Introduction

A strikingly marked and conspicuous bird of the cold, shrub-steppe environment of western North America, the Black-billed Magpie has attracted much attention and had a colorful association with early Americans. It frequently followed bison-hunting Native Americans and lived on the refuse of their hunts (Houston 1977). When Lewis and Clark first encountered magpies in 1804 in South Dakota, these birds were bold, entering tents to steal meat and taking food from the hand (Ryser 1985).

Twelve subspecies of magpies are found throughout northern Europe and Asia, with probable connections via the Bering Land Bridge to Black-billed (P. p. hudsonia) and Yellow-billed (P. nuttalli) magpies in western North America. North American Black-billed Magpies are more similar to Yellow-billed Magpies (e.g., in vocalizations) than to Eurasian magpies.

Eurasian Black-billed Magpies are well known for their ceremonial gatherings in early spring. Interpreted as territorial probings by dominant young birds, these gatherings have never been observed in either of North America’s magpie species, probably owing to fundamental differences in the types of territories they hold. Because of the marked differences in social behavior and spacing between North American magpies and those from Europe, Birkhead (1991) has suggested that they should be separated as distinct species, an opinion echoed by Zink et al. (1995), who examined mitochondrial DNA and suggested that multiple species exist within Black-billed Magpie as presently constituted.

Research on reproductive success and predator interactions of magpies in North America was conducted in South Dakota by Buitron (1983a, 1983b, 1988). A series of manipulative feeding experiments were done in Edmonton, Alberta, by Dhindsa and Boag (1990, 1992), Dhindsa et al. (1989a, 1989b), Hochachka and Boag (1987), and Komers and Boag (1988). Further field experiments were conducted in Utah by Reese and Kadlec (1982, 1984, and 1985). Finally, social dominance and communication has been explored in Idaho by Moholt and Trost (1989), Trost and Webb (1997), and Stone and Trost (1991a, 1991b).