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

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

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

Tree Cover in the Surrounding Landscape Reduces Burrowing Owl (Athene cunicularia) Occupancy of Black-Tailed Prairie Dog Colonies in South Dakota

Burrowing Owl (Athene cunicularia) population declines have led to the owl’s designation as a species of conservation concern in South Dakota. Burrowing Owls nest primarily in black-tailed prairie dog (Cynomys ludovicianus) colonies, but a significant proportion of colonies in South Dakota are not occupied by owls. We studied the influence of landscape-level habitat variables on colony selection by Burrowing Owls. We used call-playback surveys to document presence or absence of Burrowing Owls at 613 prairie dog colonies throughout western and central South Dakota. We used a geographic information system to calculate the percent cover of prairie dog colonies, grassland, cropland, and tree canopy in the surrounding landscape at four buffer sizes. We modeled Burrowing Owl occupancy of prairie dog colonies using logistic regression, and ranked models using Akaike’s Information Criterion. All competitive models contained a tree-canopy-cover variable. Increasing tree canopy cover within 800 m and 1200 m of colony centers was associated with decreasing likelihood of occupancy by Burrowing Owls. Grassland, cropland, and prairie dog colony cover variables did not influence occupancy by Burrowing Owls, and these variables did not improve model fit or discrimination. In landscapes where the presence of nesting burrows is not a limiting factor, as in central and western South Dakota, Burrowing Owls occupied colonies based on the absence of trees. Trees provide habitat for avian and mammalian predators and reduce the available foraging area for Burrowing Owls around prairie dog colonies. Management for Burrowing Owls should include conserving prairie dog colonies in landscapes with few trees and preventing the establishment of trees near occupied colonies

Application strategy for an anthraquinonebased repellent and the protection of soybeans from Canada goose depredation

Agricultural crops can sustain extensive damage caused by Canada geese (Branta canadensis) when these crops are planted near wetlands or brood-rearing sites. From 2000 to 2015, South Dakota Game, Fish and Parks spent \u3e$5.6 million to manage damages caused by Canada geese to agricultural crops (primarily soybeans) in South Dakota, USA. For the purpose of developing a repellent application strategy for nonlethal goose damage management, we comparatively evaluated the width of anthraquinone applications (i.e., 9.4 L Flight Control® Plus goose repellent/ha [active ingredient: 50% 9,10-anthraquinone] at 0–36 m versus 0–73 m perpendicular to the edge of wetlands in 2014), the timing of the first repellent application (i.e., 9.4 L Flight Control Plus goose repellent/ha at 50% versus 75% seedling emergence in 2015), the yield of soybeans (Glycine max) within repellent-treated and untreated subplots, and anthraquinone chemical residues in Day County, South Dakota. Soybean yield was greater in subplots 73 m from the water’s edge than that in the 36-m subplots (P \u3c 0.02). Among subplots first sprayed at 50% seedling emergence, soybean yield was greater at 73 m and 82 m than that at 36 m (P \u3c 0.005). In contrast, we observed no difference in yield at 36 m, 73 m, or 82 m in the subplots first sprayed at 72% seedling emergence (P \u3e 0.09). We therefore conclude that goose damages were effectively managed in subplots first sprayed at 72% seedling emergence. Anthraquinone residues averaged 674 and 629 ppm anthraquinone upon the first application of the repellent (June to July), 22 and 35 ppm anthraquinone in the mid-season hay (August to September), and 36 and 28 ppb anthraquinone in the harvested seed (October to November) in 2014 and 2015, respectively. Our results suggest that a 73-m bandwidth of anthraquinone-based repellents first applied at approximately 72% or 65–85% seedling emergence can protect soybeans from Canada goose depredation

Application Strategy for an Anthraquinone-Based Repellent and the Protection of Soybeans from Canada Goose Depredation

Agricultural crops can sustain extensive damage caused by Canada geese (Branta canadensis) when these crops are planted near wetlands or brood-rearing sites. From 2000 to 2015, South Dakota Game, Fish and Parks spent \u3e$5.6 million to manage damages caused by Canada geese to agricultural crops (primarily soybeans) in South Dakota, USA. For the purpose of developing a repellent application strategy for nonlethal goose damage management, we comparatively evaluated the width of anthraquinone applications (i.e., 9.4 L Flight Control® Plus goose repellent/ha [active ingredient: 50% 9,10-anthraquinone] at 0–36 m versus 0–73 m perpendicular to the edge of wetlands in 2014), the timing of the first repellent application (i.e., 9.4 L Flight Control Plus goose repellent/ha at 50% versus 75% seedling emergence in 2015), the yield of soybeans (Glycine max) within repellent-treated and untreated subplots, and anthraquinone chemical residues in Day County, South Dakota. Soybean yield was greater in subplots 73 m from the water’s edge than that in the 36-m subplots (P \u3c 0.02). Among subplots first sprayed at 50% seedling emergence, soybean yield was greater at 73 m and 82 m than that at 36 m (P \u3c 0.005). In contrast, we observed no difference in yield at 36 m, 73 m, or 82 m in the subplots first sprayed at 72% seedling emergence (P \u3e 0.09). We therefore conclude that goose damages were effectively managed in subplots first sprayed at 72% seedling emergence. Anthraquinone residues averaged 674 and 629 ppm anthraquinone upon the first application of the repellent (June to July), 22 and 35 ppm anthraquinone in the mid-season hay (August to September), and 36 and 28 ppb anthraquinone in the harvested seed (October to November) in 2014 and 2015, respectively. Our results suggest that a 73-m bandwidth of anthraquinone-based repellents first applied at approximately 72% or 65–85% seedling emergence can protect soybeans from Canada goose depredation

Gravitational wave detectors based on matter wave interferometers (MIGO) are no better than laser interferometers (LIGO)

We show that a recent claim that matter wave interferometers have a much higher sensitivity than laser interferometers for a comparable physical setup is unfounded. We point out where the mistake in the earlier analysis is made. We also disprove the claim that only a description based on the geodesic deviation equation can produce the correct physical result. The equations for the quantum dynamics of non-relativistic massive particles in a linearly perturbed spacetime derived here are useful for treating a wider class of related physical problems. A general discussion on the use of atom interferometers for the detection of gravitational waves is also provided.Comment: 16 pages, REVTeX4; minor changes, one figure and a few references were added, an additional appendix was included where we explain why, contrary to the claims in gr-qc/0409099, the effects due to the reflection off the mirrors cancel out in the final result for the phase shif