Josef Hamr

Winter resource selection of reintroduced elk and sympatric white-tailed deer at multiple spatial scales

Abstract Understanding limiting factors and interspecific interactions is fundamental to wildlife management and can be inferred from multiscale patterns of resource selection. We studied winter resource selection and overlap of white-tailed deer (Odocoileus virginianus) and translocated female elk (Cervus elaphus) over 2 winters in central Ontario, Canada. Microhabitat data were collected along 4 organism-centered spatial scales: site, trail, feeding station, and diet. Although winter conditions varied between years, white-tailed deer consistently traveled and fed in habitats with greater coniferous basal area than elk. Neither species demonstrated selection for coniferous basal area or snow depth across scales. At successively finer scales, female elk selected increased understory cover of trembling aspen (Populus tremuloides). For white-tailed deer, across-scale selection of sugar maple (Acer saccharum) understory cover was exhibited when winter conditions were more severe. Dietary overlap was moderate during both winters (50–57%) and coniferous forage was more important to deer than elk. Using canonical variate analysis, a gradient from shade-intolerant hardwoods to mature coniferous vegetation was found to discriminate significantly between elk and deer habitat use at trails and feeding stations. These results indicate that deer were closely associated with conifers regardless of winter conditions and that both ungulates may have been limited by forage abundance.

Development of a Sightability Model for Low-Density Elk Populations in Ontario, Canada

Abstract The status of recolonizing elk (Cervus elaphus) populations in Ontario, Canada, is unclear and there is a need for effective population survey methods that can be applied locally. We sought to develop a sightability model that could account for both low densities of elk and dense forest cover in elk-release areas in Ontario. We corrected winter aerial survey counts for sightability based on radiocollared animals known to be within observable distance of the aircraft. The multivariate model with the highest Akaikes Information Criterion corrected for sample size weight (wi = 0.427) revealed that elk group size, elk activity, dominant tree type, percent canopy cover, and percent conifer cover were significant predictors of elk sightability. The group-size effect indicated that odds of sighting an elk increased by 1.353 (95% CI = 0.874–3.689) for every additional elk. Standing elk were 5.033 (95% CI = 0.936–15.541) times more likely to be observed than were resting elk, and those located in conifer cover were 0.013 (95% CI = 0.001–0.278) times less likely to be sighted than elk in deciduous cover. Furthermore, elk located in >50% canopy cover and >50% conifer cover were 0.041 (95% CI = 0.003–0.619) times and 0.484 (95% CI = 0.024–9.721) times less likely to be sighted than elk in more open habitat, respectively. During model validation, observers detected 79% (113/143) of known elk in any given area, and population and sightability model predictions (±90% CI) overlapped with the population estimate, implying that our predictive model was robust. Unsurprisingly, large groups of elk in open habitat increased model precision, which highlights difficulties of counting Ontario elk in their northern range. We conclude that our model provided increased reliability for estimating elk numbers in Ontario compared to existing methods, and that the estimator may be useful in other areas where elk density is low and sightability is poor due to dense forest cover.

Age, sex and relocation distance as predictors of return for relocated nuisance black bears Ursus americanus in Ontario, Canada.

Relocation has been used as a management tool for nuisance black bears Ursus americanus for decades. Using tag recovery data from relocated nuisance bears in Ontario, Canada, we developed predictive models to assist managers in determining the efficacy of black bear relocation based on the sex and age of the animal, and a range of relocation distances. We considered relocation success in terms of nuisance recurrence rates and whether bears returned to within 20 km of the capture site. A minimum of 30% of relocated bears were subsequently involved in another nuisance event and adult females were the segment of the population most likely to re-offend (48%). Adult bears consistently exhibited higher return rates than juveniles (73 vs 29%), hence we modeled these two groups separately. Based on logistic regression models, the probability of return for animals 1–3 years of age increased with age, females were more likely to return than males, and return rates decreased with increasing relocation distance. For bears ≥4 years of age, these variables were poor predictors of return; the model had difficulty identifying bears that did not return. We used receiver-operating characteristic curves to estimate relocation distance thresholds for juvenile bears. The results suggest that 2- and 3-year-old male bears will not return to within 20 km of the capture area if relocated a minimum of 30 km and 64 km, respectively. Although relocation appears to be an effective strategy for the management of juvenile male bears, success rates were low for adults. Our findings can aid resource managers in making more informed decisions as to the potential effectiveness of relocation as a management tool.

Elk (Cervus elaphus) Seasonal Habitat Selection in a Heterogeneous Forest Structure

Seasonal habitat selection by the reintroduced Burwash elk population, approximately 30 km south of Sudbury, Ontario, has been analysed in order to assist in the development of future management. Twenty-five adult females were radio-collared and tracked 1–3 times a week for 3 years. The most prominent patterns included selection of intolerant hardwood forests (trembling aspen, white birch, and balsam poplar) during all seasons, while Great Lakes-St. Lawrence pines (white and red pine dominated stands) were used less than expected based on availability for all seasons. The selection patterns are likely associated with seasonal climatic conditions and forage preferences. Because the selection behaviours displayed here varied greatly from other elk habitat studies, it is suggested that managers consider the importance of population-specific habitat studies before developing related strategies.

The History of Elk ( Cervus canadensis ) Restoration in Ontario

Elk ( Cervus canadensis ) historically inhabited southern Quebec and central Ontario, but, by the early 1900s, the species was extirpated from this region. Attempts to re-establish an Elk population in Ontario during the first half of the 20th century had limited success. We reviewed historical documents, population census records, and a previous study pertaining to Elk reintroduced to Ontario in the early 1900s for clues to the cause(s) of their limited population growth. After an apparent rapid population increase in the 1940s followed by unregulated hunting during the subsequent 3 decades, Elk abundance in Ontario had not appreciably changed from 1970 to 1997, most likely because of the small founding population, unsustainable hunting, and accidental mortality. After the abolition of legal hunting in 1980, natural mortality appeared to be the main limiting factor. A limited sample of pregnancy and calf recruitment rates, body measurements, and physical condition parameters collected in 1993–1997, suggested that adults were healthy, reproducing successfully, and not limited by food availability; thus, it was concluded that remnant Elk populations could be augmented by introducing additional animals. A renewed Elk restoration effort, conducted from 1998 to 2001, imported 443 Elk from Elk Island national Park in Alberta to 4 release areas across central Ontario (Lake of the Woods, Lake Huron North Shore, Nipissing/French River, and Bancroft/North Hastings), resulting in a provincial population of about 800 Elk by 2013.

Problem behaviour of black bears ( Ursus americanus) in central Ontario: the effects of hunting and natural food availability

Problem bear behaviour in residential areas often results in human anxiety and potential injury, bear mortality and demographic instability. Identifying and understanding factors related to problem bear activity and encounters is important for developing successful management strategies. Indices of natural bear forage availability and hunting pressure were related to problem bear activity in central Ontario. Data were collected 5 years before and 5 years after the cancellation of a spring bear hunt, providing a unique opportunity to study the effect of management policy on problem behaviour. Problem bear activity indices increased significantly following the closure of the spring hunt. Natural food availability from the previous year was found to be highly correlated with early season problem bear activity indices; however, natural food availability during the same year was not significantly related to early or late season problem activity rates. This demonstrates that multiple potential causal agents of problem bear behaviour need to be considered when developing management strategies.