Blue Jay

A regular breeding resident, migrant, and permanent resident throughout Minnesota. Some individuals migrate, and some remain as year-round residents; individual birds may change their migratory status from year to year. The Blue Jay was a very abundant species during the Minnesota Breeding Bird Atlas (MNBBA).

Broadly distributed across central and eastern North America, the Blue Jay is found in southern Canada, from eastern British Columbia east to Newfoundland, and in the United States, from the northern Great Plains, south to Texas, and east to the Atlantic coast. High breeding densities can be found in portions of the Great Lakes states, including Minnesota. The highest breeding densities, however, are found along the southern Gulf coast (Figure 1).

Assigned a Continental Concern Score of 8/20 by Partners in Flight.

Resident or short-distance migrant; less than 20% of the population is believed to be migratory.

Despite its reputation as a robber of young birds and eggs, it feeds primarily on arthropods and nuts; eggs and young birds are occasionally taken. The Blue Jay is a ground gleaner and hawker.

Open-cup nest in a deciduous or coniferous tree.

The Blue Jay has long been considered a common, year-round resident in Minnesota. Roberts, in his comprehensive account of the species in 1932, includes a quote from Jonathan Carver, who was exploring the region in 1766 and 1767 and remarked, “Upon the whole this bird can scarcely be exceeded in beauty by any of the winged inhabitants of this or other climates.”

Regarding the species’ status in Minnesota, Roberts made two specific comments. First, he noted that the Blue Jay was a breeding species throughout the state but was less abundant in extensively forested landscapes. Instead, it was more common in “settled” areas, where it could easily take advantage of waste grains and cultivated fruits. Second, he included a list of 20 banding reports that provided evidence that many Blue Jays were year-round, permanent residents in the state. “If there is a winter southward movement, it is limited to only a portion of the birds.” At the time, he had compiled confirmed nesting records (nests with eggs) from 7 counties stretching across southern, central, and northwestern Minnesota: Crow Wing, Hennepin, Isanti, Meeker, Polk, Sherburne, and Stearns. An inferred nesting report (nest only) was reported from Goodhue County.

In their updated account of the species’ status, Green and Janssen (1975) again noted the species statewide distribution but made no comment about its relative abundance in the northern regions other than to comment that it was less abundant there during the winter months. Although it was considered to be both a permanent resident and a regular migrant, it was not entirely clear if the birds present at a given site in the winter were the same birds that summered there, or were instead migrants. Janssen (1987) referenced recent studies that suggested that young birds in the population migrated but also remarked that in more northern regions both the adults and the young moved south each winter.

One objective of a three-year study of Blue Jays at the Cedar Creek Ecosystem Science Reserve in Anoka and Isanti Counties in the early 1980s was to address the very question of migration (Hilton and Vesall 1980). Unfortunately, after three years of field work, which included color-banding nearly 1,000 jays, the population crashed, and the work was terminated. A brief, unpublished summary of the findings noted that Cedar Creek supported year-round breeding residents as well as migrants that bred on the site. The residents bred earlier then the “apparent” migrants, and their reproductive success was higher. Most of the 276 nestlings that were banded either dispersed or perished; very few overwintered on the site (Hilton 2016).

Despite numerous studies, the true nature of the Blue Jay’s migratory behavior remains as elusive today as it was in Roberts’s time. Smith and her colleagues (2013) summarized what is undisputed: (1) some individuals are present year-round throughout their range, (2) the proportion of the population that migrates is likely 20% or less, and (3) age does not appear to be a factor in determining which birds migrate. Indeed, studies have shown that some individuals migrated for the first time more than five years after they were banded (Stewart 1982; Hickey and Brittingham 1991). Other studies have suggested that the tendency for northern birds to migrate has subsided in response to the availability of food supplied by bird feeders (Smith et al. 2013). Although this may be influencing local populations in more residential areas, the number of Blue Jays observed migrating south at the Hawk Ridge Bird Observatory in Duluth, Minnesota, certainly indicates that a significant number of northern birds move south each winter. From 2007 through 2016, the number of migrant Blue Jays has ranged from a low of 15,077 birds (2008) to a high of 66,647 (2015); the 10-year average approximates 36,000 per year (Karl Bardon, pers. com).

As the work on Blue Jay migration unfolded, Minnesota field observers continued to document the species’ breeding distribution and status. Janssen’s 1987 account included a statewide distribution map that delineated 37 counties where nesting had been confirmed since 1970. By 1998, nesting had been confirmed in 10 additional counties, most located in southern and central Minnesota (Hertzel and Janssen 1998). Field work conducted by the Minnesota Biological Survey (MBS) beginning in the late 1980s further documented the Blue Jay’s statewide distribution. Among the 2,493 breeding season locations the MBS identified were several hundred records in the Arrowhead counties of Cook, Lake, and St. Louis (Minnesota Department of Natural Resources 2016).

During the MNBBA, observers reported a total of 6,321 Blue Jay records in 64.2% (3,067/4,778) of the surveyed atlas blocks and in 81.3% (1,900/2,337) of the priority blocks. Breeding evidence was documented in 422 blocks (Figures 2 and 3; Table 1). The birds were observed in all 87 Minnesota counties and were confirmed nesting in 69 counties. A total of 28 of the counties where breeding was confirmed were additions to the list published by Hertzel and Janssen in 1998. Blue Jays were present in nearly every priority block in the Laurentian Mixed Forest and Eastern Broadleaf Forest Provinces. Although they were common also throughout western Minnesota, they were more sparsely distributed in the Red River valley of the Prairie Parkland Province.

MNBBA data were combined with data on climate, habitat availability, and landscape context to develop a predictive model of the species’ relative abundance across Minnesota (Figure 4). Present in moderate numbers statewide, the Blue Jay is predicted to be just a little less abundant in west-central Minnesota. Scattered areas of higher abundance occur throughout the forested regions of the state but are limited in extent.

If there has been any significant change in the species’ abundance in the past century, it may be that it is now more widely distributed and present in moderate densities throughout the northern forest region. A similar increase in the number of Blue Jays in the northern forested regions was observed in Wisconsin. Uncommon in the pine forests of northern Wisconsin in the early 1900s, the state’s first breeding bird atlas (1995-2000) confirmed the species’ presence in 94.6% of all atlas quads (Cutright et al. 2006). In Michigan, however, the species has been described as an abundant species statewide since the early 1900s (Chartier et al. 2013).

Although few changes have been observed in the core of the species’ breeding range, Blue Jays began expanding west in Canada in the 1940s. Nearly 80 years later, populations continue to expand their range north and west in British Columbia (Dohms et al. 2015). The United States also witnessed an increasing number of reports from many western states, especially in the 1970s, including in Montana, New Mexico, Oregon, and Wyoming (Smith et al. 2013). Several factors have spurred the westward expansion, including urbanization, the prevalence of bird feeders, and dispersal from neighboring states and provinces (Smith et al. 2013).

*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.

The Blue Jay inhabits a wide variety of forested and woodland habitats, ranging from upland mixed deciduous-coniferous forests, to open oak woodlands and oak savannas, to farmsteads, residential areas, and parklands (Figure 5). Open woodlands and forest edges are generally preferred over dense forest stands (Kaufman 1996; Smith et al. 2013).

Although the Blue Jay has long been associated with residential areas in the southern portion of its breeding range, the association is more recent in the northern regions, beginning in the early 20th century. Some studies have linked its abundance in urban areas with the amount of forest cover surrounding cities and towns or the amount of woodlots embedded within the residential landscape. The availability of bird feeders likely also contributes to the suitability of residential areas (Smith et al. 2013).

Because acorns and seeds are common food items, forest stands with many mast-producing trees and shrubs are often favored. Able to transport five or more acorns at a time in its gular pouch and bill, each individual may harvest, eat, or cache several thousand nuts each fall (Darley-Hill and Johnson 1981; Johnson and Adkisson 1985). The Blue Jay’s affinity for caching acorns in the ground, in effect planting each seed, has been considered by some as an important factor responsible for the rapid dispersal of oaks following the latest glaciation. Some biologists have speculated that the bird’s annual movements are best explained by their response to annual production of mast, but studies have failed to demonstrate a correlation at the local or regional scale (Smith et al. 2013).

Habitat data collected at MNBBA point counts where Blue Jays were reported demonstrate the breadth of habitats utilized across Minnesota (Figure 6). Within 200 m of the point counts, upland coniferous forests were the predominant habitat, followed by bogs, pine forests, and lowland coniferous forests. Data collected by the National Forest Bird (NFB) Monitoring Program in northern Minnesota and Wisconsin also demonstrated the species’ tolerance for a wide range of habitats, including upland deciduous, coniferous, and mixed forest stands, lowland hardwoods and conifers, and young regenerating stands (Niemi et al. 2016).

Data gathered by the federal Breeding Bird Survey was used to generate a recent North American population estimate of 17 million birds (Rosenberg et al. 2016). Several years earlier, Minnesota was estimated to support 2.9% of the continental population (Partners in Flight Science Committee 2013). When that percentage is applied to the most recent estimate, Minnesota’s statewide population approximates 493,000 breeding adults. Given the species’ wide vocal array, the lack of any vocalization strongly tied to territory defense, and vocalization by males and females, a statewide population estimate was not generated.

The Blue Jay is a common and widespread species in Minnesota; the average number of Blue Jays on BBS routes in the state is 8 to 9 birds per route per year. In states along the Southeastern Coastal Plain, the number of Blue Jays per route frequently exceeds 30 (nearly 32 per route in Mississippi, 37 in Alabama, and 31 in Georgia; Sauer et al. 2017). Few estimates of local breeding densities are available. At the Cedar Creek Ecosystem Science Reserve north of the Twin Cities, approximately 18 nests or nesting pairs were found per 40 ha, but 73% of the nests were either deserted and/or preyed upon (Hilton and Vesall 1980). On the Chippewa National Forest, an average of 46.33 Blue Jays were detected on 100, 10-minute, unlimited radius point counts; on the Superior National Forest an average of 51.16 were detected (Niemi et al. 2016). This compares to an average of 210.50 Red-eyed Vireos (the most abundant species on the forest) per 100, 10-minute unlimited radius point counts on the Chippewa, and 224.79 Ovenbirds (the most abundant species on the forest) per 100, 10-minute unlimited radius point counts on the Superior. Among the top 20 species in 20 of 22 common forest cover types sampled on both forests, Blue Jays reached some of their highest breeding densities in conifer-dominated stands, including mature lowland conifers on the Chippewa National Forest (an average of 7.64 detections per point count), and midsuccessional jack pine stands on the Superior National Forest (an average of 6.42 detections per point count; Niemi et al. 2016).

Since the BBS began in 1966, data have demonstrated a significant and slow population decline of the Blue Jay across North America, averaging 0.66% per year (Sauer et al. 2017). Although it has shown wide annual fluctuations, the population in Minnesota has shown an overall stable trend line with wide fluctuations (Figure 7). On the Superior and Chippewa National Forests, the Blue Jay has shown a significant increase from 1995 to 2016. The species’ population increased an average of 1.78% per year on the Chippewa, and 1.47% per year on the Superior (Figure 8).

Blue Jays were among the first species to be impacted by the West Nile virus outbreak that began in New York City in 1999, resulting in widespread population declines throughout the eastern United States (Smith et al. 2013). West Nile Virus was first detected in Minnesota in 2002. In just one year, 2003, several thousand dead American Crows and Blue Jays were reported to the Minnesota Department of Health (2004). The impact on both species, especially Blue Jays, was particularly obvious in the Twin Cities metropolitan region.

The factors responsible for the Blue Jay’s long-term decline over the past 50 years are less clear, particularly given their adaptability to residential areas and their wide-scale use of bird feeders. In Minnesota, for example, Blue Jays were the sixth most common visitor to winter bird feeders during the winter of 2015–2016, visiting nearly 85% of the 261 feeder locations that participated in the survey (Cornell Lab of Ornithology 2016).

Although its populations have shown a slow and steady decline, the Blue Jay remains an abundant and widespread species that has readily adapted to human-modified landscapes. As a result, it was assigned a relatively low Continental Concern Score of 8/20 (Rosenberg et al. 2016). Its vulnerability to climate change is considered relatively low (North American Bird Conservation Initiative 2010).

Beloved by backyard bird watchers, the Blue Jay’s reputation is not always that of an exalted member of the bird community. Its predation of songbird eggs and young has been cited as contributing to the decline of some Neotropical migrant songbirds. Evidence regarding the Blue Jay’s overall impact on songbirds is not entirely clear, but at the local level cameras have clearly demonstrated that they can be a major nest predator (Smith et al. 2013).

Described by Audubon as a study in contrasts, its resplendent beauty belying its mischievous nest-robbing behavior, the Blue Jay will likely remain a major inhabitant of Minnesota’s woodlands and forests for many years to come.