PROTECTING BEVERLY AND QAMANIRJUAQ CARIBOU
AND CARIBOU RANGE

Data Limitations for Defining Important Habitats

The information used to produce the maps in the map atlas on this CD-ROM (Part 2) and in the report (Part 1) are subject to several limitations, which are outlined briefly below. These limitations should be taken into account by anyone using these maps to assess the importance of areas or habitats to Beverly and Qamanirjuaq caribou.

A. General Limitations

1) Information sources - Information was obtained from government files and reports, and is based primarily on the results of aerial surveys and satellite-monitoring studies of caribou locations.

Much additional information could be acquired from unmapped descriptions of caribou distribution in reports and government files, and from people in communities who have knowledge of caribou range use patterns.

2) Data availability - Limited and variable amounts of scientific data on caribou distribution and movements exist for caribou life cycle periods. Information was available from government surveys between 1940 and 1995 (a 56-year interval) for a given life cycle period for 25 years at most, and for as little as 3 years.

Survey data were available for both the Beverly and Qamanirjuaq caribou herds for more than 20 years during spring migration, calving, and late winter periods, and for less than 10 years during late summer and fall migration/rut periods.

Information was available on location and movements of female caribou monitored by satellite radio-collars for all life cycle periods for 4 years (1993-1997). Data were available for 12 Qamanirjuaq caribou in total (2-7 at any particular time) during this period, and for a single Beverly caribou for 2 years (1995-1997).

3) Surveys as "snapshots in time" - Surveys typically identify areas used by caribou for only a small portion of a given life cycle period. Surveys primarily provide information about caribou distribution and movements during the survey period (usually a few days) and for a limited time immediately before the survey (such as movements indicated by recently-used trails).

Caribou travel throughout most of the year, however, and movements vary during each life cycle period (from the least during the calving period to the most during spring and fall migration).

More continuous information on caribou locations during all life cycle periods is needed, and could be provided by monitoring additional caribou equipped with satellite radio-collars over several years.

4) Variability in geographic coverage - Survey information often provides a very incomplete picture of range use by a caribou herd, even for limited time periods. Some surveys determine the location of most caribou of specific sex and age classes (such as adult females with calves), and therefore identify most or all of the area used by that portion of the herd at a particular time. (An example would be calving ground surveys at the peak of calving.)

Other surveys examine restricted geographic areas determined by provincial/territorial borders or limited budgets, and do not identify the total area used by even a portion of the herd at a particular time. (An example would be some monitoring flights conducted for the Caribou Monitoring Program.)

More information on the total range used by adult female caribou during each life cycle period could be provided by monitoring additional caribou equipped with satellite radio-collars over several years.

5) Variability in mapping precision - Reference materials do not provide consistent information for mapping because of differences in the scale of mapping, type of information provided (such as point locations vs. general areas), accuracy and precision of mapping, degree to which information has been generalized, availability of information about surveys (such as survey areas and flight lines), and other factors.

For example, winter range mapping is based on a variety of sources and types of information, including:

• Systematic transect surveys conducted on the Beverly winter range in the southern NWT from 1979/80 to 1987/88.
• Systematic transect and unsystematic "spaghetti" surveys of caribou winter range in northern Saskatchewan from 1980/81 to 1986/87. This information was compiled, supplemented with reports of caribou distribution from communities, and generalized. Information was primarily available for Beverly caribou, but included an area in northeastern Saskatchewan that has been used as winter range by both caribou herds, where herd identity of observed caribou was often not known.
• Unsystematic "spaghetti" surveys of caribou winter range in northern Manitoba and southern Nunavut from 1977/78 to 1989/90. Information was primarily available for Qamanirjuaq caribou, mostly along river valleys in Manitoba. It also included an area in northwestern Manitoba that has been used as winter range by both caribou herds, where herd identity of observed caribou was often not known.
• Localized distribution of Beverly caribou during classification counts conducted in late February to early March 1990-95 in southern NWT.
• Maps published in early government reports that show generalized caribou distribution over an often unspecified period during winter, based on an unspecified number and type of surveys. When compiled for mapping, this type of information tended to mask the greater precision of later surveys which distinguished specific areas used vs. not used by caribou during particular times.

The scale of maps on which this information was provided ranged from 1:250,000- to smaller than 1:2,000,000-scale, and the quality of maps varied to a similar degree.

6) Importance of specific areas - The importance of specific areas to caribou cannot be determined in most cases, as we do not have enough information on the particular areas used by caribou, or where caribou were present and absent during surveys. We also do not have information on long-term (over many years or decades) range use patterns, so we cannot identify which specific areas or habitats are used most often.

Some of this information could be collected by placing large numbers of satellite radio-collars on caribou and monitoring them for many years.

B. Limitations of Satellite-monitoring Data

Broad generalizations should not be made about patterns of movement and distribution of Beverly and Qamanirjuaq caribou based on the satellite-monitoring data. During the satellite-monitoring study from March 1993 to May 1997, at any particular time a maximum of only 8 female caribou were monitored, primarily from the Qamanirjuaq herd (one of these caribou was apparently from the Beverly herd).

Although the information collected by satellite-monitoring provides insight into seasonal and annual patterns in movements and distribution for several female caribou, it does not indicate the full extent of range use by these herds, which include a total of approximately 780,000 caribou. (1994 estimates were 496,000 Qamanirjuaq caribou and 276,000 Beverly caribou.)

C. Limitations of Water and Ice Crossing Data

Knowledge of water and ice crossings and their importance to caribou is limited. Many water crossings used by Beverly and Qamanirjuaq caribou have been documented and are identified in the map atlas on this CD-ROM. However, many other sites are used by caribou to cross water bodies across the caribou range.

It is difficult to predict use of crossing sites by caribou or to assess their importance to caribou herds. Changes in herd sizes, migration routes, and locations of calving grounds result in variable use of crossings from year to year. Information on frequency and regularity of use of water crossings by caribou is unavailable or very limited for most sites, except those visited traditionally by Aboriginal people or by biologists conducting research.

Information about the BQCMB's system for evaluating the importance of water crossings to caribou.

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