by Pat Jaquith
pat@westvalleynaturalists.org

Juniper is a woody plant that provides habitat and food for a number of bird species year ’round. For more information about local Juniper species and the birds that utilize them in all seasons…

Common Juniper (Juniperus communis) in the Cypress family (Cupressaceae) is the most common species that we see here in the West Valley. This low-growing shrub with long, springy branches, prickly needles, and small oval-shaped cones with a waxy covering often grow in soils that have low nutrient levels such as old, over-grazed pastures. The dense ground cover of junipers is protective of young tree seedlings that might be subject to browse by ungulates. As the trees grow and make shade, the junipers die out from a lack of sunlight. This succession from pasture to forest is a long, gradual process, and in the meantime, the Junipers provide food and protective cover for many creatures.

In spring, Junipers produce unobtrusive blossoms that I rarely notice unless I’ve disturbed the branches, sending up a cloud of pollen. The blossoms become cones that take up to two or more years to mature. Often mistaken for berries, the little cones have 3 to 6 scales, each concealing a single seed. Birds digest the fleshy scales and pass the hard seeds in their droppings. It is reported that seeds that pass through a bird’s digestive tract have a greater germination rate.

Migrating birds sometimes stop in the West Valley to refuel on their way north where they will nest and eat insects. I happened to spot a flock of these warblers in a clump of Rocky Mountain Junipers and Hawthorn trees. They were feeding on the Junipers and warming in the sun on bare-branched Hawthorns. Yellow-rumped Warblers have the right pancreatic enzymes for digesting the waxy coating on Juniper cones, thus enabling their migration before and after some other birds when more palatable food is available.

Below, several White-crowned Sparrows and Yellow-rumped Warblers were busily picking cones from Rocky Mountain Junipers and flying in and out of the deciduous trees in the foreground in late September, 2024.

Winter migrators, some Bohemian Waxwings had joined a flock of Cedar Waxwings that live here year ’round on a frosty morning in January. When food sources become scarce in northern climates where the Bohemian Waxwings live in more temperate seasons, they set out in search of food supplies. They were harvesting cones on some Rocky Mountain Junipers (Juniperus scopulorum). This tree is less plentiful in the West Valley than the Common Juniper. As young trees, I often see their blue-ish needles and upright-growing limbs well-browsed by ungulates.

The Red Crossbills above were observed frequently feeding on these Rocky Mountain Junipers in July, 2020.

Wild Turkeys had been feeding on the ripe cones of this Common Juniper. Photo 11.11.21

11.21.23 Bowser Lakebed was a bowl of fog this cold morning until the sun broke through, revealing the beauty of a Common Juniper where Chipping Sparrows had nested that summer and the Robin pictured below had been cone-feasting with numerous friends in early October.