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Conservation planning requires information at a variety of geographic scales, and it is often unclear whether surveys designed for other purposes will provide appropriate information for management at various scales. We evaluated the use of the North American Breeding Bird Survey (BBS) to meet information needs for conservation planning in Bird Conservation Regions (BCRs). The BBS originally was developed to provide regional estimates for states, provinces, physiographic regions, and larger areas. Many analyses have used physiographic regions within states/provinces as strata. We evaluated potential consequences of using BCRs instead of the BBS physiographic regions, testing for spatial differences in sample intensity...
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Accurate determination of age is of fundamental importance to population and life history studies of waterfowl and their management. Therefore, we developed quantitative methods that separate adult and immature blue-winged teal (Anas discors), cinnamon teal (A. cyanoptera), and northern shovelers (A. clypeata) during spring and summer. To assess suitability of discriminant models using 9 remigial measurements, we compared model performance (% agreement between predicted age and age assigned to birds on the basis of definitive cloacal or rectral feather characteristics) in different flyways (Mississippi and Pacific) and between years (1990-91 and 1991-92). We also applied age-classification models to wings obtained...
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Managed moist-soil units support early succession herbaceous vegetation that produces seeds, tubers, and other plant parts used by waterfowl in the Mississippi Alluvial Valley (MAV), USA. We conducted a stratified multi-stage sample survey on state and federal lands in the MAV of Arkansas, Louisiana, Mississippi, and Missouri during autumns 2002?2004 to generate a contemporary estimate of combined dry mass of seeds and tubers (herein seed abundance) in managed moist-soil units for use by the Lower Mississippi Valley Joint Venture (LMVJV) of the North American Waterfowl Management Plan. We also examined variation in mean seed abundance among moist-soil units in 2003 and 2004 in relation to management intensity (active...
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Though the presence of a species can be unequivocally confirmed, its absence can only be inferred with a degree of probability. I used a model to calculate the minimum number of unsuccessful visits to a site that are necessary to assume that a species is absent. The model requires the probability of detection of the species per visit to be known. This probability, may vary depending on habitat, year, season, the area surveyed, the population size of the species, and the observer. I studied 3 European snake species---asp viper (Vipera aspis), smooth snake (Coronella austriaca), and grass snake (Natrix natrix)--over a 5-yr (1994--1998) interval, and made 645 visits to 87 sites during their activity periods. I used...
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A study of the effects of field applications of heptachlor on bobwhite quail (Colinus uirginianus) and other animals was conducted on three similar areas, two in Decatur County, Georgia, and one in Escambia County, Alabama, from February, 1958, to March, 1962. Heptachlor in granules was applied by aircraft on the Georgia areas for eradication of the imported fire ant (Solenopsis saevissima). Applications were directed by personnel of the U. S. Department of Agriculture, Plant Pest Control Division. The Alabama area remained untreated. Transects where whistling cocks were counted were superimposed on areas where coveys were counted. Size of areas varied from 14,000 to 20,000 acres. Each area had six transects, totaling...
Areas occupied by white-tailed prairie dogs (WTPD; Cynomys leucurus) and Gunnison's prairie dogs (GPD; C. gunnisoni) are not well-known in Colorado (USA) and elsewhere. Suitable methodology for monitoring changes in populations of WTPD and GPD over broad areas also has not been well established. We evaluated occupancy modeling methodology to establish baseline occupancy rates for WTPD and GPD in Colorado. We estimated that WTPD occupied 24.1% (SE = 12.8) of 47,710 0.25-km2 plots and GPD occupied 7.5% (SE = 1.3) of 158,225 0.25-km2 plots in Colorado during 2004 and 2005. Areas reported as colonies in the Colorado Division of Wildlife's database were not good predictors of WTPD and GPD occupancy. Occupancy rates were...
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Recently, Roseberry (1979) attempted to (1) clarify the theoretical basis for harvesting bobwhite (Colinus virginianus), (2) assess the impact of varying intensities of harvest on standing densities and long-term yields, and (3) define a harvest strategy appropriate for the bobwhite resource in Illinois. That paper, based on 24 years of field data, unfortunately contains 2 methodological or conceptual errors that are fundamental to the three objectives. Both errors are subtle, and as other have made the same or similar errors in analysis, we identify the problems in a way we hope will be taken constructively.
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The possibility of using neutron activation analyses to differentiate sources of North American waterfowl was investigated by irradiating rectrices and wing bones of birds collected in several localities, and comparing the characteristic gamma-ray spectra. Canada goose rectrices from Oregon specimens could be distinguished from those taken in Wisconsin and Colorado based on higher levels of Mn. Mallard, black duck, and blue-winged teal wing bones from Wisconsin, Colorado, and New Brunswick could not be clearly identified as to locality from levels of Ca, Al, Na, Mn, and Cl.
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We analyzed the population dynamics of a burrowing owl (Athene cunicularia) colony at Mineta San Jose International Airport in San Jose, California, USA from 1990-2007. This colony was managed by using artificial burrows to reduce the occurrence of nesting owls along runways and within major airport improvement projects during the study period. We estimated annual reproduction in natural and artificial burrows and age-specific survival rates with mark-recapture techniques, and we estimated the relative contribution of these vital rates to population dynamics using a life table response experiment. The breeding colony showed 2 distinct periods of change: high population growth from 7 nesting pairs in 1991 to 40 pairs...
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To successfully preserve or manage a species, we must understand how the community of which it is a part functions. We must know how environmental alterations affect the fitness not only of the species of interest, but also that of its competitors, predators, and prey; and we must know the form and intensity of the pertinent inter-species interactions. Interaction Assessment (INTASS) is a non-manipulative approach to constructing quantitative expressions for fitness, written as functions of measured environmental variables including local population densities of conspecifics and other interacting species. We applied this approach to, and evaluated its consistency from, data on the European land snail (Cepaea nemoralis),...
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Spawning cutthroat trout (Oncorhynchus clarkii bouvieri) were historically abundant within tributary streams of Yellowstone Lake within Yellowstone National Park and were a highly digestible source of energy and protein for Yellowstone’s grizzly bears (Ursus arctos) and black bears (U. americanus). The cutthroat trout population has subsequently declined since the introduction of non-native lake trout (Salvelinus namaycush), and in response to effects of drought and whirling disease (Myxobolus cerebralis). The trout population, duration of spawning runs, and indices of bear use of spawning streams had declined in some regions of the lake by 1997–2000. We initiated a 3-year study in 2007 to assess whether numbers...
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Identification of ecological factors that drive animal distributions allows us to understand why distributions vary temporally and spatially, and to develop models to predict future changes to populations–vital tools for effective wildlife management and conservation. For waterbird broods in the boreal forest, distributions are likely driven by factors affecting quality of nesting and brood-rearing habitats, and the influence of these factors may extend beyond singles species, affecting the entire waterbird community. We used occupancy models to assess factors influencing species richness of waterbird broods on 72 boreal lakes, along with brood distributions of 3 species of conservation concern: lesser scaup (Aythya...
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Big Cypress National Preserve constitutes approximately one-third of the range of the endangered Florida panther (Puma concolor coryi). Because recreational hunting is allowed in Big Cypress National Preserve, we examined 8 response variables (activity rates, movement rates, predation success, home-range size, home-range shifts, proximity to off-road vehicle trails, use of areas with concentrated human activity, and habitat selection) to evaluate how Florida panthers respond to human activity associated with deer and hog hunting. Data consisted of panther radiolocations collected since 1981 by the Florida Fish and Wildlife Conservation Commission and the National Park Service, which we augmented with radiolocations...
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To improve understanding of northern pintail (Anas acuta) distribution in central California (CCA), we radiotagged 191 Hatch-Year (HY) and 228 After-Hatch-Year (AHY) female northern pintails during late August-early October, 1991-1993, in the San Joaquin Valley (SJV) and studied their movements through March each year. Nearly all (94.3%) wintered in CCA, but 5.7% went to southern California, Mexico, or unknown areas; all that went south left before hunting season. Of the 395 radiotagged pintails that wintered in CCA, 83% flew from the SJV north to other CCA areas (i.e., Sacramento Valley [SACV], Sacramento-San Joaquin River Delta [Delta], Suisun Marsh, San Francisco Bay) during September-January; most went during...
Black-footed ferrets (Mustela nigripes) excavate subsoil from black-tailed prairie dog (Cynomys ludovicianus) burrows and deposit it in unique piles. Black-tailed prairie dogs tend to fill in or "plug" burrows visited or occupied by ferrets (Hillman 1968, Henderson et al. 1969, Fortenbery 1972). In this paper, we describe the configuration, rate of production, persistence, and seasonality of ferret diggings and rate of burrow plugging by prairie dogs within white-tailed prairie dog (C. leucurus) colonies. Published in Journal of Wildlife Management, volume 48, issue 4, on pages 1441 - 1444, in 1984.
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A 4-year production study of upland nesting waterfowl on the Missouri Coteau area of North Dakota showed that pair numbers, nesting densities and nest success were generally reduced by grazing. It is suggested that cover removal such as regular grazing and mowing be discontinued on areas managed primarily for waterfowl production and that management practices which create dense rank cover be substituted.
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The relationship between habitat conditions in prairie breeding areas of North America and mallard (Anas platyrhynchos) survival rates was investigated. Annual survival-rate estimates for mallards generally were higher during years of high May pond numbers and low mallards-per-pond ratios than during years of low pond numbers and high ratios. This tendency was most pronounced among males. These results suggest that mallard survival probabilities may be affected by breeding-ground habitat conditions.