Penstemon × jonesii is described as having flowers with the colors of “Tyrian rose,” “amaranth purple,” or “red-purple to maroon.” It has been recorded only in localized areas of southwestern Utah and just over the border of Arizona, where both putative parents commonly occur in sandy soils. Penstemon × jonesii has been reported and widely accepted as a natural hybrid of P. laevis × P. eatonii, though no research has been conducted to verify this assumption. We examined claims of its hybrid origin by making interspecific reciprocal first-generation hybrid plants from the 2 suspected parental species (P. eatonii and P. laevis) as well as by making second-generation hybrids through backcrossing to both parental species. Using 9 Penstemon simple sequence repeat (SSR), or microsatellite, markers, we examined the allelic variation among natural populations of P. × jonesii, P. eatonii, and P. laevis in southwestern Utah. These SSR data, in conjunction with our controlled crosses, support claims that P. × jonesii likely descends from hybridization events between P. eatonii and P. laevis. Flower color of the typical P. × jonesii reported in the literature and found in herbarium samples does not resemble the flower color of F₁P. eatonii × P. laevis hybrids from our controlled crosses. However, in subsequent controlled backcrossing of the F₁ hybrids to P. eatonii, we found blossom morphotypes and corolla colors matching previous descriptions of P. × jonesii. We also observed many hybrids with lighter corolla colors, such as light pinks, pinkish yellows, and lavender, which are not recorded in the literature or found in herbarium specimens. Field surveys for natural color variation in P. × jonesii populations also revealed greater flower color variation than previously reported, which should be considered as part of this hybrid taxa as well, though the predominant floral colors of P. × jonesii are “Tyrian rose,” “amaranth purple,” and “red-purple to maroon,” which suggests some selective bias. We suggest that pollinator preference for dark red to purple blooms may be responsible for this phenomenon.

The Colorado River in Grand Canyon is highly regulated, with hypolimnetic releases that are generally unfavorable for endemic native fishes. However, both long-term drought and changes in dam operations have led to changes in river conditions, including the addition of approximately 125 km of riverine environment due to the contraction of Lake Mead. Through sampling of small-bodied fish, we were able to describe the Grand Canyon fish community and define the current native fish distribution from near Bright Angel Creek downstream to Pearce Ferry. Beginning in 2014 and continuing through 2018, we sampled the fish community via seining and documented a fish community that was dominated (>95%) by native fish through approximately 300 km of river. Nonnative species that were once commonly captured, such as Red Shiner Cyprinella lutrensis, Common Carp Cyprinus carpio, and Channel Catfish Ictalurus punctatus, were rarely encountered in Grand Canyon during this more recent sampling, which makes the Colorado River in Grand Canyon National Park a rare contemporary example of native fish populations regaining dominance over invasive fishes in the desert southwest.

Dispersal in mammals is typically male-biased and occurs primarily in sexually immature individuals. These dispersal characteristics are especially true for ground-dwelling sciurids, such as black-tailed prairie dogs (Cynomys ludovicianus), that have polygynous breeding systems, with dispersing males and philopatric females. Prairie dogs are small, colonial rodents found in patches throughout the Great Plains of North America. Previous literature reports that females exist in philopatric units called coteries, typically with one unrelated breeding male. Yearling males disperse from their natal coterie in order to form their own coteries. We observed 1450 prairie dogs over 3 consecutive years in one colony near the northern limit of this species' range, in Grasslands National Park, Saskatchewan. We found that female dispersal occurred at higher rates than previously reported in the literature. We found no difference between the rate of intracolony dispersal for males and females in our study population. Also, we observed that the majority (14/21) of the dispersing females had recently experienced reproductive failure. We suggest that these females dispersed to increase their potential fitness by attempting reproduction in a new territory. This finding is the first instance of a ground-dwelling sciurid demonstrating female-biased breeding dispersal and suggests that factors influencing dispersal are more complicated than previously reported for black-tailed prairie dogs.

California Newts (Taricha torosa) are common amphibians throughout much of California, yet their life history has been little studied. We examined T. torosa in 2 physically separated breeding locations, a farm pond and a nearby stream, between February and June 2015. We synoptically collected physical measurements on adults as well as tissue samples from a subset of the newts present in both locations throughout the time period. Stable isotopes of carbon and nitrogen were used to characterize the trophic niche space among newts of different locations and ages. Our results suggest differentiated breeding phenologies as well as unique trophic signatures in the 2 different locations. In our sampling, the pond group bred and developed a few weeks earlier in the season and ate at a higher trophic level, while the stream group bred and developed later and ate lower on the food chain. Taken as a whole, our results suggest that the newts in this area exhibit some degree of ecological and life history plasticity.

Plains Killifish Fundulus zebrinus (subgenus Plancterus) is native to river basins in Oklahoma, New Mexico, and Texas. Original descriptions of Plains Killifish life history information are now applicable to the sister taxon Northern Plains Killifish Fundulus kansae following recognition of the 2 species in 2001. Study objectives were to quantify (1) length of the reproductive season, using the gonadosomatic index and categories of gonadal maturation, (2) batch fecundity, and (3) number of age groups for Plains Killifish taken from 2 rivers within the upper Red River basin of Texas. Reproductive season was from March through September, with the production of multiple batches and a maximum batch of 131 mature oocytes. Plains Killifish were sexually mature at age 1 and had an estimated life span of 2–3 years. Reproductive season, production of multiple batches, and age of Plains Killifish were similar to those reported for Northern Plains Killifish and 2 other closely related subgenera, Wileyichthys and Zygonectes. These similarities suggest strong trait conservatism among a monophyletic group of fundulids that inhabit a diversity of freshwater and saltwater environments in western shallow bays and salt marshes, southwestern arid and prairie streams, and eastern low-gradient streams of North America.

Springsnails (genus Pyrgulopsis, hereafter pyrgs) are small freshwater aquatic gastropods that occur in isolated springs in western North America. Pyrgs are species of conservation concern, but patterns of occupancy and speciation are complex. We investigated patterns of occurrence for pyrgs in the Spring Mountains, Clark County, Nevada. We were primarily concerned with identifying springs containing the species P. deaconi, the Spring Mountains pyrg, and P. turbatrix, the southeast Nevada pyrg. We identified species through genetic analysis of the COI-1 mitochondrial region and examined patterns of genetic structure. We located aquatic gastropods in 26 springs and analyzed 420 aquatic gastropods, of which 392 were pyrgs, the remainder representing an unknown species of Physa. Of the 26 springs, 25 contained pyrgs and 5 contained Physa sp. For pyrgs, at COI-1 we identified a total of 29 haplotypes that formed 6 distinct monophyletic groups. Five of the 6 groups were consistent with pyrgs previously identified: P. bacchus, P. deaconi, P. fausta, P. turbatrix, and an unknown species which had been identified previously in the Grapevine Springs. The sixth group, found in 2 springs, does not match any reference specimen and is genetically divergent from the other 5 groups. It is most closely related to P. micrococcus. Prior to this study, P. bacchus had not been located in the Spring Mountains. Both P. deaconi and P. turbatrix were located in multiple springs on both the east and west sides of the Spring Mountains, even though the Las Vegas Valley (east) and Pahrump Valley (west) are hydrologically distinct. At the scale of the hydrologic basin, genetic structure was not discernable; haplotype divergence did not align with basin boundaries and the most common haplotype for P. turbatrix occurred on both the east and west sides of the Spring Mountains. While there was little evidence for genetic structuring at the hydrologic-basin level, there was good evidence for structuring at the level of the individual spring. All told, 79% (23/29) of pyrg haplotypes were unique to specific springs, suggesting that pyrg diversity primarily occurs at the level of the individual spring.

We revisited 26 of the 28 known collection sites for the California vole, Microtus californicus, in Baja California, Mexico. With live trapping, we were able to confirm the continued presence of the vole at 7 of these sites, which include all 3 of the subspecies endemic to Baja California. At 14 of these sites, no viable habitat was found. These 14 sites included all known occurrences of M. californicus sanctidiegi in Baja California. Based on capture numbers or lack of habitat, population size may be drastically reduced at all sites except one. Effective conservation actions are required for recovery of California vole populations in Baja California.

West Nile virus (WNV) is an introduced pathogen, transmitted by mosquitos, that spread across North America following its arrival there in 1999. Birds host the virus, but consequences of the disease to bird species have been variable. A small number of avian species are especially susceptible to WNV, experience high mortality rates when infected, and have shown regional declines apparently because of the disease. Other species have seemingly been unaffected. Transmission of WNV is associated with climate, with higher incidence of transmission in dry areas with warm winters. The north-central United States is an area that exhibits clines in temperature and precipitation, and in this area changes in species abundance due to WNV have not been closely examined. We used Christmas Bird Count (CBC) data to investigate changes in winter abundance of selected species before and after the arrival of WNV in the Great Plains. After arrival of WNV, average estimated abundances of Black-billed Magpie (Pica hudsonia) were significantly lower than projected abundances across much of the Great Plains. Black-capped Chickadee (Poecile atricapillus) abundances reached their lowest counts in portions of the Great Plains immediately after the arrival of WNV and experienced overall negative annual declines from 1988 to 2017. Two other species that were examined did not experience changes in abundance across the study area. Abundances of Black-billed Magpies and Black-capped Chickadees have declined over the past 30 years in the Great Plains, and WNV has likely played a major role in recent declines of magpies throughout the study area.

We investigated the uptake of selenium (Se) at 14 sites in a Se-rich watershed, using an aquatic bryophyte (Hygrohypnum ochraceum). We expressed uptake using the symbol K_d to underscore the relationships between Se in water and Se in plants as “partitioning coefficients” related to the bases of aquatic food chains. A 2-way analysis of variance (ANOVA) was performed with K_d as the dependent variable and season and stream segment (location) as main effects. Selenium concentrations, measured as dissolved Se, total Se, and pore water Se, were also examined. There were significant differences in K_d values with respect to stream segment (P < 0.001); however, the differences were mainly not associated with season, although pore water Se showed a slight association with season (P = 0.052). The interaction effects between season and stream segment were significant for dissolved Se (P = 0.016) and total Se (P = 0.041). Further analysis showed strong negative correlations to the 3 Se water concentrations in spring (dissolved Se: r = –0.973, P < 0.001; total Se: r = –0.972, P < 0.001; pore water Se: r = –0.867, P < 0.001). Fall associations of K_d values to the 3 Se water concentrations were considerably weaker. Dissolved Se and total Se both still showed statistically significant positive correlations to K_d in the fall, but total Se did not. Based on the results of recent studies, it appears that the bryophytes might have preferentially bioconcentrated selenite over selenate in the upper watershed basin rather than in the lower basin. To conclude, the bryophytes appeared to be suitable natural receptors of Se at the bases of numerous food chains in a complex watershed by exhibiting differences in Se uptake based on site location, season, and diverse Se water concentrations.

Ambystoma altamirani is an endangered salamander found in high mountain streams in the vicinity of México City, and its populations might be threatened by urban growth. Here we report our research on a previously unstudied population of A. altamirani at the Llano de Lobos in the Sierra de las Cruces. The study ran from September 2018 to September 2019. The number of observed individuals was relatively constant across months. The only months when we observed gilled adults were February and July, and the only months when we saw juveniles without gills were January, February, and August, suggesting that the transformation of juveniles to adults takes place twice a year, once in January–February and once in July–August. We observed egg masses in December and January, and larvae from March to May and also in July. The sex ratio was significantly female-biased (about 2:1). We observed A. altamirani at 3 of the 25 permanent sites during the study period. Our comparison of the characteristics of occupied sites with those of unoccupied sites suggests that availability of sunlight (i.e., less cover) and low levels of human impact are important for occupancy by A. altamirani. These findings are consistent with observations of other populations of A. altamirani, suggesting that these characteristics might be important in their management and conservation.

We observed cannibalism, the act of consuming a conspecific, of eggs and nestlings by Common Ravens (Corvus corax; hereafter “raven”) by video-monitoring nests in Nevada and California. Specifically, within the sagebrush steppe of Nevada, adult ravens killed and consumed raven chicks from an active nest. Additionally, on the coast of California, we observed adult ravens consume inviable eggs from their own nest following full-term incubation. To our knowledge, these observations represent the first documented cannibalistic behavior by ravens.

Wiregrass (Ventenata dubia [Leers] Coss.), an annual grass from the Mediterranean region of North Africa and Eurasia that has aggressive invasion potential in many North American plant communities, has only recently been reported in low-elevation sagebrush steppe. We first encountered wiregrass in 2014 in the John Day Fossil Beds National Monument, a low-elevation steppe protected area in central Oregon. This discovery was incidental to formal vegetation monitoring that was initiated in the monument in 2009. We first encountered wiregrass in monitoring plots in 2016, and, from plot data, we documented rapid spread during 2017–2019. Wiregrass infestation increased within our 4674-ha monitored area from 21 ha (95% CI, 3 to 106 ha) in 2016 to 138 ha (95% CI, 31 to 265 ha) in 2018, and declined to 63 ha (95% CI, 13 to 119 ha) in 2019, representing a cumulative increase of 300% over the 4-year period. Variation in weather may explain this annual variation in wiregrass. We examined mean monthly water balance deficit during the autumn, winter, and spring preceding each survey year and found evidence of a potential correlation between winter deficit and wiregrass. The lowest winter deficit occurred in 2018 prior to the survey documenting the largest wiregrass increase. Wiregrass exhibited a broad ecological niche within our survey area, occurring across all surveyed elevations and on all but steep southern slopes. Invaded sites were in well-drained clay soils in association with other invasive annual grasses. Our observations contribute to the growing evidence that wiregrass poses a greater threat to low-elevation sagebrush ecosystems than previously recognized. It also illustrates the kinds of external stressors that are impacting sagebrush steppe protected areas and the need for continued early detection and rapid response measures, as well as long-term monitoring of invasions and response effectiveness.

PIT tags are a common tool used to identify and track movements of fishes. Although technological advances facilitated the use of PIT tags across a wide range of fish body sizes, we do not yet fully understand the effects of PIT tagging on basic aspects of many species' life histories (e.g., survival, spawning success, or reproductive output). We observed 2 small-bodied fishes, Red Shiner (Cyprinella lutrensis) and Bluntnose Minnow (Pimephales notatus), achieve successful spawns after PIT tagging. Age-0 fish of both species were observed in multiple experimental stream units during an outdoor mesocosm study in which only PIT-tagged fish were stocked. Although these observations suggest that qualitative effects on spawning success of PIT-tagged, small-bodied fish might be negligible, more quantitative studies need to be conducted to test these assumptions. As use of PIT-tagging technology continues to increase, understanding the effects of PIT tags on fish life histories will ensure that tagging studies provide reliable data without negatively impacting fish populations.

During the twentieth century, the North American porcupine (Erethizon dorsatum) was common in the Black Hills of western South Dakota and northeastern Wyoming. However, the low number of recent observations in the region has led to concern that porcupine populations have declined. We conducted systematic surveys to assess porcupine occurrence at two hundred and sixty-three 1-ha sites in the Black Hills National Forest, Custer State Park, Jewel Cave National Monument, Mount Rushmore National Memorial, and Wind Cave National Park during 2016–2017. We observed no porcupines or recent feeding sign. We also noted few recent observations in information compiled from online databases and from other natural resource surveys with which we have been involved in the South Dakota Black Hills. Given the apparent abundance of porcupines in this area in the twentieth century, our results suggest that populations have declined dramatically. Predation by mountain lions (Puma concolor), habitat loss, and human-caused mortality are potential contributing factors, but estimating the degree of population declines and assessing hypotheses about the causes are hindered by a lack of long-term data on the region's porcupine populations. Moreover, accounts of the region's mammalian fauna suggest that porcupines were not abundant in the region during the late 1800s but became common in the early twentieth century.

Birds inhabiting hot, arid ecosystems contend with trade-offs between heat dissipation and water conservation. As temperatures increase, passerines engage in various behaviors to reduce exposure to heat, solar radiation and insolation, and reradiation of heat from the ground. These responses to rising temperatures may result in subordination of reproductive urgency or nutrient acquisition to the need for thermoregulation. During studies on Arizona Grasshopper Sparrow (Ammodramus savannarum ammolegus) life history and ecology, we noted that these sparrows abandoned territoriality and foraging behaviors under certain circumstances in favor of cooler microsites. In this paper we document the extreme temperatures to which these and other ground-foraging and ground-nesting birds are exposed in southwestern desert grasslands, and we present evidence that A. s. ammolegus avoids exposure to extreme air and ground temperatures by using shrubs as thermal refugia. Our observations have implications for Arizona Grasshopper Sparrows and other desert grassland passerines in the southwestern United States, where the climate is projected to become hotter and drier. We provide some of the only behavioral data, and associated temperature data, associated with the use of thermal refugia by desert grassland birds. We encourage further studies that use more robust methods to supplement our observational data.