In August and September 1998, the Canadian Wildlife Service, Parks Canada, and the Friends of Mount Revelstoke & Glacier initiated a project to monitor local bird-habitat relationships within the Columbia River valley at Revelstoke (CRR), British Columbia. Funding provided by Living Landscapes: Columbia Basin Past, Present and Future made the project possible. The project tested the suitability of several sites in and around Revelstoke for long-term migration monitoring. The CRR Migration Monitoring Station aimed to track population trends of landbirds and to provide local information on their migration and habitat needs. The project also encouraged public communications to inform Columbia Basin residents of the need for bird migration monitoring and to illustrate a variety of methods used to monitor North American birds.

Land bird monitoring stations across North America are cooperative ventures between the Canadian Wildlife Service, Bird Studies Canada and the National Biological Service (formally the US Fish and Wildlife Service), who are responsible for coordinating conservation efforts of bird clubs, government agencies and dedicated volunteers.

Riparian habitat in the Revelstoke area along the original Columbia River, between Mica Dam and Shelter Bay, was evaluated for potential sites to host a fall migration monitoring station. Site selection, conducted in early August, was based on the following factors: accessibility, land ownership, long-term vegetation management, suitability for line transects, censuses, mist netting, and public education opportunities. The location chosen for the pilot project was a small island (at high water) situated in the Upper Arrow Reservoir just north of the Revelstoke Airport runway.

Vegetation on the island varied from cottonwood forest through willow to wet grassland and sedge wetland. The soil was generally sandy loam underlain by gravel. The east side of the island was chosen as the main banding site due to its large concentration of bird activity and species variety.

Components of the banding site include a bird processing area and the mist nets which are situated in individual tracts referred to as net lanes. Mist nets are 2.6 m high by 12 m long and are designed especially for capturing small birds without injury. Twelve net lanes were initially selected, increasing to 19 possible net lanes by the end of the season (Fig.1). Thirteen nets were positioned in the willow and grass fringe on the east edge of the island, with 3 in the willow-cottonwood transition and 3 in the cottonwood forest. These areas were likely to be used as stopover sites by migrating songbirds, particularly warblers, sparrows and thrushes.

A line transect, used for censusing birds, intersected the entire island for a total of 1 km. This marked route is monitored by 2-3 people who walk along the transect and record all birds seen or heard in a strip 100 m wide by 1000 m long.

The CRR Migration Monitoring Station opened from August 8^th- October 3^rd for 42 days of bird banding using the standard-effort method. This method involves operating the station in the same way day-to-day and year-to-year. This includes having the same number of nets opened in the same locations for the same amount of time each day. The use of the standard-effort method allows data to be scientifically compared on an annual basis with other migration monitoring stations across North America.

The CRR station logged a total of 2247 open net hours in 1998 (weather and personnel constraints reduced the actual net hours below the potential maximum). The recorded net hours enables daily totals of species abundance to be standardized, allowing for comparisons by rate of capture (i.e. 4 birds per net hour). Captured birds were removed from the nets and biological measurements were taken in the process of banding. Bird bands are specifically sized metallic strips placed on the leg of the bird. Each band includes a unique number series which internationally identifies individual birds and where and when banding occurred.

Classification of the birds captured included newly banded, unbanded and recaptured. This ensured that those individuals that were caught frequently would not bias the overall results. Upon completion of this banding routine the birds were released at the processing area.

Coordinated by the Friends of Mount Revelstoke & Glacier, this project enlisted the help of over 20 local volunteers, who donated 932 hours in the field and over 200 hours entering and editing banding data in an accessible database format.

In 1998, 2748 individual birds were handled, of which 67.3% were newly banded and 31.1% were recaptures (Fig. 2). A total of 44 bird species were captured, and 42 of these were banded (Fig. 3). Of the captured species, 72.1% are known neotropical migrants and 26.7% are short-distance migrants. The most abundant species caught and banded during the fall migration at CRR was Common Yellowthroat, followed by Yellow-rumped Warbler and Yellow Warbler (Figs. 4, 5, 6,7). These results support the initial assessment that this riparian habitat serves as an important staging ground for migrating songbirds such as sparrows and warblers as well as Traill's Flycatchers. A summary of species captured compared with their census coverage using other monitoring techniques is presented in Appendix I.

Monitoring recaptures as well as newly banded species allows us to estimate the length of time that individuals are spending in the Revelstoke area, feeding and putting on weight for the next stage in their long journey south. Common Yellowthroats for example, have been known to stay in the area for several weeks bulking up their fat supplies. In addition to local recaptures of birds banded at CRR, several foreign banded birds (banded elsewhere than CRR) were caught. One Song Sparrow recaptured at CRR 3 times had been banded earlier in the summer at Skunk Cabbage Boardwalk in Mount Revelstoke National Park, approximately 22 km east of Revelstoke, as a part of another bird survey, Monitoring Avian Survivorship and Productivity (MAPS). Also, a Common Yellowthroat banded at the same MAPS station in 1998 was recaptured at CRR as it traveled through the riparian valleys.

The CRR Migration Monitoring Station was open for public tours throughout the monitoring program. Volunteers explained the objectives and methods of the banding station to visitors while allowing them a first hand look at the banding operation. The Friends of Mount Revelstoke & Glacier Newsletter advertised a call for volunteers, while Parks Canada and Revelstoke Times staff wrote additional informative articles in the weekly newspaper. In October 1998, the Friends of Mount Revelstoke & Glacier sponsored an open house for the community to celebrate the success of the project. Work is currently underway on a school education kit, for children in grades K-5, to be used in combination with a site visit or slide show presentation.

Presentations on the CRR Migration Monitoring Station and other local bird projects will be made to regional elementary teachers at the upcoming Interior Regional Teacher Conference being held in Revelstoke and at the "Birds and Bears Festival" in Golden this May. The data gathered in 1998 has already been used to suggest vegetation restoration beneficial to migrating land birds along the Arrow Lakes Reservoir.

In 1999, the CRR Migration Monitoring station proposes to commit to 10 years of monitoring in the Columbia Basin and become the newest member of the Regional Migration Monitoring Network in B.C. The station will open earlier in 1999, with plans to conduct line transects in May and June to observe spring migrants. Banding is proposed from July 15^th to Sept 15^th, will allow the station to monitor the earlier migration of adult birds. Future plans for CRR include establishing a spring migration monitoring program, the creation of a provincial training centre to encourage skill development of regional banders and volunteers, and potential addition of stable isotope analysis (see below) to allow linking migration corridors to bird breeding areas.

There are many questions to address in migration monitoring. At the station level the aim is to observe the number and species of birds that migrate through the station and how this varies from year to year. But when looking at the ecosystem level, the questions broaden greatly: where are the birds coming from and where are they going? Bird-banding helps us to observe stop-over sites along migration paths and infer general patterns and destinations. But with the lack of sufficient monitoring in the northern breeding areas of Canada and Alaska and southern wintering areas of Central and South America, these questions can not be precisely answered.

The process of identifying migratory patterns and specific breeding locations will be enhanced with future studies using isotopic indicators. Stable isotopes are naturally occurring forms of an element that differ in molecular weight (e.g. C₁₃, C₁₄). Each isotope contributes a certain percentage to the composition of the element in the environment.

These isotopic signatures can be measured by analysis of feather samples and used like a "fingerprint" to mark different environments. When birds moult on their breeding grounds they grow new feathers using the chemical energy of that environment, thus capturing a specific composition of isotopes in their feathers. Therefore, isotope levels in feather samples taken from migrant birds will indicate the location of the bird's breeding grounds. Knowing which areas provide key habitat for target or vulnerable bird species will aid international conservation efforts to address declining neotropical migrant populations in relation to the disturbance and destruction of their natural habitats.

For more information regarding the Columbia River-Revelstoke Migration Station, please contact:

Dr. John Woods
Parks Canada
Mount Revelstoke and Glacier National Parks
P.O. Box 350
Revelstoke, B.C.
V0E 2S0
john_woods@pch.gc.ca

Janis Jarvis
Friends of Mount Revelstoke & Glacier
P.O. Box 2992
Revelstoke, B.C.
V0E 2S0
mtllamas@junction.net