Spherical Harmonic Analysis of the Angular Distribution of Gamma-Ray Bursts

We compute the angular power spectrum C_l of the BATSE 3B catalog, and find no evidence for clustering on any scale. These constraints bridge the entire range from small scales, probing source clustering and repetition, to large scales constraining possible Galactic anisotropies, or those from nearby cosmological large scale structures.Comment: 5 page conf. proceedings, with one figure included. Postscript. More detailed version at http://astro.berkeley.edu/~max/bursts.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/bursts.html (faster from Europe) or from [email protected]

Habitat Use by Beaver Along the Big Sioux River

Habitat utilization and lodge site selection by beaver (Castor canadensis) were investigated during 1985 and 1986 along the Big Sioux River in eastern South Dakota. Because livestock grazing has affected the number and size of trees available for beaver use, the study area was portioned into grazed, ungrazed, and farmed habitat. Diameter at breast height (DBH) of trees in grazed areas was greater (p \u3c 0.01) than in ungrazed or farmed areas. Almost half (48%) of the trees in ungrazed areas were small (DBH \u3c 7.5 cm), while a majority (58%) of the trees in grazed areas had large diameters (DBH \u3e 30 cm). Beaver activity was evident on 286 of 2410 (11.8%) trees (DBH \u3e 2.5 cm) and 756 of 7,794 (9.7%) stems (DBH \u3c 2.5cm) sampled. A greater proportion (p \u3c 0.01) of trees were cut by beavers in ungrazed than in grazed areas. Beaver did not select tree species for cutting according to availability (p \u3c 0.01). Green ash (Fraxinus pennsylvanica) was selected for cutting while both boxelder (Acer negundo) and hawthorn (Crataegus mollis) were selected against. Sandbar willow (Salix exigua) stems were important for food and building materials. Trees cut by beaver were significantly smaller in diameter (p \u3c 0.01) than uncut trees. Mean distance from water of cut trees was also less (p \u3c 0.01) than for uncut trees. Over half (52%) of the trees damaged by beaver were not killed and either resprouted or remained alive and standing. Of 8 variables examined at lodge sites, analysis indicated that the 2 most important factors in beaver lodge site selection were riverbank slope and horizontal cover density between 0.9 m and 1.8 m above ground (read from 10 m). Mean slope of the riverbank at lodge sites (40.7 degrees) was greater (p \u3c 0.01) than at control sites (26.7 degrees), while mean horizontal cover density between 0.9 m and 1.8 m (read from 10 m) was also greater (p \u3c 0.01) at lodge sites (53%) than at control sites (28%). Ungrazed habitat was selected by beaver for lodge sites, and grazed areas were selected against. Although 40% of the study area was ungrazed, 27 of 33 (82%) active lodges were located in these areas. Ungrazed areas along the Big Sioux River are important for beaver populations and selection for these areas by beaver reflects habitat quality

Improved limits on gamma ray burst repetition

We tighten previous upper limits on gamma ray burst repetition by analyzing the angular power spectrum of the BATSE 3B catalog of 1122 bursts. At 95% confidence, we find that no more than 2% of all observed bursts can be labeled as repeaters, even if no sources are observed to repeat more than once. If a fraction f of all observed bursts can be labeled as repeaters that are observed to burst v times each, then all models with (v-1)f>0.05 are ruled out at 99% confidence, as compared to the best previous 99% limit (v-1)f>0.27. At 95% confidence, our new limit is (v-1)f>0.02. Thus even a cluster of 6 events from a single source would have caused excess power above that present in the 3B catalog. We conclude that the current BATSE data are consistent with no repetition of classical gamma ray bursts, and that any repeater model is severely constrained by the near perfect isotropy of their angular distribution.Comment: 18 pages, with 2 figures included. Postscript. Submitted to ApJL. Latest version at http://astro.berkeley.edu/~max/repeaters.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/repeaters.html (faster from Europe) or from [email protected]

REPRODUCTION AND POPULATION CHARACTERISTICS OF WHITE-TAILED JACKRABBITS IN SOUTH DAKOTA

We evaluated the reproductive biology of314 white-tailed jackrabbits (Lepus townsendii) in 44 counties throughout South Dakota from June 2004 to September 2005. We classified jackrabbits as juveniles or adults based on the closure of the proximal epiphysis of the humerus using X-ray analysis. We determined annual reproductive activity through fluctuations in measured weights of reproductive organs for both sexes. The 2005 breeding season started in late February and proceeded until mid-July, approximately 142 days, allowing for females to potentially produce 3.3 litters. We found four distinct breeding periods by the overlap of estimated conception and parturition dates. Mean litter size was 4.6 per female (range 1-8). Prenatal mortality from preimplantation and postimplantation loss was highest (32%) in the first littering period in 2005

RELATIVE ABUNDANCE OF NORTHERN FLYING SQUIRRELS AND RED SQUIRRELS IN DIFFERENT FOREST TYPES, BLACK HILLS, SOUTH DAKOTA

Northern flying squirrels (Glaucomys sabrinus) and red squirrels (Tamiasciurus hudsonicus) in the Black Hills National Forest (BHNF) of South Dakota represent isolated populations. Because data on both species in the region are limited, and because the northern flying squirrel in South Dakota and the Black Hills National Forest has species of concern status, we trapped throughout BHNF to determine relative abundance in different forest types for both populations. For northern flying squirrels, capture rate was higher in the northern and western hills compared to the southern and eastern hills, whereas for red squirrels, capture rate was higher in the western hills, followed by the southern and eastern hills. The northern hills are classified as mesic coniferous forest transitioning to a dry coniferous forest in the southern hills. In addition, the northern hills is characterized by a mixed coniferous-deciduous forest, whereas the southern and eastern hills are characterized by even-aged managed coniferous stands. Understanding the abundance of these two isolated squirrel populations in the different forest types of the BHNF is important in intensively managed forests, because management decisions can impact isolated populations

HEALTH AND FERTILITY IMPLICATIONS RELATED TO SEASONAL CHANGES IN KIDNEY FAT INDEX OF WHITE-TAILED JACKRABBITS IN SOUTH DAKOTA

White-tailed jackrabbit (Lepus townsendii) populations in the Northern Plains have been in a general decline for the past decade or longer. A suggested reason for this population decline was reduced body condition of individual jackrabbits due to habitat changes. In order to evaluate body condition, we determined the kidney fat index of 314 white-tailed jackrabbits harvested in 44 counties throughout South Dakota. We removed and weighed kidneys and all perirenal fat associated with the kidneys from collected jackrabbits. We measured kidney weight to determine times of high metabolic activity as indicated by an increase in mass. Body condition was assessed by measuring the amount of kidney fat within each collected jackrabbit. Seasonal fluctuations were evident in average kidney weight and kidney fat for both sexes of white-tailed jackrabbits. The kidney fat index in both male and female peaked in winter and was near 0% in summer. We believe that changes in body condition as indicated by the kidney fat index were related to the onset of breeding season rather than availability of food resources

HEALTH AND FERTILITY IMPLICATIONS RELATED TO SEASONAL CHANGES IN KIDNEY FAT INDEX OF WHITE-TAILED JACKRABBITS IN SOUTH DAKOTA

White-tailed jackrabbit (Lepus townsendii) populations in the Northern Plains have been in a general decline for the past decade or longer. A suggested reason for this population decline was reduced body condition of individual jackrabbits due to habitat changes. In order to evaluate body condition, we determined the kidney fat index of 314 white-tailed jackrabbits harvested in 44 counties throughout South Dakota. We removed and weighed kidneys and all perirenal fat associated with the kidneys from collected jackrabbits. We measured kidney weight to determine times of high metabolic activity as indicated by an increase in mass. Body condition was assessed by measuring the amount of kidney fat within each collected jackrabbit. Seasonal fluctuations were evident in average kidney weight and kidney fat for both sexes of white-tailed jackrabbits. The kidney fat index in both male and female peaked in winter and was near 0% in summer. We believe that changes in body condition as indicated by the kidney fat index were related to the onset of breeding season rather than availability of food resources

Availability of Suitable Habitat for Northern River Otters in South Dakota

Currently, the northern river otter (Lontra canadensis) is listed as a threatened species in South Dakota. We determined whether adequate habitat was available for reintroducing river otters in South Dakota. The 17 rivers/creeks included in the analysis were selected according to stream size, water gradient, and water permanence. A vegetation transect was conducted and a water sample was collected at each study site, ranging from one to four per river. Rivers/creeks were rated (1 = least suitable to 5 = most suitable) according to habitat requirements of river otters in the following categories: stream characteristics, watershed features, water quality, prey availability, and other factors. Based on the habitat survey and rating criteria, rivers/creeks with high ratings have sufficient riparian habitat (vegetation bordering water), water quality, and prey availability for river otters. The five highest-rated rivers were the Bad, Big Sioux, James, North Fork of the Whetstone, and Little White

Ion microprobe elemental analyses of impact features on interplanetary dust experiment sensor surfaces

Hypervelocity impact features from very small particles (less than 3 microns in diameter) on several of the electro-active dust sensors used in the Interplanetary Dust Experiment (IDE) were subjected to elemental analysis using an ion microscope. The same analytical techniques were applied to impact and containment features on a set of ultra-pure, highly polished single crystal germanium wafer witness plates that were mounted on tray B12. Very little unambiguously identifiable impactor debris was found in the central craters or shatter zones of small impacts in this crystalline surface. The surface contamination, ubiquitous on the surface of the Long Duration Exposure Facility, has greatly complicated data collection and interpretation from microparticle impacts on all surfaces

Evaluation of foliar sprays to reduce crop damage by Canada geese

South Dakota Department of Game, Fish and Parks annually spends \u3e$500,000 managing crop damage caused by grazing Canada geese (Branta canadensis). Foliar applications of a chemical feeding deterrent could provide an effective alternative to the methods currently being used to reduce damage. In 2011 and 2012, we evaluated Rejex-It Migrate Turfguard®, Bird Shield®, Avian Control®, and Avipel® as grazing deterrents. We used a ground sprayer to apply the treatments every 7 days to plots in soybean fields in Day County, South Dakota. We monitored activity in the plots using time-lapse photography. We began treating the plots after geese had begun using them (late June through mid- July). Damage was estimated after geese had abandoned the plots (August). The methyl anthranilate products (Rejex-It, Bird Shield, and Avian Control) were ineffective at reducing crop damage. Damage was 100% on all plots treated with these products. Use of plots significantly increased (P \u3c 0.02) between the pretreatment and postreatment periods for Rejex-It (180 minutes/day and 313 minutes/day) and Bird Shield (200 minutes/day and 299 minutes/day); whereas, use was similar (P = 0.99) between plots treated with Avian Control (111 minutes/day) and reference plots (104 minutes/day). Less time was spent on plots treated with the anthraquinone-based product, Avipel (44 minutes/day) than on reference plots (132 minutes/day; P \u3c 0.01). Additionally, soybean damage was less on Avipel-treated plots than on reference plots (P \u3c 0.01). We recommend more research on Avipel to assess rates and timing of application to make this product efficacious and economical in the field