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We repeatedly sampled 8 sites on the Crooked River in British Columbia's Arctic watershed for adult and nymph mayflies (Ephemeroptera) over the course of 2 years. Using taxonomic keys and DNA barcoding, we report 8 new species records for the province: 5 members of the family Baetidae (Acerpenna pygmaea, Baetis phoebus, Baetis vernus, Iswaeon anoka, and Procloeon pennulatum), 1 Heptageniidae (Leucrocuta hebe), 1 Leptohyphidae (Tricorythodes mosegus), and 1 Siphlonuridae (Siphlonurus alternatus). Three of these, Acerpenna, Iswaeon, and Leucrocuta, are also new genus records for the province. In total, we detected 40 species in 8 families as indicated by clustering into BINs (Barcode Index Numbers), by morphological keys, and by matches in the Barcode of Life Database. One of those species, Ameletus vernalis, is of conservation concern. Our analysis indicated that a number of other specimens may represent new species or genus records for British Columbia. In addition, this unique and anthropogenically impacted river may contain cryptic species of Baetis tricaudatus (Baetidae), Leptophlebia nebulosa (Leptophlebiidae), and Paraleptophlebia debilis (Leptophlebiidae).
Cirsium ownbeyi is a habitat-specific, endemic, polycarpic thistle in northwest Colorado, northeast Utah, and southwest Wyoming. In 1998, seven C. ownbeyi populations, which ranged from 4 to >30,000 plants, were known from Wyoming. The population genetics of C. ownbeyi and the threat posed by an exotic flower head–feeding weevil, Rhinocyllus conicus, in Wyoming are unknown. Between 2014 and 2016, we visited Wyoming C. ownbeyi populations to determine (1) changes in population sizes since 1998, (2) extent of R. conicus use, and (3) amount and distribution of genetic variation within and between populations. We quantified densities of plants within populations by life stage, population spatial extents, and, for 10 plants per population, proportion of flower heads with R. conicus ovipositions. Data at 6 simple sequence repeat loci were also collected. Three C. ownbeyi populations were <10% of their 1998 estimated size, 3 populations were unchanged, and one population was substantially larger than in 1998. We found Rhinocyllus conicus oviposition in all Wyoming C. ownbeyi populations, and we interpret increasing use by this weevil over our monitoring period as indicating recent colonization. Low FST and FIS values suggest that levels of C. ownbeyi inbreeding were low and that there was considerable gene flow among populations. Genetic variation increased with popu lation size, although a small C. ownbeyi population was the most divergent. We conclude that C. ownbeyi was less abundant in Wyoming in 2015–2016 than was estimated in 1998. Causes of changes in population sizes are unknown and likely vary among populations. The positive relationship between population size and genetic diversity notwithstanding, protecting small populations can preserve unique local gene pools in this rare species.
The Boreal Toad (Anaxyrus boreas boreas) is widely distributed in western North America and has declined throughout portions of the Rocky Mountains. One mechanism to expand populations is to translocate toads into unoccupied habitats. Wild-captured juvenile (n = 229) and subadult/adult (n = 42) Boreal Toads were translocated into 2 unoccupied spring-fed ponds located near 10 known breeding populations in the Grouse Creek Mountains, northwestern Utah. Boreal Toad egg strands were observed at one pond in 8 of 9 years following the last translocation of toads (n = 1–5 egg strands deposited per year) and in 3 of 5 years in the second pond (n = 1–4 egg strands deposited per year). Both translocations were considered short-term successes. Between 1999 and 2017, 1964 Boreal Toads >55 mm SVL were PIT-tagged in the Grouse Creek Mountains, and recaptures were used to develop a growth curve that explained 79% of the size-age variability in this population. The growth curve will allow managers to reasonably identify age-1 and age-2 toads based on SVL and better evaluate Boreal Toad recruitment during population monitoring. Eight Boreal Toads were documented to have lived 11–16 years, and movements up to 7.6 km were documented across a relatively arid sagebrush/juniper landscape.
Water is the most limiting and important natural resource in drylands, where low precipitation, high evaporative demand, and drought events are common. Groundwater is the critical resource for human livelihoods to persist through the intra-annual dry periods in dryland ecosystems. Overexploitation of groundwater resources and the externalities associated with depleted aquifers make understanding the ecohydrology of drylands an essential issue. We focus on the water balance and climatic drivers of big sagebrush ecosystems, an important dryland ecosystem type in Wyoming that covers a large spatial extent. The goal of this project was to understand how groundwater recharge (GWR) may change in magnitude and seasonality across multiple sites in Wyoming in the future. We used a combination of fieldwork and simulation modeling to explore key climatic and ecohydrological drivers of GWR. We simulated soil water balance using SOILWAT2, a process-based ecosystem-scale soil water model, and future climate data to estimate change in GWR through 2100. We found that mean annual temperature and precipitation explained 65% of the variation in future change in GWR. High-elevation (>2200 m) wet sites had larger increases in GWR in the future compared to low-elevation dry sites. The among-site variability in GWR was also higher for sites >2200 m, which indicates that mean annual precipitation and perhaps snowpack are important explanatory variables for GWR. Our research suggests that GWR for high-elevation big sagebrush sites may increase in magnitude from current values and may occur earlier in the year, with important implications for the timing and availability of water resources.
Grass species are important for phytoremediation on native prairies affected by petroleum oil production. One of the major limitations in remediation and reclamation using plant species is seed germination failure. The objective of this study was to evaluate grass seed germination and seedling growth affected by drill cuttings. Sixty-five grass species (including 5 cereal crops) were included in the study. Germination of all species was reduced by drill cuttings. The reduction in germination ranged from 9.2% to 100%. Two species were tolerant, 18 species were moderately tolerant, 27 species were moderately sensitive, and 18 species were sensitive. Based on tolerance levels in the preliminary screening, 9 species were selected for further evaluation in response to different levels of drill cuttings in soil. Buffalograss (Buchloe dactyloides (Nutt.) Engelm.) was the most tolerant based on EC50 of seed germination as well as biomass production. For phytoremediation and soil reclamation of soils with drill-cutting contamination, species with tolerance to hydrocarbons, salinity, and other toxics are desired. Very few grass species are tolerant to all those components. Our study showed that buffalograss can potentially be used for reclamation of soils contaminated with drill cuttings.
The ornate box turtle (Terrapene ornata Agassiz) is a species of greatest conservation need in South Dakota. Habitat loss through agricultural development and fragmentation is the main threat to the species throughout its range, which extends from Wisconsin and northern Indiana through the central Great Plains, and from southern South Dakota to Arizona, northern Mexico, and the Gulf Coast of Texas. The objectives of this study were to determine the ornate box turtle's preferred vegetation characteristics (microhabitat) compared to the available habitat (macrohabitat) on the Pine Ridge Reservation, South Dakota Sandhills region, during 2010–2011. In both years, using a modified Robel pole method, we determined that turtles selected microhabitat with greater visual obstruction readings (VORs) than those within the random available macrohabitat (P < 0.01), with means of 22 cm and 15 cm, respectively. Higher VOR values indicate greater vegetation height and/or density. Canopy cover results showed that ornate box turtles exhibited high selection (P < 0.01) for sand sagebrush (Artemisia filifolia Torr.) coverage (38%) but selected lower cover than available within the macrohabitat for total grasses (37%), total forbs (19%), and bare ground (14%). Shrubs, such as sand sagebrush, are an important component of box turtle microhabitat, as they facilitate thermoregulation by providing cool areas during the summer and favorable hibernation sites during the winter. Shrub coverage is highly reco mmended for consideration when developing habitat management plans that aim to increase or sustain ornate box turtle populations in the Sandhills ecological type.
Populus tremuloides Michx. (aspen) is an iconic species of the southwestern United States, where it is known for its extensive clonality. The size of clones and pattern of clonal distribution within and among stands can provide important clues to the species' evolution and ecology, but there are very few studies that have conducted the type of sampling necessary to define these features. We examined the genetic composition and habitat associations of aspen in a mixed-species forest in Cedar Breaks National Monument on the Markagunt Plateau, southwestern Utah. Genetic analysis of 94 stems ≥1 cm diameter at breast height (dbh) selected from a population census of 2742 stems within a contiguous 13.64-ha plot revealed 2 spatially cohesive triploid genets and 2 diploid genets (all differing in 8 to 15 alleles). Aspen abundance within the 13.64 ha varied between 0 and 634 stems/ha across 8 distinct habitat types. Regenerating aspen stems (1 cm ≤ dbh < 5 cm) varied between 0 and 112 stems/ha, with higher levels of regeneration in habitats with greater aspen dominance relative to other tree species. Recent regeneration may have been stimulated by a Dendroctonous rufipennis outbreak in the 1990s, which killed a high proportion of Picea engelmannii. Even though the visual impression is of a single aspen clone, the 4 identified genets suggest a higher-than-expected level of genetic diversity in this mixed-species stand which may confer resilience to increasing climate variability and drought. Furthermore, aspen regeneration in areas of both low and high adult aspen densities show that these mixed stands can support vigorous aspen populations.
Native mussels likely occurred in Mill Creek and the Jordan River, Utah, in the past. However, humaninduced impacts have virtually eliminated the possibility of their continued existence in these waters. We conducted an intensive native mussel survey upstream and downstream of a water reclamation facility discharge into Mill Creek and the Jordan River to determine its effects on mussel populations. The survey was conducted from September to October 2017 and resulted in approximately 7.6 m3 of >4 mm-sized substrate particles being thoroughly examined at near 100% efficiency. We then used statistical models to estimate population densities as a function of probability of detection and search efficiencies based on this and other surveys. Regrettably, no live or recently dead native mussels were found. Given that our survey methods provided near perfect search efficiency, native mussel densities were estimated to be <<0.03 per m2, which is much lower than what we consider to be a viable population density. Combined with multiple lines of evidence from other surveys, this low density strongly points toward the conclusion that native mussels are extinct in the survey area. Reasons for the demise of native mussels in Mill Creek and the Jordan River are numerous, and these factors need to be aggressively addressed if native mussels are to survive in the drainage.
Feral horses roaming North America are distinct not only because of their acclimatization to the wild but also because of their diversified ancestry. The wild horses inhabiting the Ochoco National Forest near Prineville, Oregon, are one of the remaining wild mustang herds and are protected by the Wild Horse and Burro Acts of 1971 and 1978. With deterioration of their rangeland, drought, vegetation conditions, human encroachment, fencing off of grazing lands, competition with wildlife, and other livestock grazing on public lands, a critical balance between conserving the natural ecology of rangelands and protecting and managing the wild horses needs to be monitored. Supplementing traditional visual censuses with genetic analyses can enhance management and conservation efforts because DNA analyses provide insight into the genetic fitness and inbreeding status of the population. The objective of this study was to provide a genetic analysis using noninvasive sample collection methods to assess the genetic health of this small herd and to determine their genetic fitness. A total of 52 individuals from the Big Summit wild horse herd and adjacent herd management areas (HMAs) were genotyped for 17 short tandem repeat (STR) loci, mtDNA haplogroups, and major histocompatibility complex STR loci. Cluster analysis exhibited an admixed population with discernable contribution from Iberian ancestry, the major influence coming from Andalusian and Lusitano breeds. The deficiency of hetero zygosity, a deviation from Hardy–Weinberg equilibrium, together with a positive inbreeding coefficient for the neutral STRs in the Big Summit population suggested a parallel to an “island population” phenomenon leading to loss of genetic diversity within the herd. These findings improve understanding of the genetic structure of feral herds from different HMAs, which in turn will enable enhanced conservation and management strategies.
New records of Douglas's squirrel (Tamiasciurus douglasii) document the species in 2 mountain ranges of the Great Basin where tree squirrels have not been previously reported, including 2 sites in the White Mountains, California, and 1 site in the Desert Creek Mountains, Nevada. In the White Mountains, squirrels were photographed by a camera trap on 9 different dates in winter and spring 2016–2017 at a site on the east side of the range crest near the Crooked Creek Field Station of the White Mountain Research Center (3125 m). In early winter 2018, two Douglas's squirrels were observed and photographed 25 km distant and 716 m lower in Leidy Canyon (2409 m) on the lower east side of the White Mountains, 3.5 km west of the Nevada state line. In the Desert Creek Mountains, Douglas's squirrels were observed on 4 days in autumn 2017 and winter 2018 along Desert Creek from 2005 m to 2307 m. We present evidence to suggest that at least the White Mountains records represent recent colonization(s) and, as such, call into consideration the question of how montane mammals are able to migrate into isolated mountain ranges of the Great Basin during warm Holocene climates.
The June Sucker Chasmistes liorus mictus is a large-bodied catostomid endemic to Utah Lake, Utah. It is a federally listed endangered species, and one component to its recovery is a stocking program with a target of releasing 2.8 million fish averaging 200 mm long. Because size is implicated as a factor in poststocking survival of western native fishes, particularly in the presence of nonnative fishes, over a 4-year period a combination of telemetry and remote sensing was used to demonstrate size-specific poststocking survival of June Sucker in Utah Lake. A total of 88 June Sucker were released with acoustic tags to estimate short-term survival, and remote PIT scanners were deployed to examine longterm survival. Survival of telemetry fish varied from 0.0 to 0.83, with larger fish exhibiting the greatest survival in the final year. Size-specific survival was most evident in the analysis of PIT scanning data in which survival ranged from 2% for fish shorter than 200 mm to 90% for fish stocked at 300 mm. The causes of mortality are unknown, but likely culprits are nonnative fish and piscivorous birds. Both are well documented preying on June Sucker and similar species. Controlling predation may be impractical, but releasing fewer numbers of larger fish presumably will increase or maintain the population and be more cost effective than the current strategy. Overall, conservation and recovery of June Sucker will be a challenging endeavor going forward.
We present the first photographic evidence of the American black bear (Ursus americanus) in the southwestern limit of its distribution, representing the second record from the state of Hidalgo and the first photographic evidence of a live specimen in Los Marmoles National Park. The black bear recorded in photographs and videos was a subadult male. A total of 51 photo captures of the black bear in oak and pine-oak forests were obtained in 4 localities of Los Marmoles National Park within an altitude range of 1566 m to 1915 m. It is important to implement an adequate management and protection program to conserve the temperate forests in northwestern Hidalgo; these ecosystems could be an important refuge for large carnivores like the black bear.
Little is known concerning predation of rough-footed mud turtles (Kinosternon hirtipes), a species of conservation concern in Texas, USA. During field studies conducted from 2007 to 2016, we documented 8 instances (1 juvenile, 2 males, and 5 females) of predation among individuals of one of the few (<10) remaining populations of K. hirtipes in Texas. Predation was attributed to raccoons (Procyon lotor; n = 5) and feral pigs (Sus scrofa; n = 2); the predator responsible for the death of one of the turtles could not be determined. Turtles are vulnerable to predation when exposed by low water levels in ponds, when making overland movements between ponds, and during nesting forays ashore. To reduce the likelihood of predation, we recommend maintaining adequate water levels in wetlands, linking wetlands with ditches, encouraging the growth of aquatic vegetation, and providing experimental raccoon-proof nest mounds.
We clarify misleading published information on the distribution of the endangered California vole (Microtus californicus) in Baja California, Mexico. We photo-document recent records for 2 of the 4 subspecies reported from Mexico and provide a map that includes several locations not previously published.