The Steller’s Jay (Cyanocitta stelleri)

While sometimes mistakenly called “blue jays”, Steller’s jays (Cyanocitta stelleri) are a unique species of their own. Steller’s jays are in the same genus as blue jays, Cyanocitta, and are members of the family, Corvidae, however, the two species rarely have overlapping ranges, with Steller’s jays occurring in western North America and blue jays in the east (Audubon).
Steller’s jays are a long-lived species, with the oldest wild Steller’s jay being 16 (All About Birds). Steller’s jays acquired their name from the German naturalist Georg Wilhelm Steller, and share this namesake with several other familiar species, such as Steller’s sea lion (Eumetopias jubatus) and Steller’s eagle (Haliaeetus pelagicus). Steller described the jays while stopped on Kayak Island, Alaska during his 1741 voyage. The species was later given its name by Johann Friedrich Gmelin in 1788 (Birds of North America). In 1987 the Steller’s Jay was voted by the public to be B.C.’s provincial bird, beating the peregrine falcon (Falco peregrinus) by around 2,000 votes (Yearwood-Lee, 2006).

Description

Steller’s jays are distinguished by their stark colours, mainly blues and black, and by the triangle-shaped crest of feathers extending from the tops of their heads. Younger birds will be a duller grey compared to the dark black found on adults (Sibley, 2000).

It is not possible to identify the sex of the bird based on visual identifiers, especially from a distance (Sibley, 2000). Their striking blue colours are a result of light reflecting off air and keratin found in the feathers. The production of these structural colours may serve as an indication of a bird’s quality to potential mates (Zirpoli et al., 2013).

Subspecies

There have been 16 described subspecies of Steller’s Jay (All About Birds), with at least 13 occurring in North America (Wiebe, 1995). Different subspecies will have different colours present and small differences in sizes. For example, Cyanocitta stelleri ridgwayi, a subspecies found in Chiapas and west Guatemala, have more blue than Northern subspecies (Madge and Burn, 1994)

There are three to four subspecies found in B.C.; Cyanocitta stelleri stelleri, C. s. carlottae, C. s. annectens and C. s. paralia. The C. s. paralia populations in B.C. are possibly mixes between C. s. stelleri, C. s. annectens and C. s. paralia. C. s. paralia has also sometimes been grouped with C. s. stelleri (Wiebe, 1995).

The coastal B.C. subspecies (C. s. stelleri), have medium to dark blue streaks on their crests, with some on Vancouver Island being lighter blue.

Interior subspecies (C. s. annectens and C. s. paralia): have breast feathers that are lighter blue and a greyish back. The majority have light blue streaks on their crests and a white spot above their eye. C. s. paralia look similar to C. s. annectens but may be slightly smaller and darker.

The Haida Gwaii are home to an endemic subspecies, C. s. carlotte. Most birds are lacking coloured streaks in their crest and this subspecies is relatively darker and larger than the other B.C. subspecies (Wiebe, 1995).

To further confuse the things, not only can subspecies overlap (Wiebe, 1995), Steller’s jay and blue jay hybrids have been observed in Colorado, where the species’ ranges meet (All About Birds). The behaviour of these hybrids was observed to match that of Steller’s jay when feeding, and the hybrids were observed using both Steller’s jay and blue jay calls (Williams and Wheat, 1971).

Habitat and Range

Steller’s jays can be found in, pine, spruce, fir, and mixed oak forests (Audubon). They tend to reside higher in trees and in small groups (Sibley, 2000). When the jays are not nesting, they may venture into other habitats, such as orchards and suburbs, and are a striking visitor at bird feeders. While their ranges are usually fixed and they are a non-migratory species, during the winter they may migrate to lower elevations, possibly depending on food availability (Audubon).

Steller’s Jay populations are considered stable (All About Birds). However, Environment Canada has listed the species as a “priority species” for assessing and maintaining their populations in coastal B.C., especially C. s. carlotte, the subspecies endemic to Haida Gwaii (Canadian Wildlife Service, 2013).

Sounds

Steller’s jays are vocal and make a variety of calls, such as a harsh “shaaaaar” (or “wah“), or multiple and rapid “shek shek shek” (or “weh“) noises (Sibley, 2000). Many of their calls are used in communication, especially when interacting with other jays during courtship or confrontation (All About Birds).

These two calls may also function as alarm signals to other jays (Billings et al., 2017). “Wah” calls have been observed when a group of jays were seen mobbing a Cooper’s hawk (Accipiter cooperii) and may possibly be used to confuse the predator during the mobbing (Ficken, 1989). Groups of Steller’s jays will alter the number of “wah” and “wek” calls in the presence of different potential predators. For example, when presented with the audio or visual cues of a well-known predator, Northern goshawks (Accipiter gentilis), Steller’s jays produced more alarm calls than when presented with a less-threatening predator, Northern pygmy owls (Glaucidium californicum) (Billings et al., 2017).

Steller’s jays are known to mimic many other species, including red-tailed hawks (Buteo jamaicensis), northern flickers (Colaptes auratus), northern goshawks, white-breasted nuthatches (Sitta carolinensis), and squirrels. They have also mimicked mechanical noises in their environment, such as sprinklers (All About Birds). There are different theories as to why jays mimic predatory species. One possibility is that they may be able to exclude other birds from feeding by scaring them off. Another idea is that these calls are made by the group to serve as alarm calls. When the call of a red-tailed hawk was played to a group of feeding Steller’s jays, the groups reacted by mimicking the call and then fleeing the feeding area (Billings et al., 2017).

Nesting

Steller’s jays will form long-term pairs that work together to build their nests, feed nestlings, and defend territory (Overeem et al., 2014). Their nests are built usually in conifers. It takes approximately 16 days each to build a nest and incubate their young. Their nests are made of twigs, leaves and other plant material or animal hair stuck together with mud. Females usually have one brood per year, with 2-6 eggs per clutch. The colour of the eggs can range from bluish-green to spotted brown or olive (All About Birds).

Diet

Steller’s jays will forage year-round and are known to eat a wide variety of foods, such as nuts, seeds, insects, berries, eggs, garbage, suet, and smaller animals (All About Birds, Audubon). During periods of prolonged snow and cold in Arizona, there have been observations of Steller’s jays capturing and eating an adult Pygmy Nuthatch (Sitta pygmaea) and adult Grey-headed Juncos (Junco hyemalis caniceps) (Carothers et al., 1972).

As previously mentioned, Steller’s jays also consume the eggs of other birds. An example of a species they prey upon is the endangered marbled murrelet (Brachyramphus marmoratus). These birds nest inland in the canopy of conifer trees. Predation by Corvids (e.g. crows, ravens, jays) is thought to one of the factors affecting the survival of this species (Hébert and Golightly, 2007). Gabriel and Golightly (2014) showed that wild Steller’s jays can be taught to avoid marbled murrelets eggs when presented with mimic eggs that contain a low, non-toxic level of emetic carbachol, a substance that induces retching and vomiting. The Steller’s jays learned to associate these reactions with the eggs, and predation of mimic eggs was reduced by 37% in the field.

Caching

Many species of jays will cache their food, meaning they will store a food item and return later to consume it. Steller’s jays will store foods such as acorns and other seeds by burying them (Kalinowski et al., 2015). These caches may be accessed during the winter when food is scarce or for short term use soon after the item has been cached (Rockwell et al., 2013).

Steller’s jays are also known to take advantage of other caching species of bird. They have been seen robbing the caches of Canada jays (Perisoreus canadensis) and Clark’s nutcrackers (Nucifraga columbiana) (Burnell and Tomback, 1985). The behaviour of these two species has been seen to change when in the presence of a Steller’s jay, often by delaying caching (Burnell and Tomback, 1985). Similarly, a study by Kalinowshi et al. (2015) observed how Steller’s jays alter their own behaviour in the presence of other Steller’s jays, by travelling and hiding their caches from mates (when not breeding) and travelling even farther when around non-mate Steller’s jays.  

Considerable research has been done on the caching behaviour of Steller’s jays. Rockwell et al. (2013) showed that Steller’s jays will asses the quality of a potential caching item, for example a peanut, by weight and the intactness of the shell. The jay would more often take heavier peanuts and peanuts with uncracked shells away for caching, while preferring to eat cracked peanuts at the feeding site. It was also shown that these damaged peanuts had a higher chance of being consumed by insects when cached, compared to peanuts with intact shells.

The caching done by Steller’s jays plays an important ecosystem role by dispersal of seeds and acorns, especially for endangered Garry oak (Quercus garryana) ecosystems in B.C. (Fuchs et al., 2000). Steller’s jays bury Garry oak acorns underground, which potentially protects them form predators and drying out. If some of these cached acorns are forgotten by the jay, the acorns may be able to germinate and sprout. On Vancouver Island, B.C., Steller’s jays have been observed to cache Garry oak acorns up to 600 m from their parent tree, and in a variety of habitats. Some of these habitats are well-suited for oak growth and survival (Fuchs et al., 2000).

Take Home Messages

Steller’s jays are intelligent and striking birds found in Western North America and Central America. There are various subspecies throughout their range. They are vocal birds and forage for various foods. Putting out seeds, suet, and peanuts by your bird feeders is a good way to attract Steller’s jays to your yards (All About Birds), but as the video below shows, you may need to be prepared for the possibility of mischievous behaviours!

Literature Cited

All About Birds: Steller’s Jay. (n.d). Retrieved October 27, 2019. https://www.allaboutbirds.org/guide/Stellers_Jay/id

Audubon: Steller’s Jay. (n.d). Retrieved October 27, 2019. https://www.audubon.org/field-guide/bird/stellers-jay

Billings, A. C., E. Greene, and D. MacArthur-Waltz. 2017. Steller’s jays assess and communicate about predator risk using detection cues and identity. Behavioral Ecology, 28: 776-783.

Birds of North America: Steller’s Jay. (n.d.) Retrieved October 27, 2019. https://birdsna.org/Species-Account/bna/species/stejay/introduction

Burnell, L. K. and D. R. Tomback. 1985. Steller’s jays steal Gray jay caches: Field and laboratory observations. The Auk, 102: 417-419.

Canadian Wildlife Service. 2013. Bird conservation strategy for Bird Conservation Region 5 : Northern Pacific Rainforest. Environment Canada, Gatineau, Quebec. 148 p.

Carothers, S. W., N. J. Sharber, and R. P. Balda. 1972. Steller’s Jays prey on Gray-headed Juncos and a Pygmy Nuthatch during periods of heavy snow. The Wilson Journal of Ornithology, 84: 204-205.

Ficken, M. S. 1989. Are mobbing calls of Steller’s jays a “confusion chorus”? Jorunal of Field Ornithology, 60: 52-55.

Fuchs, M. A., P. G., Krannitz, and A. S. Harestad. 2000. Dispersal of Garry oak acorns by Steller’s jays. Proc. Biology and Management of Species and Habitats at Risk, 1: 263-266.

Gabriel, P. O. and R. T. Golightly. 2014. Aversive Conditioning of Steller s Jays to Improve Marbled Murrelet Nest Survival. Journal of Wildlife Management, 78: 894-903.

Hébert, P. N. and R. T. Golightly. 2007. Observations of predation by corvids at a Marbled Murrelet nest. Journal of Field Ornithology, 78: 221-224.

Kalinowski, R. K., P. O. Gabriel, and J. M. Black. 2015. Who’s watching influences caching effort in wild Steller’s jays (Cyanocitta stelleri). Animal Cognition, 18: 95-98.

Madge, S. and H. Burn. 1994. Genus Cyanocitta. In Crows and Jays, S. Madge and H. Burn. Christopher Helm Publishers, London 191 p. 

Overeem, K. R., P. O. Gabriel, J. A. Zirpoli, and J. M. Black. 2014. Steller Sex: Infidelity and sexual selection in a social Corvid. PLos ONE, 9: e105257

Rockwell, C., P. O. Gabriel, and J. M. Black. 2013. Foraging dynamics in Steller’s Jays: size and viability of cacheable food items. Animal Behaviour, 86: 783-789.

Sibley, D.A. 2016. The Sibley Birds West. Alfred A. Knopf, New York, New York. 477 p.

Wiebe, K. L. 1995. A review of the morphology and taxonomy of Steller’s jays (Cyanocitta stelleri) in British Columbia. British Columbia Birds, 5: 3-11. 

Williams, O. and P. Wheat. 1971. Hybrid jays in Colorado. The Wilson Journal of Ornithology, 83: 343-346.

Yearwood-Lee, E. 2006. British Columbia’s Provincial Emblems. Legislative Library of British Columbia, 2-8.

Zirpoli, J. A., J. M. Black, and P. O. Gabriel. 2013. Parasites and plumage in Steller’s jays: an experimental field test of the parasite-mediated handicap hypothesis. Ethology Ecology & Evolution 25: 103-116