Estimating biomass of berries consumed by gray wolves

Gray wolves (Canis lupus) consume berries and other wild fruits seasonally when available or abundant. However, a method to convert percent frequency of occurrence or percent volume of berries in wolf scats to percent biomass has not yet been developed. We used estimates of the average number of blueberry (Vaccinium spp.) seeds in 10 individual wolf scats collected in and adjacent to Voyageurs National Park, Minnesota, USA, along with published values of the number of seeds per blueberry and blueberry masses to estimate that a wolf scat containing only berries equated to an average of 0.468 kg of berries consumed. We recommend using this berry conversion factor (0.468 kg/scat) to convert the percent frequency of occurrence or percent volume of berries and other wild fruits to percent biomass when estimating wolf diets from scats

Where and How Wolves (Canis lupus) Kill Beavers (Castor canadensis)

Beavers (Castor canadensis) can be a significant prey item for wolves (Canis lupus) in boreal ecosystems due to their abundance and vulnerability on land. How wolves hunt beavers in these systems is largely unknown, however, because observing predation is challenging. We inferred how wolves hunt beavers by identifying kill sites using clusters of locations from GPS-collared wolves in Voyageurs National Park, Minnesota. We identified 22 sites where wolves from 4 different packs killed beavers. We classified these kill sites into 8 categories based on the beaver-habitat type near which each kill occurred. Seasonal variation existed in types of kill sites as 7 of 12 (58%) kills in the spring occurred at sites below dams and on shorelines, and 8 of 10 (80%) kills in the fall occurred near feeding trails and canals. From these kill sites we deduced that the typical hunting strategy has 3 components: 1) waiting near areas of high beaver use (e.g., feeding trails) until a beaver comes near shore or ashore, 2) using vegetation, the dam, or other habitat features for concealment, and 3) immediately attacking the beaver, or ambushing the beaver by cutting off access to water. By identifying kill sites and inferring hunting behavior we have provided the most complete description available of how and where wolves hunt and kill beavers

The role of forage availability on diet choice and body condition in American beavers (\u3ci\u3eCastor canadensis\u3c/i\u3e)

Forage availability can affect body condition and reproduction in wildlife.Weused terrestrial and aquatic vegetation sampling, stable isotope analysis, and livetrapping to investigate the influence of estimated forage biomass on diet, body condition, and reproduction in American beavers (Castor canadensis) in the Namakan Reservoir, Voyageurs National Park, Minnesota, USA, May 2008–September 2009. Available terrestrial and emergent aquatic forage varied greatly among territories, but floating leaf aquatic forage was low in abundance in all territories. Variation in estimated biomass of available emergent and terrestrial vegetation did not explain variation in respective assimilated diets, but variation in floating leaf vegetation explained 31% of variation in assimilated floating leaf diets. No models using available vegetation explained variation in body condition. Body condition of individual females in spring did not affect kit catch per unit effort, and overwinter body condition of subadults and adults was similar between territories with and without kits. We found no evidence that available aquatic vegetation affected beaver body condition or fitness. Available forage may be above minimum thresholds to detect differences in diet choice or body condition. Other factors such as water level fluctuations or climatic variables may also explain variation in beaver body condition

An Aged Canid with Behavioral Deficits Exhibits Blood and Cerebrospinal Fluid Amyloid Beta Oligomers

Many of the molecular and pathological features associated with human Alzheimer disease (AD) are mirrored in the naturally occurring age-associated neuropathology in the canine species. In aged dogs with declining learned behaviour and memory the severity of cognitive dysfunction parallels the progressive build up and location of Aβ in the brain. The main aim of this work was to study the biological behaviour of soluble oligomers isolated from an aged dog with cognitive dysfunction through investigating their interaction with a human cell line and synthetic Aβ peptides. We report that soluble oligomers were specifically detected in the dog’s blood and cerebrospinal fluid via anti-oligomer- and anti-Aβ specific binders. Importantly, our results reveal the potent neurotoxic effects of the dog’s cerebrospinal fluid on cell viability and the seeding efficiency of the cerebrospinal fluid-borne soluble oligomers on the thermodynamic activity and the aggregation kinetics of synthetic human Aβ. The value of further characterising the naturally occurring Alzheimer-like neuropathology in dogs using genetic and molecular tools is discussed

The Problems with Pooling Poop: Confronting Sampling Method Biases in Wolf (Canis lupus) Diet Studies

Wolf (Canis lupus L., 1758) diet is commonly estimated via scat analysis. Several researchers have concluded that scat collection method can bias diet estimates but none of these studies properly accounted for inter-pack, age-class, and temporal variability, all of which could bias diet estimates. We tested whether different scat collection methods yielded different wolf diet estimates after accounting for these other potential biases. We collected scats (n = 2 406) monthly from 4 packs via 3 scat collection methods (at homesites, at clusters of GPS locations, and opportunistically) in and adjacent to Voyageurs National Park, Minnesota during April 2015â October 2015. Diet estimates were not affected by scat collection method but did vary temporally, among packs, and by age-class. To more accurately estimate wolf population diets, researchers should collect 10â 20 adult scats/pack/month from homesites and/or opportunistically from packs that are representative of the population of interest. Doing so will minimize the potential biases associated with temporal, inter-pack, and age-class variability.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