Barn owl diet includes mammal species new to the island fauna of the Great Salt Lake

An investigation of the diet of the Common Barn-owl ( Tyto alba ) on Antelope Island, Great Salt Lake, Utah, yielded four mammal species not previously known to occur on any island in the Great Salt Lake ( Microtus pennsylvanicus, M. montanus, Ondatra zibethicus , and a Sorex sp.). Two other species, known from other islands, were added to the list of fauna of Antelope Island ( Perognathus parvus and Reithrodontomys megalotis ). The barn owl diet on Antelope Island was remarkably like that of barn owls feeding in farmlands adjacent to the Great Salt Lake despite major vegetational differences.     

Breeding ecology of Long-billed Curlews at Great Salt Lake, Utah

We qualified nest site characteristics, breeding densities, and migratory chronology of Long-billed Curlews at the Great Salt Lake, Utah. The species is apparently declining in Utah, and little is known about their breeding in the eastern Great Basin Desert. This study was designed to provide wildlife biologist with the baseline data useful for their successful management. Curlews arrived in northern Utah in late March and generally departed by mid-August. Nest densities at Great Salt Lake ranged from 0.64 to 2.36 males/km 2 . The habitat at curlew nest sites consisted of significantly shorter vegetation than nearby random locations ( ˉx = 5.7 versus 9.0 cm, respectively; P < .01). Nests tended to be located in small patches of vegetation near barren ground. Maintenance of relatively short vegetation appears to be important in managing curlew habitat. In addition, only 2 of 10 nests we monitored in 1992 were successful, with most lost to mammalian predators. Further research is needed to determine impact of mammalian predators on curlew populations.     

Potential use of Great Salt Lake water for lobster culture

Three experiments were conducted to determine if water from the Great Salt Lake altered in chemical composition and dilution can be used successfully to sustain a species of hermit crab Pagarus sp. and the American Lobster ( Homarus americanus ). Great Salt Lake water altered by freshwater dilution will not sustain the hermit crab or the American lobster. Great Salt Lake water can be altered chemically by dilution to support growth of the American lobster. American lobsters maintained in Instant Ocean synthetic sea water (control) grow at a more rapid rate than animals sustained in altered Great Salt Lake water. A plastic primer coat used for plastic tank repair appears to be a moult inhibitor for the American lobster. Lobsters afflicted by the primer coat are not able to reverse the damage by continued moults.     

Insular biogeography of mammals in the Great Salt Lake

The distribution of 21 species of nonvolant mammals among nine islands in the Great Salt Lake was analyzed for biogeographic patterns. The number of species inhabiting an island is closely correlated with island area That the slope of the regression line describing this relationship (z or b) is relatively shallow compared to (1) totally isolated island systems or (2) island systems where an equilibrium between rates of colonization and extinction have been attained suggests that isolation plays little role in accounting for the variation in mammalian species diversity among islands. Stepwise multiple regression confirms this, while demonstrating that area alone accounts for 88 percent of the variation in species diversity among islands. However, endemic subspecies comprise a significant proportion of the insular mammalian fauna, suggesting that isolation for small mammals restricted to certain habitats may be substantial. A general scenario of the processes determining insular mammalian diversity and endemism is discussed for the Great Salt Lake, where the dynamic lake level creates a potential for different biogeographic processes over time.     

Taphonomy and significance of Jefferson's ground sloth (Xenarthra: Megalonychidae) from Utah

While a variety of mammalian megafauna have been recovered from sediments associated with Lake Bonneville, Utah, sloths have been notably rare. Three species of ground sloth, Megalonyx jeffersonii, Paramylodon harlani, and Nothrotheriops shastensis , are known from the western United States during the Pleistocene. Yet all 3 are rare in the Great Basin, and the few existing records are from localities on the basin margin. The recent discovery of a partial skeleton of Megalonyx jeffersonii at Point-of-the-Mountain, Salt Lake County, Utah, fits this pattern and adds to our understanding of the distribution and ecology of this extinct species. Its occurrence in Lake Bonneville shoreline deposits permits a reasonable age determination of between 22 and 13 ka.     

Birds of Gunnison and Cub islands, Great Salt Lake, Utah

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} A total of 87 avian species were recorded on islands of Great Salt Lake by Behle, with 17 observed on Gunnison and Cub islands. This paper presents sightings and salvaged carcasses recorded on Gunnison and Cub islands, 1972 &ndash; 1974. Of the 112 species observed, 95 are first records for Gunnison and Cub islands and 49 are first records on or near any island of Great Salt Lake. Over 90 percent of species observed on the islands were transients.     

Response of nesting waterfowl to flooding in Great Salt Lake wetlands

Great Salt Lake wetlands were inundated in 1983, displacing approximately 20,000 nesting waterfowl. Ten protected marshes in the Great Basin were surveyed for changes in numbers of breeding pairs of waterfowl during each of four years preceding Great Salt Lake flooding and four years following flooding. The hypothesized increase in numbers of breeding birds did not occur, indicating that flood-displaced waterfowl did not move into nearby suitable habitat to nest.     

Decreases of juniper woodland in the Utah and Salt Lake valleys since settlement

Although pinyon-juniper woodland is common throughout most of Utah, it is less so in Utah and Salt Lake valleys. Even so, stands do occur in the valleys and are known to have been there since presettlement times. Three such stands occurring along the eastern sections of the valleys have shown major decreases in area since settlement times, and one has all but disappeared. Their disappearance is attributed to early use for fuel, agricultural, and urbanization purposes. &nbsp;     

On the relative importance of floral color, shape, and nectar rewards in attracting pollinators to Mimulus

Pollinator preferences were observed for the six species of section Erythranthe of the genus Mimulus using greenhouse-grown plants placed in a meadow in the Red Butte Canyon Natural Area, Salt Lake County, Utah. The principal pollinators were hummingbirds and bumble bees. Hummingbirds preferred the species with the most reflexed tubular flowers regardless of color, whereas bumblebees preferred pink. lavender, or yellow flowers to red flowers regardless of shape. Results for the six species were confirmed by observations of F 2 hybrid recombinant plants selected such that flower color could be held constant and flower shape varied and vice versa.     

Inventory of Utah crayfish with notes on current distribution

Crayfish distribution and composition in Utah are poorly documented. Based upon limited collections, the native Pacifastacus gambelii is widespread and often abundant in the Bear and Weber river drainages and is occasionally represented in smaller tributaries to the Great Salt Lake and to the Raft River. Pacifastacus leniusculus was collected from Utah County and Procambarus clarkii from Tooele County; the origin of these populations is not known. The nonnative crayfish Orconectes virilis is currently abundant in the Virgin, Price, and Duchesne river basins and the Glen Canyon, Flaming Gorge, Deer Creek, and Starvation reservoirs; it is expanding in Huntington North, Scofield, and Willard reservoirs. Further work is required to develop a more complete inventory and monitor the impacts on aquatic ecosystems of expanding nonnative crayfish populations. Surreptitious stockings can be dealt with only if the public is made aware of the adverse consequences of ill-conceived introductions.     

Status of introduced fishes in certain spring systems in southern Nevada

We record eight species of exotic fishes as established, reproducing populations in certain springs in Clark, Lincoln, and Nye counties. Nevada. These include an unidentified species of Hypostomus, Cyprinus carpio, Poecilia mexicana, Poecilia reticulata, a Xiphophorus hybrid, and Cichlasoma nigrofasciatum. Tilapia mariae, established in a spring near the Overton Arm of Lake Mead, and Tilapia zilli, established in a golf course pond in Pahrump Valley, are recorded for the first time from Nevada waters. Though populations of transplanted Gambusia affinis persist, other populations of Poecilia latipinna are apparently no longer extant. Cichlasoma severum, Notemigonus crysoleucas, Poecilia latipinna, and Carassius auratus were apparently eradicated from Rogers Spring in 1963.     

Three new records for diatoms from the Great Basin, USA

Three diatom species recently collected from Great Basin localities represent new records of these taxa from this region of western North America. Cocconeis scutellum &nbsp; Ehr. and Melosira dubia &nbsp; Kuetz. were collected from a thermal spring in Tooele County, Utah. Nitzschia hustedtiana &nbsp; Salah was collected from newly flooded marshes at the south end of the Great Salt Lake, Tooele Countv, Utah.     

Ostracod fauna of salt Lake Acıgöl (Acı Tuz) (Turkey)

Lakes and wetlands in Mediterranean regions are overexploited and contaminated without sufficient local governmental control. The biodiversity of Salt Lake Ac?göl (Turkey), an internationally recognized ecosystem, is presently endangered by management plans. This study aims to analyse the ostracod community to establish its ecological status as a base for future paleoecological studies using ostracods to reconstruct the recent evolution of this wetland. Samples were collected seasonally and 13 species were recorded. Multivariate classification and ordination statistical methods revealed a major difference between assemblages related to the relative abundance of species tolerant of desiccation vs. species preferring permanent waters. Cyprideis torosa, mainly found in saline, low diversity sites, is a euryhaline species regarded as an indicator of future lake conditions if inappropriate water resource management continues.     

Autumnal migration of Eared Grebes ( Podiceps nigricollis ) through southwestern Wyoming: a key to assessing the size of the North American population

In autumn the vast majority of the North American population of Eared Grebes ( Podiceps nigricollis ) congregates for several months at Great Salt Lake, Utah, and Mono Lake, California. Because the lakes are so large, it has not been possible to monitor grebe migration with sufficient accuracy to determine when peak numbers are reached. To clarify migration phenology, we analyzed data from 2 isolated wetland areas in southwestern Wyoming where grebes land en route between breeding areas in the interior and Great Salt Lake. Occasional birds, probably nonbreeders or failed breeders, begin moving southward as early as mid-June. Migration of postbreeding birds starts in late July, peaks in late August and September, and is largely completed by the end of October, with very small numbers arriving into November. The pattern of migration and number of birds encountered varied annually, but 95% of the migration was usually completed by 15 October. As a result, censuses at the major staging lake made on or after 15 October but before the grebes depart for wintering areas can be used to study trends in size of the North American population.     

Red Butte Canyon Research Natural Area: history, flora, geology, climate, and ecology

Red Butte Canyon is a protected, near pristine canyon entering Salt Lake Valley, Utah. It contains a well-developed riparian zone and a perennial stream; hillside vegetation ranges from grasslands on the lower limits to Douglas-fir and aspen stands at the upper elevations. In this paper we describe the history of human impact, natural history aspects of climate, geology, and ecology, and faunal and floral information for key species in the canyon. The role and importance of Research Natural Areas is discussed, particularly with respect to the need to protect Red Butte Canyon:one of the few remaining undisturbed riparian ecosystems in the Intermountain West.     

Occurrence of Phaedactylum Tricornutum in the Great Salt Lake, Utah, USA

The diatom Phaedactylum tricornutum Bohlin forms blooms in the south arm of the Great Salt Lake, Utah, during cool months. This represents the first report of this taxon from Utah and the first from nonmarine waters in the United States.     

Productivity, food habits, and associated variables of Barn Owls utilizing nest boxes in north central Utah

Productivity and food habits of the Barn Owl ( Tyto alba ) utilizing nest boxes in Juab, Utah, and Salt Lake counties, Utah, During 1979-1984 were examined. Average clutch size was 5.8 eggs for the 6-yr period; mean number fledged was 3.9 young per successful nest. While severe weather during the 1981-82 winter did not result in significant decrease in productivity during the 1982 breeding season, it may have resulted in a significant overproduction of female young. Barn Owls in north central Utah fed almost exclusively on mammalian species, particularly Microtus spp. Difference in clutch size between areas and years may be a response to availability as well as abundance of prey.     

Behavioral and physiological responses of Eared Grebes ( Podiceps nigricollis ) to variations in brine shrimp ( Artemia franciscana ) densities

Eared Grebes ( Podiceps nigricollis ) use the Great Salt Lake (GSL) primarily as a fall staging area. They feed on brine shrimp ( Artemia franciscana ) to build up energy reserves to complete their southward migration. Whereas it has been speculated that timing of grebe departure from the GSL is due to declining shrimp density, this hypothesis has not been tested. We monitored grebe weight, behavior, and departure dates to test this hypothesis and to determine the effects of declining shrimp densities on Eared Grebes during 1999, 2000, and 2001 when there were different shrimp densities. Despite differences in shrimp densities, grebes left the GSL about the same time each year. Juvenile and subadult mass was significantly lighter ( P P > 0.05) in dive or surface duration between 1999 and 2000, there were differences in the percentage of time spent foraging. Our results indicated that at shrimp densities ?1 , grebes increased their foraging effort to offset the declining food resource instead of departing the GSL at an earlier date.     

Population structure and ecological effects of the crayfish Pacifastacus leniusculus in Castle Lake, California

The recent appearance of the ""California crayfish,"" Pacifastacus leniusculus , in Castle Lake, California, and interest in its potential impacts on the lake ecosystem provided motivation for a study of the population structure and habitat use of this species and its effects on aquatic macrophytes. Mark-recapture studies indicated that the total number of adult (3 + yr or older) crayfish in the lake was ca 10,100 individuals, yielding an estimate of lakewide crayfish density in preferred crayfish habitats of 0.13 adults m -2 . Using mean body mass of individuals, we estimated that ambient biomass density was 5.9 g m -2 . Length-weight relationships determined for captured individuals were sex dependent, with males having greater body mass for a given carapace length. Length-frequency and weight-frequency diagrams indicated that P. leniusculus reaches larger sizes in Castle Lake than do populations of P. leniusculus in ultraoligotrophic Lake Tahoe. Population-wide, males were significantly larger in both carapace length and body mass than females. We also examined sex dependence of interhabitat differences in crayfish body size by comparing animals trapped in rocky areas with those from areas with macrophytes and soft sediments. No significant differences in overall body size were found between habitats, but a significant habitat-sex interaction term occurred because the sex-dependent size differences were more pronounced in sediment than in rocky areas. Exclosure and enclosure experiments indicated that crayfish had large but differential impacts on Castle Lake macrophyte species, as the abundance of two of the dominant species ( Chara sp., Potamogeton richardsonii ) declined in the presence of crayfish and, in one case, increased in exclosures. These effects occurred via both consumptive and nonconsumptive mechanisms. These studies indicate that and expanding population of P. leniusculus in Castle Lake may be producing sizable impacts on the littoral zone habitat.     

Status and conservation of salmonids in relation to hydrologic integrity in the Greater Yellowstone Ecosystem

Native salmonid status was evaluated with an index quantifying distribution and abundance of cutthroat trout ( Oncorhynchus clarki ) and grayling ( Thymallus arcticus ) in 41 watersheds comprising the Greater Yellowstone Ecosystem. We assessed hydrologic integrity with a percentile-based index measuring cumulative effects of reservoirs, surface water withdrawals, and consumptive water use. Status of native salmonids was poor in 70% of the watersheds; exceptions occurred in a north-south core extending from the Upper Yellowstone southward through the national parks to Bear Lake. Hydrologic integrity was highest in headwater areas and lowest in lower-elevation watersheds. Status of native and nonnative salmonid populations currently existing in the ecosystem was positively correlated with hydrologic integrity ( r = 0.58), indicating that the hydrologic index performed well on a watershed scale in quantifying suitability of stream environments for salmonids. However, native trout status and hydrologic integrity were similarly correlated ( r = 0.63) only when watersheds receiving the lowest possible native salmonid index score were removed from analysis because these watersheds were uniformly distributed across hydrologic integrity. We infer that nonphysical factors such as interactions with introduced fish species have played an important role in the disappearance of native salmonids. The highest priority for conservation is preservation of core watersheds, where both hydrologic integrity and native trout status are high. Restoration opportunities exist in the Teton, Idaho Falls, Willow Creek, Central Bear, and Bear Lake watersheds, where viable cutthroat trout populations remain but are threatened by habitat degradation.