Intraspecific Phylogeography of Red Squirrels (Tamiasciurus hudsonicus) in the Central Rocky Mountain Region of North America

We used variation in a portion of the mitochondrial DNA control region to examine phylogeography of Tamiasciurus hudsonicus, a boreal-adapted small mammal in the central Rocky Mountain region. AMOVA revealed that 65.66% of genetic diversity was attributable to variation within populations, 16.93% to variation among populations on different mountain ranges, and 17.41% to variation among populations within mountain ranges. Nested clade analysis revealed two major clades that likely diverged in allopatry during the Pleistocene: a southern clade from southern Colorado and a northern clade comprising northern Colorado, Wyoming, eastern Utah, and eastern Idaho. Historically restricted gene flow as a result of geographic barriers was indicated between populations on opposite sides of the Green River and Wyoming Basin and among populations in eastern Wyoming. In some instances genetic structure indicated isolation by distance.     

Distribution and Pathogenicity of Batrachochytrium dendrobatidis in Boreal Toads from the Grand Teton Area of Western Wyoming

The pathogen Batrachochytrium dendrobatidis (Bd), which causes the skin disease chytridiomycosis, has been linked to amphibian population declines and extinctions worldwide. Bd has been implicated in recent declines of boreal toads, Bufo boreas boreas, in Colorado but populations of boreal toads in western Wyoming have high prevalence of Bd without suffering catastrophic mortality. In a field and laboratory study, we investigated the prevalence of Bd in boreal toads from the Grand Teton ecosystem (GRTE) in Wyoming and tested the pathogenicity of Bd to these toads in several environments. The pathogen was present in breeding adults at all 10 sites sampled, with a mean prevalence of 67%. In an experiment with juvenile toadlets housed individually in wet environments, 10⁶ zoospores of Bd isolated from GRTE caused lethal disease in all Wyoming and Colorado animals within 35 days. Survival time was longer in toadlets from Wyoming than Colorado and in toadlets spending more time in dry sites. In a second trial involving Colorado toadlets exposed to 35% fewer Bd zoospores, infection peaked and subsided over 68 days with no lethal chytridiomycosis in any treatment. However, compared with drier aquaria with dry refuges, Bd infection intensity was 41% higher in more humid aquaria and 81% higher without dry refuges available. Our findings suggest that although widely infected in nature, Wyoming toads may escape chytridiomycosis due to a slight advantage in innate resistance or because their native habitat hinders Bd growth or provides more opportunities to reduce pathogen loads behaviorally than in Colorado.     

Characterization of microsatellite loci isolated in midget faded rattlesnake (Crotalus viridis concolor)

Primers for five polymorphic microsatellite loci were developed for the midget faded rattlesnake (Crotalus viridis concolor), a rare subspecies of western rattlesnake (Crotalus viridus) found only in parts of Wyoming, Colorado, and Utah. Five polymorphic microsatellites were isolated, four of which had relatively high levels of diversity (eight to nine alleles). We found only two departures from Hardy–Weinberg equilibrium and they occurred in different loci, so null alleles are likely not a problem. Moreover, we found that no two loci were linked. These loci will be applicable for population genetic analysis and perhaps analysis of paternity and mating systems.     

Genomic inference accurately predicts the timing and severity of a recent bottleneck in a nonmodel insect population

The analysis of molecular data from natural populations has allowed researchers to answer diverse ecological questions that were previously intractable. In particular, ecologists are often interested in the demographic history of populations, information that is rarely available from historical records. Methods have been developed to infer demographic parameters from genomic data, but it is not well understood how inferred parameters compare to true population history or depend on aspects of experimental design. Here, we present and evaluate a method of SNP discovery using RNA sequencing and demographic inference using the program δaδi, which uses a diffusion approximation to the allele frequency spectrum to fit demographic models. We test these methods in a population of the checkerspot butterfly Euphydryas gillettii. This population was intentionally introduced to Gothic, Colorado in 1977 and has as experienced extreme fluctuations including bottlenecks of fewer than 25 adults, as documented by nearly annual field surveys. Using RNA sequencing of eight individuals from Colorado and eight individuals from a native population in Wyoming, we generate the first genomic resources for this system. While demographic inference is commonly used to examine ancient demography, our study demonstrates that our inexpensive, all‐in‐one approach to marker discovery and genotyping provides sufficient data to accurately infer the timing of a recent bottleneck. This demographic scenario is relevant for many species of conservation concern, few of which have sequenced genomes. Our results are remarkably insensitive to sample size or number of genomic markers, which has important implications for applying this method to other nonmodel systems.     

Capsule Treatments to Enhance Seedling Emergence of Gaura neomexicana ssp. coloradensis

Management of riparian vegetation is difficult because these communities are frequently impacted by herbivores, invasive weeds, and altered hydrologic regimes. Multiple and intertwined factors affecting rare species recruitment are particularly difficult to identify. Gaura neomexicana ssp. coloradensis Munz (Gaura) is a short‐lived perennial forb endemic to riparian areas in mixed‐grass prairies of Wyoming, Nebraska, and Colorado, U.S.A. It became a federally listed threatened species in October 2000. Because the species is a recruitment‐limited monocarpic perennial, we studied the effects of six capsule‐collection dates, a 2‐month cool‐moist stratification, 24‐hr leaching, and 24‐hr imbibition on Gaura seedling emergence. Seedling emergence did not vary with collection date. Capsules collected from Gaura plants grown at the Bridger Plant Materials Center in Montana exhibited greater emergence than capsules harvested from endemic populations near Cheyenne, Wyoming, suggesting that maternal plant growing conditions impact dormancy. Because cool‐moist stratification enhanced seedling emergence of Gaura and leaching did not, sufficient moisture during cool temperatures may be more critical than leaching of germination inhibitors as might occur with normal stream flows. Spring flooding may enhance Gaura recruitment by increasing the availability of riparian sites that are inundated during periods of cool temperatures. If so, hydrologic and climatic regimes must be considered in restoring the unique conditions needed for germination of this rare riparian endemic.     

A new species of Cymopterus (Apiaceae) from the Rocky Mountain region, U.S.A.

Cymopterus constancei is described as new from mostly western portions of Wyoming, Colorado, and New Mexico and from eastern Utah and Arizona. It has been confused withC. bulbosus A. Nelson but differs in several features of its bractlets, phenology, and habitat. The novelty is among the earliest of the native flora to bloom and is quite uniform morphologically. The number of collections encountered exceeds 200, a fourfold increase, in the past 22 years.     

Genetic diversity in a reintroduced swift fox population

Swift fox (Vulpes velox) were historically distributed in southwestern South Dakota including the region surrounding Badlands National Park (BNP). The species declined during the mid-1800s, largely due to habitat loss and poisoning targeted at wolves (Canis lupus) and coyotes (Canis latrans). Only a small population of swift foxes near Ardmore, which is located in Fall River County, South Dakota, persisted. In 2003, a reintroduction program was initiated at BNP with swift foxes translocated from Colorado and Wyoming. Foxes released in the years 2003, 2004 and 2005 were translocated from Colorado (BNP-Colorado) whereas in 2006, released foxes were translocated from Wyoming (BNP-Wyoming). Our objective was to evaluate genetic diversity and structure of the restored swift fox population in the area surrounding BNP compared to source fox populations in an area of Colorado and Wyoming, as well as the local swift fox population neighboring BNP near Ardmore in Fall River County, South Dakota. A total of 400 swift foxes (28 released in 2003, 28 released in 2004, 26 released in 2005, 26 released in 2006, 252 wild-born foxes, 40 individual foxes from the Ardmore area of South Dakota) was genotyped using twelve microsatellite loci. We report mean gene diversity values of 0.778 (SD = 0.156) for the BNP-Colorado population, 0.753 (SD = 0.165) for the BNP-Wyoming population, 0.751 (SD = 0.171) for the BNP population, and 0.730 (SD = 0.166) for the Fall River population. We also obtained F_st values ranging from 0.014 to 0.029 for pair-wise comparisons of fox populations (BNP, Fall River, BNP-Wyoming, BNP-Colorado). We conclude that the reintroduced fox population around BNP has high genetic diversity comparable to its source populations in Colorado and Wyoming. Although genetic diversity indicates that the reintroduction was successful, additional time is necessary to fully evaluate long-term genetic maintenance and interconnectivity among these populations.     

A revision of Sullivantia (Saxifragaceae)

Sullivantia (Saxifragaceae) is restricted to the United States; its species occur in very specialized habitats such as wet cliffs and moist canyon walls in scattered localities from Washington and Oregon, eastward to Wyoming, Montana, Colorado, Missouri, Iowa, Illinois, Minnesota, Wisconsin, Indiana, Ohio, and Virginia. Relationships in the genus were reevaluated using data from morphology (including the use of greenhouse-grown plants), crossability, and flavonoid chemistry. The conclusion of this study is thatSullivantia comprises four morphologically similar allopatric taxa:S. oregana, S. hapemanii var.hapemanii, S. hapemannii var.purpusii, andS. sullivantii.     

Karyotypes of sixteen populations of the Thomomys talpoides complex of pocket Gophers (Rodentia-Geomyidae)

Chromosome material of mitotic bone marrow cells from 59 individuals representing 16 populations of Thomomys talpoides was studied. These populations were found in southern Wyoming, Colorado, northern New Mexico and northern Arizona. A limited amount of intrapopulation variation in form but not number of chromosomes was found. Bight distinct karyotypes were observed. These can be characterized by the following diploid numbers and fundamental numbers of chromosomes: 40(70), 44(70), 56(70), 60(70), 58(76), 48(78), 56(78) and 46(82). Among the six populations with 48 chromosomes some interpopulation variation was noted. In several instances karyotype differences coincided with populations that co-exist without interbreeding.     

Human Skeletal Populations Of The Northwestern Plains: A Preliminary Analysis

Abstract

Preliminary analysis has been completed on samples of American Indian skeletons from three museums in Wyoming, and special collections from Montana, Wyoming, northern Colorado and western Nebraska. All 84 specimens come from burial sites within the Northwestern Plains geographical region, and cover a temporal span of approximately 5,000 years. Fifty-four cranial and postcranial measurements, and 47 morphological observations were recorded for each complete specimen; and means and indices were compared among the various regional and temporal samples. Important temporal changes and a few regional differences are suggested by the preliminary results.     

A Diverse Dinosaur-Bird Footprint Assemblage from the Lance Formation,Upper Cretaceous,Eastern Wyoming: Implications for Ichnotaxonomy

A diverse assemblage of dinosaur and bird tracks from Niobrara County, Wyoming, represents the first vertebrate ichnofauna reported from the bone-rich Lance Formation (Maastrichtian, Upper Cretaceous). The ichnofauna includes a hadrosaur track with skin impressions; three theropod track types, including the tetradactyl track Saurexallopus zerbsti (ichnosp. nov.); a tridactyl dinosaur footprint with a fusiform digit III; possible Tyrannosaurus tracks; four distinctive avian ichnites; and invertebrate traces. The footprints are generally well-preserved and so offer a unique insight into the ecology of a small river valley during the Maastrichtian.

Saurexallopus zerbsti ichnosp. nov. from the Lance is similar to Saurexallopus lovei recently reported from the Maastrichtian, Harebell Formation, of northwestern Wyoming, but is represented by much better material, facilitating amendment of the ichnogenus. Skeletal equivalents for Saurexallopus are not currently known. Similarly, the tridactyl track with fusiform digit III is similar to footprints reported from the coeval Laramie Formation of Colorado and may also be similar to ichnogenus Ornithomimipus from the Edmonton Group of Alberta (though not necessarily of ornithomimid affinity). The hadrosaurian track with the skin impression is reminiscent of a similar ichnite reported from the Maastrichtian, St. Mary River Formation in Alberta, which is herein named Hadrosauropodus langstoni as part of a reassessment of Cretaceous ornithopod track ichnotaxonomy. Such correlations demonstrate the utility of tracks for local or regional biostratigraphy (palichnostratigraphy) in western North America. It is also clear that tracks add to our knowledge of the composition and distribution of dinosaurian and avian components of Maastrichtian faunas. In particular the bird tracks indicate a diversity of at least four species, one of which was a semi-palmate form, hitherto unknown in the ichnological record and named Sarjeantichnus semipalmatus.     

Hemiacodon engardae, a new species of omomyid primate from the earliest Uintan Turtle Bluff Member of the Bridger Formation, southwestern Wyoming, USA

In this paper, we describe a new species of Hemiacodon known only from University of Colorado Museum Loc. 92189 (Donna's Locality) in the Turtle Bluff Member of the Bridger Formation, Green River Basin, southwestern Wyoming. Donna's locality has yielded a diverse mostly small-bodied mammalian assemblage of Bridgerian and first appearance Uintan mammalian taxa, as well as range-through taxa. Together with H. engardae sp. nov., the faunal assemblage from Donna's Locality and more recently discovered localities in the same stratigraphic interval provides the first conclusive paleontological evidence of an earliest Uintan age (Ui1A biochron) for the Turtle Bluff Member of the Bridger Formation.The new species is represented by a sample of 11 specimens consisting of well-preserved upper and lower premolars and lower molars. H. engardae is distinct from H. gracilis on the basis of overall larger size as well as a combination of features of the premolars and molars related to a greater development of shearing crests. This suggests that H. engardae may have incorporated more foliage into its diet than the Bridgerian species, H. gracilis.     

The History of Dinosaur Footprint Discoveries in Wyoming with Emphasis on the Bighorn Basin

Dinosaur traces are well known from the western United States in the Colorado Plateau region (Utah, Colorado, New Mexico, and Arizona). Utah contains the greatest abundance of known and documented dinosaur footprints and trackways. Far less well known, however, is the occurrence and distribution of dinosaur footprint-bearing horizons in Wyoming. Scientific studies over the past 10 years have shown that three of the four Middle and Upper Jurassic formations in northern Wyoming contain dinosaur footprints. Two of the footprint-bearing horizons are located in geologic intervals that were once thought to have been deposited in offshore to nearshore marine settings and represent rare North American examples of Middle Jurassic (Bajocian and Bathonian) dinosaur remains. Some of these new Wyoming sites can be correlated to known dinosaur footprint-bearing horizons or intervals in Utah. Wyoming has a great potential for additional discoveries of new dinosaur footprint-bearing horizons, and further prospecting and study is warranted and will ultimately lead to a much better understanding of the geographic distribution and behavior of the potential footprint-makers.     

Rosette Recruitment of a Rare Endemic Forb (Gaura neomexicana Subsp. coloradensis) with Canopy Removal of Associated Species

Gaura neomexicana subsp. coloradensis Munz (Onagraceae), (Colorado butterfly plant), a short‐lived perennial forb, became listed as a threatened species by the U.S. Fish and Wildlife Service in October 2000 because of its small global range and population size. This endemic subspecies consists of only 18 extant populations within southeastern Wyoming, southwestern Nebraska, and northeastern Colorado. Wyoming occurrences are on private land with the exception of three occurrences on F. E. Warren Air Force Base, near Cheyenne. Gaura neomexicana subsp. coloradensis may be displaced by many competitors, including Cirsium arvense (L.) Scop. (Canada thistle), an invasive, noxious weed. In June 1998, three G. neomexicana subsp. coloradensis populations were examined for rosette establishment in the presence of and after removal of associated species. The four study treatments removed: (1) Cirsium arvense, (2) grass and forb canopy and associated litter, (3) grass and forb canopy, litter, and C. arvense, and (4) no removal of associated plant species (control). Mature G. neomexicana subsp. coloradensis plants were evaluated for height, number of leaves, and capsule production. The mature plant characteristics monitored in 1998 were not good indicators of subsequent G. neomexicana subsp. coloradensis rosette densities in the following spring. Recruitment was assessed by counting new rosettes in the fall 1999. Although both G. neomexicana subsp. coloradensis and the exotic C. arvense have comparable habitat, removal of C. arvense did not increase G. neomexicana subsp. coloradensis vegetative growth, seed capsule production, or rosette density. Removal of other forbs, grass, and litter, however, increased G. neomexicana subsp. coloradensis rosette density in the following two years, indicating that canopy removal of associated species can enhance rosette establishment of this rare native. The accumulation of dense vegetative cover and litter associated with the absence of herbivory and fire may contribute to the decline of rare species in rich riparian habitats. Return of herbivory and fire in mesic sites to reduce standing biomass accumulations should be considered in restoring recruitment potential to rare monocarpic species.     

Dragma Hippomanicum VII: A new alpine astragalus (Leguminosae) from western Wyoming

Astragalus (sect.Minerales) shultziorum, related toA. molybdenus Barneby which is endemic to the tundra zone of the Colorado Rocky Mountains, is described from the crest of the Salt River Range in western Wyoming, illustrated and discussed.     

New species of ceratocystis from conifers

Summary Five new species ofCeratocystis wood staining fungi are described. The speciesCeratocystis abiocarpa is common in recently killed subalpine fir (Abies lasiocarpa (Hook)Nutt.), trees or felled logs in the Central Rocky Mountain area from Wyoming to Northern Arizona and New Mexico. It also occurs commonly in Engelmann spruce (Picea engelmannii Perry) logs infested withIps sp. bark beetles in this same area. C. minuta-bicolor is widespread in beetle infested logs of spruce, firs, pines and other conifers.C. nigrocarpa was isolated only occasionally but is apparently rather widespread in bark beetle infested pine logs.C. leucocarpa was isolated only occasionally from beetle infested pine logs and rarely in other conifers. It has been encountered mainly in the Fort Collins, Colorado area and from southern Oregon.The fifth new species (C. seticollis) was isolated only once from ambrosia beetle galleries in sapwood of a hemlock stump in eastern New York state.This study was supported by a grant from the National Science Foundation (GB-2407).     

A digital land cover map of Wyoming,USA: a tool for vegetation analysis

Abstract. A Landsat Thematic Mapper (TM) based digital land cover map has been created for the state of Wyoming, USA, at moderate spatial (l-km² minimum mapping unit) and high typal (41 land cover types) resolution as part of the Wyoming Gap Analysis Program (WGAP). This map presents opportunities for regional characterization of land cover, especially vegetation, and for examination of ecological phenomena that manifest themselves over large areas. Using the digital land cover data, we describe Wyoming vegetation and examine positions of three prominent physiognomic transitions in Wyoming: the elevation of upper and lower treeline, and the position of the biogeographic boundary between shruband grass-dominated vegetation. By area, the three leading land cover types in Wyoming are Artemisia tridentata ssp. wyomingensis sagebrush (33.4 %), mixed grass prairie (17.5 %) and Pinus contorta forest (6.5 %). Average upper-treeline elevation in Wyoming is 2947 m, and decreases with increasing latitude at an average rate of about 0.5 m/km, less than the rate of about 0.9 m/km reported by Peet (1978) for a gradient from Mexico to Canada. Lower-treeline occurs at an average elevation of 2241 m, and decreases with increasing latitude and with southerly aspect. In Wyoming, shrub-dominated communities are more likely to occur than grass-dominated communities as summer precipitation decreases below 282 mm. All of these relationships are subtle, and it appears that for particular areas, local factors are more important than regional climatic trends in explaining the position of phytogeographic boundaries.     

Pollination biology of a disjunct population of the endangered sandhills endemic <Emphasis Type="Italic">Penstemon haydenii</Emphasis> S. Wats. (Scrophulariaceae) in Wyoming,USA

We studied the breeding system and flower visitors of the endangered plant, Penstemon haydenii, at several south-central Wyoming, USA occurrences. In agreement with earlier studies of the species 300 km to the east in Nebraska, we found Wyoming plants to be self-incompatible and pollinator-dependent for sexual reproduction. Flower visitors were several species of native bees in the families Apidae (particularly bumblebees), Halictidae (small sweat bees), and Megachilidae (especially in the genus Osmia); and the masarid wasp Pseudomasaris vespoides. Especially important was Osmia brevis, an abundant megachilid bee, and one of only two species (the sweat bee Lasioglossum (Dialictus) pruinosum was the other) present at all five sites. As in Nebraska, fruit set did not differ between our experimental cross-pollination treatment and an open-pollinated control. However, unlike Nebraska, open-pollinated treatments in Wyoming produced significantly fewer seeds per fruit than the experimental out-crossing treatment. We discuss several possible explanations for seed limitation: (1) a scarcity of pollinators early in the flowering season; (2) resource competition for developing ovules on open-pollinated inflorescences but not on experimental inflorescences; (3) the deposition of self pollen through intra-inflorescence and intra-genet pollinator movements; (4) few S-alleles and mating types in the Wyoming metapopulation compared to the Nebraska metapopulation, from which it likely derives.     

CYTOGEOGRAPHICAL STUDIES IN THE GENUS ARNICA (COMPOSITAE: SENECIONEAE). I

A total of 134 chromosome counts representing 21 taxa of the genus Arnica are presented. Counts are published here for the first time for A. lonchophylla (n = 38) and A. nevadensis (n = 38). Ten previously unreported counts representing 9 taxa are also presented. The basic chromosome number of the genus is x = 19. With respect to chromosome number, the genus exhibits maximum diversity in the Rocky Mountains of Colorado and Wyoming. Arnica angustifolia, A. cordifolia and A. mollis are recognized as mature polyploid complexes, containing several wide ranging polyploid races and only a few highly restricted or scattered diploid races. Within the genus in general, diploids tend to be restricted to unglaciated areas while polyploids are much wider ranging, particularly in unglaciated areas.     

INVESTIGATIONS OF NORTH AMERICAN CYCADEOIDS: TRUNKS FROM WYOMING

Delevoryas , Theodore . (University of Illinois, Urbana.) Investigations of North American cycadeoids: trunks from Wyoming . Amer. Jour. Bot. 47(9): 778–786. Illus. 1960.—A study was undertaken of the cycadeoid trunks from Wyoming to more fully understand the morphology and evolutionary significance of these trunks and to determine the validity of the genus Cycadella. The stem named Cycadeoidea (or Cycadella) utopiensis is not the same morphologically as those from Carbon County, Wyoming, and because of its unknown source, it is not a reliable specimen for the study of cycadeoids from the Morrison formation. The Morrison, Carbon County specimens included in Ward's genus Cycadella were shown to have trunk structure, leaf bases, and cones like those in Cycadeoidea. The cone vascular bundle is derived from a fusion of 4 leaf traces. From the fused bundle complex, 4 leaf traces are separated farther out in the cortex, and 1 of these supplies the subtending leaf. In spite of the relatively complex pattern of cone trace formation, there does not seem to be any significant means of distinguishing specimens called Cycadella from the more common Cycadeoidea. Furthermore, it is evident that the genus Cycadeoidea represents a fairly homogeneous group with a wide geographic and geologic range. Pattern of formation of cone traces is interpreted as possible further evidence for regarding cycadeoid cones as portions of foliar systems.