Who Takes the Bait? Non-target Species Use of Bear Hunter Bait Sites

Hunting bears (Ursus spp.) over baits is legal in many countries, states, and provinces, but the practice remains a controversial topic among wildlife managers, hunting groups, and the general public. The baits used to attract bears may also provide a pulsed resource on the landscape that can be used by other wildlife species, particularly carnivores. To determine what other species might use bear bait sites, we constructed and monitored 21 bear bait sites with camera traps from August to October 2016 in the western Upper Peninsula of Michigan, USA. The sites mimicked typical American black bear (U. americanus) hunter bait sites. We tested recorded changes in carnivore visitation before and during hunting season using paired t-test and analyzed carnivore temporal shifts between the 2 periods using a nonparametric kernel density estimation procedure. We analyzed 7,915 images, of which 81.9% were nontarget species. Bear daily visitation at the bait sites was reduced by 49.3% during hunting season while nontarget carnivore visitation increased by 33.0%. Bears also increased their nocturnal activity by 22.4% during the legal hunting season while other carnivore species maintained their diel patterns. Because of the high rates of nontarget species use of the bear hunter bait sites, there is a potential for disease spread and conflict with hunters. Managers should evaluate the potential impacts on target and nontarget species when establishing hunter bait regulations

Territorial landscapes: incorporating density-dependence into wolf habitat selection studies.

Habitat selection is a process that spans space, time and individual life histories. Ecological analyses of animal distributions and preferences are most accurate when they account for inherent dynamics of the habitat selection process. Strong territoriality can constrain perception of habitat availability by individual animals or groups attempting to colonize or establish new territory. Because habitat selection is a function of habitat availability, broad-scale changes in habitat availability or occupancy can drive density-dependent habitat functional responses. We investigated density-dependent habitat selection over a 19-year period of grey wolf

Berry Important? Wolf Provisions Pups with Berries in Northern Minnesota

Wolves (Canis lupus) primarily provision pups by catching mammalian prey and bringing remains of the carcass to the pups at a den or rendezvous site via their mouths or stomach. In August 2017, we observed an adult wolf regurgitating wild blueberries (Vaccinium spp.) to pups at a rendezvous site in the Greater Voyageurs Ecosystem, Minnesota, USA, which is the only known observation of wolves provisioning pups with wild berries. This observation, in combination with other evidence from the Greater Voyageurs Ecosystem, suggests wild berries might be a more valuable food source for wolves in southern boreal ecosystems than previously appreciated

Walruses Attack Spectacled Eiders Wintering in Pack Ice of the Bering Sea

We observed walruses (Odobenus rosmarus) pursuing spectacled eiders (Somateria fischeri) within pack ice of the Bering Sea, 70–90 km from the nearest land. We used both direct observations from a helicopter and a heligimbal camera system that can film animals from a helicopter at high altitudes. The eiders were in monospecific flocks of thousands of birds within large leads. The walruses apparently tried to catch the eiders from below; the eiders responded with a “flash expansion” (explosive radial movement), wing-flapping and running along the water surface to escape. Disturbance by individual walruses could restrict flocks of thousands of birds to small portions of the open water. In eight such events that we witnessed over 75 min of observations, we were unable to confirm that walruses captured any of these full-grown, flight-capable eiders. However, the high rate of attacks and the eiders’ dramatic escape response suggest that walruses can at times be effective predators on them, and may affect the eiders’ dispersion and energy balance.Nous avons observé des morses (Odobenus rosmarus) en train de pourchasser des eiders à lunettes (Somateria fischeri) sur la banquise de la mer de Béring, soit à une distance de 70 à 90 kilomètres de la terre ferme la plus près. Nous nous sommes servis à la fois d’observations directes faites à partir d’un hélicoptère et d’un appareil héligimbal capable de filmer les animaux à partir d’un hélicoptère à haute altitude. Les eiders se tenaient en bandes monospécifiques constituées de milliers d’oiseaux faisant partie de gros groupements. Il semblait que les morses essayaient d’attraper les eiders par en-dessous; les eiders réagissaient en faisant une « expansion éclair » (un mouvement radial explosif), en battant des ailes et en courant le long de la surface de l’eau afin de s’échapper. Les perturbations exercées par les morses individuels pouvaient avoir pour effet de restreindre les bandes de milliers d’oiseaux à de petites nappes d’eau libre. Dans huit cas de telle nature dont nous avons été témoins pendant plus de 75 minutes d’observation, nous n’avons pas été en mesure de confirmer si les morses avaient réussi à capturer des eiders adultes en état de voler. Cependant, le taux élevé d’attaques de même que la réaction dramatique des eiders qui tentaient de s’échapper laissent entrevoir que les morses pourraient être des prédateurs efficaces en ce qui les concerne, ce qui pourrait exercer une influence sur l’expansion des eiders et sur leur bilan énergétique

Finding wolf homesites: improving the efficacy of howl surveys to study wolves

Locating wolf (Canis lupus) homesites is valuable for understanding the foraging behavior, population dynamics, and reproductive ecology of wolves during summer. During this period wolf pack members (adults and pups) readily respond to simulated wolf howls (i.e., howl surveys), which allows researchers to estimate the location of the homesite via triangulation. Confirming the actual locations of homesites via ground truthing is labor intensive because of the error surrounding estimated locations. Our objectives were (1) to quantify observer error during howl surveys and compare amongst experience levels, (2) provide a simple method for locating homesites in the field by incorporating observer error, and (3) further document the value of this method for monitoring wolf packs throughout the summer. We located 17 homesites by howl surveys during 2015–2017 in the Greater Voyageurs Ecosystem, Minnesota, USA. Of 62 bearings taken by observers during howl surveys, bearings erred by an average of 7.6° ± 6.3° (SD). There was no difference in observer error between novice and experienced observers. A simple way to increase efficiency when searching for homesites is to search concentric areas (bands) based on estimated observer error, specifically by: (1) adding ±10° error bands around howl survey bearings when ≥3 bearings can be obtained, (2) ±10° and ±20° error bands when 2 bearings are obtained, and (3) ±10° and ±26° error bands when 1 bearing is obtained. By incorporating observer error and understanding how frequently and how far wolves move homesites, it is possible to monitor wolf packs and confirm most, if not all, homesites used by a pack from at least June until August without having a collared individual in a pack

Does persistent snowpack inhibit degradation of fecal stress indicators?

Physiological stress in wildlife can be a useful indicator of a population’s response to environmental factors. By using non-invasive endocrinological techniques, such as fecal sampling, potential confounding factors associated with the stress of capture can be avoided. A potential drawback of fecal sampling, however, is degradation of samples which may produce aberrant measurements of fecal glucocorticoid metabolites. In vertebrates, glucocorticoids, such as corticosterone, become elevated in response to stress. We sought to gauge the reliability of measurement of fecal glucocorticoid metabolites from white-tailed deer (Odocoileus virginianus) fecal samples exposed to a temperate winter with substantial snow cover and cold temperatures for up to 90 days, by repeatedly subsampling fecal samples every 10 days and performing a corticosterone enzyme-linked immunosorbent assay (ELISA). Measurements of fecal glucocorticoid metabolites at 10 days were consistent with initial measurements, after which (20 days) they became aberrant following a period of thawing. Consequently, glucocorticoid metabolite levels in feces appear to remain stable under ambient conditions if temperatures remain below freezing at least for 10 days. While it’s possible that samples may remain useful beyond this time frame based on previous laboratory studies of samples stored in a freezer, further work is needed to determine how samples weather in situ under extreme cold (e.g. Arctic) or periods of partial thawing

Modeling Marine Protected Areas for Threatened Eiders in a Climatically Changing Bering Sea

Delineating protected areas for sensitive species is a growing challenge as changing climate alters the geographic pattern of habitats as well as human responses to those shifts. When human impacts are expected within projected ranges of threatened species, there is often demand to demarcate the minimum habitat required to ensure the species\u27 persistence. Because diminished or wide-ranging populations may not occupy all viable (and needed) habitat at once, one must identify thresholds of resources that will support the species even in unoccupied areas. Long-term data on the shifting mosaic of critical resources may indicate ranges of future variability. We addressed these issues for the Spectacled Eider (Somateria fischeri), a federally threatened species that winters in pack ice of the Bering Sea. Changing climate has decreased ice cover and severely reduced the eiders\u27 benthic prey and has increased prospects for expansion of bottom trawling that may further affect prey communities. To assess long-term changes in habitats that will support eiders, we linked data on benthic prey, sea ice, and weather from 1970 to 2001 with a spatially explicit simulation model of eider energy balance that integrated field, laboratory, and remote-sensing studies. Areas estimated to have prey densities adequate for eiders in 1970–1974 did not include most areas that were viable 20 years later (1993–1994). Unless the entire area with adequate prey in 1993–1994 had been protected, the much reduced viable area in 1999–2001 might well have been excluded. During long non-foraging periods (as at night), eiders can save much energy by resting on ice vs. floating on water; thus, loss of ice cover in the future might substantially decrease the area in which prey densities are adequate to offset the eiders\u27 energy needs. For wide-ranging benthivores such as eiders, our results emphasize that fixed protected areas based on current conditions can be too small or inflexible to subsume long-term shifts in habitat conditions. Better knowledge of patterns of natural disturbance experienced by prey communities, and appropriate allocation of human disturbance over seasons or years, may yield alternative strategies to large-scale closures that may be politically and economically problemati

Bear-Baiting May Exacerbate Wolf-Hunting Dog Conflict

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