The Steller’s Jay, a striking bird with deep blue and black plumage and a prominent crest, is common in western North America’s evergreen forests. These intelligent birds are found in mountainous regions, campgrounds, parks, and backyards. Their noticeable presence and social behaviors often lead to a common question: do Steller’s Jays mate for life?
Steller’s Jay Mating Behavior
Steller’s Jays do not mate for life, typically forming monogamous pair bonds for a single breeding season. While socially monogamous during breeding, these bonds often dissolve afterward. Pairs usually come together in late March, with breeding activity peaking in April and May.
The formation of these seasonal pair bonds involves various courtship rituals. Males may feed the female, and the pair engages in “sexual sliding,” actively searching for a nest together. During this, males might align sideways to a female, spread their tail, and tilt their wings to display their dorsal surfaces. Courtship songs, consisting of quiet whistled, gurgled, and popping sounds, are heard from males and sometimes females. Though monogamous for the season, some jays can be unfaithful.
Nesting and Raising Young
Once a pair bond is established, Steller’s Jays collaborate during nesting and chick-rearing. Both male and female select a nest site, usually high in a conifer, or sometimes lower in deciduous trees or shrubs. They construct a bulky, cup-shaped nest from twigs, weeds, moss, and leaves, cementing it with mud. The interior is then lined with softer materials like fine grass, rootlets, pine needles, or animal hair.
The female lays a clutch of 2 to 6 pale blue-green eggs, speckled with brown or olive. Incubation, lasting 16 to 18 days, is primarily performed by the female. During this time, the male feeds the incubating female and guards the nest.
After chicks hatch, both parents share the responsibility of bringing food, including insects, seeds, berries, and even eggs or nestlings of other birds. Steller’s Jays, normally vocal, become quiet and secretive to avoid attracting predators. Young jays fledge around 16 to 18 days after hatching, but parents continue to feed them for about a month as they learn to forage independently.
Life After the Breeding Season
After the breeding season, the family unit and pair bond of Steller’s Jays transform. As the young become independent, parental investment decreases, and the pair bond gradually dissolves. While some pairs might re-form in subsequent seasons, this is not a consistent pattern.
Individual Steller’s Jays often transition from breeding territories to join larger, non-breeding flocks. These social groups are common outside the nesting season, with jays traveling and foraging together. During autumn and winter, jays may move to lower elevations, seeking more abundant food. This flocking period allows individuals to forage efficiently and prepare for the next breeding season, which involves establishing new temporary pair bonds.