus (Coryphantha scheeri var. robustispina), a small hemispheric cactus of desert scrublands and grasslands of south-central Arizona and northern Sonora, Mexico. In 2014, we examined survival of Pima pineapple cactus documented in 2009 or 2010 within grasslands of Buenos Aires National Wildlife Refuge in Arizona. Of the 72 sites observed, 35 had no burn after documentation and 37 experienced prescribed fire. Refuge staff removed vegetation between 0.3 and 3.0 m from the cactus preburn. We found that Pima pineapple cacti in areas subjected to prescribed fire and with preemptive clearing had the same survival statistically as cacti from sites that were not burned.

We evaluated Ictidomys tridecemlineatus for sexual dimorphism by taking 40 skeletal measurements from 267 specimens from Texas, New Mexico, and Oklahoma. We compared measurements from males and females using discriminant-function analysis with included analyses of variance. Males and females were significantly different overall. Of the nine characters that were significantly different, eight were larger in males, while females had a greater sacrum width.

Catastrophic weather can affect individuals unequally and lead to episodic selection, but the effects of weather events are rarely documented. In August 2015, a nighttime thunderstorm led to the deaths of hundreds of purple martins (Progne subis) roosting in downtown Tulsa, Tulsa County, Oklahoma. We compared samples of birds dying to those that survived, and we found nonrandom mortality based on age and sex. Yearling females were overrepresented among the dead, and juveniles were overrepresented among the survivors. The results could reflect differences in where birds were in the roost, and they suggest the potential for age- or sex-based selection on perch preference, dominance, or migratory phenology.

We report the age and distance moved for an individual paddlefish (Polyodon spathula) that was tagged March 1998 in the Cimarron River Arm of Keystone Lake, Oklahoma, and snagged by an angler in April 2016 downstream of Eufaula Dam, Oklahoma. The fish was part of a cohort spawned in 1995. At the time of initial capture, the fish measured 795 mm eye–fork length, was estimated to be 3 y old, and 18 y had elapsed before its recapture by an angler in 2016, indicating this fish was 21 y old at recapture. Although paddlefish as old as 27 have been estimated in the Grand River basin of Oklahoma, this is the oldest fish known in the Arkansas River basin of Oklahoma. At the place of its recapture, this fish would have traveled approximately 235 km, passing downstream through three dams before moving upstream to Eufaula Dam.

Based on herpetofaunal records, New Mexico is one of the most diverse states in the American Southwest. We visually summarized reptile and amphibian diversity in New Mexico using occurrence data from the past 20 years. We also identified patterns of species richness by county and discuss survey bias as a factor. In general, northwestern counties had the lowest number of species while central and southwestern regions had the highest numbers of species. We also recognized species-rich counties with few to no new county records in the past 20 years as areas that potentially reached survey saturation.

As human population densities grow around the boundaries of protected areas in lower-income economies, there are frequently concomitant increases in environmental degradation. The purpose of this study was to examine water chemistry and the isotopic signatures of primary consumers in streams in and around a national park in the tropics to document whether park watersheds were affected by untreated wastewater. Three of the six study sites had concentrations of soluble reactive phosphorus >39 μg/L. Additionally, there was a strong, positive correlation between δN¹⁵ values of grazing snails and phosphorus concentrations of the water, suggesting that sewage effluent is influencing trophic ecology in the protected aquatic habitats. The results from this study lend support to recent calls for management beyond riparian buffers for conservation of freshwater ecosystem integrity in protected areas.

We report a record of the endangered Central American little spotted cat (Leopardus tigrinus oncilla) from Volcán Barú National Park in the state of Chiriquí, Panama, from a scat identified through noninvasive genetics. This record, from just below the summit of Panama's highest peak, represents the highest-elevation record for the species in Panama. Additionally, we designed new DNA primers for identification of L. tigrinus oncilla from scat samples.

From 1944 to 1990, only 10 razorback suckers (Xyrauchen texanus) were captured in the Colorado River within the Grand Canyon, Arizona. Except for a single larval razorback sucker captured in 1998 near Havasu Creek, the species was not found during fish surveys conducted between 1990 and 2011. Biologists confirmed the presence and spawning of razorback sucker within the Grand Canyon in 2014 and 2015 when conducting sampling for small-bodied (age 0 ) and larval fishes. Although no juvenile or adult razorback suckers were found, larvae were captured indicating that razorback sucker are using historical Colorado River habitats within the Grand Canyon.

Using the isotopic carbon and oxygen ratios present in dental enamel, the diet and the habitat of an individual of the Pliocene rhinoceros Teleoceras fossiger from San Francisco de los Reyes, Michoacán, México, were inferred. The values of δ¹³C and δ¹⁸O indicate that this animal fed on C₃ plants and lived in enclosed areas similar to those found in some Florida specimens. However, because only one specimen was analyzed, it is not possible to determine if these rhinoceroses in Mexico were specialists or generalists in their diet.

Little is known about the antipredator strategies of juvenile collared peccaries (Pecari tajacu). This note reports camera trap footage of an interaction between a young collared peccary and two potential predators, a gray fox (Urocyon cinereoargenteus) and a bobcat (Lynx rufus), as well as a personal observation of two young peccaries in what appeared to be physiological thanatosis (a state of tonic immobility). Juvenile mammals are particularly vulnerable to predation, and survivorship in this age class is a critical driver of population dynamics. Documenting the antipredator behaviors used by collared peccaries contributes to our understanding of the distribution of such behaviors among ungulate taxa, which is important in understanding the evolution of responses to predation.

Bobcats (Lynx rufus) are solitary felines, having minimal interaction between individuals except for mating or rearing of kittens by females. We report observations of nonaggressive interactions observed and photographed among bobcats in an impacted landscape of the Southern High Plains of Texas. These included the temporary mixing of bobcat litters with at least one adult female present, interactions involving related females and a juvenile, a male bobcat in the presence of a nursing female and her kittens, and several adult bobcats accompanied by a juvenile.

Dipodomys merriami is a rodent inhabiting grassland and desert scrub. Its distribution covers southwestern United States to southern Zacatecas. During 2015 a specimen was collected near the lagoon of Santiaguillo, Durango, Mexico. This species is reported for Durango; however, the new record extends the distribution about 58 km southwest from the nearest populations of Dipodomys merriami ambiguus, and about 75 km northwest of Dipodomys merriami atronasus distribution.