Early development of the razorback sucker, Xyrauchen texanus (Abbott)

  Fertilized ova of razorback sucker, Xyrauchen texanus, were adhesive for 3 to 4 hours after fertilization. Cleavage was completed at 24 hours, gastrulation occurred at 34 hours, and blood circulation was established at 117 hours. Hatching occurred from 5.2 to 5.5 days after fertilization. Larvae were from 6.8 to 7.3 mm TL at hatching. Yolk was assimilated at 13 days (10 mm TL). All fins were formed and had ossified rays at 64 days (27 mm TL). The unique nuchal keel appeared about 200 days after fertilization.     

Vegetation characteristics of mountainous northeastern Nevada sagebrush community types

Vegetation characteristics of 15 sagebrush community types identified on the Humboldt National Forest, northeastern Nevada, are described. A total of 218 plant species were found over the 372 relatively undisturbed rangeland communities sampled. The dominant plant families encountered were the Asteraceae (45 taxa), Poaceae (32 taxa), Scrophulariaceae (14 taxa), and the Fabaceae (12 taxa). Average annual dry weight production of the community types ranged from about 400 kg/ha/yr on types with Artemisia nova as the dominant sagebrush species to 1,200 kg/ha/yr on some A. tridentata ssp. vaseyana community types. A general increase in species richness and vegetation plus litter ground cover was observed within community types as the dominant sagebrush species changed from A. nova to A. arbuscula to A. longiloba to A. tridentata spp. tridentata to A. tridentata ssp. vaseyana . Major differences in plant species production and constancy exist between the sagebrush community types studied.     

Predatory bird populations in the east Mojave Desert, California

We surveyed 7 species of predatory birds weekly during a 12-month period (December 1992 through November 1993) in the east Mojave Desert, California. The Common Raven ( Corvus corax ) was the most frequently observed species with an average of 6.9 sightings per 100 km. Turkey Vultures ( Cathartes aura ), Red-tailed Hawks ( Buteo jamaicensis ), Loggerhead Shrikes ( Lanius ludovicianus ), American Kestrels ( Falco sparverius ), Golden Eagles ( Aquila chrysaetos ), and Prairie Falcons ( Falco mexicanus ) were seen in decreasing order of frequency of observation through the study period. Ravens, Red-tailed Hawks, Loggerhead Shrikes, American Kestrels, and Prairie Falcons were seen throughout the year. Turkey Vultures were not present during winter months, while Golden Eagles were seen only during November and December. Turkey Vultures, Red-tailed Hawks, and ravens were most numerous on agricultural lands, while Loggerhead Shrikes were most common at urban areas. Raven numbers increased with increasing number of linear rights-of-way parallel to the survey route. Perching was the most common behavior type, although Turkey Vultures and ravens were often observed soaring, flying, or standing on the ground near highways. Transmission powerline towers and telephone poles were used as perch sites disproportionately to availability.     

Habitat characteristics of small mammals in southeastern Utah

We describe habitat characteristics of 8 small mammal species occurring in the Manti-LaSal National Forest in southeastern Utah. Thirty-seven grids across 7 vegetation types were sample by live-trapping from May through October 1994 and 1995. Logistic regression models of habitat measurements correctly classified small mammal presence 36%-87% of the time. Except for 1 instance, 4 Peromyscus species present in a specific vegetation type were negatively associated with forb or grass cover. Microtus montanus was present primarily on mesas and was positively associated with tall tree and low shrub cover. Neotoma mexicana was present only in canyons and was found primarily in the pinyon-juniper ( Pinus edulis-Juniperus osteosperma ) vegetation type. Tamias spp. was present in all vegetation types. Our results allow better management of these species by providing greater understanding of their use of habitat within vegetation types.     

Habitat use of leatherside chub ( Gila copei ) in the presence of predatory brown trout ( Salmo trutta )

The objectives of this study were to (1) examine distribution and habitat use of leatherside chub ( Gila copei ) in a creek with high densities of predatory brown trout ( Salmo trutta ), and (2) compare study results with published accounts of leatherside chub habitat use in streams with few or no brown trout. A 14-km section of Diamond Fork Creek, Utah, was point-shocked to determine macrohabitat (main channel and lateral habitat) and microhabitat (current, depth, substrate, and cover) use of leatherside chug. At the macrohabitat level, leatherside chub were most common in lower reaches of Diamond Fork Creek where the channel was braided and lateral habitats (cutoff pools and backwaters) were abundant. Only a single leatherside chub was found in the main channel of Diamond Fork. Investigations in other systems lacking brown trout indicated that leatherside chub occupy main channel habitats. At the microhabitat level, we found significant positive associations between presence of leatherside chub and both habitat depth and silt. In addition, we found a significant negative association between presence of leatherside chub and number of brown trout. Our results suggest predation by brown trout may limit leatherside chub to lateral habitats that could provide refugia against predation. The introduction of brown trout to systems with little lateral habitat could have serious effects on persistence of resident leatherside chub populations.     

Habitat use and subspecific status of Merlins, Falco columbarius , wintering in central Utah

Most ornithological literature for Utah reports the status of the Merlin ( Falco columbarius ) as rare or scarce. Only the most recently published checklists (Behle and Perry 1975, Behle et al. 1985) record it as uncommon. Likewise, a 1998 printed checklist (Utah Ornithological Society 1998) list it as uncommon. Also misrepresented in the literature are the status and distribution of the 3 rather distinct subspecies, each of which occupies dissimilar habitats during the breeding season. We made random observations of Merlins in northern Utah beginning in the 1950s and then studied them continuously between 1992 and 1997 in Utah County, Utah. During the 1992-1997 period, we were able to clearly allocate 95 males and 76 females to subspecies, including within our count 58 falcons trapped (some fitted with radio telemetry). The winter habitat in which they occurred was categorized as either urban (mainly dense residential area) or rural (agricultural lands, dairy farms, or scattered homes). There was a statistically significant ( X 2 F. c. columbarius frequenting urban areas 68% of the time, and prairie parkland-breeding F. c. richardsonii frequenting rural habitats 78% of the time.     

Characteristics of natal and non-natal kit fox dens in the northern Chihuahuan Desert

We studied kit fox den characteristics of the northern McGregor Range of Fort Bliss Military Reservation, New Mexico, during 1994 to 1995. Twenty radio-collared kit foxes used 132 different dens, including 16 natal dens. Kit fox dens were located primarily in creosote-dominated habitat found in relatively flat, well-drained terrain. Natal dens were virtually indistinguishable from non-natal dens; however, natal den entrances were taller than non-natal den entrances. Entrances found at all dens were oriented more frequently toward the northwest and southwest. Kit foxes used more dens during the breeding (January-February) and pup-rearing season (May-July) than during gestation.     

Annotated key to Eriogonum (Polygonaceae) of Nevada

Seventy - three species of Eriogonum (Polygonaceae) are reported for Nevada. A key is provided for the identification of these species along with brief notes on their distribution in the state and elsewhere.         

Reptiles and amphibians of Idaho, No 2

For about 20 years Richard P. Erwin collected amphibians and reptiles in southwestern Idaho. This report is an attempt to indicate some of his herpetological activities, and to list the numerous individuals, universities, and museums that were recipients of his collections.