Seed banks of Bromus tectorum -dominated communities in the Great Basin

We seeded Agropyron cristatum and 16 native Great Basin perennial species on Bromus tectorum -dominated sites to compare temporal patterns of seedling emergence and early survival among species. To indicate variability between sites and between years, plots were planted on 2 sites in western Utah in autumn 1994, and plantings were repeated near 1 site in autumn 1995. Two sites included burned and unburned seedbed treatments. We monitored seedling emergence and survival from early winter until July of the 1st year. Four seasonal patterns of emergence were evident, indicating considerable potential for different seasonal patterns of precipitation to favor recruitment of difference species. Emergence of all shrubs, except Ephedra nevadensis , began in February and essentially ended by April. Seedlings of Ephedra nevadensis and of the grasses Agropyron and Pseudoroegneria spicata emerged over an extended period from February through June. Most other grasses and the 2 forbs began emerging in April and continued into June. Pleuraphis jamesii emergence did not begin until May. Although many seedlings of the 3 chenopod shrubs emerged, none survived, suggesting their episodic recruitment is more a function of survival than of emergence. Survival of 2 Chrysothamnus species was also low. Pseudoroegneria and Agropyron had the highest numbers of seedlings surviving on the moister site, followed by Elymus elymoides and Stipa comata . Survival of Agropyron , but not the native Elymus , was more depressed on the drier of the 2 sites planted in 1994. Stipa, Oryzopsis hymenoides , Pleuraphis , and Ephedra survived as well on the drier site as on the moister site, or better. On the 1995 planting sites Bromus was greatly reduced by the burn treatment, and, in contrast to the effect of burn treatments on the 1994 site, survival of all species except Oryzopsis and Ephedra was higher on burned than on unburned treatments. Overall, Stipa, Oryzopsis , and Pleuraphis had low emergence but consistently higher survival.     

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 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.     

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.         

Winter macroinvertebrate communities in two montane Wyoming streams

Macroinvertebrate communities were examined on 4 winter dates over a 4-yr period in 2 high-altitude Rocky Mountain streams to document overwintering assemblages potentially experiencing spring acid pulses. Taxa richness values were comparable to other published lists for alpine and montane stream systems despite the fact that most literature reflected summer collections. Mean benthic density ranged from 1406 to 19,734 organisms/m 2 , and drift rates ranged from 0 to 1740 organisms/100 m 3 . Benthic collections showed higher taxa richness than drift collections while the Ephemeroptera and Plecoptera occurred in greater proportions in drift than in benthos. The Nemouridae (Plecoptera), Ephemerellidae and Heptageniidae (Ephemeroptera), Chironomidae (Diptera), and Hydracarina were the numerically dominant taxa in benthic collections. Grazer/scrapers and shredder/detritivores were always the numerically dominant functional feeding groups at all sites, composing 60-90% of the benthos. Predators, constituting approximately 15% of the community, occurred in the same relative proportion at all sites on all dates. Winter macroinvertebrate communities in these low-order, montane streams exhibit high taxonomic richness and benthic densities as great as lower-elevation mountain streams in the West.     

Habitat use by small mammals in southeastern Utah, with reference to Mexican Spotted Owl management

We determined temporal and spatial differences in abundance and habitat use by small mammals in southeastern Utah as part of an effort to enhance management of the Mexican Spotted Owl ( Strix occidentalis lucida ), listed by the federal government as threatened. Woodrats ( Neotoma spp.) were captured only in canyons and most frequently in the pinyon-juniper ( Pinus edulis-Juniperus osteosperma ) vegetation type. White-footed mice ( Peromyscus spp.) were found in a variety of vegetation types in both canyons and mesas. The deer mouse ( P. maniculatus ) was generally the most frequently captured species among vegetation types. We found seasonal and yearly differences in relative abundance of each small mammal species. Our data suggest that the pinyon-juniper vegetation type within canyons is an important component of Mexican Spotted Owl habitat.     

Catastrophic wildfire and number of populations as factors influencing risk of extinction for Gila trout ( Oncorhynchus gilae )

We used the computer program RAMAS to explore the sensitivity of an extinction-risk model for the Gila trout ( Oncorhynchus gilae ) to management of wildfires and number of populations of the species. The Gila trout is an endangered salmonid presently restricted to very few headwaters of the Gila and San Francisco river tributaries in southwestern New Mexico. Life history data for 10 extant populations were used to examine sensitivity of the species viability to changes in a variety of factors including population size, fecundity, life stage structure, number of populations, severity and probability of forest fires, and a regulated fishery. The probability and severity of forest fires and number of populations had the greatest effect on viability. Results indicate that successful conservation of Gila trout requires establishment of additional populations and reduction of the severity of forest fires through a program incorporating more frequent, but less severe, fires.     

New synonymy and new species of American bark beetles (Coleoptera: Scolytidae), Part III

New synonomy is proposed as follows: Metacorthylus Blandford (= Paracorthylus Wood), Corthylus spinifer Schwarz (= Corthylus tomentosus Schedl), Cryptocarinus brevicollis Eggers ( = Cryptocarenus coronatus Wood), Dendrocranulus guatemalensis (Hopkins), n. comb. (= Dendrocranulus parallelus Schedl), Dendroterus mexicanus Blandford (= Conophthocranulus umbratus Schedl), Hypothenemus cylindricus (Hopkins) (= Hypothenemus guadeloupensis Schedl), Hypothenemus erectus LeConte (= Stephanoderes discedens Schedl), Hypothenemus javanus (Eggers) (= Stephanoderes pistor Schedl, Stephanoderes prosper Schedl), Xyleborus pseudotenuis Schedl (= Xyleborus tenuis Schedl), and Xyleborus villosulus Blandford (= Xyleborus coccotrypoides Eggers, villosus Schedl). Scolytodes punctiferus n. n. is proposed for Scolytodes punctifer Wood, 1971 (nec Wood 1969). The following species are named as new to science: Amphicranus argutus, A. fulgidus, A. micans, Pityophthorus inops, P. debilis, P. strictus. P. galeritus. P. sobrinus, P. laetus, P. lenis, P. conspectus P. medialis (Costa Rica), P. perexiguus (Costa Rica and Panama), P. scitulus (Panama), P. costatulus, P. costabilis, P. detentus, P. nebulosus, P. melanurus, P. indigens, P. burserae, P. molestus, P. diligens, P. corruptus (Mexico), P. tenax, P. nugalis, P. minutalis (Guatemala), P. nemoralis, P. morosus, P. hermosus (Honduras), Araptus gracilens (Mexico).     

New taxa in miscellaneous families from Utah

Named are the following: Astragalus limnocharis Barneby var. tabulaeus Welsh var. nov., from the pass between Boulder Mountain and the Table Cliff Plateau, Garfield County, Utah; A. eremiticus Sheldon var. ampularioides Welsh var. nov. from Washington County, Utah; Lupinus argenteus Pursh var. moabensis Welsh var. nov., from southeastern Utah, validated by inclusion of a Latin diagnosis; Erigeron zothecinus Welsh sp. nov. described from moist alcoves along Lake Powell, eastern Kane County, Utah; Cleomella palmerana Jones var. goodrichii Welsh var. nov. described from Uintah County, Utah; Arabis vivariensis Welsh sp. nov. named from northeastern Uintah County, Utah; Draba kassii Welsh sp. nov. described from material taken in the Deep Creek Mountains, western Tooele County, Utah.