Brewer's Sparrows and Sage Thrashers were the "rock stars" of this study.
Sagebrush Songbirds
Four years of dedicated research demonstrates that sagebrush-obligates have higher reproductive success when trees are removed for sage grouse.
Increase in Brewer's Sparrow fledgling production where encroaching trees were removed
More Vesper Sparrows found in areas where encroaching trees were removed
Sage Thrashers found in areas where trees had encroached
Summers the research team spent in southwest Montana collecting data
In this three-part video, a Brewer’s Sparrow returns to its nest to feed its hungry nestlings, a fledgling “fledges” and leaves the nest, and a garter snake discovers the nest and makes a meal of one of the fledglings.
Brewer’s Sparrows are sagebrush obligates and require intact, tree-free sagebrush habitat for breeding and brood rearing.
In this two-part video, two Green-tailed Towhees feed their young and a weasel attacks the nest and makes off with the chicks. Green-tailed Towhees prefer “edge” habitat where scattered trees intermix with sagebrush, shrubs, and native wildflowers and grasses.
Taking their habitat needs into account is important for land managers working in the sagebrush biome, especially when designing and implementing conifer-removal projects.
In this two-part video, an adult Sage Thrasher returns to its nest with an insect to feed its hungry chicks and a red-tailed hawk finds the nest and makes off with one of the chicks.
Sage thrashers are very sensitive to trees encroaching into sagebrush habitat. This research from southwest Montana found that no Sage Thrashers were present in areas with tree encroachment; however, they recolonized and successfully bred in areas where trees were removed.
In this two-part video, a Vesper Sparrow feeds its chicks and days later, the chicks, now fledglings, leave the nest.
Vesper Sparrows are a “generalist” species, and they live in sagebrush rangelands even if trees are present. However, this research from southwest Montana found that Vesper Sparrows are more abundant and have greater reproductive success in areas where encroaching conifers were removed compared to areas where the trees remained.
“It’s one of those really fun stories where we can have this win-win relationship, where management action that’s beneficial for wildlife, not just birds but also big game, also has benefits for cattle and people who rely on this land for their livelihoods.”
Elise Zarri, Lead Researcher
Researcher Elise Zarri’s study examined how removing conifer trees for sage grouse impacted abundance and reproductive success of eight songbird species that primarily nest in sagebrush habitat – two sagebrush-dependent species, two shrubland-generalists, and four others that live in sagebrush country but are more associated with edge and woodland habitat.
Importantly, Zarri’s research focused both on bird abundance and on how successfully they reproduced over the course of a season. The findings show that population benefits accrue when songbird habitat use aligns with that of sage grouse.
This research appeared in the Journal of Applied Ecology in spring 2024.