The lesser prairie-chicken (Tympanuchus pallidicinctus) occurs in the semiarid southern Great Plains, a region prone to periods of drought. Researchers generally believe that lesser prairie-chickens are able to satisfy their water requirements through preformed water and metabolic processes, but also know that they experience low survival and reproductive success during periods of drought. We used motion-sensing cameras to assess lesser prairie-chicken visits to man-made free water sources over a 48-month period from March 2009 to February 2013 in west Texas. Our objective was to examine temporal patterns of water use by lesser prairie-chickens, and to explore life history phenology and environmental conditions that may influence the species' use of free water. We documented 1,439 visits to water sources by lesser prairie-chickens. Their use of water sources was high during the winter months (December–February; 92 visits per 100 trap days) but the highest average visit rate to water sources occurred during the lekking-nesting life stage (March–May; 146 visits per 100 trap days). Water use was lower during the brood-rearing stage (June–August; 71 visits per 100 trap days) and lowest during the brood dispersal and independence stage (September–November; 19 visits per 100 trap days). Water use was strongly associated with dew point (P < 0.0001) and temperature (P = 0.0002) but was not associated with precipitation (P = 0.1037). These data indicate life-cycle stage (e.g., lekking-nesting) and reduced availability of preformed water may influence use of free water sources by lesser prairie-chickens. Current climate models predict the region of the study area will experience increases in temperature and decreases in frequency of precipitation. The combined effect of this would be reduced environmental moisture. If the prediction of increasing aridity in the region holds true, man-made water sources may become a tool for conservation of the species.

Ontogenetic changes in the ecological requirements of fishes are thought to influence intraspecific patterns of occurrence and abundance, yet patterns of variation in the distribution of different cohorts are unknown for many species. In prairie stream headwaters with variable habitats, we predict cohort occurrences, densities, and juvenile growth rates to vary considerably over both space and time. Specifically, the differences in abiotic factors across sites will likely affect the occurrence and growth of different age classes. To evaluate factors associated with cohort structure, we evaluated population dynamics of two cyprinid species, central stoneroller Campostoma anomalum and southern redbelly dace Chrosomus erythrogaster, using a long-term monitoring data set that included six sites sampled semiannually for 8 to 14 years. Densities of adult stoneroller were higher in pools while juveniles had higher densities in riffles, leading to within-site spatial differences in the occurrence of each age class. Across-site habitats also varied in the occurrence of different age classes of stonerollers, with sites being either suitable for both adults and juveniles, specialized for one age class, or temporally variable for both age classes. In contrast to stonerollers, all age classes of dace were pool specialists with constantly high occurrences of both age classes during all times of the year. Age-specific growth, for both species, did not vary across sites, but growth was higher for stonerollers during wet years compared with drier years at two sites. Headwater streams provide important habitat for many fishes, but the use of age-specific habitats is variable among species and likely driven by species traits as well as biotic and abiotic characteristics of those habitats.

The Joshua tree (Yucca brevifolia, Y. jaegeriana) is a large, evergreen monocot distributed patchily across the southwestern United States. The plant occurs on alluvial fans, plains, and bajadas primarily in the Mojave Desert, but populations can also be found in the Great Basin and Sonoran Deserts. Named by the Mormon pioneers for the branching, supplicating arms reaching toward the sky, the species has become an emblematic symbol of the Mojave Desert for residents and visitors alike. Joshua trees inhabit cooler, moister microclimates within the larger desert macroclimate, and research has indicated the species may be vulnerable to future climatic regimes characterized by warmer and drier conditions. Here we present a concise review examining the past distribution, the current population status and threats, and the viability of the species under differing habitat and climate scenarios projected for the future. Additionally, we identify knowledge gaps to guide future research directions. Our results provide insight into management and conservation actions and contribute to a greater understanding of range-wide effects of ongoing environmental change on this species.

I investigated behavioral niche partitioning in two morphologically similar and sympatric Emblyna spiders by collecting webs of Emblyna francisca and Emblyna reticulata from Sambucus and Atriplex plants at the Panorama Vista Preserve in Kern County, California. I measured web heights and identified prey found in webs to compare web placement and prey distributions in each habitat. Emblyna francisca webs contained more prey than did E. reticulata webs in both habitats. The two spiders had similar abundance in Atriplex, but in Sambucus, E. reticulata was more abundant than E. francisca. Emblyna reticulata placed its webs higher than E. francisca in Atriplex but not in Sambucus, and the distribution of prey in webs differed between the two spiders in Sambucus, but not in Atriplex.

Knowledge of the diversity of terrestrial vertebrates in the Sierra La Mojonera Natural Protected Area and its surroundings is quite limited. Therefore, the objectives of this study were to update the list of terrestrial vertebrate species that inhabit the area of influence of the Sierra La Mojonera, to investigate the subspecies, and to highlight the conservation status of the species in terms of national and international regulations. We sampled 30 locations in 850 km² of the area of influence of the Sierra La Mojonera between 2010 and 2013. We recorded amphibians, reptiles, birds, and mammals by observation, capture (by hand or with mist nets), or trace evidence (footprints, scats, or ecdysis). We recorded 51 species: 3 amphibians, 9 reptiles, 14 birds, and 25 mammals. We recorded 29 species (3 amphibians, 8 reptiles, 8 birds, and 10 mammals) for the first time in the area, including Anaxyrus debilis, Anaxyrus punctatus, Hypsiglena jani, Cophosaurus texanus, Caracara cheriway, Charadrius vociferus, Myotis yumanensis, and Notiosorex crawfordi. The subspecies of seven species have distribution boundaries in the study area. Other species are remarkable because of their protection category, such as Crotalus molossus, Cynomys mexicanus, and Leptonycteris nivalis. The area of influence of Sierra La Mojonera contains numerous important charismatic species in need of conservation. We strongly recommend that scientists specialized in each group of terrestrial vertebrates conduct a complete and detailed inventory of the species that inhabit the protected natural area and its surroundings. As part of these investigations, it is important to ensure scientific collection obtains reference specimens (vouchers) and that collectors deposit these specimens in recognized scientific collections in order to contribute to the knowledge of the biodiversity of the region and to increase the information on the vertebrates in this report.

We implemented stable isotope analysis to evaluate the molt behavior of the Colima warbler (Leiothlypis crissalis), an understudied migratory songbird occurring in Mexico and recently discovered breeding in the southern part of Texas, USA. We built a geostatistical model showing variation in deuterium precipitation values (d²H_p) across a latitudinal gradient within the Colima warbler breeding range in northeastern Mexico. Then, based on stable isotope ratios of deuterium in feathers (d²H_f), we assigned wintering Colima warblers captured in Central Mexico to possible molting areas near the southwestern portion of the species' breeding range. To the best of our knowledge, this is the first field study documenting Colima warbler captures and recaptures within the Parque Ecológico de la Ciudad de México, near the mountain ranges surrounding the Basin of Mexico. Overall, our study demonstrates the potential of winter ecology fieldwork in conjunction with molecular study techniques, such as stable isotope analysis, for revealing the migratory and molting behavior of warblers with restricted distribution ranges.

Scabiosa atropurpurea is an invasive herbaceous plant now found in 9 states, including 19 counties in north-central Texas and 2 counties in adjacent Oklahoma. Scabiosa atropurpurea forms dense colonies along roadsides and in old agricultural fields and poses a threat to native and improved grasslands. We evaluated the response of S. atropurpurea to mowing and prescribed fire. Mowing caused a marked increase in the density of S. atropurpurea. However, S. atropurpurea declined when there was no management at all and when exposed to growing season fire. Mowing of S. atropurpurea during roadside management and other management contexts leads to persistence and spread of this species. In complex communities, this plant will likely decline and growing season fires may help accelerate these declines.

Although melanism is common in some species of North American squirrels, its occurrence in the California ground squirrel (Otospermophilus beecheyi) was only anecdotal and reported in the early 20th century. Here we report on melanistic individuals in this species in northwestern Baja California in 2013 and 2020.

Sawfly larvae of the family Diprionidae are defoliators of conifers, undergoing cyclical outbreaks. Here, we present a tachinid fly, identified as a Chetogena species, which was found parasitizing diprionid larvae from a recent outbreak on Jeffrey pines (Pinus jeffreyi) in Baja California's Sierra San Pedro Mártir National Park. The findings reported here are a new distributional record for Chetogena in Baja California.

We tested the restricted movement paradigm (RMP) for heterogeneous movement within populations using plains killifish (Fundulus zebrinus) in the Red River on the border of Texas and Oklahoma. During June–August 2020, we marked 564 plains killifish within a 5-km stream segment and recaptured 23 individuals. Recaptured individuals spent on average 17.3 days at large, moved on average 178.2 m/day, and the maximum movement observed was 935 m. Distributions of movement distances and movement rates were leptokurtic, and although distributions were skewed, there was no difference in the number of fish that moved upstream versus downstream. Our results suggest the RMP predicts broad-scale movement patterns of F. zebrinus, but fine-scale movements might be larger in magnitude compared with other Fundulus spp.

Pigmentation abnormalities in fur or wings membranes have been reported in >100 bat species worldwide. In the case of the Mormoopidae family, abnormalities have been documented in Pteronotus mesoamericanus, Pteronotus quadridens, and Mormoops megalophylla. This work represents the first record of Pteronotus fulvus with a coloration pattern different from the one commonly reported in their entire range.

We report our observation of an adult solitary eagle (Buteogallus solitarius) in northeastern Mexico, in the Sierra del Abra Tanchipa Biosphere Reserve, on 18 October 2019. We took photographs of the solitary eagle for identification and then reviewed available records of its distribution in Mexico from different information sources. Recent sightings of the solitary eagle are very rare in Mexico, and our observation in northeastern Mexico is noteworthy considering (1) the rarity of the species and (2) that our sighting was outside of its known distribution.

Body temperature influences the activity and behavior of reptiles, with warmer body temperatures typically being associated with improved performance. Nocturnal ambush-hunting rattlesnakes would therefore benefit from selecting warmer substrate hunting sites, allowing them to stay in ambush longer as the environment cools and, presumably, to have a higher probability of striking prey successfully. Here, we tested whether free-ranging sidewinder rattlesnakes (Crotalus cerastes) might select ambush sites based on substrate temperature. We used a thermal imaging camera to measure snake body temperature and substrate temperature at ambush sites and random locations. Rattlesnake body temperature showed a strong positive correlation with substrate temperature at the ambush site, and the substrate at ambush sites was significantly warmer than randomly chosen sites. This suggests snakes might select ambush sites based on substrate temperature. Desert pit vipers appear highly attuned to environmental conditions and might integrate several criteria to select microhabitats that increase predation success.