Recreation Effects on Wildlife: A Review of Potential Quantitative Thresholds

Outdoor recreation is increasingly recognised for its deleterious effects on wildlife individuals and populations. However, planners and natural resource managers lack robust scientific recommendations for the design of recreation infrastructure and management of recreation activities. We reviewed 38 years of research on the effect of non-consumptive recreation on wildlife to attempt to identify effect thresholds or the point at which recreation begins to exhibit behavioural or physiological change to wildlife. We found that 53 of 330 articles identified a quantitative threshold. The majority of threshold articles focused on bird or mammal species and measured the distance to people or to a trail. Threshold distances varied substantially within and amongst taxonomic groups. Threshold distances for wading and passerine birds were generally less than 100 m, whereas they were greater than 400 m for hawks and eagles. Mammal threshold distances varied widely from 50 m for small rodents to 1,000 m for large ungulates. We did not find a significant difference between threshold distances of different recreation activity groups, likely based in part on low sample size. There were large gaps in scientific literature regarding several recreation variables and taxonomic groups including amphibians, invertebrates and reptiles. Our findings exhibit the need for studies to measure continuous variables of recreation extent and magnitude, not only to detect effects of recreation on wildlife, but also to identify effect thresholds when and where recreation begins or ceases to affect wildlife. Such considerations in studies of recreation ecology could provide robust scientific recommendations for planners and natural resource managers for the design of recreation infrastructure and management of recreation activities

Habitat use by Dall sheep and an interior Alaska mammal community

2016 Spring.Includes bibliographical references.Anthropogenic disturbances are increasingly recognized for effects on the behavior and physiology of wildlife species. Military training, a potential source of disturbance, has shown mixed behavioral and physiological effects on wildlife, including mountain ungulates. Dall sheep (Ovis dalli dalli) are an important species for hunting and wildlife viewing in Alaska and have shown an aversion to some forms of human disturbance such as direct overflights. Military training is expanding into potential Dall sheep habitat on two training areas of Fort Wainwright, Alaska; Molybdenum Ridge and Black Rapids Training Area. I placed camera traps in expected optimal and sub-optimal Dall sheep habitat to estimate the spatiotemporal habitat use of sheep and to make training recommendations to the U.S. military. Then, I further explored the available data and estimated the habitat use of species in four different mammalian guilds and the co-occurrence of habitat use between apex predators and potential prey species. In Chapter 1, I introduce the impetus for the study, the use of 54 camera traps in respect to mountain sheep, and the overall study design. My cameras captured over 8,000 images of sheep during the continuous 15-month sampling period. I successfully captured images of sheep traveling, foraging, resting, and interacting with other individuals. Occupancy models of detection-non-detection data suggest that abiotic covariates including slope, snow depth, and distance to escape terrain were the most important factors determining habitat use. Seasonal differences in habitat use suggested higher use of the Molybdenum Ridge study site during pre-rut, rut, winter, and lambing seasons with limited use during the summer, while habitat use estimates of Black Rapids were too imprecise to make broader inferences. Detection probabilities were temporally constant, but were positively correlated with cameras on a wildlife trail. From these results, I recommend that the U.S. Army concentrates training on Molybdenum Ridge during the early-July to early-September period and minimize training on both study sites during the lambing periods of May and June. If training were to occur on Molybdenum Ridge outside of this period, training should be concentrated around the easternmost valley/bowl of the ridge and the eastern half of the major south-facing slope of the ridgeline. In Chapter 2, I expanded upon the analysis of Dall sheep habitat use and investigated the alpine habitat use of ten species within four mammalian guilds. I analyzed how spatial covariates and temporal patterns correlated with habitat use of these species within and between guilds. Further, I modeled two-species occupancy of grizzly bears and wolves with different prey species (e.g., caribou and sheep). My results suggest that small and large herbivore habitat use positively correlated with vegetation and rock ground coverages, while large herbivores also correlated with broader abiotic covariates. Meso- and apex predator detections were sparse possibly leading to imprecise estimates of habitat use and little support for most habitat covariates. Detection probabilities of Dall sheep and predators were improved by cameras on trails. Two-species models suggested co-occurrence of habitat use between grizzly bear/caribou and wolf/caribou and independence of habitat use between grizzly bear/squirrel and wolf/sheep

Recreation effects on wildlife: a review of potential quantitative thresholds

Outdoor recreation is increasingly recognised for its deleterious effects on wildlife individuals and populations. However, planners and natural resource managers lack robust scientific recommendations for the design of recreation infrastructure and management of recreation activities. We reviewed 38 years of research on the effect of non-consumptive recreation on wildlife to attempt to identify effect thresholds or the point at which recreation begins to exhibit behavioural or physiological change to wildlife. We found that 53 of 330 articles identified a quantitative threshold. The majority of threshold articles focused on bird or mammal species and measured the distance to people or to a trail. Threshold distances varied substantially within and amongst taxonomic groups. Threshold distances for wading and passerine birds were generally less than 100 m, whereas they were greater than 400 m for hawks and eagles. Mammal threshold distances varied widely from 50 m for small rodents to 1,000 m for large ungulates. We did not find a significant difference between threshold distances of different recreation activity groups, likely based in part on low sample size. There were large gaps in scientific literature regarding several recreation variables and taxonomic groups including amphibians, invertebrates and reptiles. Our findings exhibit the need for studies to measure continuous variables of recreation extent and magnitude, not only to detect effects of recreation on wildlife, but also to identify effect thresholds when and where recreation begins or ceases to affect wildlife. Such considerations in studies of recreation ecology could provide robust scientific recommendations for planners and natural resource managers for the design of recreation infrastructure and management of recreation activities

The relationship between biodiversity and wetland cover varies across regions of the conterminous United States.

Identifying the factors that determine the spatial distribution of biodiversity is a major focus of ecological research. These factors vary with scale from interspecific interactions to global climatic cycles. Wetlands are important biodiversity hotspots and contributors of ecosystem services, but the association between proportional wetland cover and species richness has shown mixed results. It is not well known as to what extent there is a relationship between proportional wetland cover and species richness, especially at the sub-continental scale. We used the National Wetlands Inventory (NWI) to model wetland cover for the conterminous United States and the National Land Cover Database to estimate wetland change between 2001 and 2011. We used a Bayesian spatial Poisson model to estimate a spatially varying coefficient surface describing the effect of proportional wetland cover on the distribution of amphibians, birds, mammals, and reptiles and the cumulative distribution of terrestrial endemic species. Species richness and wetland cover were significantly correlated, and this relationship varied both spatially and by taxonomic group. Rather than a continental-scale association, however, we found that this relationship changed more closely among ecoregions. The species richness of each of the five groups was positively associated with wetland cover in some or all of the Great Plains; additionally, a positive association was found for mammals in the Southeastern Plains and Piedmont of the eastern U.S. Model results indicated negative association especially in the Cold Deserts and Northern Lakes & Forests of Minnesota and Wisconsin, though these varied greatly between groups. Our results highlight the need for wetland conservation initiatives that focus efforts at the level II and III ecoregional scale rather than along political boundaries

Spatiotemporal habitat use by a multi-trophic Alaska alpine mammal community

Evaluating sympatric habitat use of a mammal community can help determine intra- and inter-guild interactions and identify important habitats, potentially improving the management of these communities with a changing climate. Increasingly variable climatic patterns in Alaska are raising concerns of mismatched phenologies and altered ecosystem structures. We studied the occupancy of ten mammal species over 15 months, via camera traps, occupying alpine areas of the Alaska Range in interior Alaska, USA from 2013-2014. We tested hypotheses about how habitat use of these species within and between groups varied by spatial and temporal covariates. Further, we modeled two-species occupancy of brown bears and wolves against different potential prey species. Our results suggest that medium-sized and large herbivore use was positively correlated with fine scale covariates including rock, forb, and graminoid coverage. Large herbivore habitat use was also correlated with abiotic landscape covariates. Detection probabilities of predators and Dallâ s sheep (Ovis dalli dalli Nelson, 1884) was improved by camera traps on wildlife trails. Two-species models suggested co-occurrence of habitat use between brown bear/caribou and wolf/caribou. Results demonstrate the sympatric habitat use by multiple groups of mammals within Alaskan alpine ecosystems and the importance of incorporating multiple groups and spatial scales when making management decisions.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Differential sensitivity of prefrontal cortex and hippocampus to alcohol-induced toxicity.

The prefrontal cortex (PFC) is a brain region responsible for executive functions including working memory, impulse control and decision making. The loss of these functions may ultimately lead to addiction. Using histological analysis combined with stereological technique, we demonstrated that the PFC is more vulnerable to chronic alcohol-induced oxidative stress and neuronal cell death than the hippocampus. This increased vulnerability is evidenced by elevated oxidative stress-induced DNA damage and enhanced expression of apoptotic markers in PFC neurons. We also found that one-carbon metabolism (OCM) impairment plays a significant role in alcohol toxicity to the PFC seen from the difference in the effects of acute and chronic alcohol exposure on DNA repair and from exaggeration of the damaging effects upon additional OCM impairment in mice deficient in a key OCM enzyme, methylenetetrahydrofolate reductase (MTHFR). Given that damage to the PFC leads to loss of executive function and addiction, our study may shed light on the mechanism of alcohol addiction

Templates for qPCR-based BER activity assay.

<p>Whole cell extracts were isolated from brain tissue and exposed to a template DNA containing a single nucleotide lesion (A) and control template (B). BER activity was calculated by comparing the ΔΔCt values (Ct is the number of cycles required for the fluorescent signal to cross the threshold) of the repaired and control templates.</p

OCM impairment is involved in ethanol-induced oxidative DNA damage and neuronal apoptosis effects in the PFC.

<p>The brain sections (PFC) of WT and <i>Mthfr+/−</i> mice exposed for 3 weeks or 4 days (acute) to the Lieber-DeCarli liquid diet with- or without ethanol (5%) were triple-labeled with NeuN (purple), TUNEL (green) and cleaved caspase-3 (red). Hoechst 33342 (blue) was used to identify all cell nuclei. Fluorescence was visualized by confocal microscopy. Scale bar = 20 µm. Note increased number of TUNEL/caspase-3-positive neurons in PFC of <i>Mthfr+/−</i> mice chronically exposed to ethanol, compared with corresponding WT mice (arrows). Also, note a higher density of TUNEL/caspase-3-positive neurons in PFC of chronically, compared with acutely exposed to ethanol WT mice (arrows).</p

PFC is more vulnerable to ethanol-induced neuronal apoptosis than hippocampus.

<p>Brain sections double-labeled with TUNEL and MAP-2 in the PFC and hippocampus (Hip) and quantified by stereological counting; Values are means ± SEM; *p<0.01. Neither the number of MAP-2-positive cells (neurons) nor volumes of the brain structures were affected by chronic 3-week ethanol exposure. Note significantly higher density of TUNEL- positive neurons in PFC than in hippocampus of ethanol-exposed mice.</p

OCM impairment is involved in ethanol impact on DNA repair in the PFC.

<p>(A) Blood Hcy levels in WT and <i>Mthfr+/−</i> mice following acute or chronic 3- week (3 w) or 5-week (5 w) ethanol exposure. Values are means ± SEM; *p<0.01; **p<0.001. Note chronic alcohol-induced increase in blood Hcy levels, compared with the acute exposure and the heightening this increase by MTHFR deficiency. (B) DNA repair activity in the PFC of WT and <i>Mthfr+/−</i> mice exposed to acute and chronic ethanol. Values are means ± SEM; *p<0.01; **p<0.005; ***p<0.002. Note a decrease in DNA repair activity in the PFC following 3-week (3 w) and even more so following 5 week (5 w) exposure, compared with acute alcohol exposure and a significant exaggeration of this decrease by MTHFR deficiency.</p