Much is known about movements of female white-tailed deer (Odocoileus virginianus). However, relatively few investigations have been directed toward free-ranging male deer and even fewer have involved mature (≥4 years old) males. Our objectives were to characterize utilization distributions and site fidelity, and to evaluate the subdominant-dominant-floater model using an extensive radiotelemetry dataset collected from male deer ≥1.5 years old in southern Texas. We generated home ranges and core areas of 96 males from 16,696 location estimates collected during January 1993–June 1995. Annual home-range size did not differ among age categories. Males maintained smaller home ranges during spring than during other seasons and old males (≥7 years old) displayed smaller seasonal home ranges than young or mature males. Deer exhibited greater fidelity to home range during summer than during spring, prerut, and rut seasons. We detected limited evidence supporting the subdominant-dominant-floater model. The high fidelity to home range between years that we saw suggests little between-year shifting; however, annual home-range sizes exceeded the acreage of most private landholdings, which should be considered when formulating management plans.

The tawny deermouse (Peromyscus perfulvus), a semiarboreal endemic in western Mexico, exhibits attributes associated with extinction vulnerability. In January 2003 and 2004, we conducted mark-and-recapture studies at Playa de Oro, Colima, Mexico. Each year, five 100-station live-trap grids (each station with one ground and one arboreal trap; 10 by 10 configuration) were set up for 8 nights in areas with dense vegetation. Only one tawny deermouse was caught in 2003. In 2004, we trapped 16 individuals (12 males, 4 females) 47 times, with 91.4% of captures being in arboreal traps. Captures in 2004 were at 25 stations, all on the same grid, in habitat representing a mixture of thorn forest, mangrove, and palm trees (density 13.6 mice/ha). Considering all 500 trap stations in 2004, we used stepwise logistic regression to evaluate differences based on 13 structural-vegetation measures of the 25 stations where tawny deermice were found versus the 475 where it was not caught. Tawny deermice tended to inhabit locations with trees close-by, sparse low-level vegetation, little litter, and dense high-level vegetation. For the one grid where we caught tawny deermice (25 stations where present versus 75 absent), only distance to nearest tree was significantly predictive; mice avoided even small forest openings. Tawny deermice were trapped at only a small subset of sites within what heretofore has been considered its suitable habitat. Evidence of restricted spatial structure and other limiting demographic features indicate a need for increased concern in conservation of this endemic species.

We measured size of home range (adaptive kernel and minimum convex polygon methods), size of nest trees, and distance to nest trees during nightly activity of 13 northern flying squirrels (Glaucomys sabrinus) in two types of forests in Plumas Co., California. We used 95 and 50% adaptive kernel and 95% minimum convex polygon analyses to determine home ranges. Juvenile males had smaller home ranges (6.3 ± 1.6 ha) than adult males (25.5 ± 4.0 ha). There was no significant difference in area of home range by gender or type of forest among adults. Mean size of home range was 29.3 ± 4.5 ha for all adults. Most nests were cavities in live trees and snags, although some external nests were used. Mean distance from locations of northern flying squirrels to the nearest nest tree did not vary throughout the night; however, females tended to travel farther from nest trees.

We present the first non-breeding-season time budget of adult burrowing owls (Athene cunicularia). We evaluated the hypothesis that during the non-breeding season the gender-specific allocation of time and effort observed diurnally in the breeding season changes, with males and females exhibiting more similar time budgets. Owls spent most of their time alert (58.4 ± 7.2% and 42.6 ± 8.3%) and in the burrow (19.3 ± 5.3% and 46.2 ± 7.2% for males and females, respectively). Females tended to spend more time in the burrow, and males spent more time alert. Although we found little evidence for temporal variation of these patterns for males, females were found more often in the burrow during early afternoon. Our results support a hypothesis that time-allocation differences between males and females during the breeding season are at least partially retained into the non-breeding season. The major finding of the study was the high percentage of time owls spent within the nest burrow during the non-breeding season, contrary to previous understanding of the ecology of this species from which management guidelines are based. Our findings indicate that considerable care should be taken when modifying areas that contain burrows within areas occupied by burrowing owls during the non-breeding season.

The Mexican spotted owl (Strix occidentalis lucida) was listed as a threatened species under the Endangered Species Act in 1993. We developed a predictive, vegetation-based model for habitat of the species in the Jemez Mountains, New Mexico, using logistic-regression modeling techniques and analyzed seven habitat variables with six of the variables included in the final model. A plot analysis using Receiver Operating Characteristics indicated a high performance of the model, and validation of the model confirmed proper function. Compared with random unoccupied sites, the model indicates that owls in the Jemez Mountains prefer habitat with greater diversity, density, and height of trees, canopy cover, and shrub density, which is in agreement with much of the literature on biology of the Mexican spotted owl. This model can be used with fine-scale assessments of habitat for land-management agencies that have a priority to accurately delineate habitat of the Mexican spotted owl. Los Alamos National Laboratory will use this model to re-delineate habitat of owls to reduce assessment costs and to better protect appropriate habitat.

Growth boxes were used in a greenhouse to evaluate aboveground and belowground growth, and biomass allocation in seedlings of Acacia farnesiana and Celtis laevigata in infertile and fertile soils. Acacia farnesiana is a N-fixing, heliophyte, which is a dominant in mesic, early successional communities in some areas of the southern United States and northern Mexico. Celtis laevigata is a sciophyte, which assumes dominance as many of these communities mature. Length of stem, length of root, number of leaves, and basal diameter of seedlings of A. farnesiana were significantly greater than those of C. laevigata, regardless of nutrient level. Both species showed increased length of stem, length of root, and number of leaves when nutrients were added; however, the amount of increase in length of root depended on species. Shoot, root, and total dry mass of seedlings of A. farnesiana was significantly greater than in C. laevigata. Addition of nutrients increased dry masses of both species. Additions of nutrients had no effect on root:shoot allocation of either species; however, root:shoot ratios were greater in C. laevigata than for A. farnesiana. Data suggest that for the late-successional species C. laevigata to establish in the successional sequence, some factor other than nutrients, such as light levels, must inhibit the continued establishment of seedlings of A. farnesiana.

We reviewed the conservation status of rare and endangered species of mussels in southeastern Oklahoma by completing surveys of 10 long-term monitoring sites on the Kiamichi River and five sites in the Little River. We found extant populations of the Ouachita rock pocketbook, Arkansia wheeleri, scaleshell, Leptodea leptodon, winged mapleleaf, Quadrula fragosa, and rabbitsfoot, Quadrula cylindrica cylindrica. This is the first reported documentation of Q. fragosa in the Little River. When our data are compared to historic records, populations, particularly of A. wheeleri and Q. cylindrica, appear to be declining.

We examined ecological interactions between two ecosystem engineers, Gunnison's prairie dogs (Cynomys gunnisoni) and Botta's pocket gophers (Thomomys bottae), across a 67,000-km² range of northern Arizona. We examined densities of burrows, composition of vegetation, and characteristics of soil associated with locations where each species occurred alone and compared them to where they were both present. Density of T. bottae was significantly lower in the presence of C. gunnisoni than where occurring alone, while density of C. gunnisoni more than doubled at locations where they occurred with T. bottae compared to where they were alone. Vegetational communities associated with locations where C. gunnisoni occurred alone were significantly different from locations where T. bottae occurred alone and where both species were present. We also detected that burrows of T. bottae and C. gunnisoni occurred in soils that did not differ significantly in depth, texture, or rock content, but characteristics of soil played an influential role in patterns observed in vegetational communities.

The presence of species disjunct from more northern distributions and quantitative aspects of species associations were studied on the Sierra La Asamblea, an isolated range reaching 1,661 m elevation at about 29.3°N on the Baja California Peninsula. The flora above 800 m is composed of ≥299 species of tracheophytes, notably including Pinus monophylla and Adenostoma fasciculatum. Eighty-seven species are considered disjunct from more northern distributions, of which only 19 have affinity limited to the California Floristic Province. Data from 10 transects and adjacent flora show few species that are either broadly distributed or locally common, and both composition and structure differ from studies at lower elevations. Disjuncts were most common in association with P. monophylla. Range extensions (38) are reported, including three new records for the peninsula, and a floristic list is provided.

We surveyed four spring sites of the Edwards Aquifer to determine current distribution and abundance of spring and cave-adapted invertebrates, including three that are federally listed as endangered. We found 18 species from 12 families of endangered and stygobiontic fauna, similar to other surveys completed 10 years prior, and recorded new localities for Tethysbaena texana, Cirolanides texensis, Lirceolus hardeni, Lirceolus smithii, Stygobromus longipes, Stygobromus flagellatus, and Artesia subterranea. We also report discovery of new species of Bogidiellidae (near Parabogidiella), Ingolfiella, and Almuerzothyas.

A survey of Amistad National Recreation Area in Val Verde Co., Texas, was conducted using field sampling, literature records, and museum vouchers to compile a current list of the mammal fauna. Field work was conducted May 2003–July 2004. Small mammals were trapped along 21 transects for a total of 3,150 trap nights and medium-sized mammals were trapped on nine transects for 135 trap nights. Additional records were obtained through observations, collecting in specific habitats (rocky bluffs, grassy roadsides, etc.), salvaging road kills, and recording visual evidence of presence. Overall, 50 species of terrestrial mammals were identified as probably occurring in Amistad National Recreation Area, including seven non-native species. Previous studies documented 38, 47, and 46 species. With the exception of the northern pygmy mouse (Baiomys taylori), none of the native mammals captured during this study appear to be expanding their range.

Worthen's sparrow (Spizella wortheni) is probably one of the least known sparrows of North America. Its breeding range is uncertain, as there are questionable records from several localities in Mexico and from the type locality near Silver City, New Mexico, in the United States. Currently, the only unquestionable records are from Coahuila and Nuevo León. Here we describe new localities for this species from the state of Nuevo León and confirm already known localities from Coahuila. These new records were gathered during a bird-monitoring program within colonies of the Mexican prairie dog (Cynomys mexicanus) in northeastern Mexico. We surveyed seven grassland areas and recorded Worthen's sparrow at four of them; Los Angeles, La Perforadora, La Soledad, and El Guerrero. Our records add more detail to the known distribution of this species and our behavioral observations suggest they breed in all four localities.

Restoration of riparian areas is an important step toward improving water flow and water quality of the Río Conchos in northern Mexico. To provide background data for restoration decisions we characterized the ecological integrity of a 40-km-long riparian corridor along the middle Río Conchos. The characterization consisted of determining dominant species of trees and shrubs, structure, and quality of riparian habitat using standard transect sampling and a riparian habitat-quality index (QBR index) along the corridor. Our data indicate that willow (Salix nigra) and mesquite (Prosopis glandulosa) are the dominant trees in the riparian zone, and that although invasive saltcedar (Tamarix ramosissima) populate nearby agricultural lands and irrigation canals, they have not yet invaded the riparian areas of the middle Río Conchos. Habitat degradation is occurring; the major sources of negative impacts to riparian habitat are, in order, overgrazing, sewage input into the river, and gravel extraction from the river channel.

This paper reports shrews (Soricidae, Soricomorpha) in Colima, Mexico, namely, Cryptotis parva, Sorex saussurei and the threatened Megasorex gigas. They were recorded in cloud, pine, and pine-oak forests. Voucher specimens were catalogued in the Colección Nacional de Mamíferos (CNMA), Instituto de Biología de la Universidad Nacional Autónoma de México (UNAM), in Mexico City. This research contributes to the knowledge of the biodiversity of western Mexico, provides the first museum specimens of these taxa in the CNMA and confirms the presence of taxa of conservation concern.

Intense predation on larval and juvenile fishes by introduced piscivores can be detrimental to recruitment of threatened and endangered native fishes. Introduced largemouth bass (Micropterus salmoides) in the San Juan River, New Mexico, Colorado, and Utah, rarely are collected as adults; however, juveniles (<200 mm total length) often occur in the same habitats as young-of-the-year native fishes. To evaluate the prevalence of native fishes in the diet of juvenile largemouth bass, stomach samples from juveniles were collected from the San Juan River in New Mexico during July and August 2005, when young-of-the-year native and nonnative fishes were present. Stomach contents of largemouth bass were identified as native catostomids, native cyprinids, or nonnative cyprinids based on pharyngeal teeth. Although nonnative fishes comprised >80% of the potential prey base, significantly more native fishes were identified in stomachs than nonnative fishes. The disproportional abundance of native fishes in the diet of juvenile largemouth bass suggests greater susceptibility of young-of-the-year natives to predation by largemouth bass in the San Juan River.

We report on 14 western diamond-backed rattlesnakes (Crotalus atrox) that were located at or near communal-type dens in late winter and observed to harvest and consume water from rain, sleet, and snow. Observations occurred on 11 and 19 March 2006, and were conducted at two sites in the Sonoran Desert of southern Arizona. On both days, weather conditions were inclement, with near-freezing (≤5°C) ambient air temperatures, rain mixed with sleet or snow, gusty winds, and 100% cloud cover. Individuals involved in harvesting water from their bodies assumed stereotypic postures that were similar to those reported in other species of rattlesnakes. We suggest that protracted extreme drought (e.g., 175 days without precipitation from mid-September to early March) coincident with record-high temperatures during this period contributed to dehydration in the populations of C. atrox studied. Consequently, despite harsh weather, benefits of harvesting water from rain, sleet, or snow possibly overrode risks of predation and other factors.

Western ribbon snakes (Thamnophis proximus) were collected at the Old Sabine Bottom Wildlife Management Area, Smith Co., Texas. Distended individuals were palpated to recover recently ingested prey, which resulted in discovery of five new prey items. This report also provides updated nomenclature of previously reported prey items. After comparing previously reported localities of prey items with current range descriptions and taxonomy, it was concluded that two anurans should be removed as documented prey items of T. proximus.

Swift foxes (Vulpes velox) and Arctic foxes (Alopex lagopus) often use barking to communicate information to mates, members of social groups, and other conspecifics. Barking by the closely related kit fox (V. macrotis), however, remains largely unobserved and undocumented. We observed barking among a population of radiocollared San Joaquin kit foxes (V. m. mutica) inhabiting Bakersfield, Kern Co., California, during August 2002–March 2003. We observed 150 barks, including 56 from two adult (≥1 year old) males, 83 from an adult female, and 11 from two juveniles (<1 year old). Of these, we recorded nine barks, each of which consisted of a series of short, discrete elements repeated in rapid sequence; similar in structure and sound to barking sequences by swift and Arctic foxes. Barking occurred rarely and concentrated mostly around the mating period in mid-December. Our observations suggest that barking functions to contact or attract mates or potential mates and serves little territorial importance.

We collected 409 Pimephales vigilax (bullhead minnow) and 32 Percina macrolepida (bigscale logperch) from Elephant Butte Reservoir, Sierra Co., New Mexico, during a small-bodied fish survey in August and December 2005, and January and August 2006. The bullhead minnow is considered nonnative in the Rio Grande in New Mexico, but has been collected downstream of Elephant Butte Reservoir. Collections of this species document its establishment within Elephant Butte Reservoir. The bigscale logperch had not been collected previously from the Rio Grande in New Mexico and these collections represent a range extension for this species. Both species are now established in Elephant Butte Reservoir and these unnatural range extensions are related to human activities, but the exact cause remains unknown.

Statistical analysis of a series of measurements from great horned owls (Bubo virginianus) revealed no difference in wing chord and tail length among three groups studied (B. v. pallescens, B. v. virginianus, or intermediate) in Texas.