USING GIS TO MODIFY A STRATIFIED RANDOM BLOCK SURVEY DESIGN FOR MOOSE

We modified the standard, stratified random block design used typically in aerial surveys of moose (Alces alces). We laid a grid of approximately 9 km2 cells over our study area, and GIS was then used to allocate polygons into one of 2 strata within each grid cell. The 2 strata were based upon vegetation attributes that were predicted to have either high or low moose density from previous research. We assumed that polygons of early seral forest stands (<40 yr), shrubs, and meadows would have high moose density relative to other vegetation attributes. Vegetation polygons were often <1 km2, consequently, single grid cells usually included >1 high and low density polygons. Adjacent cells were amalgamated to produce sample units with >4 km2 of high density stratum area. Real-time navigation was used and the flight track was recorded over a map of sample units, strata boundaries, and topographic features to accurately identify polygon boundaries and assign each sighted moose to the appropriate strata. We concluded that our approach was efficient and effective in fine-grained environments where the relative selection by moose for vegetation patches is well understood, and those patches are mapped in digital databases

Chemical composition of lick soils: functions of soil ingestion by four ungulate species

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), Stone's 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

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 Stone's 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 Stone's 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 tradeoff 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