Blue Jay: A New Look At a Common Feeder Bird

This week, I checked several local birding websites in Idaho, mainly hoping to find reports of unusual owl sightings. Last winter, a Great Gray Owl was regularly seen roosting nearby, and we have also encountered Snowy Owls and Northern Hawk Owls in the region.

This year, however, the real excitement had nothing to do with owls. Instead, many of the reports were about Blue Jays.

Blue Jays (Cyanocitta cristata) are becoming increasingly common in Idaho and other parts of the Northwest, which means they still attract plenty of attention. I grew up in Pennsylvania, where seeing Blue Jays was completely ordinary. In fact, many backyard bird watchers there did not particularly like them. This cannot simply be explained by the idea that people dislike animals because they are familiar. Northern Cardinals are also extremely common, yet they continue to receive plenty of affection from bird enthusiasts. Blue Jays, on the other hand, have a reputation for being noisy, assertive, and dominant.

But is that reputation really justified? I have always been fond of Blue Jays. If you take another look at these birds, you may discover that they are among the most fascinating and attractive visitors you can encounter in your backyard during winter.

Who Rules the Feeder?

Blue Jays are often unpopular at backyard feeders because many people view them as overly aggressive. That criticism is somewhat ironic considering the aggressive history of our own species. Nevertheless, backyard bird enthusiasts often prefer to see numerous supposedly peaceful species feeding together. When a loud Blue Jay suddenly sends other birds scattering, it can seem to ruin that peaceful scene.

At least, that is the common assumption.

Blue Jays are undeniably intelligent and highly adaptable. They belong to the corvid family, which also includes crows and ravens, birds that are widely recognized for their intelligence. Blue Jays display many behaviors that attract the attention of both humans and other birds.

Anyone walking through eastern forests is likely to recognize their loud and sometimes alarming calls. Blue Jays have an extensive range of vocalizations and are particularly well known for copying the calls of Red-tailed Hawks and Red-shouldered Hawks.

There are several theories about why they imitate these raptors, although the scientific explanation remains unsettled. One possibility is that the calls function as warnings, alerting other Blue Jays to potential danger. Another theory suggests that the imitation may help Blue Jays frighten other birds away from food.

Anyone who maintains a bird feeder has probably witnessed the familiar scene: suddenly, the other birds disappear, and one or two Blue Jays swoop in and take advantage of the available food. The strategy appears to work, but usually only briefly, since many of the other birds soon return.

Because of this behavior, Blue Jays are sometimes described as backyard bullies. But their reputation may not tell the whole story.

Blue Jays and Competition

Some commonly repeated accusations against Blue Jays appear to come from individual observations that have been generalized to the entire species. Similar assumptions have been made about other birds, such as magpies, which are often blamed for a wide range of mischief.

One of the most persistent claims is that Blue Jays are major nest predators that routinely raid nests and consume the eggs and young of songbirds. However, research conducted since 1897 indicates that eggs and birds account for only about 1 percent of the Blue Jay's diet.

There are plenty of videos and personal accounts showing Blue Jays eating eggs, but these observations do not mean that nest raiding represents a major part of their overall feeding behavior. Most of their diet consists of insects, seeds, and nuts.

Blue Jays also have an important ecological role because they collect and hide large quantities of acorns. They fail to retrieve many of the acorns they bury, allowing some of those seeds to remain in the ground and contribute to the growth and regeneration of eastern forests. Rather than viewing them simply as destructive birds, it may be more appropriate to recognize their importance to woodland ecosystems.

Their interactions at bird feeders are also more complicated than they initially appear. Research referenced by the Cornell Lab of Ornithology includes a study from Florida showing that Blue Jays are not necessarily the dominant birds at feeders. Red-bellied Woodpeckers, Red-headed Woodpeckers, Florida Scrub-Jays, Common Grackles, and even Gray Squirrels can strongly dominate Blue Jays and may prevent them from accessing food.

The citizen-science project Project FeederWatch has collected extensive information about interactions among birds at feeding stations. The resulting observations reveal that there is considerable competition and movement happening around feeders, and some of the findings are surprisingly complex.

Blue Jays certainly can drive other birds away, but they are far from the only species that behave this way. Studies indicate that body size plays an important role in determining dominance at feeders. In simple terms, larger birds often displace smaller birds.

The most dominant visitor may come as no surprise: the Wild Turkey. Regardless of how assertive a Blue Jay may be, it is unlikely to intimidate a turkey away from a feeding area.

Blue Jays may be especially conspicuous because they are loud, which contributes to their reputation as bullies. Yet smaller and much-loved birds such as chickadees can also repeatedly harass other birds until they leave.

Observations from Project FeederWatch have even revealed complicated relationships between different species. European Starlings, for example, dominate Red-headed Woodpeckers, while Red-headed Woodpeckers dominate Red-bellied Woodpeckers, and Red-bellied Woodpeckers in turn dominate European Starlings. This unusual non-linear hierarchy may help maintain a balance in continental bird populations. Each species competes with another for nesting cavities, but no single species consistently wins every encounter.

Similar interactions can be observed at backyard feeders and in urban parks. Keeping track of these encounters and recording what happens can provide valuable information about how birds behave and interact with one another.

Blue Jay Mysteries

Despite being common and familiar birds, Blue Jays still have many unanswered mysteries. One particularly interesting question concerns their movements and migration.

Most Blue Jays do not migrate. Across much of their range, they remain present throughout the winter. Nevertheless, bird observatories regularly record large groups of Blue Jays moving southward during autumn, especially around the Great Lakes and along the Atlantic Coast.

Why some Blue Jays migrate while others remain in place is still not fully understood. Cornell estimates that fewer than 20 percent of Blue Jays migrate in any given year. Even among those that migrate, individuals do not necessarily make the journey every year.

For a long time, some researchers suggested that migration mainly involved younger birds dispersing from their birthplace, while others proposed that older birds were responsible for these movements. More recent research indicates that both age groups can participate.

Like many other corvids, Blue Jays have complicated social relationships. They frequently form lifelong pair bonds and may remain with their mate throughout the entire year. During winter, they often live in loose groups and appear to maintain some type of social hierarchy.

Even though Blue Jays are familiar backyard visitors, scientists still have much to discover about their social behavior and seasonal movements.

The Spread of Blue Jays

One thing is clear about Blue Jays: their populations are doing well, and their geographic range is expanding.

Recent reports have highlighted dramatic declines in North American bird populations over recent decades. Against that broader trend, Blue Jays represent a comparatively unusual positive example. Their population increased by 28 percent between 1966 and 2015.

Historically, Blue Jays were year-round residents from the eastern United States and Canada westward to the Great Plains. In recent decades, however, they have increasingly appeared during winter in the northwestern United States. Before 1972, they were rare or essentially absent from much of this region.

Although a Blue Jay sighting can still generate excitement among Idaho bird watchers, reports now occur every year. Similar observations have been recorded in Washington, Utah, Montana, and other western states.

Their adaptability is one factor behind this expansion. Blue Jays do particularly well in edge environments created by suburbs, residential areas, and small patches of woodland. They are also enthusiastic visitors to bird feeders.

Conservationists have suggested that as Blue Jay populations increase, some individuals may move into previously unoccupied areas. Historically, a Blue Jay entering the Northwest would have encountered extensive wilderness already occupied by Steller’s Jays and other species.

Today, however, the landscape contains abundant human settlements and fragmented woodland habitats. These environments provide the combination of food, trees, and open spaces that Blue Jays can readily exploit, creating favorable conditions for the species to continue expanding its presence across the Northwest.