The larval polytene chromosomes of 17 of the 22 known cytotypes of the Simulium arcticum Malloch complex were analyzed and compared at 59 collection sites in the Pacific Northwest of the United States. Cytotypes range from those that were broadly distributed, such as IIL-9, which was found at 25 different sites, to those that were found at only one or two sites, such as IIL-73·74. Cytotypes are “clustered” in a geographic sense, suggesting that once a new cytotype is described, if it is found again, it will be found nearby. The cytotype S. arcticum IIL-9 was found at 11 of the 25 sites where S. arcticum IIL-19 exists. Finally, based on its sibling species status and widespread distribution throughout the Pacific Northwest, Simulium brevicercum may be an early ancestor of the complex given that it occurs at 44 of the 59 sites sampled. The observations and conclusions of this research are scientifically important because previous research suggests that reproductive isolation may have begun among these cytotypes at these sites, and unless their locations are reported, they cannot be studied further. Future work should incorporate a multiomic approach to study the putative initial divergences within this complex.

A 10-year study (2004–2013) was conducted to determine mosquito distribution and the prevalence of West Nile virus (WNV) on the Nevada National Security Site (NNSS) in south-central Nevada. Mosquito traps baited with dry ice were set overnight at sites where standing water provided potential breeding sites for mosquitoes. Captured mosquitoes were identified to species and tested for WNV. A total of 556 mosquitoes representing 6 species were captured and identified at 20 sites around the NNSS during 124 surveys. A vast majority (89%) of mosquitoes were Culex tarsalis. Two samples, both Culiseta inornata, tested positive for WNV in 2005 and 2006, both from Well 3 Pond, Yucca Flat, Nye County. Additionally, 24 birds representing 5 species were opportunistically collected and tested for WNV with no positive results. Results from this study reveal patterns of mosquito distribution across the NNSS and suggest that NNSS workers are at low risk of being exposed to WNV.

In Canada, subspecies of the yellow-pine chipmunk (Neotamias amoenus luteiventris) and red-tailed chipmunk (Neotamias ruficaudus ruficaudus) co-occur in a small area of the Rocky Mountains in southwestern Alberta and southeastern British Columbia. Some N. a. luteiventris individuals in this area are of hybrid ancestry, carrying a mitochondrial DNA gene of N. r. ruficaudus. We tested for phenotypic hybridization by comparing genital bone morphology, body size, cranial mandibular morphology, and tail color of mitochondrial hybrids with specimens of the 2 parental reference groups identified from genetics or genital morphology. Hybrids were indistinguishable from the N. a. luteiventris reference group, demonstrating no intermediacy or increased variability. Our results are consistent with genetic data that suggest minimal nuclear gene flow between the 2 taxa. Five hybrid locations were within the contact zone, but 6 were 14–98 km beyond the known range extent of N. r. ruficaudus. These peripheral occurrences may be a legacy of a past range decline of N. r. ruficaudus in response to Holocene climatic changes that left hybrids outside the present-day contact zone. We recommend more field research in the Canadian Rocky Mountains to determine the full range extent of N. r. ruficaudus and N. a. luteiventris of hybrid ancestry.

The Snake River pilose crayfish Pacifastacus connectens and pilose crayfish Pacifastacus gambelii are sister species endemic to western North America that require increased conservation attention due to apparent range declines. We report results of molecular analyses that sought to clarify where P. connectens and P. gambelii occur relative to each other as well as morphological analyses that sought to help nonspecialists reliably identify these species in the field. We conducted our analyses on voucher specimens recently collected from across the presumed native ranges of both pilose crayfish species. We sequenced the mitochondrial cytochrome c oxidase subunit I gene of these crayfish specimens and then built Bayesian and maximum likelihood phylogenetic trees on these sequence data. Next, we made a series of morphological measurements on crayfish specimens, which we analyzed as morphological ratios in a principal component analysis. We found that P. connectens represents a diverse polytomy of multiple lineages distributed in the middle Snake River watershed and adjacent Harney Basin, whereas P. gambelii represents a monophyletic lineage of extremely low genetic diversity distributed primarily in the upper Snake River watershed and adjacent Bonneville Basin. We also confirmed that the pilose crayfishes are morphologically distinct relative to each other, with P. connectens reliably possessing a narrow or acute rostrum and P. gambelii reliably possessing a broad or obtuse rostrum. Alternatively, some other morphological characters historically associated with the 2 pilose crayfish species were less reliable in differentiating P. connectens and P. gambelii. Our findings should help natural resource managers, like fisheries biologists, anticipate where the pilose crayfishes occur and identify them under field conditions. Future investigations into the taxonomic status and phylogenetic relationships between these crayfish species would benefit from high-throughput sequencing focused on the nuclear genome.

Basking is an essential behavior for thermoregulation in turtles. Although basking is widely studied, this behavior varies among populations, habitats, and microclimates. In this study, we evaluated the effectiveness of game cameras for studying basking activity of Rio Grande Cooter (Pseudemys gorzugi), a New Mexico state-threatened species. From August 2018 to July 2019, images were taken hourly from 07:00 to 19:00 at 3 locations along or near the Black River, New Mexico. We used a generalized linear mixed-effect model to find associations between basking patterns and environmental variables. The species was active year-round, with the greatest number of basking turtles in spring. Basking activity was significantly correlated with water temperature, season, light intensity, difference between water and air temperatures, and time of day. Game cameras were effective for long-term monitoring of turtles in this study. This method was noninvasive and created low disturbances while providing high-resolution data. Overall, this study provides a deeper understanding of the basking habits of P. gorzugi as well as its activity periods across seasons, which can also aid in determining an appropriate time for conducting visual surveys of the species in southeastern New Mexico.

Desert fishes are among the most imperiled yet poorly studied groups of fishes on Earth. Human modifications of the environment and introductions of invasive species frequently drive population declines and extinctions of fishes in arid regions of North America. One recent example is the extirpation of Gambusia senilis from the Devils River in Texas following the construction of Amistad Reservoir on the Rio Grande. The direct cause of this extirpation is unclear, but it has been hypothesized that the introduction of predatory bass (Micropterus spp.) to the river played at least some role. We tested this hypothesis using a geometric morphometric analysis as well as examining other specific morphological traits considered adaptive to high-predation conditions. We found variation among populations in all traits examined, but the relationship between these traits and predation risk was relatively ambiguous. Two populations with introduced sunfish (Lepomis spp.), the Río San Pedro at Pedro Meoquí and Río Chuviscar at Aldama, exhibited the combinations of traits that might be most likely to facilitate success in a high-predation environment, but it is not clear that any population of G. senilis could coexist with predatory bass.

Pubescence has significant ecological roles modifying herbivory or physiology. Effects of mechanical ice damage on a small scale, such as loss of pubescence, are typically neither observed nor investigated. The objective of this study is to determine whether microscale ice damage occurs at a degree sufficient for potential ecological impacts. I documented differential loss of pubescence in the field on leaves and stems experiencing frequent snow and freezing rain. I also experimentally demonstrated in the lab the potential for hair loss due to ice formation under windy conditions. Observations in the field document that pubescence is removed from plants exposed above the snowpack, but plants beneath the snowpack are less affected. Plants in low-elevation sites not experiencing snow or ice show little loss of pubescence. Hair loss can be replicated experimentally with glaze ice, but only under windy conditions. These results extend the potential impacts of snow and ice damage to small scales. Given the multiple ecological roles of pubescence, such impacts may be important for plant success and may potentially influence community composition shifts under changing climates.

The American black bear (Ursus americanus) is one of largest terrestrial mammals found in Texas. Despite the black bear's large size and charismatic nature, its distribution across the state has been difficult to determine due to outdated distribution maps. Although recent sighting reports indicate that the current distribution of black bears in Texas may be expanding in some areas, researching changes in black bear populations can be difficult and cost prohibitive. Data from community science initiatives and natural history collections can be useful to better understand species distributions and ecology. We used records from Texas Parks and Wildlife Department, iNaturalist, and VertNet to describe the distribution of U. americanus in Texas. Our results indicate that black bears may not be widely distributed across Texas and may be breeding in only a small number of counties. Our study highlights the usefulness of successful community science programs and the long-term historical importance of natural history collection records and natural resource agency data sets in better understanding geographic distributions of various species, including U. americanus. These initiatives paired with improved communication and collaboration between natural history collections, community scientists, and municipal, state, and federal natural resource and wildlife agencies can provide valuable information for a variety of species and facilitate future research.

The biogeography and habitat affinities of the Recent taxa of terrestrial mollusks of Nevada, western USA, are discussed herein. A total of 52 land snails and slug species were found in Nevada, of which 21 are newly reported records. Two native land snails found previously were not found by this author, and 6 additional species are possible for the state. Of the 47 species of land snail found in the state, 42 are considered native, while 5 are introduced. Only one slug, Deroceras laeve, is considered native, while 4 others are introduced. Land mollusks in eastern and central Nevada are derived from the Rocky Mountain Molluscan Province, such as Pupilla hebes, Microphysula ingersolli, and Oreohelix strigosa depressa (9 species, 18%), while southern Nevada supports species derived from the Southwestern Province, such as Gastrocopta spp., Striatura meridionalis, and Eremarionta rowelli (8 species, 16%). A Californian and Oregonian influence includes Pristiloma chersinella and Punctum californicum. Introduced land snails and slugs such as Deroceras reticulatum, Lehmannia valentiana, Cepaea nemoralis, and Rumina decollata are found in the gardens and parks of urban areas in Nevada. The present native land snail distributions in Nevada result from Miocene and Pliocene dispersal and establishment in the mountains of the Great Basin followed by Pleistocene and Holocene fragmentation and isolation. Xeric habitats such as sagebrush steppe, Pygmy conifer woodlands, and dry alkaline lake beds dominate much of the state and support very few or no land mollusks. Nine habitats are identified as being used by terrestrial mollusks in Nevada. Mountain woodlands, springs, and chaparral support 71% of the total fauna, which includes 36 land snail species and the slug Deroceras laeve where water, coniferous and deciduous vegetation, and moist litter are available between 1400 and 2800 m elevation. The more xeric Mojave Desert in the south (165–1100 m) and sagebrush steppe of the Great Basin (800–2000 m) support 3 and 4 species, respectively. The Pygmy coniferous woodlands occasionally support 2 species, except when the woodlands are associated with limestone cliffs and shrubs, where 5 species may be present (1600–2200 m). River valleys, perennial streams, and meadows (800–2000 m) make up only 1% of the state's land area but support 19 species of land mollusks. Subalpine and alpine habitats in the high mountains (2800–3400 m) support 13 species of land snails. Urban areas with greenhouses, parks, and casino gardens support 9 species of introduced land snails and slugs.

During the spring of 2006, we observed predation by California whiptail (Aspidoscelis tigris munda) on the endemic coastal roach (Hesperoleucus venustus) from an isolated pool along an intermittent reach of Coyote Creek, Santa Clara County, California, USA. Our observation is the first published record, to the best of our knowledge, of a whiptail in the genus Aspidoscelis in the southwestern United States preying upon fish. We also report on subsequent observations during 2014, 2015, and 2020 of California whiptail foraging along isolated, intermittent stream pools within this watershed.

A diminutive shrew from Sioux County, Nebraska, is shown to be the first state record for the dwarf shrew, Sorex nanus. This specimen appears to be a member of a dwarf shrew population occurring on the Great Plains in the vicinity of the Black Hills in western South Dakota, eastern Wyoming, and southeastern Montana, but not within the Black Hills proper. Other populations of this species occur in montane environments in the Rocky Mountains, from Montana south through Wyoming, Colorado, New Mexico, Utah, and some isolated mountains in Arizona. The arid grassland habitats inhabited by the Great Plains population are strikingly different from the alpine and subalpine rockslides, coniferous forests, montane streams, and sagebrush communities at elevations generally above 1400 m occupied by other populations. Future researchers should examine genetic and ecological relationships among these populations of the dwarf shrew.

Intake of medusahead (Taeniatherum caput-medusae (L.) Nevski) by livestock is typically low given the poor nutritional quality of the weed, but utilization may increase through the provision of supplemental nutrients. This study compared cattle that initially grazed on a supplemented pasture (SUP) of established cool-season perennial grasses and forbs to nonsupplemented cattle that grazed only medusahead-infested rangeland (NSUP) in order to determine whether supplemental nutrients could increase use of medusahead. The quality of different forage types in the plant community and grazing events on these forage types were assessed. Supplemented animals grazed medusahead to a greater extent than NSUP animals in the medusahead-infested pastures (P = 0.003). Thus, grazing of improved pastures in close temporal proximity to grazing of medusahead-infested rangeland may represent a management tool that contributes to enhancing medusahead utilization by cattle. However, future long-term studies need to be conducted in order to examine whether medusahead use by cattle can be used as a practical, low-cost tool for medusahead management.

During the last century, the range of the American burying beetle (Nicrophorus americanus Olivier) has been reduced by >90%. Only isolated, extant populations of this federally threatened species now exist, primarily in the Great Plains. Although the primary reason for this decline remains unclear, anthropogenic changes to habitat and vertebrate food sources used for reproduction have played a significant role. Other factors may be contributing to the decline, but little research has been conducted on understanding predators of N. americanus and how the beetle avoids them. Herein, we document a new predatory species for N. americanus, the northern short-tailed shrew (Blarina brevicauda Say), and report anecdotal evidence that beetles may avoid the musky scent of this predator. In June 2019, we observed the death of at least 2 N. americanus in the presence of a male B. brevicauda in a baited pitfall trap in Tripp County, South Dakota. In August 2020, we observed predation of carrion beetles by a female B. brevicauda that did not produce any noticeable scent. In 2019, after predation and with the presence of the male's musky scent, we noted avoidance of the baited trap by carrion beetles (Silphidae) for the remainder of the 5-day sampling period. Understanding potential predators of and predator avoidance by N. americanus will help aid recovery efforts and improve trapping protocols.

This study reports an occurrence of Eurasian Wigeon (Mareca penelope) at Lago de Guadalupe in Cuautitlán Izcalli, State of Mexico. In January, February, and March 2021, we documented one individual foraging and swimming. Our observation is the first record of this species in central Mexico, 650 km southwest of the closest prior record in Mexico. We concluded that the Eurasion Wigeon individual probably migrated with American Wigeon (Mareca americana) individuals.

During summer 2019, we recorded an apparent vocal interaction, lasting just under 4 min, between a pair of Great Horned Owls (Bubo virginianus) and a gray wolf (Canis lupus) in Yellowstone National Park. To our knowledge, this is the first report of such an acoustic interaction in the scientific literature. The increased use of passive acoustic recorders, which record spontaneous vocalizations emitted by animals over long periods, will allow us to better document and study the importance of such interspecific interactions.

We observed Trumpeter Swans (Cygnus buccinator) nesting on top of an active muskrat (Ondatra zibethicus) lodge, indicating simultaneous breeding uses of a constructed vegetation mound not previously recorded in the literature. Specifically, within the Red Rock Lakes National Wildlife Refuge in southwestern Montana, we observed 4 eggs in an actively tended Trumpeter Swan nest, while underneath the swan nest bowl was a muskrat nursery occupied by 3 neonate muskrats. Swans are known to use abandoned muskrat lodges as nest foundations, but not active lodges. Our observations point to a close association between breeding muskrats and Trumpeter Swans in the shallow wetlands of North America and emphasize the benefit of robust muskrat populations for Trumpeter Swan restoration.

The diet of the Golden Eagle (Aquila chrysaetos) was studied in 4 territories in northwestern Chihuahua, México, during the breeding season. Prey remains and pellets were collected from 4 nests during 2014, 2015, and 2016. We identified 12 vertebrate species. Black-tailed jackrabbits (Lepus californicus) were the most important prey remains in terms of frequency (72%) and ingested biomass (86%). We estimated mean prey size to be 1291 g (SE = 3364), indicating that Golden Eagles prey on medium-sized animals (e.g., lagomorphs). The main threats to Golden Eagles are connected to habitat loss and habitat fragmentation, but other factors also affect eagles. We hope our information will help to establish better species management programs.

Detection, pursuit, capture, and consumption of prey by predators may be time consuming or not, depending on predators and prey, and this time allocation affects other aspects of predator ecology. Pacific salmon contribute substantially to coastal brown bear (Ursus arctos) diets, with implications for predators, prey, and their ecosystem. Brown bears were observed capturing sockeye salmon (Oncorhynchus nerka) at Mikfik Creek, Alaska, to determine capture and consumption rates. Bears averaged 3:00 min (SD = 5:24) to capture and 2:26 min (SD = 1:33) to completely consume small adult sockeye salmon. These foraging activities thus occupied only a small fraction of their total time budget at this site.