As the northern hemisphere begins its journey back toward the sun we feel and see life return to the Yellowstone landscape. As snow fields disappear grass and flower shoots start to push their way out of the soil. The once quiet landscape begins to erupt with new bird songs; with each passing day a new bird species arrives. One common but overlooked bird that comes with the transition of spring is the Brewers Sparrow. Like many species, Brewers Sparrows welcome in the next generation during this time. The nesting period of songbirds such as the Brewers Sparrow marks a new season, and a period of new beginnings.

In Yellowstone, the sage steppe supports some of the first signs of new life including the nesting birds of spring. As life returns to the limbs of the sagebrush a nursery takes shape. The newly revived Sagebrush, also known as Artemisia tridentata, a member of the Asteraceae family, will support a variety of songbirds in their pursuit of bringing forth the next generation. The sagebrush provides shelter as well as a cornucopia of insects, and nesting material. However, some birds prefer a scrubbier bush known as rabbitbrush. Equally as important to the sage steppe nesters. Rabbitbrush, also known as Ericameria nauseosa– part of the Asteraceae family, provides habitat for bird species that nest on the ground. As snow melts away the first birds in the ecosystem chose the dry sagebrush canopies for their nursery’s.

The Brewers Sparrow is a common early arrival on the landscape that seeks out sagebrush. The Brewers Sparrow arrives in the ecosystem in April to May looking for sagebrush and territory that will support their new brood. The Brewers Sparrow males start erupting in song shortly after their arrival as they defend new nesting territory and mates. The complex song of the Brewers Sparrow can be heard into late July, but once chicks have successfully fledged those songs will taper off.  Through careful selection the Brewers Sparrow chooses which sagebrush will support their nests as that can determine their success and hopes of bringing forth the next generation… Brewers Sparrows tuck their nests against the trunk of a sagebrush, no more than about four inches off the ground, trying to conceal its precious blue-green and brown speckled eggs. Often in one clutch a Brewers Sparrow will have between 3-5 eggs and may havAe as many as two clutches in one season. As the adult Brewers Sparrow pair waits for the arrival of chicks, they will try to trick potential predators leading them away from their nest as they flush away low to the ground. Sometimes when flushing off the nest they will pretend to have a broken wing to be more enticing for predators, so they don’t pursue the nest. Between eleven and thirteen days of incubation will pass before the first hatchlings emerge, it’s a time of anticipation and hope. The springtime nests of songbirds, such as the Brewers Sparrow, act as a symbol for new beginnings brought with the changing of the seasons.

Spring is often characterized as a season of optimism and growth; in Yellowstone this is evident with the welcoming of new birds like the Brewers Sparrow. The beginning of spring foreshadows the summer season to come, with the influx of new life into the ecosystem Yellowstone comes alive after a long period of dormancy. As you visit this remarkable ecosystem, don’t forget to keep an eye out for species like the Brewer Sparrow that are often overlooked as harkening in the changing seasons.

Article and nest images by Abbey Thomas, YF Field Educator
Featured image: USFWS, Tom Koerner