Viviparous fishes of the family Poeciliidae have been model systems in the study of life histories because of their remarkable variation in life-history traits both within and among species, and because of the diversity of selective environments that they occupy. However, the life histories of several poeciliids remain unknown. In this study, we describe the life history of Gambusia vittata, a poorly known poeciliid endemic to eastern Mexico. We analyze variation in number of embryos per reproductive female, size of individual embryos, size at maturity, reproductive effort, the amount of maternal transfer of nutrients to developing embryos, and the relationship between female size and life-history traits. We collected individuals from three sites across 3 months. We found that brood size varied significantly across sites and that brood size, embryo mass, and reproductive allotment varied across months within sites. Brood size, embryo mass, and reproductive allotment all increased with female size. We found that this species exhibits moderate matrotrophy, meaning that females transfer small amounts of nutrients to embryos during development. We compare our results to other poeciliid species and provide tentative explanations for the patterns of intraspecific variation that we observed in the life history of G. vittata.

We stocked four cohorts (larvae and juveniles) of razorback suckers (Xyrauchen texanus) into a managed floodplain wetland in the middle Green River, Utah, from 2008–2009. Our objectives were to determine razorback sucker early life stage survival and growth rates in a natural wetland setting. We used fyke, trammel, and dip nets in addition to boat electrofishing to address project objectives and to recover stocked fish from the wetland for translocation to the Green River. We released 1,515 razorback suckers from this wetland into the Green River, of which 110 (7.3%) have been detected in the river since stocking. Larval razorback suckers survived when few nonnative fish were present, but none survived when many were present. Juvenile fish had high mortality during summer months. We suggest fish and bird predation as plausible sources of mortality for razorback suckers in this wetland.

We report the first record of Spongilla cenota occurrence among drainages of the Edwards Plateau, a large karst area within the western gulf slope drainages of central Texas, and provide the first quantitative habitat description for this species. Spongilla cenota was common in the two rivers of the Edwards Plateau, occurring within 23% of the quadrats surveyed in the Devils River and 31% of the quadrats surveyed in the Llano River. Among multivariate gradients, S. cenota was positively associated with moderate current velocities and coarser substrates and negatively associated with vegetation. The majority (74%) of the quadrats with S. cenota had boulder or bedrock substrates with the remaining sponges attached to aquatic macrophytes and cobble substrate. Among univariate gradients, S. cenota were observed at water depths from 0.5 to 2.5 m and current velocities from 0.1 to 0.6 m/s. Occurrence and abundance of S. cenota potentially provides a novel bioindicator of a sound ecological environment within streams of the Edwards Plateau.

Griffith Park in Los Angeles is notable for its high ecological integrity within a highly urbanized region. We present results of a 2008 bat survey conducted in the park that confirmed seven bat species, and discuss an additional three species that have been recorded incidentally nearby. On the basis of our research, the Griffith Park bat community is notable for the abundance of the canyon bat (Parastrellus hesperus), for a population of the hoary bat (Lasiurus cinereus), and for the relatively minor representation of urban-adapted bats, considering its location.

We evaluated the effects of long-term flow alteration on primary-producer assemblages. In 1962, Flaming Gorge Dam was constructed on the Green River. The Yampa River has remained an unregulated hydrologically variable river that joins the Green River 100 km downstream from Flaming Gorge Dam. In the 1960s before dam construction only sparse occurrences of two macroalgae, Cladophora and Chara, and no submerged vascular plants were recorded in the Green and Yampa rivers. In 2009–2010, aquatic plants were abundant and widespread in the Green River from the dam downstream to the confluence with the Yampa River. The assemblage consisted of six vascular species, Elodea canadensis, Myriophyllum sibiricum, Nasturtium officinale, Potamogeton crispus, Potamogeton pectinatus, and Ranunculus aquatilis, the macroalgae Chara and Cladophora, and the bryophyte, Amblystegium riparium. In the Green River downstream from the Yampa River, and in the Yampa River, only sparse patches of Chara and Cladophora growing in the splash zone on boulders were collected. We attribute the observed changes in the Green River to an increase in water transparency and a reduction in suspended and bed-load sediment and high flow disturbances. The lack of hydrophyte colonization downstream from the confluence with the Yampa River has implications for understanding tributary amelioration of dam effects and for designing more natural flow-regime schedules downstream from large dams.

Two species of shrews and four species of bats are described for Late Pleistocene fossils from Térapa, Sonora, Mexico. Shrews include Notiosorex and an indeterminate genus and species of Soricidae. Bats include several vespertilionids (Lasiurus, Antrozous pallidus, and Myotis) and a molossid (Tadarida brasiliensis). Previous interpretations based on evidence from sediments and other fossils at Térapa suggested the Late Pleistocene presence of a riparian corridor that was wetter and more tropical than at present, including a slow-moving stream, riparian forest, ponded water, marsh, and savanna, or a submerged to emergent grassland. Vertebrate fossils including a crocodylian, certain birds, and a capybara supported the more-tropical interpretation for these habitats. The bats and shrews in the Pleistocene paleofauna support these inferred paleohabitats but only weakly support the more-tropical aspect. Only one bat (Tadarida brasiliensis) has largely tropical biogeographic affinities; the others are widespread or temperate-zone taxa. None of the Neotropical families Phyllostomidae, Mormoopidae, or Natalidae that presently occur in the vicinity of Térapa are yet represented by fossils there. This fact might reflect a nonanalog Late Pleistocene fauna or might simply be due to the general rarity of bat and shrew fossils in fluvio-lacustrine deposits.

State agencies and managers seek more efficient and cost-effective survey methods to monitor wildlife populations in an attempt to maintain biologically defensible results amid continued budgetary constraints. We employed a noninvasive approach using infrared cameras and a skunk-based lure on 52 grids to estimate detection and occupancy rates of swift foxes (Vulpes velox) in eastern Colorado. We used eight camera stations within 31-km² grids, monitored each grid for five consecutive nights, and collected 331 swift fox detections from August–October 2011. We documented 78 more swift fox detections on 25% more grids using remote cameras with skunk lure while deploying 60% fewer survey stations per grid than previous mark–recapture surveys. Our estimates showed improvements in precision and accuracy for detecting swift foxes and estimating occupancy across eastern Colorado. Using infrared cameras and a skunk-based lure proved to be an efficient and effective technique for monitoring swift foxes on a landscape scale by reducing labor costs, survey time, and potential biases that may result from using cameras or other survey techniques.

Recent analyses suggest that the big brown bat (Eptesicus fuscus) may be less of a beetle specialist (Coleoptera) in the western United States than previously thought, and that its diet might also vary with temperature. We tested the hypothesis that big brown bats might opportunistically prey on moths by analyzing insect fragments in guano pellets from 30 individual bats (27 females and 3 males) captured while foraging in Fort Collins, Colorado, during May, late July–early August, and late September 2002. We found that bats sampled 17–20 May (n = 12 bats) had a high (81–83%) percentage of volume of lepidopterans in guano, with the remainder (17–19% volume) dipterans and no coleopterans. From 28 May–9 August (n = 17 bats) coleopterans dominated (74–98% volume). On 20 September (n = 1 bat) lepidopterans were 99% of volume in guano. Migratory miller moths (Euxoa auxiliaris) were unusually abundant in Fort Collins in spring and autumn of 2002 and are known agricultural pests as larvae (army cutworms), suggesting that seasonal dietary flexibility in big brown bats has economic benefits.

Plant parasitic dodders (Cuscuta spp.) are globally distributed holoparasites that form a direct connection to host vascular tissue. Using Cuscuta campestris as a live bridge between plants, this study investigated potential nutrient movement between pairs of tomato plants (Solanum lycopersicum). Specifically, the study addressed two questions: 1) If two hosts are connected by dodder, does nutrient supplementation for one plant (the “donor”) lead to increased growth in an unmanipulated plant (the “receiver”)? 2) Does shading the donor lead to reduced growth in the receiver? As expected, donor plants in the nutrient addition and nutrient shade addition treatments showed higher above- and belowground growth than control donor plants. However, the unmanipulated receiver plants showed no significant differences in growth, regardless of treatment. These results suggest that few (if any) nutrients passed through dodder from the donor to the receiver plant and that shading the donor did not impact the growth of the receiver plant.

In North American glyptodonts, the identification of the genus Glyptotherium revolves primarily around characters of the carapace. However, previous studies suggest the possibility of a wide range of intraspecific variation. We report two glyptodont specimens from the Mexican states of Tamaulipas and Tlaxcala. We offer a description of their skeletal and carapace elements as well as a brief review of glyptodont distribution in Mexico. Our initial analysis led us to conclude that the glyptodont from Tamaulipas bears similarities to Glyptotherium cylindricum whereas the Tlaxcala specimen resembles Glyptotherium floridanum. However, further study of previously unreported skeletal elements, in association with characters of the carapace, suggested similarity between the two species. Hence we assigned the two glyptodonts to the species G. cylindricum, which has nomenclatural priority. The addition of new morphological characteristics helped to discern synonymy of these two glyptodont species.

In gregarious mammals, female philopatry promotes the formation of local lineage associations, but the extent of this effect is unclear for most solitary mammals, including raccoons. The current study examined 839 raccoons captured 1,870 times on a 13.8-km2 study area in southwestern Tennessee. The data did not support the prediction that closely related raccoons would remain geographically clustered over multiple years. The distance between the 71 pairs of full sibs detected by microsatellite analysis was <1 km for 64.7% of the pairs but >69 km for 7.1% of the pairs, with a mean of 7.0 km. Rarely did sib groups shift locations together, comprise more than three individuals, or remain intact in the same vicinity for more than a year. The spatial dispersion among closely related raccoons was greater in males than in females, in older adults than in younger adults, and during dry years than during wet years. These patterns of dispersion would not facilitate the development of gregariousness but could speed the spread of key diseases. Further study is needed to understand these patterns and effectively manage raccoons in the southern United States where multiannual fluctuations in environmental conditions, such as precipitation, occur.

In this study we report avian and mammalian scavengers foraging on migratory bird carcasses in the Sonoran Desert. We used remote cameras to monitor carcasses we found along a power line right-of-way (n = 25). We documented four species scavenging 10 carcasses (kit fox, Vulpes macrotis, n = 4; coyote, Canis latrans, n = 3; common raven, Corvus corax, n = 2, and greater roadrunner, Geococcyx californianus, n = 1) and recorded coyote tracks at three additional carcasses. Neither remote cameras nor tracks indicated the scavenger species of the remaining carcasses. Our data suggest migrant birds might provide an important food source for resident scavengers, particularly in desert habitats where food can be scarce. Our study also supports prior assertions that failure to account for removal of carcasses by scavengers might cause errors in estimates of mortality.

Based on identification of bat species submitted to the Oklahoma State Department of Health for rabies testing, and from literature accounts, the incidence of rabies in bats in Oklahoma from 1987–2012 is discussed. Of the 1,079 bats submitted, 1,061 were tested for rabies over the last 26 y. Twelve species were identified. The most-frequently submitted species was the Eastern red bat, Lasiurus borealis. The percentage of bats that tested positive for rabies was 9.7%.

How bronzed cowbirds (Molothrus aeneus) find nests to parasitize is poorly known, especially whether they use host vocalizations as sources of information about nest location and status. We conducted 120 point-count surveys, followed by broadcasts of host songs, at Santa Ana National Wildlife Refuge in the Lower Rio Grande Valley of Texas in 2008 and 2009. Bronzed cowbirds responded to songs of potential host species by flying toward the source of the playback as single females or males or multiple females and males. Bronzed cowbirds responded in greater numbers to the songs of oriole species (Icterus) than to olive sparrow (Arremonops rufivirgatus), a lower-quality host species. Such responses by bronzed cowbirds could facilitate the location of host nests for nests of species difficult to find or to look into.

We describe a morphometric technique for distinguishing the sexes of loggerhead shrikes (Lanius ludovicianus) in California, USA. We used standard morphometric measurements, as well as additional quantitative or qualitative assessments of the pattern of color on the sixth primary flight feather (P6). We reduced subjectivity in these qualitative assessments by asking six independent observers to score P6 photos of each shrike. We then developed and compared discriminant functions and multiple logistic regression models from 54 shrikes sexed by deoxyribonucleic acid. Our best models included the extent of white coloration on the primaries, tail length, bill depth, and quantitative or qualitative measurements of the angle of the black/white color transition on P6. On the basis of jackknife cross-validation procedures, our best models accurately predicted sex 86–88% of the time, despite the age and geographic variation inherent in our sample. Our results suggest that these, and potentially other, quantitative or qualitative metrics can enhance the performance of multivariate predictive models of sex identification. Furthermore, we proffer our independent observer approach as a viable means for reducing subjectivity and potential biases in the assignment and measurement of character states.

We measured fire damage to 250 riparian trees in 2003–2004, and again in 2012–2013, in a southeastern Arizona grassland burned by wildfires in 2002, 2009, or both. Following a single fire, combined mortality or survival only by ground-level resprout was 64% for desert willow (Chilopsis linearis), 57% for Fremont cottonwood (Populus fremontii), 48% for Arizona walnut (Juglans major), 32% for velvet ash (Fraxinus velutina), and 25% for Wright's sycamore (Platanus wrightii). A second fire burned 120 of the trees that happened to have been less damaged by the first fire. Distinctions among species in overall fire damage persisted after the second fire but to a lesser degree. By the conclusion of our study, 26% of the 250 trees had died completely while another 32% survived only as relatively small resprouts. We conclude that the fires substantially reduced both the abundance and crown volume of mature riparian trees in the study area.

The antelope jackrabbit (Lepus alleni) is a lagomorph indicative of Neotropic savanna and thornscrub in south-central Arizona, west-central Sonora, and western Sinaloa <1,200 m elevation. We found populations in Arizona are most abundant in tropic–subtropic areas of low relief, characterized by velvet mesquite (Prosopis velutina) with an herbaceous understory (= Sonoran savanna grassland), and receiving a mean annual rainfall of between 200 and 450 mm, >90 mm of which falls as summer precipitation. In Mexico, this hare most commonly occurred in savanna grasslands or thornscrub interrupted by open areas receiving between 200 and 450 mm of precipitation per annum. Cacti were important habitat components for the hares and mean annual temperatures were >18°C with <60 d a year having temperatures below 0°C. Although sympatric with Lepus californicus over portions of its range, the two species preferred different habitats and rarely occurred together, and L. alleni was more prone to occur in groups than was L. californicus. We calculated the distributional range of L. alleni as ca. 102,000 km² in Arizona and Mexico.

In northwestern Mexico, studies on hantavirus in rodent hosts are scarce. Our objective was to conduct serological tests to detect antibodies against hantavirus in rodents from the Janos–Nuevo Casas Grandes prairie dog complex (JCGC) in northwestern Mexico. In December 2007 and April 2008, we captured 149 rodents and tested for immunoglobulin G antibodies to New World hantaviruses. Three Peromyscus maniculatus from grassland habitats without prairie dog colonies were antibody positive. This is the first record of hantavirus prevalence in wild rodents from JCGC and from the state of Chihuahua. Further molecular analysis is needed to describe which hantavirus is circulating in this area.