Michael P. Gillingham

A MULTISCALE BEHAVIORAL APPROACH TO UNDERSTANDING THE MOVEMENTS OF WOODLAND CARIBOU

We assessed the response of woodland caribou (Rangifer tarandus caribou) to land-cover type, predation risk, energetic costs of movement, and patch configuration at multiple spatial scales. We applied a nonlinear model to frequent locations collected with Global Positioning System (GPS) collars to identify discontinuities in the scales of movement by caribou found in forested and alpine (above tree line) habitats. We differ- entiated intra- from interpatch movements and identified collections of patches (multiple- patch scale) where caribou concentrated intrapatch movements. On average, intra- and interpatch movements were 450.7 and 1268.8 m, respectively, and multiple-patch move- ments occurred over an area of 182 ha. Intrapatch movements were highly correlated, indicative of a strong relationship between behavior and place. Caribou in the forest selected patches of Pine terrace, whereas caribou in the alpine selected patches of Alpine-little vegetative cover. Predation risk was not a factor influencing movements of caribou at the intrapatch scale. Selection of cover types was more variable during interpatch movements. At that scale, caribou selected patches of Pine terrace, Lakes/rivers, Alpine-little vegetative cover, and Alpine-grass. The routes selected by caribou had lower energetic costs relative to surrounding terrain, and during some winters, caribou were subjected to higher levels of predation risk during those movements. At the multiple-patch scale, selection was more specific and encompassed patches of Alpine-little vegetative cover, Alpine-grass, and Pine terrace. Predation risk was relatively unimportant at the multi-patch scale, but animals that moved from forested to alpine habitats reduced their relative risk of predation. Patch con- figuration was a poor predictor of those areas where caribou concentrated intrapatch move- ments. There was some evidence of caribou selecting patches of Pine terrace within a matrix of Wetlands and Pine-black spruce/black spruce patches. Caribou in the alpine avoided patches of Alpine-little vegetative cover adjacent to forest types. Our results indicate that forest managers should maintain widely distributed patches of Pine terrace and implement silvicultural regimes that do not stimulate predator populations across areas used for in- terpatch movements.

Calf Survival of Woodland Caribou in a Multi-Predator Ecosystem

Abstract The proximate role of predation in limiting caribou (Rangifer tarandus) populations is well documented, but the long-term effects of predation pressure on selection of calving areas and the subsequent impacts to calving success remain unclear. We examined the relationships among calf survival, predation risk, and vegetation characteristics among 3 calving areas and across spatial scales in the Besa-Prophet River drainage of northern British Columbia. Fifty woodland caribou (R. t. caribou) neonates were collared and monitored twice daily for the first month and once weekly during the next month of life in 2 summer field seasons (2002 and 2003). Predation risk was estimated using resource selection functions (RSFs) from Global Positioning System (GPS) locations of 15 grizzly bears (Ursus arctos) and 5 gray wolf (Canis lupus) packs. The Normalized Difference Vegetation Index (NDVI) derived from Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) data were used to quantify large-scale characteristics of vegetation (indices of biomass and quality). We incorporated small- and large-scale characteristics (i.e., predation risk, vegetation, and movement of woodland caribou calves) of neonatal calving sites into logistic regression models to predict survival for the calving (25 May–14 Jun) and summer (15 Jun–31 Jul) seasons. Predation risk and vegetation characteristics were highly variable among calving areas and calving sites, and parturient woodland caribou responded to these characteristics at different scales. Minimizing gray wolf risk and selecting against areas of high vegetation biomass were important at large scales; areas with high biomass were likely associated with increased predation risk. Calving in areas high in vegetation quality was important across scales, as parturient woodland caribou took higher levels of predation risk to access areas of high vegetative change. Models using small-scale characteristics of calving sites to predict survival performed better in the calving season than in summer. Large-scale characteristics predicted survival of woodland caribou neonates better in summer than in the calving season, probably in part because of the unexpected role of wolverines (Gulo gulo) as the main predator of woodland caribou calves during calving. Gray wolves were the main cause of mortality during the summer. Movement away from calving sites corresponded to higher calf survival and appeared to be in response to increased access to forage during the peak demands of lactation and/or minimizing gray wolf risk in the summer. High variation in predation risk and vegetation attributes among calving areas and at calving sites within calving areas, with no differences in calf mortality related to that variation, illustrates the importance of behavioral plasticity as a life-history strategy for woodland caribou.

An evaluation of mapped species distribution models used for conservation planning

SUMMARY The widespread use of spatial planning tools in conjunction with increases in the availability of geographic information systems and associated data has led to the rapid growth in the exploration and application of species distribution models. Conservation professionals can choose from a considerable number of modelling techniques, but there has been relatively little evaluation of predictive performance, data requirements, or type of inference of these models. Empirical data for woodland caribou Rangifer tarandus caribou was used to examine four species distribution models, namely a qualitative habitat suitability index and quantitative resource selection function, Mahalanobis distance and ecological niche models. Models for three sets of independent variables were developed and then a temporally independent set of caribou locations evaluated predictive performance. The similarity of species distribution maps among the four modelling approaches was also quantified. All of the quantitative species distribution models were good predictors of the validation data set, but the spatial distribution of mapped habitats differed considerably among models. These results suggest that choice of model and variable set could influence the identification of areas for conservation emphasis. Model choice may be limited by the type of species locations or desired inference. Conservation professionals should choose a model and variable set based on the question, the ecology of the species and the availability of requisite data.

Interpreting Resource Selection at Different Scales for Woodland Caribou in Winter

Abstract Scientists commonly use resource selection functions (RSFs) to identify areas important to large herbivores. Defining availability of resources is scale dependent and may limit inference on biological mechanisms of selection, particularly if variation in selection of resources is high among individuals within a population. We used logistic regression, the information-theoretic approach, and Global Positioning System (GPS) radiotelemetry data from 10 female woodland caribou (Rangifer tarandus caribou) and 5 wolf (Canis lupus) packs to model resource selection by individual caribou in the winter and late-winter seasons. We evaluated the influence of spatial scale on the relative importance of cost of movement and components of predation risk. We examined attributes of the risk of wolf predation within availability data at 2 spatial scales, and quantified variation in resource selection among individual caribou. Energetic cost of movement was the most important covariate for all caribou at a spatial scale defined by seasonal movement. Increasing distance to areas of high wolf risk was more important at the larger spatial scale of home range. Variation was high in the selection of resources among caribou, although commonalities among individuals enabled pooling data on use and availability into 2 selection strategies. Researchers and managers should conduct multiscale analyses with varied definitions of availability, quantify variation among individuals, and pool data into common selection strategies to identify mechanisms of selection and to map a populations selection for resources on the landscape.

Estimates of critical thermal environments for mule deer.

Mule deer (Odocoikus hemlonus hemionus) can be thermally stressed under a wide range of ambient conditions. We developed a model that provides examples of the combinations of wind, solar radiation, and air temperature that may result in thermally critical environments for standing, full-fed adult mule deer during winter in snow-covered and snow-free, open habitats, and in meadows in summer. Critical thermal combinations of environmental variables are shown as 3-dimensional surfaces and tables. Animal size, age, pelage characteristics, and gound cover (height and albedo) further affect the energy costs for thermoregulation by mule deer. The need for habitat managers to consider the provision of thermal cover to reduce beat or cold stress in mule deer depends on the combinations of environmental variables in a particular habitat and geographic location. Implications, limitations, and management consideratiom of our estimates are discussed.

Chemical Composition of Lick Soils: Functions of Soil Ingestion by Four Ungulate Species

Abstract Perspectives on the importance of natural salt licks to ungulates have been broadened beyond the role of providing sodium. This study examined the chemical compositions of wet and dry licks in north-central British Columbia, and defined the benefits of licks to elk (Cervus elaphus), moose (Alces alces), Stones sheep (Ovis dalli stonei), and mountain goats (Oreamnos americanus). We analyzed soils for buffering compounds (carbonates) and estimated available elements from extractions with solutions at a low, digestive-tract pH. Even though the 2 types of licks are visually distinct, with different concentrations of chemical components, they serve similar functions as concentrated sources of sodium, carbonates, magnesium, and sulfate. Sodium and sulfate concentrations were typically higher at both wet and dry licks than control sites. Carbonates and magnesium were elevated in soils from dry licks and magnesium also was high in inflow waters to wet licks. We estimated elemental intake by ungulates from the composition of forage samples. Forages used by all 4 ungulate species were too low in sodium to meet requirements. Spring and summer forages contained high potassium levels. Licks in our study, therefore, provide ungulates with supplemental sources of sodium that are particularly beneficial to offset increasing demands during lactation and with carbonates to help stabilize rumen pH after forage changes in spring. Supplemental sources of magnesium may be actively sought by ungulates when high levels of dietary potassium affect absorption. To assess the importance of clay in soils ingested at licks, we determined the clay mineral types at licks and compared the buffering capacity of clay-filled fecal material collected at licks with fecal material collected away from licks. Further studies are needed to define the roles of clay in improving forage palatability and digestibility.

USE OF NATURAL LICKS BY FOUR SPECIES OF UNGULATES IN NORTHERN BRITISH COLUMBIA

Abstract Use of licks influences the movements and distribution of ungulates. We recorded attendance patterns, duration of visits to licks, and time spent licking by 4 ungulate species at wet and dry licks to examine possible influences on the timing of use of licks in northern British Columbia, Canada. Within-species licking intensity (based on regressions between time spent licking per visit and duration of visits to licks) was higher for elk (Cervus elaphus) than for moose (Alces alces) at wet licks, and higher for mountain goats (Oreamnos americanus) than for Stones sheep (Ovis dalli stonei) at dry licks. Lick response variables (duration of visits to licks, time spent licking per visit, and proportion of time spent licking) did not vary significantly among early, mid-, and late summer seasons, but there were species-specific differences in the timing of highest attendance. High use of wet licks by both female and male elk in late May followed vegetation greening at low elevations. Average attendance by female elk was highest in late June, coinciding with high lactation demands. Attendance by moose at wet licks was highest in mid-July, potentially coinciding with other aspects of forage phenology such as increased plant defensive compounds. Attendance by Stones sheep and mountain goats at dry licks was high in early July, following forage change at high elevations and again in early August, potentially related to the trade-off between lactation demands and predation risk. Across species, consumption of lick soils allows ungulates to improve rumen function and nutrient absorption during the transition to spring and summer forage and to supplement elemental intake by females during the nutritional stress associated with lactation.

Behavioural trade-offs in response to external stimuli: time allocation of an Arctic ungulate during varying intensities of harassment by parasitic flies

1. Macroparasites may be a major factor shaping animal behaviour. Tundra ecosystems inhabited by caribou and reindeer (Rangifer tarandus) are known for large concentrations of ectoparasites including mosquitoes (Culicidae) and black flies (Simuliidae), as well as endoparasitic oestrid flies (Oestridae). 2. Increased intensity and duration of insect harassment because of climatic warming is hypothesized as a potential factor in recent declines of Rangifer across the circumpolar north. Although there is a well-observed relationship between insect harassment and caribou/reindeer behaviour, the influence of ecto- relative to endoparasitic species is unclear. Climatic changes may favour the activity patterns, distribution or abundance of certain insect species; thus, understanding differential effects on the behaviour of Rangifer is important. 3. We recorded caribou behaviour using group scan and focal sampling methods, while simultaneously trapping insects and recording weather conditions on the postcalving/summer range of the Bathurst barren-ground caribou herd in Northwest Territories and Nunavut, Canada, during 2007-2009. 4. We developed statistical model sets representing hypotheses about the effects of insects, weather, habitat/location, and date/time on caribou behaviour. We used multinomial logistic regression models to explore factors affecting the relative dominance of behaviour types within groups of caribou and fractional multinomial logistic regression models to determine factors influencing time allocation by individual caribou. We examined changes in feeding intensity using fractional logistic regression. 5. Relative dominance of insect avoidance behaviour within caribou groups and time allocation to insect avoidance by individual caribou increased when oestrid flies were present or black flies were active at moderate-high levels. Mosquito activity had relatively little effect on caribou behaviour. Time spent feeding was reduced by the greatest degree when all three insect types were present in combination. Feeding intensity was influenced to a greater extent by the accumulation of growing degree days over the course of the postcalving/summer season than by insect activity. Changes in Arctic systems that increase the activity/abundance of ecto- and endoparasites could have implications for the productivity of Rangifer populations.

Habitat selection by female Stone's sheep in relation to vegetation, topography, and risk of predation

ABSTRACT Stones sheep (Ovis dalli stonei) are susceptible to anthropogenic disturbances, but few data have been available to help minimize impacts. We used the movements of individuals to define use and availability, and resource-selection functions (RSF) and the information-theoretic approach to examine seasonal habitat selection and interannual variation in selection of attributes by groups of Stones sheep. Movement rates of Stones sheep followed consistent yearly patterns, with highest rates occurring in summer and fall. Models that contained vegetation, topography, and risk of predation best explained resource selection. Topographic features ranked better, however, than components of vegetation or risk of predation from grizzly bears (Ursus arctos) and wolves (Canis lupus) at explaining habitat selection. Selection strategies were variable among groups of Stones sheep and between years within groups even though consistencies in selection for steep slopes, ridge-like topography, south aspects, and upper elevations were common. This research provides the first comprehensive analysis of habitat selection by Stones sheep, which show strong fidelity to seasonal ranges but also exhibit behavioural plasticity in selection of attributes within those ranges. Nomenclature: Hultén, 1974; Nowak & Paradiso, 1983.

Reliability of Motion-Sensitive Radio Collars for Estimating Activity of Black-Tailed Deer

Radio collars containing motion-sensitive devices were attached to four adult black-tailed deer (Odocoileus hemionus columbianus). Comparisons between telemetric data and concurrent visual observations of animal behavior were made to evaluate the extent that the equipment could reliably predict activity. Mercury tip-switch devices containing a 12-minute, motion-reset switch and variable-pulse collars that varied pulse rates instantaneously with amount of movement were tested. Pulse-rate patterns were broadly indicative of activity level but could not be used to identify specific behaviors. The tip-switch collar was found to be more accurate in predicting overall activity budgets. Proportion of time active could not be estimated from these telemetry data with greater than 90% accuracy (P < 0.05) for the tip-switch collars and 75% for the variable-pulse collars. The variable-pulse collar provided a poorer estimate of activity and was more difficult to radio-locate; the reliability of the motion-reset circuit in the tip-switch collar was questionable. J. WILDL. MANAGE. 49(4):951-958 Radio-instrumentation is often the major means of obtaining location and activity information about species whose habitats or circadian rhythms impede visual observations. Use of a particular nest-site or lodge by some species may enable estimation of activity patterns from radiolocations alone (Lancia and Dodge 1977), but often this has not been possible for freeranging animals. Activity estimation from interpretation of signal quality as discussed by Cochran and Lord (1963) has been widely used (Lindzey and Meslow 1977, Lancia et al. 1979, and Erlinge 1980 among others). However, Singer et al. (1981) concluded that radio signal strength provided a poor index to the activity of European wild boar (Sus scrofa). Knowlton et al. (1968) suggested use of motion-sensitive switches in telemetry transmitters to quantify animal activity. These devices have since received wide application (e.g., Kolz et al. 1973, Garshelis and Pelton 1980). Two types of motion-sensitive transmitters are in use. Tipswitch devices alter the transmitted pulse rate using a mercury-switch to indicate changes in collar position, either from side to side or from head-up to head-down, depending on switch orientation. Reset-collars transmit one of two discrete pulse-rates depending on the presence or absence of movement during a specified interval. Garshelis et al. (1982) equipped 61 black bears (Ursus americanus) with both sensor types and provided criteria for determining activity based on pulse-modes for each. They concluded that tip-switches were more useful in making continuous judgements of activity and that they might be used to differentiate types and degrees of activity. Actual activity was not known, however, and tests were based on correlations between distance moved per hour and activity as indicated by criteria applied to collar pulse