Black-billed Magpie

Permanent resident; an uncommon species during the Minnesota Breeding Bird Atlas (MNBBA).

The Black-billed Magpie has two apparently disjunct populations. The first is located along the southern Pacific coastline of Alaska and in southwestern Yukon Territory and northwestern British Columbia. The second is farther south and ranges across the southern Canadian provinces, from British Columbia east to the southwest corner of Ontario, south in the United States through eastern Washington, Oregon, and northeast California, and east to portions of Kansas, Nebraska, the Dakotas, and northern Minnesota. The species reaches some of its highest breeding densities from central Alberta south to northern New Mexico (Figure 1).

Assigned a Continental Concern Score of 9/20 by Partners in Flight.

The Black-billed Magpie does not engage in regular migratory movements, but individuals may disperse after the breeding season and in the winter months.

An omnivore that feeds primarily on the ground in open areas. Carrion forms a major portion of the diet, as do grains, small mammals, and a variety of ground-dwelling arthropods.

An elaborate nest placed at variable heights within a tree or tall shrub and measuring nearly 2 ft in height and 1 ft in diameter. Its most characteristic feature is the frequent inclusion of a large dome that covers the entire nest; one or more openings are left for the birds to enter.

The Black-billed Magpie has an interesting history in Minnesota. At the time of Roberts (1932), the bird was known only as a “straggler into Minnesota from the west.” He went on to comment that “there are numerous records from 24 counties distributed from the Canadian boundary on the north to the Iowa line on the south, and as far east as Pine and Goodhue counties.” All reports fell within a seasonal window from late September through mid-February, after which the birds retreated west to their breeding grounds in the Dakotas. When the birds appeared in the fall, it was not unusual to observe small groups of magpies traveling together. Roberts is the first to make mention of a major invasion in the fall of 1921, when he received reports of 51 individuals, exceeding the cumulative number of records in all prior years. At the time of his writing, there were no confirmed nesting reports, although there were 2 unconfirmed records from Lake of the Woods County (1920) and Marshall County (1921).

The number of reports of Black-billed Magpies continued to increase through the first half of the 20th century. Nearly 25 years after Roberts published his treatise on Minnesota birds, Erickson (1957) provided a comprehensive update on the species’ status. His report included information on each of 9 known specimens in the state (8 deposited at the University of Minnesota, and 1 mounted bird at St. Cloud State University), as well as information from an extensive network of observers and resource professionals across the state. Records were documented from 43 counties, which were dispersed throughout all but extreme northeast and southeast Minnesota. He also reported on the state’s first confirmed nesting record. In 1951, a nesting pair was documented in Eland Township of Beltrami County, just east of Upper Red Lake. In addition to the 1921–1922 invasion that Roberts (1932) reported, he noted three additional invasions, in the fall and winters of 1936–1937, 1949–1950, and 1954–1955. The magnitude of each invasion was still rather small, averaging 20 to 50 birds reported each time. In between these years, birds continued to appear during the fall and depart the following spring but in far fewer numbers. Erickson speculated on the causes of these annual movements. Was it a partial migration? Was it a normal population expansion? Was it young-of-the-year birds wandering after their post-juvenal molt? He ended his musings with a plea for further study.

Although the birds continued to occur more regularly in the fall and winter, the number of observations during the summer months was sparse. Burger and Howe (1971) identified just 4 summer records that had been reported since Erickson published his paper in 1957. They included records in Polk County (1965), Lake County (1966), Roseau County (1967), and Marshall County (1970). Twenty years would pass until the second confirmed nesting was documented in the state. In just one summer season, in 1971, there were 3 confirmed nesting reports in Marshall County (Burger and Howe 1971).

When Green and Janssen prepared their account of the magpie’s status in 1975, they classified the species as a migrant, a winter visitor, and a casual summer resident. Major fall invasions continued to occur approximately every 10 years. They observed that invasions that occurred in the 1920s and 1930s “came into the state from the southwest; since the 1940s migration and invasions have come into the state from the northwest.” In addition to the confirmed nesting records from Beltrami and Marshall Counties, nesting was documented in Clay County in 1972 and in Roseau County in 1973. During the summer, the magpie was considered a casual resident in these 4 counties, where they nested, and in nearby Clearwater and Polk Counties.

By the time Janssen (1987) prepared a further update on the status of Minnesota birds, Black-billed Magpies had been confirmed nesting in 6 northwestern counties since 1970 (Kittson, Marshall, Norman, Pennington, Polk, and Roseau) and farther east in Aitkin and St. Louis Counties. Over a period of 25 to 30 years they had become firmly established as a permanent resident in northwestern and north-central Minnesota and in portions of northeastern Minnesota. Janssen reported on several more fall invasions. During the winter of 1972–1973, the birds were sighted as far east as Hennepin County, northeast to Cook County, southwest to Cottonwood County, and southeast to Goodhue County. By 1998 Hertzel and Janssen had added Pennington County to the list of counties where nesting had been confirmed since 1970.

The Minnesota Biological Survey reported 195 breeding season locations before they initiated survey work in the north-central region of the state (Minnesota Department of Natural Resources 2015). In addition to records from St. Louis and Aitkin Counties in northeastern Minnesota and records from numerous counties in the far northwest, there was a remarkable concentration of records in Clearwater County and southern Beltrami County, together accounting for nearly one-third of all observations.

During the MNBBA, observers reported 551 records of Black-billed Magpies from 7.2% (345/4,781) of the surveyed atlas blocks and from 8.5% (199/2,337) of the priority blocks. Breeding was confirmed in 60 atlas blocks (Figures 2 and 3; Table 1). The birds were observed in 22 of Minnesota’s 87 counties and were confirmed breeding in 17 counties. Nine counties were additions to the list published by Hertzel and Janssen (1998): Becker, Cass, Clearwater, Crow Wing, Itasca, Koochiching, Mahnomen, Norman, and Red Lake. The birds remained most abundant in the Tallgrass Aspen Parklands Province but were regular as far east as St. Louis County and as far south as Aitkin County. During the atlas there was 1 sighting as far south as southern Stearns County (Figure 2).

The predicted breeding distribution map generated by combining MNBBA occurrence data with data on climate, habitat availability, and landscape context also shows the Black-billed Magpie’s strong association with the Tallgrass Aspen Parklands Province, extending east into the Agassiz Lowlands Subsection (Figure 4). Scattered pockets of predicted moderate and low abundance occur farther east and south of this area, extending to central St. Louis County in the east, and to Morrison and Mille Lacs Counties in the south.

In the course of 100 years, the Black-billed Magpie has gone from being a rare but regular straggler in western Minnesota to a regular, permanent resident throughout northwestern and north-central Minnesota. The changes witnessed in Minnesota likely are part of the species’ recovery from earlier declines and range contractions. Prior to European settlement, the magpie had a close relationship with many of the Great Plains tribes, resulting in part from the birds’ habit of following bison hunts and taking advantage of scraps left in each hunt’s wake. As bison were slaughtered by the new settlers, the magpie’s range receded (Trost 1999). At the same time, its reputation as “vermin” led to wide-scale persecution. In North Dakota alone, bounty was paid on approximately 10,500 magpies each year from 1950 through 1956 (Erickson 1957). Despite these early setbacks, the bird has expanded its range in a number of areas, including east in Minnesota, south in Arizona, and north in areas of Canada where the unbroken boreal forest has been opened with increasing development (Trost 1999).

*Note that the definition of confirmed nesting of a species is different for Breeding Bird Atlas projects, including the definition used by the Minnesota Breeding Bird Atlas, compared with a more restrictive definition used by the Minnesota Ornithologists’ Union. For details see the Data Methods Section.

In the Great Plains the Black-billed Magpie is an open-country bird. During the breeding season, it selects riparian areas with dense thickets of trees and shrubs. Shelterbelts associated with farmsteads, particularly with livestock, also provide suitable habitat (Trost 1999). Many of the magpies nesting in northern Minnesota are nesting and roosting close to small settlements or in thickets or shelterbelts close to small farms (Figure 5). Because it is a ground forager, open grasslands and fields are an important feature of their year-round habitat. MNBBA habitat data collected at point count localities demonstrate the species’ affiliation with grasslands and croplands (Figure 6).

Data collected by the federal Breeding Bird Survey (BBS) have been used to generate a population estimate for the North American Black-billed Magpie of 6.1 million breeding adults (Rosenberg et al. 2016). In 2013, biologists estimated that Minnesota supported approximately 0.40% of the continental population (Partners in Flight Science Committee 2013). Applying that percentage to the most recent population estimate establishes a statewide population of approximately 24,000 adults.

The Black-billed Magpie is on the eastern periphery of its range in Minnesota, and densities are relatively low compared to states and provinces farther west in the core of the species’ range (Figure 1). In Minnesota, an average of less than 1 bird is observed per BBS route in the state each year. In the Boreal Taiga Plains, an ecological region that stretches from Canada’s Northwest Territories south through northern British Columbia, Alberta, central Saskatchewan, and Manitoba, an average of 25 magpies are observed per route. In the United States, the highest numbers are seen in Colorado (an average of 18 per route) and Idaho (an average of 21 per route) (Sauer et al. 2017). Local nesting densities range from 2 per km² in South Dakota to 35 per km² in Idaho (Trost 1999).

BBS data demonstrate a significant population decline across the magpie’s range since the survey began in 1966. From 1966 through 2015, the species declined an average of 0.49% per year; in the past 10 years the population data suggest a more stable trend (Figure 7). Factors responsible for the range-wide decline are unknown, but a reduction in brood size is apparently widespread due to starvation, either related directly to food availability or to disturbance at the nest site. Trost (1999) suggests that the current decline in the magpie population is due to their sensitivity at nest sites resulting from years of persecution. Predation on young is also high, averaging 24% to 30% (Trost 1999).

The continental decline contrasts strongly with the population trend in Minnesota. Although the species’ relatively low abundance in the state compromises statistical analysis of the statewide population trend, the species has clearly experienced a rather remarkable increase in numbers, especially in the past 30 years (Sauer et al. 2017). Its expansion into Minnesota may be a consequence of increased protection throughout the species’ range. Populations in neighboring North and South Dakota, however, have experienced significant declines since 1966.

The Black-billed Magpie is not a conservation priority at either the national or state level and has been assigned a moderate Continental Concern Score of 9/20 (Rosenberg et al. 2016). As noted earlier, for many years magpies were considered “vermin” because of their consumption of carrion, their opportunistic feeding on game birds and poultry, and their habit of picking parasites from large mammals. There are many accounts of the birds repeatedly pecking open wounds on horses and mules in their pursuit of parasites until the animals died (Linsdale 1937). For years, western states paid bounties for both the birds and their eggs.

The Black-billed Magpie has been classified a “climate endangered” species by the National Audubon Society. Despite its adaptability to human-modified landscapes, the species’ range is relatively restricted. Audubon biologists found that climate and geography may restrict the species’ overall distribution, as it seems to prefer cooler climates in western regions. Models predict that as temperatures warm, the magpie could lose nearly 86% of its current breeding range by the year 2080 (Langham et al. 2015; National Audubon Society 2017).

In the interim, the opportunities for Minnesotans to capture a glimpse of this remarkable bird continue to increase. And only a brief glimpse of its striking plumage is necessary to positively identify it as a Black-billed Magpie!