Quick Answer
Steller’s jays are known for being bold, inquisitive, and at times aggressive birds. They have a reputation for taking food from picnic tables and backpacks and swooping at perceived threats near their nests during breeding season. However, their aggression is often misunderstood or exaggerated. Steller’s jays are highly intelligent, social birds that exhibit normal territorial behaviors to protect resources and their young. With some care and basic understanding of their behavior, issues with aggression can often be avoided.
Steller’s Jay Overview
The Steller’s jay (Cyanocitta stelleri) is a large, striking member of the corvid family found along the North American west coast. They range from southern Alaska down through western Canada, Washington, Oregon, and northern California.
Steller’s jays are medium-sized birds, around 12 inches long with a wingspan up to 15 inches. They have dense blue and black plumage on their backs and wings, with black heads and blue feather crests. Their chests and bellies are grayish-white. While shy in undisturbed forests, they are known for being very comfortable around humans when living near developed areas.
Steller’s jays are omnivorous and opportunistic eaters. Their diverse diets include seeds, nuts, fruits, eggs, small animals, insects, and even human food scraps when available. They have strong beaks well-adapted for cracking nuts and acorns.
Steller’s jays form lifelong monogamous pair bonds and family groups of 3-4 birds that cooperate to rear young and defend territory. They are also highly social and intelligent birds that communicate with an extensive array of vocalizations and behaviors. Their brain-to-body mass ratio rivals that of chimpanzees.
Territorial and Nest Defense
Steller’s jays are year-round residents in their territory and thus are highly invested in defending the resources needed to survive and successfully raise their young. Their typical territory ranges from 2 to 10 acres in size. Like most birds, Steller’s jays are especially defensive of the area immediately around their nest when breeding.
Steller’s jays often begin courtship and nest building in late winter or early spring. The female lays between 2-6 eggs which hatch after about 16 days. Young jays leave the nest after another 16-21 days but remain dependent on their parents for 1-2 months. There is only 1 brood per year.
During this whole period – nest building, incubation, and rearing young – jay pairs work hard to protect the nest area from potential threats. The jays harass intruders by loudly scolding, diving and swooping, and even making physical contact. Intruders include other jays, potential nest predators like crows and ravens, and nearby humans. These defensive actions help ensure their young survive.
Aggressive swooping and diving at heads is mostly bluffing meant to startle and intimidate so the intruder leaves the area. Serious injuries from contact are rare. The jays tend to target people who get too close to the nest, which may occur unintentionally. This behavior usually stops within a few weeks after the young leave the nest.
Food Protection
In addition to defending nest sites, Steller’s jays use aggression to protect reliable food sources which are critical to their survival. This food-guarding behavior tends to peak in late summer and fall when food becomes more scarce.
One common trigger is the presence of backyard bird feeders. Steller’s jays will claim a feeder as a food source and attempt to frighten away other birds that try to feed there. Jays have also been known to “raid” unattended human food at campsites and picnics. These actions are motivated by hunger and Survival, not malice.
As with nest defense, aggressive actions around food are mostly loud vocalizations, swooping, bluffing charges, and flashing of their wing patches to startle perceived competitors. Rarely is physical contact made unless a smaller bird like a chickadee persists in approaching despite their harassment. Often the jay’s mere visible presence near a feeder is enough to deter other birds from approaching.
In the event of actual food theft by a Steller’s jay, the best deterrents are to bring food inside when leaving the area, cover unattended food, or use feeders designed with weight-sensitive perches. Bluff charges and swooping around food sites can be reduced by positioning feeders in more open areas, scattering feed over a wider space, or using feeder designs that accommodate multiple birds.
Mobbing Potential Predators
Steller’s jays may also mob potential predators such as hawks, crows, ravens, cats, and other animals that could threaten jays, their young, or eggs. Mobbing involves multiple jays calling loudly, diving and swooping at the intruder, and attempting to drive it out of the area.
This cooperative mobbing is risky for the jays but helps alert other jays to danger and chase the predator away. Mobbing events can appear aggressive as the jays try to intimidate a potential threat. But it is defensive behavior essential to the jay’s survival rather than random aggression.
Intelligence and Curiosity
Steller’s jays are extremely intelligent, inquisitive birds. They have large brains for their body size and an innate curiosity about their surroundings.
Jays will readily explore new objects and situations in their environment. This often brings them into close contact with humans across many settings – backyard feeders, campsites, parks, etc. Their intelligence and adaptability allow them to thrive in these human-altered habitats.
However, their inquisitive nature can also lead them to take advantage of unsecured human food or other items that catch their interest. Jays will make quick work of unpacking a backpack for crumbs or investigating an interesting item like a shiny watch or keys. This resourcefulness and opportunism is not necessarily aggression, but a clever bird exploring its environment.
Securing food and belongings, or gently shooing away an investigating jay, is usually sufficient to deter undesirable behavior. And providing jays their own source of peanuts or other treats in acceptable feeders can satisfy their curiosity in a safe, controlled way.
Jays Versus Crows and Ravens
Steller’s jays are a member of the corvid family along with crows, ravens, magpies, and others. Jays often form mixed flocks in winter with California scrub jays, giving the impression of a large group of aggressive birds.
Jays naturally compete with crows and ravens that overlap in their habitat and food sources. So jays may appear more aggressive by comparison with these similar species. Jays will dive-bomb and mob both crows and ravens near their nests or food sources. But crows and ravens are also aggressive on their own when defending resources.
Jays are simply exhibiting normal territorial behavior for their size and neighborhood, not exhibiting abnormal aggression compared to related species in the corvid family. Their territorial nature serves the purpose of protecting limited resources needed to survive and successfully reproduce each year.
Preventing Conflicts
While Steller’s jays have a reputation for aggression, there are steps humans can take to reduce negative encounters and conflicts:
- Respect their space during nesting season – avoid lingering near their nests.
- Cover or secure loose food at campsites and picnics.
- Use jay-friendly bird feeders positioned smartly to minimize bullying.
- Provide peanuts in shells or other treats to satisfy their curiosity.
- Use deterrents like noisemakers, water spray, or reflective tape to discourage unwanted behavior like food theft.
- Remove food attractants when issues occur.
- Be patient, as nest defense is temporary – jays will back down once their young leave the nest.
Understanding the context of jays’ behavior and taking a few simple precautions will help minimize negative encounters. Many problems result from jays exploiting easy food sources from humans. With some care, jays and humans can comfortably co-exist.
Conclusion
Steller’s jays are naturally defensive, inquisitive, resourceful birds. They exhibit aggressive behaviors like alarm calling, dive bombing, food theft, and mobbing of intruders. However, these actions are driven by specific triggers like defending nests and food or warding off potential threats. Their behavior follows typical patterns for an intelligent, adaptable bird dependent on limited resources.
While jays certainly can be bold and pesky at times, their aggression is often exaggerated. With proper precautions around nesting areas and available food, problems are usually preventable. Steller’s jays play an important ecological role in their forest habitats and, when properly understood, can be either tolerated or enjoyed from a slight distance as the stunning birds they are. Their intelligence and social nature provide excellent opportunities to observe nature where their ranges overlap with human spaces and activities.