Sights and sounds of spring in the Sierra Nevada
Tahoe Institute for Natural Science
Spring is in full swing, and in the mountains that not only means longer days and warmer temperatures but also an eruption of singing birds, flowering plants, and busy animals looking for a mate … or mates.
There is a lot to pay attention to in the forests and meadows that surround our homes. Be on the lookout for the many signs that make the season a time of new growth, change and vitality.
By now most of the snow at lower elevation is gone, and the snow line continues to creep up to higher elevations. As snow melts, green plants emerge out of the wet soils. Although many of these plants may have been slowly growing under the snow for weeks prior to the snow melting, once uncovered, the greenery fills the ground and quickly grows taller towards the sky.
Some of the first flowering plants remain low to the ground, however, including various species of yellow buttercups (Ranunculus sp.) and the delicate Beckwith’s Violets (Viola beckwithii); a tiny purple and lavender flower with a yellow interior that emerges at lower elevations.
Quaking Aspens are flowering before they begin to grow their leaves. Take a moment to look closely at these flowers to see the fuzzy stamens protruding out and reaching for the sun. Another plant on display is our famous Snowplant (Sarcodes sanguinea); a scarlet mycoheterotroph, which means the plant parasitizes and feeds from fungi in soil instead of getting its food from the sun.
Not only do the first bright blooms of spring represent the return of green, and the bounty for summer, but also provide beacons of interest for pollinating insects.
Flying insects fill the air, including some of our favorites: butterflies and moths. Here in Tahoe, most butterflies and moths overwinter as caterpillars, with pupa (chrysalises and cocoons) being the next most common strategy. Very few pass the winter as eggs, but a few species do spend the winter as adults hiding in snug, protected places like behind the peeling bark of dead trees. Butterflies that overwinter as adults, include the Mourning Cloak (Nymphalis antiopa) and Zephyr Anglewing (Polygonia gracilis zephyrus).
Once awakened from hibernation, these butterflies search for food in the form of tree sap, old fruit, dung, and nutrient-filled mud. All of these flying insects are important because the larvae are a primary food source for the many birds migrating to and through Tahoe during spring.
One of the most welcoming sounds of spring is the familiar “cheese-bur-ger” song of the Mountain Chickadee (Poecile gambeli), a small gray and black bird with a white eyebrow that stays in Tahoe year-round. However, most bird species that inhabit the lake are seasonal migrants. Though some animal movements and migrations occur throughout the calendar year, the spring migration is most dramatic, breaking the quiet months of winter with the promise of the summer ahead.
Birds that have already arrived to Tahoe to nest include Yellow-headed Blackbird (Xanthocephalus xanthocephalus), barking from the tops of cattails, Osprey (Pandion haliaetus), diving into the lake to feed on fish, and several species of thrushes, singing flutelike melodies in the grass and trees.
The sounds and colors of this season are an invitation to explore the outdoors and witness the vitality of spring, so be sure to get out there and pay attention to the changing beauty that surrounds us in the Sierra Nevada.
This article was provided by the Tahoe Institute for Natural Science (TINS). If you would like to learn more about Tahoe’s natural history, come explore with TINS by joining us on one of our many free nature tours. To learn more, visit us at http://www.tinsweb.org