By Frances Clark
The members of the Corvid or Crow family are smart, often showy, and have a reputation. As a group they are omnivores, eating a range of food from carrion to berries to bugs. They are known for their intelligence, such as remembering locations of food stashed months previously and faces of humans who have treated them well or ill. Each species is distinctive in appearance and voice and their behaviors reflect their habitat and social communities. As permanent residents of Jackson Hole, Corvids can be a fascinating group to observe and nature map in the coming months as many of the summer visitors move on.
The most common sightings are Common Ravens and Black-billed Magpies. They are well known as scavengers of carrion, raiding nests for baby birds and eggs, and preying upon small mammals—in short not very appealing behavior from our human perspective. However they are also nature’s clean-up crew, as they are willing to eat most anything.
American Crows are unusual in Teton County, and perhaps overlooked due to their similarity to the larger Ravens—It can be hard to determine size against the scale of sky and mountains. Crows are smaller with less bulky beaks and a flat-ended tail when flying, vs the raven’s heavier beak and “wedge-tail” visible in flight. Crows tend to be seen more in flocks around town where they are well adapted to human spaces, while ravens are generally in pairs or family groups out in the larger landscape. The typical caw caw caw voice of crows is higher pitched that of the husky croaking sounds of ravens.
Clark’s Nutcrackers are renowned for their mutualistic relationship with white-bark pine. These gray, white, and black birds move around the West in family groups seeking areas with productive white-bark pines. At this time of the year, they will use their substantial beaks to peck and pry out pine seeds from closed cones, gulp dozens into a “sublingual pouch” and then stash them on snow-free mountainsides. Each bird can remember 1000s of locations! Notably, males have an incubation patch to warm the eggs hatched in the heart of winter, so the females can retrieve their own stores. Over subsequent months, parents will continue to count on seeds for their survival, but also leave enough propagules to start a new generation of white-bark pines. These smart, flashy birds play a critical role in sustaining high-elevation ecosystems.
Canada Jays and Steller’s Jays are two other Corvids found mostly in our evergreen forests. Canada Jays, called “Gray Jays” until 2018, are also known as Camp Robbers and Whiskey Jacks. They are gray, plumpish birds with whitish heads touched with black. They have the smallest beaks of corvids in Jackson Hole. They fly about in bonded pairs often making a series of starling squawking sounds.
Canada Jays are boreal birds, adapted to cold evergreen forests with spruce, but here in northwest Wyoming, they are also found in mixed stands of evergreens and aspens. True to their name, they are well adapted to tough, cold conditions. Their feathers can puff up and cover both feet and bills and also allow for solar radiation to penetrate deeply for extra warmth.
Mated for life, pairs scatter-stash their food to get by over the long winter months. These Jays have glands that produce a very sticky saliva, and they use their bills to make blobs of their food and stick them under bark and lichen an on twigs and needles. Favorite foods are berries—including huckleberries, arthropods, and fungi. Like Nutcrackers, they remember 1000s of locations. They produce young in February and March when it can be -20F, using their frozen food packets to nurture both parent and offspring. They will not have a second brood even if the first fails, despite the coming of easier spring conditions.
Another unusual behavior of Canada Jays, is by late spring, the largest of the brood pushes its siblings from the parental territory and gains the benefit of pilfering the stashes of its parents and learning sites for next winter’s stores. Its siblings have to look for adoptive parents who may have lost their brood and have food reserves to share.
Canada Jays can be beguiling. When scouting for food, they glide and hop from limb to limb, tilting their heads to check out what you may have in hand. I saw several groups a week ago along the south shore of Leigh Lake, a favorite place for picnickers. Their arrival was heralded by startling cranky calls and whistles.
Steller’s Jays are more elegant in appearance, but perhaps less interesting in behavior than Canada Jays. They are found in similar habitats and eat similar food. Steller’s Jays in addition will look for white-bark pine nuts and stash single seeds, but do so much less efficiently than Clark’s Nutcrackers. They also watch and remember where other animals store their food and pilfer as needed.
Steller’s Jays have a complex social system called “site-related dominance”. In essence, the dominant pair defends an area around its nest with the male dominant over the other males, and the female ruling over nearby females. Other pairs are kept 5-25’ away from this central nest, whereas couples farther out are more gregarious with each other. Scientists have determined all sorts of posturing and sounds associated with this complex community.
Hawks—Red-tail, Goshawk, Cooper’s–as well as ravens are all threats to Steller’s Jays. The jays respond to their presence by “mobbing” the intruder—squawking, diving, and otherwise driving it off. This is the advantage of living in a neighborhood of jays.
While our Jays don’t migrate, in winter higher-elevation breeders can move down-slope. This is when we may see Steller’s Jays at our feeders instead of up on Teton Pass. Occasionally there may be an irruption of flocks of young birds moving about. These are all interesting movements to Nature Map.
Finally, rarely, we see the Eastern Blue Jay, a close relative of the Steller’s Jay. They both have the arched crest, iridescent blue feathers, and decorative highlights. The more boldly marked Blue Jays tend to prefer acorns typical of more eastern forests, while Steller’s seek pine seeds of our montane forests of the Rocky Mountains. Last year, Nature Mappers recorded several Blue Jays in and around Jackson.
As we all remain hunkered down during this year of covid-19, let’s get out and enjoy the Corvids. Learning their differences in identity, habitat, location, and particularly their behaviors enhances our appreciation of being in Jackson Hole. And you help our local understanding of these birds by Nature Mapping what you see!
For more information:
All About Birds https://www.allaboutbirds.org/news/ a free site from Cornell Labs.
“Birds of the World” formerly Birds of North America – website sponsored by Cornell Labs: https://birdsoftheworld.org/ a subscriptions site with lots more detail
Regarding the name change of Gray to Canada Jay: https://www.audubon.org/news/the-gray-jay-will-officially-be-called-canada-jay-again
Differences in calls and meaning of Ravens vs. Crows: A YouTube by Cornell Lab of Ornithology: https://www.youtube.com/watch?v=eZ5iippq3rA