PROTECTING BEVERLY AND QAMANIRJUAQ CARIBOU
AND CARIBOU RANGE

A. The Importance of Water Crossings to Caribou

Water is an important environmental component in the life of caribou. Waterbodies are numerous throughout the Beverly and Qamanirjuaq caribou range, and cover an especially large portion of the Beverly herd's winter range.

In summer, open water can be a barrier to caribou. Caribou are reluctant to swim across large lakes, wide rivers, and rapids with high waves provided that easier crossing points are nearby. There are several accounts of many caribou drowning when crossing lakes and rivers. Circumstances include strong winds that create large waves and severe rapids and falls. For example, biologists have documented caribou that drowned crossing the middle of Aberdeen Lake and in rapids and falls on the Hanbury River.

Water also provides benefits to caribou in summer. In July, caribou seek relief from insects and high temperatures by grouping down wind of lakes. They escape from wolves by running into lakes and rivers. Some injured caribou remain by lakes until their condition improves.

Caribou have movement patterns that have evolved because they enhance reproduction or reduce the death rate, or both. There is a need to cross rivers in order to travel where environmental conditions are best in most years. There is a system of permanent trails on the tundra that indicate travel routes used for thousands of years. Such trails indicate preferred and alternative routes to caribou with no previous experience in the area.

Where large lakes are found along rivers there are certain crossing points that caribou must use to gain access to the best habitats. Even where large lakes do not occur there are locations on rivers more favorable to cross than others. (For instance, narrower portions require a shorter swim.) At times, parts of rivers may be clogged with ice or have snow or ice ledges that overhang the water.

If they cannot cross at these preferred sites, caribou must double back and cross at some other location. As a result, they must travel further and expend more energy to get to where they want to go, or they are diverted to less favorable range.

Ice crossings are less of a concern. An exception is during ice formation or if there is a warm period after formation of thin ice. There are periods in the autumn when caribou fall through the ice and sometimes die of exhaustion attempting to get out. In November 1982, a large proportion of caribou sampled by biologists at Porter Lake had bruises on their legs from escaping a dunking through thin and rotting ice in late October and early November.

In winter, caribou travel across frozen lakes and lowlands between them. They rest on lakes when not feeding in nearby forests. The benefits of frozen lakes include ease of travel and some security from wolves.

Caribou should not be disturbed at water crossings. Caribou sometimes gather at a crossing for hours before they cross. At times, any disturbance can move them away from the crossing area. Once a large number of undisturbed caribou have successfully crossed, others are likely to follow. Caribou may be able to alert others of danger by certain odors (pheromones) from scent glands in the feet. Hunters in Baker Lake stated that they would not disturb caribou where they entered the water and would permit some caribou to cross before starting to hunt.

Many crossing sites remain unmapped. Caribou cross hundreds of rivers, streams, narrow lakes and arms and bays of lakes in the course of spring, summer, and autumn.

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