Tree Swallow Banding Near Saskatoon, Saskatchewan

efore the settlement of the nearly treeless plains of southern Saskatchewan (Houston and Bechard 1983), cavity nesting birds such as the Mountain Bluebird (Sialia currucoides) and Tree Swallow (Tachycineta bicolor) were uncommon because of the lack of nest sites.They depended on decayed stumps and in the case of the bluebird, crevices in clay cliffs.Settlement brought telephone poles and fence posts with holes dug by Northern Flickers (Colapres auratus), mail boxes, twine boxes on binders, and crevices in buildings.These made excellent nesting sites, resulting in increasing numbers of Mountain Bluebirds and Tree Swallows (Houston 1977).Unfortunately, House Sparrows (Passer domesticus), followed in the 1940s by European Starlings ISturnus vulgaris), also increased in number, and gradually usurped most of the sites suitable for Mountain Bluebirds.The lack of nest sites, and the resultant decrease in bluebird populations, motivated Dr. Jack Lane of Brandon, Manitoba, and his Junior Birders, to build and set out nest boxes, each with an entrance hole 1.5 inches in diameter, too small to admit a starling.Observing Lane's success, Lorne Scott of Figure 1.Map of Prairie Bluebird Trail from Denholm, ß Glaslyn Indian Head, Saskatchewan, began building boxes and connected with Lane's trail in 1968.The Saskatoon Junior Natural History Society began a trail that met with Scott's in 1970 at Raymore, 120 miles southeast of Saskatoon (Scott 1970, Houston 1971).By 1975 there were about 2500 miles of connecting trails with the extremities (at Denholm, near North Battleford, Saskatchewan, and Winnipeg, Manitoba) about 600 miles apart (Figure 1).For a few years we tried to monitor all boxes on the western portion of the trail, as far east as Raymore, but after 1973 we restricted regular visits to those 250 (on average) boxes between Delisle and Hanley.This regularly studied portion of the trail, from northwest to southeast, is 76 miles long, 36 miles on the west side of the South Saskatchewan river and 40 east of the river.All of these boxes are within 40 miles of Saskatoon, and the most distant extremities are 48 miles apart (as the bluebird flies).Our boxes are placed on fence posts.To minimize their use by the House Sparrow and House Wren (Troglodytes aedon), they are positioned away from farm yards and preferably at a distance from trees or bushes.When the boxes are placed along busy roads, there is less temptation for vandals to stop and investigate.The boxes are Saskatchewan to Winnipeg, Manitoba.

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