Differences among Nonresident Tourists Making Consumptive and Nonconsumptive Uses of Alaskan Wildlife

Tourism is an important sector of Alaska's economy; 23% of 4202 parties of tourists vacationing in Alaska from October 1982 to September 1983 indicated they hunted or fished. Tourists making consumptive use (hunting or fishing) of wildlife differed significantly from other visitors. Those who hunted or fished: (1) were in larger groups that contained a higher proportion of males; (2) tended to be younger; (3) were more involved in planning their vacation as indicated by starting the planning for their trip earlier and using more sources of information; (4) spent longer in the state and camped more often; (5) were more likely to charter aircraft within Alaska; (6) rated their experience highly, but thought they received a lower value for monies spent; (7) expended fewer total funds on their vacation; and (8) were more likely to return to Alaska than their counterparts who neither hunted nor fished. Visitors who used wildlife consumptively provided funds directly to the state for the conservation of these species through the purchase of hunting and fishing licenses and the subsequent receipt by the state of federal funds via the Pittman-Robertson and Dingell-Johnson acts. No formal mechanism exists for nonconsumptive users to aid wildlife conservation even though some nonconsumptive uses of resources are detrimental to wildlife. Although wildlife and their habitats are an important attractor for tourists, too little attention is given to the long-term benefits from the tourism industry in assessing the economic value of resource development and use that affects wildlife.

Population Characteristics, Morphometry, and Growth of Harvested Gray Wolves and Coyotes in Alaska

Few concurrent studies exist of sympatric gray wolf (Canis lupus) and coyote (C. latrans) harvest at far northern latitudes. Moreover, no studies explicitly examine effects of concurrent harvest on phenotypes of wolves and coyotes. We documented changes in sex and age characteristics and morphology of gray wolves and coyotes harvested by hunters near Ptarmigan Lake, east-central Alaska, USA, between 1998 and 2001. We hypothesized that the harvest would result in larger, heavier canids, reduce densities, and increase young to adult ratios in both wolves and coyotes. We generated von Bertalanffy growth curves indicating that wolves and coyotes of both sexes increased in length or weight until 2 or 3 years old. No significant changes in either mean length or weight or length to weight ratios occurred during the 3-year study, except that coyote mean length was longer over the last winter of study. Catch-per-unit effort (CPUE) for wolves ranged from 0.061 to 0.112 killed/day and for coyotes from 0.552 to 0.11 killed/day over the study. CPUE indicated that coyotes but not wolves declined in abundance. Changes in male to female and young to adult ratios did not differ significantly for either canid. We posit that coyote populations were disproportionately affected by the conflation of the severe Arctic environment and sustained harvest. Our findings will be beneficial for managing sympatric canid populations and for understanding demographic responses to density-dependent processes in wolves and coyotes, especially at far northern latitudes.Il existe peu d’études concomitantes sur la récolte du loup gris (Canis lupus) et du coyote (C. latrans) sympatriques dans les hautes latitudes nordiques. Par ailleurs, aucune étude n’examine explicitement les effets de la récolte concomitante sur les phénotypes des loups et des coyotes. Nous avons documenté les changements sur le plan de la morphologie et des caractéristiques du sexe et de l’âge des loups gris et des coyotes récoltés par les chasseurs à proximité du lac Ptarmigan, dans le centre-est de l’Alaska, aux États-Unis, de 1998 à 2001. Nous avons formulé l’hypothèse voulant que la récolte donnerait lieu à des canidés plus gros et plus lourds, réduirait les densités et augmenterait les rapports entre jeunes et adultes, tant chez les loups que chez les coyotes. Nous avons produit des courbes de croissance de von Bertalanffy selon lesquelles la longueur ou le poids des loups et des coyotes des deux sexes augmentait jusqu’à l’âge de deux ou trois ans. Sur le plan de la longueur ou du poids moyen, ou des rapports moyens entre la longueur et le poids, aucun changement important n’a été enregistré pendant l’étude de trois ans, sauf que la longueur moyenne du coyote était plus grande au cours du dernier hiver de l’étude. Pour le loup, la capture par unité d’effort (CPUE) variait de 0,061 à 0,112 bête tuée/jour, tandis que pour le coyote, elle variait de 0,552 à 0,11 bête tuée/jour dans le courant de l’étude. Selon la CPUE, l’abondance des coyotes a chuté, mais pas celle des loups. Pour l’un ou l’autre des canidés, les variations en matière de rapports entre les mâles et les femelles, et entre les jeunes et les adultes n’étaient pas considérables. Nous postulons que les populations de coyotes ont été touchées de manière disproportionnée à la fois par l’environnement arctique rigoureux et par une récolte soutenue. Nos constatations joueront un rôle dans la gestion des populations de canidés sympatriques et dans la compréhension des réponses démographiques aux processus dépendant de la densité chez les loups et les coyotes, surtout dans les hautes latitudes nordiques

Chronic wasting disease detection and mortality sources in semi-protected deer population

Surveillance for wildlife diseases is essential for assessing population dynamics of ungulates, especially in free-ranging populations where infected animals are difficult to sample. Chronic wasting disease (CWD) is an emerging infectious disease of concern because of the potential for substantial negative effects on populations of cervids. Variability in the likelihood that CWD is detected could invalidate traditional estimators for prevalence. In some instances, deer located after death cannot be tested for infectious diseases, including CWD, because of lack of availability or condition of appropriate tissues. We used various methods to detect infectious diseases that could cause mortality for deer Odocoileus spp. residing in Wind Cave National Park, South Dakota, USA, and we report survival estimates for animals in this population. We included 34 monthly encounters of deer resightings and 67 mortalities. We tested live deer by tonsillar biopsy for CWD and estimated pooled prevalence (mean ± SE) at 5.6 ± 3.0% over the three-year study. Live deer potentially had exposure to several infectious diseases, including bluetongue, epizootic hemorrhagic disease, bovine viral diarrhea, West Nile virus, and malignant catarrhal fever, but no apparent morbidity or mortality from those diseases. We tested survival and influence of covariates, including age and sex, using known-fate analysis in Program MARK. Those data best supported a model with time-invariant encounter probability and an annual survival of 72.8%. Even without direct pressure from hunting within the park, average life expectancy in this population was 3.2 years. Only 68% of mortalities contained sufficient material for CWD sampling (because of predation and scavenger activity) and \u3e42% of these were CWD-positive. These findings underscore the possible biases in postmortem surveillance estimates of disease prevalence because of potential for subclinical infected animals to be removed by predators and not tested

Migrating Mule Deer: Effects of Anthropogenically Altered Landscapes

Background: Migration is an adaptive strategy that enables animals to enhance resource availability and reduce risk of predation at a broad geographic scale. Ungulate migrations generally occur along traditional routes, many of which have been disrupted by anthropogenic disturbances. Spring migration in ungulates is of particular importance for conservation planning, because it is closely coupled with timing of parturition. The degree to which oil and gas development affects migratory patterns, and whether ungulate migration is sufficiently plastic to compensate for such changes, warrants additional study to better understand this critical conservation issue. Methodology/Principal Findings: We studied timing and synchrony of departure from winter range and arrival to summer range of female mule deer (Odocoileus hemionus) in northwestern Colorado, USA, which has one of the largest natural-gas reserves currently under development in North America. We hypothesized that in addition to local weather, plant phenology, and individual life-history characteristics, patterns of spring migration would be modified by disturbances associated with natural-gas extraction. We captured 205 adult female mule deer, equipped them with GPS collars, and observed patterns of spring migration during 2008–2010. Conclusions/Significance: Timing of spring migration was related to winter weather (particularly snow depth) and access to emerging vegetation, which varied among years, but was highly synchronous across study areas within years. Additionally, timing of migration was influenced by the collective effects of anthropogenic disturbance, rate of travel, distance traveled, and body condition of adult females. Rates of travel were more rapid over shorter migration distances in areas of high natural-gas development resulting in the delayed departure, but early arrival for females migrating in areas with high development compared with less-developed areas. Such shifts in behavior could have consequences for timing of arrival on birthing areas, especially where mule deer migrate over longer distances or for greater durations

Scent marking by male caribou: an experimental test of rubbing behavior

We studied scent marking by adult male caribou (Rangifer tarandus) during rut in September 1998 at the Large Animal Research Station in Fairbanks, Alaska, USA. We used an experimental approach involving two captive groups of two males each to test for effects of social status, tree size, texture, and scent on rubbing behavior by caribou. Dominant males did not rub more often or for a longer duration than subordinates. Caribou rubbed trees with smaller diameters more often than large-diameter trees. Males preferred trees with bark for rubbing to those trees with their bark removed prior to the experiment. Caribou exhibited no preference for posts with pine-oil applied compared with posts without that aromatic scent. We hypothesize that rubbing of trees by male caribou is related to synchronization or priming of estrus in females, but more research is needed to test that potential function of scent marking

VISIBILITY OF MOOSE IN A TEMPERATE RAINFOREST

Aerial surveys are the principal methods used to estimate populations of moose (Alces alces gigas) in Alaska. Accounting for missed animals during aerial surveys is problematical, especially in forested habitats; incorporation of a visibility correction factor to account for the proportion of animals missed is known to improve accuracy of population estimates. Our purpose was to study factors affecting visibility of radio-collared moose during aerial surveys in a temperate rainforest on the Yakutat Foreland, Alaska, USA. Wildlife managers in the area typically assume they observe only 50% of moose during surveys regardless of widely varying conditions. We used logistic regression to examine factors that influenced visibility including vegetation, light conditions, snow cover, and sex, age, and group size of moose. We then used logistic regression to develop a simpler model that only contained variables easily measured during aerial surveys: forest cover, snow cover, light, open versus vegetated habitat, and group size. We used that model to estimate a visibility correction factor. The mean correction factor was 1.304, ranging from1.005-2.138, yielding a population estimate of 699 (90% CI = 671-724) moose from a survey count of 595 animals. Our correction factor was within the range reported for other populations of moose, and lower than the correction factor (2.0) currently used in this area. We conclude that application of site and time-specific visibility models is critical when estimating populations of large ungulates, especially in forested habitats

Hunting and mountain sheep: Do current harvest practices affect horn growth?

The influence of human harvest on evolution of secondary sexual characteristics has implications for sustainable management of wildlife populations. The phenotypic consequences of selectively removing males with large horns or antlers from ungulate populations have been a topic of heightened concern in recent years. Harvest can affect size of horn-like structures in two ways: (a) shifting age structure toward younger age classes, which can reduce the mean size of horn-like structures, or (b) selecting against genes that produce large, fast-growing males. We evaluated effects of age, climatic and forage conditions, and metrics of harvest on horn size and growth of mountain sheep (Ovis canadensis ssp.) in 72 hunt areas across North America from 1981 to 2016. In 50% of hunt areas, changes in mean horn size during the study period were related to changes in age structure of harvested sheep. Environmental conditions explained directional changes in horn growth in 28% of hunt areas, 7% of which did not exhibit change before accounting for effects of the environment. After accounting for age and environment, horn size of mountain sheep was stable or increasing in the majority (similar to 78%) of hunt areas. Age-specific horn size declined in 44% of hunt areas where harvest was regulated solely by morphological criteria, which supports the notion that harvest practices that are simultaneously selective and intensive might lead to changes in horn growth. Nevertheless, phenotypic consequences are not a foregone conclusion in the face of selective harvest; over half of the hunt areas with highly selective and intensive harvest did not exhibit age-specific declines in horn size. Our results demonstrate that while harvest regimes are an important consideration, horn growth of harvested male mountain sheep has remained largely stable, indicating that changes in horn growth patterns are an unlikely consequence of harvest across most of North America.Utah Division of Wildlife Resources; National Wild Sheep Foundation (WSF); Wyoming Wild Sheep Foundation; Alberta Wild Sheep Foundation; California Wild Sheep Foundation; Arizona Desert Bighorn Sheep Society; Wyoming Governor's Big Game License Coalition; Iowa Foundation for North American Wild Sheep; Utah Foundation for North American Wild Sheep; Pope and Young ClubOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Hunting and mountain sheep: do current harvest practices affect horn growth?

The influence of human harvest on evolution of secondary sexual characteristics has implications for sustainable management of wildlife populations. The phenotypic consequences of selectively removing males with large horns or antlers from ungulate populations has been a topic of heightened concern in recent years. Harvest can affect size of horn‐like structures in two ways: 1) shifting age structure toward younger age classes, which can reduce the mean size of horn‐like structures; or 2) selecting against genes that produce large, fast‐growing males. We evaluated effects of age, climatic and forage conditions, and metrics of harvest on horn size and growth of mountain sheep (Ovis canadensis ssp.) in 72 hunt areas across North America from 1981 to 2016. In 50% of hunt areas, changes in mean horn size during the study period were related to changes in age structure of harvested sheep. Environmental conditions explained directional changes in horn growth in 28% of hunt areas, 7% of which did not exhibit change before accounting for effects of the environment. After accounting for age and environment, horn size of mountain sheep was stable or increasing in the majority (~78%) of hunt areas. Age‐specific horn size declined in 44% of hunt areas where harvest was regulated solely by morphological criteria, which supports the notion that harvest practices that are simultaneously selective and intensive might lead to changes in horn growth. Nevertheless, phenotypic consequences are not a foregone conclusion in the face of selective harvest; over half of the hunt areas with highly selective and intensive harvest did not exhibit age‐specific declines in horn size. Our results demonstrate that while harvest regimes are an important consideration, horn growth of harvested male mountain sheep has remained largely stable, indicating that changes in horn growth patterns are an unlikely consequence of harvest across most of North America

EFFECTS OF PREVIOUS BROWSING ON THE SELECTION OF WILLOW STEMS BY ALASKAN MOOSE

We tested whether regrowth from stems of willows (Salix glauca) browsed by Alaskan moose (Alces alces gigas) in the previous winter would affect selection for browse by moose in the following winter. We sampled willow in a power-line corridor near Fairbanks, Alaska, USA, during autumn 1995 and winter 1996. We collected current annual growth for 90 stems from 30 willows to establish relationships among stem length, stem diameter at the bud-scale scar, and dry mass. Strong curve-linear regressions were obtained between stem length and dry mass (R2 = 0.91), and stem diameter and dry mass (R2 = 0.90); stem length was linearly related to diameter (r2 = 0.74). we randomly sampled an additional 30 willows to investigate levels of browsing by moose on leaders of new growth. Overall levels of browsing were high (70.4% ± 20.2% SD), but feeding on stems that were browsed previously was significantly (P < 0.001) higher (84.6% ± 16.0% SD). We estimated dry mass available to moose on willow stems not browsed in the previous or current winter (0.62 g ± 0.18 g SD), stems browsed in the previous winter but not the current one (0.87 g ± 0.48 g SD), and stems browsed during both winters (4.0 g ± 2.7 g SD); this pattern in biomass available to moose differed significantly (P < 0.001). We also estimated that moose removed 1.6 g (± 1.0 g SD) of current annual growth from each stem they browsed. This amount was greater than available on stems that were not browsed in winter 1995-1996, and may help explain selection of moose for regrowth from previously browsed stems. Consequently, moose would obtain more food for the same effort by feeding upon stems they had browsed previously. This outcome also may help explain why moose use traditional areas for feeding and other activities