Steller’s jays (Cyanocitta stelleri) are intelligent, adaptable birds that thrive in coniferous forests across western North America. As temperatures drop and winter sets in, Steller’s jays undergo behavioral and physiological changes to survive the cold months.
Do Steller jays migrate for winter?
No, Steller’s jays do not migrate for the winter. They are permanent residents throughout their range, which extends along the Pacific Coast from Alaska to Central America. While some individual jays may wander outside their normal territory in search of food, the species does not undertake any major migratory journeys.
How do Steller jays survive cold winters?
Steller’s jays have several adaptations that allow them to survive harsh winters in their habitat:
- Thick plumage – Their feathers provide ample insulation against the cold.
- Caching food – They stash away nuts and seeds to eat later in winter.
- Omnivorous diet – They eat a variety of plant and animal matter, which helps them find food year-round.
- Partnerships – Mated pairs stay together and cooperate to survive the winter.
- Communal roosting – Groups of jays huddle together in nests or conifers to share body heat.
- Adaptability – They are very intelligent and can adjust their behavior as needed to find food and shelter.
How does their plumage change in winter?
Steller’s jays do not undergo a dramatic change in plumage color for the winter, but their feathers do become fluffier and more dense compared to summer. This winter plumage provides extra insulation against cold temperatures and wet conditions. The blue and black barring pattern of their feathers remains the same.
One interesting plumage change is that Steller’s jays tend to sprout more elongated nasal bristles as winter approaches. These bristles likely help protect the birds’ nostrils and face against frigid winds and air.
What foods do Steller jays eat in winter?
Steller’s jays are omnivorous generalists, feasting on a wide variety of plant and animal material throughout the year. Some of their key winter foods include:
- Nuts and seeds – Acorns, pine nuts, hazelnuts, and seeds cached from other seasons.
- Fruit – Persimmons, wild berries, crabapples.
- Insects – Beetles, caterpillars, spiders.
- Eggs and nestlings – Jays may raid birds’ nests for eggs and young.
- Fungi – Mushrooms, lichens.
- Small vertebrates – Nestling birds, small rodents and lizards.
- Human food – Peanuts, suet, and food scraps from bird feeders.
Their versatile palate allows Steller’s jays to take advantage of any nutrients they can find during lean winter months.
How do Steller jays find and store food?
Steller’s jays have excellent spatial memory and caching skills, which serve them well in winter. Each fall, they start stashing away food like nuts, seeds, and acorns in hidden caches throughout their home territory, disguising the spots with debris. They can remember the locations of thousands of caches and retrieve the hidden food when needed over the winter and spring.
Jays use several tactics to find scarce food in winter:
- Foraging widely through their territory
- Probing fallen logs and leaf litter for insects
- Following mixed foraging flocks to find food
- Actively hunting smaller birds, eggs, and mammals
- Remembering successful foraging locations from previous years
How do Steller jays cooperate and share food?
Mated pairs of Steller’s jays often stay together year-round and cooperate to survive the winter. Family groups may also forage and cache food together. When food is scarce, jays become quite social and aggregations of 6-12 birds may form communal feeding flocks, sharing information about food locations.
At communal roosts in winter, dominant birds like breeding pairs tend to control the best sleeping spots, but jays generally tolerate each other and shuffle positions, giving all individuals a chance to warm their exposed feet against their bodies.
What are Steller jay winter roosting habits?
On cold winter nights, Steller’s jays roost in dense conifer trees or large nests built of twigs, bark, moss, and plant fibers. Preferences include:
- Thick evergreen trees – spruce, fir, cedar, pine.
- Vine maple trees.
- Old nests from previous years.
- Cavities or crevices in trees.
- Woodpecker holes.
Roost sites are usually close to a source of water. Jays accumulate insulatory feather loft by fluffing out their plumage while roosting. Groups of 4-12 or more jays may roost communally, benefiting from each other’s body heat.
Do Steller jays build winter nests?
Steller’s jays do not build full nests for winter shelter, but may repair and reinforce old nests from previous years to use as winter roosts. They generally start breeding in March or April when spring arrives, building fresh nests high up in conifers out of soft bark strips, moss, lichens, and twigs.
Do Steller jays migrate or relocate for winter?
Steller’s jays are non-migratory and do not make major movements or relocations specifically for winter. However, as temperatures drop and food becomes scarce, jays may wander outside of their normal territories searching for resources. Movements of 5-10 miles away from an individual’s breeding territory are not uncommon over winter.
Some altitudinal migration to lower elevations near the Pacific Coast may occur as inland montane habitats become icy and inhospitable. But most jays tough out the winter wherever they reside without migrating far distances.
How does winter weather affect Steller jays?
Harsh winter weather presents challenges for Steller’s jays, but their resilience allows them to endure quite well:
- Snow – Makes it harder to find food, but jays are intelligent and adapt. They switch to eating cached food.
- Cold temperatures – Their dense plumage and communal roosting provide warmth. Heat loss reduces at night.
- Icy rain – Difficult for foraging and dangerous for heat loss. Jays fluff feathers to shed ice.
- Wind – Nestle into dense cover. Bristles protect face. Cooperate to find shelter.
Overall, healthy Steller’s jays are well equipped to withstand winter conditions in their range. Long harsh winters do take a toll on individuals though.
How do Steller jays interact in winter flocks?
In winter, Steller’s jays form loose flocks of around 6-12 birds for foraging and roosting. Flocks usually consist of mated adult pairs, younger jays, and family members. Interactions are mostly peaceful, although some chasing and bickering occurs.
There is a dominance hierarchy based on gender, age, and family status. Breeding pairs are dominant over younger jays. Flocks cooperate to find food but dominant pairs get first access. At night, dominant jays get the warmer middle spots in roosts.
Do Steller jays mate in winter?
No, Steller’s jays do not mate during the winter months. Breeding season occurs in spring, from March to June depending on latitude. Monogamous pairs remain bonded over winter and may roost and forage together, but do not engage in courtship or nesting activities until spring.
How do juvenile Steller jays fare in winter?
Juvenile Steller’s jays born the previous spring and summer face their first winter about 8-10 months old. Survival can be challenging:
- They lack adult fat reserves and insulation.
- Without a mate, solitary juveniles may struggle.
- They have slimmer foraging skills than adults.
- Dominant adults monopolize the best food sources.
- Many juveniles disperse from their parents’ territory in fall.
However, benefits like communal roosting and joining mixed flocks help offset juveniles’ disadvantages. Those that make it through the first winter typically have strong odds of future survival.
How do Steller jays interact with other species in winter?
Steller’s jays have a mix of affiliations during the winter months:
- Compete with other medium-sized birds like woodpeckers, nuthatches, and chickadees for food.
- Join mixed foraging flocks led by chickadees or nuthatches.
- Mob predators like hawks and accipiters when detected.
- May steal food cached by other species.
- Sometimes hunt smaller birds for eggs or nestlings.
- Alert each other to threats with loud alarm calls.
Overall, their relationships are complex. Jays gain survival benefits from flocking with other species, but also compete with them when resources are limited.
Conclusion
Steller’s jays are well adapted for surviving the challenges of winter in western North America. Instead of migrating, they stick out the cold season via caching food, communal roosting, versatile diet, and intelligence. Pairs and family groups form loose flocks and support each other. While deep snow, ice, and long winters do impose costs on jays, the species as a whole flourishes across its range in both winter and summer.