Wooded draws comprise about 1% of the landscape in the Northern Great Plains but provide various mammalian and avian species, including some listed as species of conservation priority, with food, cover, and protection. However, understanding the status of wooded draw health is lacking. Therefore, our objectives were to identify if wooded draws were regenerating by assessing long-term trends of sampled wooded draws while using predictive equations to assign the seral stage of each sampled wooded draw as an indicator of wooded draw health in North Dakota, USA. We found decreasing numbers of green ash (Fraxinus pennslyvanicus) and American elm (Ulmus americanus) stems temporally while percent cover of Prunus spp and Symphoricarpos spp increased temporally. However, we found a general trend for percent shrubby cover to decrease within our microplots. Using predictive equations, we classified 61% of wooded draws as late seral stage, 7% as late intermediate, 8% as early intermediate, and 24% as early successional by their last year of data collection. Our results indicate most wooded draws in North Dakota are aging and not regenerating. Given the importance of this rare cover type, management strategies aimed at regenerating wooded draws are discussed.
Studies on the effectiveness of fish passage structures to allow for upstream movements through dams have mostly focused on recreationally important fishes. A Denil fishway fitted with a passive integrated transponder (PIT) tag array was constructed on the Cedar River near Spalding, Nebraska, in 2015. We evaluated whether this passage structure would allow for upstream movement of five non-game species. Individuals were captured, implanted with PIT tags, and released during 2016–2018. An attempt at passage was noted if an individual passed the antenna placed at the bottom of the fish passage structure and successful passage was defined as crossing the antenna at the top of the fish passage structure. The number of attempts and successful passages by date and species were monitored. Passage attempts and successful passage occurred between April and September for all five species, but peaked in May in 2017 and 2018 and later in the year in 2016. The rates of attempts varied from 15% for Platygobio gracilis (Flathead Chub) to 67% for Carpiodes carpio (River Carpsucker). The rates of successful passage varied from 66% for Cyprinus carpio (Common Carp) to 100% for Flathead Chub. Results of this study indicate that non-game fish use and successfully move upstream through a Denil fish passage structure on the Cedar River in Nebraska. Similar structures might be useful to facilitate movement of non-game fishes through dams in Great Plains rivers.
Exposure of a dam to pathogens may potentially affect her fawns positively or negatively. Mammalian females transfer immunologic protection to their offspring via colostrum obtained while nursing. Conversely, chronic diseases in dams may potentially result in small and weak neonates, reduced milk production or quality, or infection. Little is known about how pathogen exposure in adult female white-tailed deer (Odocoileus virginianus) affects offspring survival. Our objective was to assess pathogen exposure for female white-tailed deer and subsequent survival rates of fawns in Dunn and Grant counties, North Dakota, and Perkins County, South Dakota, USA. We collected blood serum from 150 adult female deer during 2014. We compared survival of 49 fawns to maternal exposure to 10 pathogens from 37 of 150 adult females. There was no difference in fawn mass between dams based on antibody status and no difference in fawn survival for nine pathogens. The 12-wk survival for fawns born to mothers with antibodies against bovine herpesvirus 1 (BoHV-1, causing infectious bovine rhinotracheitis) was lower than for fawns born from mothers without antibodies against BoHV-1; however, the indirect or direct impacts of BoHV-1 exposure in mothers on fawn survival are unclear. Although our findings suggest that the cost of exposure to previous diseases may have minimal impact on short-term fawn survival for most pathogens, additional research with increased sample sizes is needed to confirm our findings.
The relict plains cottonwood (Populus deltoides subsp. monilifera) forest along the Missouri River between Lakes Sakakawea and Oahe includes trees as large as two meters in diameter. We cored 24 of these trees to determine their age and suitability for flow reconstruction. Because most of the trees were rotten in the center, we developed a method to estimate the date of the center ring that accounts for the increase in ring width toward the center. Estimated center ring dates were as early as 1806. Cottonwood growth at a dry site was correlated with April–August flow prior to construction of Lake Sakakawea (1929–1953; r = 0.50, P = 0.011) and to Palmer Drought Severity Index following construction (1954–2014; r = 0.38, P = 0.003). We conclude that cottonwood rings can be used to improve reconstructions of Missouri River flows before the beginning of stream-gage records.
Black-backed woodpeckers (Picoides arcticus, [BBWO]) and American three-toed woodpeckers (P. dorsalis, [ATTW]) are uncommon inhabitants of conifer forests and are sympatric in some areas, including the Black Hills. Both species exhibit genetic characteristics associated with isolated populations, are species of special management concern, and for which data are lacking concerning populations and habitats. We developed resource selection models of forest vegetation within 500 m radius plots (78.5 ha) for BBWOs and ATTWs to provide forest managers with stand-level information to estimate how forest management might affect habitat for these species in the Black Hills. Relative probability of selection by BBWOs increased with greater area of ponderosa pine (Pinus ponderosa) stands 41-70% overstory canopy cover up to approximately 20% (16 ha) of the surrounding area then declined when these stands comprised greater than 20% of the area. Relative probability of selection by ATTWs increased with greater area of white spruce (Picea glauca) up to a maximum of approximately 66% (50 ha) of the surrounding area and subsequently declined when white spruce comprised greater than 66% of the surrounding area. Increased area of aspen (Populus temuloides) stands increased the relative probability of selection by ATTWs. During a period when the Black Hills lacked extensive disturbance from fire or insect infestation, BBWPs selected areas that were managed for moderate overstory canopy of ponderosa pine and ATTWs selected stands with large diameter spruce and aspen at the higher elevations that were not extensively harvested.
In the early 2000’s, declines in the brown trout ( Salmo trutta ) fishery in Rapid Creek, South Dakota, caused concern for anglers and fisheries managers. We conducted a radio telemetry study in 2010 and 2011 to identify predation mortality associ ated with mink, using hatchery-reared (2010) or wild (2011) brown trout. Estimated predation rates by mink ( Mustela vison ) on radio-tagged brown trout were 30% for hatchery fish and 32% for wild fish. Size frequency analysis revealed that the size distri bution of brown trout lost to predation was similar to that of other, radio-tagged brown trout. In both years, a higher proportion of predation mortality (83–92%) occurred during spring, consistent with seasonal fish consumption by mink. Predation by mink appeared to be a significant source of brown trout mortality in our study.
Aboveground net primary production provides valuable information on wildlife habitat, fire fuel loads, and forage availability. Aboveground net primary production in herbaceous plant communities is typically measured by clipping aboveground biomass. However, the high costs associated with physically harvesting plant biomass may prevent collecting sufficient data to account for natural spatial and temporal variability of vegetation at a landscape scale. Various double-sampling techniques have been developed to increase sample size while reducing cost. We applied a biomass estimation technique previously developed for estimating shrub biomass using representative samples or “reference units” to estimate herbaceous grassland biomass. Our reference units consisted of major grass species and functional groups that involved combining species with similar origin (native vs. introduced) and life-form characteristics. This study was conducted in 2010 on and around prairie dog colonies on the Buffalo Gap National Grassland in southwestern South Dakota, which provided a range of plant communities for testing the method. Results of the study demonstrate that reference units can provide accurate and precise estimates of herbaceous plant biomass on grasslands, including multi-species functional groups. Twenty-five of 26 double sampling calibrations were validated by time with no changes in observer estimation trends over the sampling season. Use of the reference unit method was consistent among observers and is a viable option for estimating and monitoring herbaceous grassland aboveground biomass.
Habitat disturbance events are critical to ecological systems in which some bird species have become specialized. The vegetation community, reduced competition, ability to avoid predators, nest site characteristics, and forage opportunities within a disturbed ecosystem are all aspects that make it desirable for selection by particular species (Svardson 1949, Cody 1981, Martin 1998). Specifically, avian species rely on the forest conditions created by fire, insects, and disease (Brawn et al. 2001, Hunter et al. 2001, Devictor et al. 2008). In the Black Hills National Forest (BHNF) of South Dakota, two major types of natural disturbances include wildfires and mountain pine beetle (Dendroctonus ponderosae; MPB) infestations. Dead trees (snags) created by these disturbances attract a suite of insects and wildlife species. Bark beetles (Family: Curculionidae, Scolytinae) and wood borer beetles (Families: Buprestidae and Cerambycidae) are of particular importance to black-backed woodpeckers (Picoides arcticus; BBWO) because they feed almost exclusively on the larvae of these insects (Beal 1911, Murphy and Lehnhausen 1998, Hutto 2006, Bonnot et al. 2008, Bonnot et al. 2009). Black-backed woodpeckers are of key interest to resource management agencies due to their habitat specialization needs and the management activities like wildfire salvage logging and pre-thinning that occur in these disturbance areas (Hutto 1995, 2006). These management activities potentially reduce nest site and food availability for BBWOs and, as a result, they were recently petitioned for protection under the Endangered Species Act (Hanson et al. 2012). Following a fire event or insect infestation, the relative probability of using trees affected by the disturbance increases over surrounding healthy trees (Rota 2013). As a result, we were interested in understanding the food that is available to the woodpeckers following these forest disturbances.
