Songbird is a nonscientific term generally used to describe Passerines or perching birds (species in sequence from flycatchers to finches in most bird field guides). Songbirds are known for their musical voices and foot morphology (three forward-oriented toes and one rear-oriented toe - perfect for perching) and range in size from the tiny bushtit at 0.19 ounces to the raven weighing up to 3 pounds. Songbirds that breed in the northern hemisphere and winter south of the Tropic of Cancer are termed neotropical migrants. Some songbirds such as American robin and song sparrow are short range migrants - meaning some members of the breeding population move to lower latitudes or elevations during winter, while some may remain on their breeding grounds depending on local conditions. Other songbirds such as mountain chickadee, golden-crowned kinglet and dark-eyed junco remain as winter residents in the mountains and valleys of the Greater Yellowstone Ecosystem (GYE). Idaho has 243 breeding birds, 119 (49%) are neotropical migrants. Songbird diversity is most evident in the GYE from mid-May to mid-July when bird courtship vocalizations resonate through every habitat in the Ecosystem.

Yellowstone National Park and surrounding lands of the National Forest System are commonly considered to encompass the core habitats of the GYE. However, much of this core lies at higher elevations with limiting biophysical conditions (climate, soil, vegetation, etc…) to songbirds. Depending on land use and condition, low-elevation private lands may provide more productive habitat for breeding birds than high elevation public lands. Perhaps no landscape exemplifies this potential in the GYE more than the cottonwood riparian forests along the South Fork of the Snake River from Swan Valley Bridge to Heise, Idaho. The largest remaining cottonwood riparian forests in Idaho exists along this section of the South Fork where researchers have recorded more than 120 bird species, including approximately 60 species of breeding songbirds.

Western riparian habitats, such as the South Fork cottonwood forests, attract 10 times the number of migratory birds (short range and neotropical migrants) during the breeding season than adjacent uplands and 14 times the birds during fall migration1. Neotropical migrants, in particular, rely heavily on riparian landscapes and ongoing population declines of this group are partially attributed to loss and degradation of riparian habitat. Idaho Partners in Flight (PIF) categorizes high conservation priority bird species based on their relative vulnerability. PIF priority songbirds that breed along the South Fork include yellow warbler, MacGillivray's warbler, dusky flycatcher and willow flycatcher. The yellow-billed cuckoo, a rare near-passerine in Idaho and a candidate for listing under the Endangered Species Act, is more commonly detected in South Fork Canyon than any other area of the state. Presence of this rare and vulnerable species is indicative of the quality of the cottonwood habitat, particularly the high degree of connectivity (i.e. habitat is relatively unfragmented), large patch size of cottonwood stands, and presence of open canopy forest conditions with a complex understory.

Land ownership along this portion of the South Fork is a mix of public and private lands, which complicates protection and management of the unique natural resources.

Research conducted on the Snake River in Jackson Hole, Wyoming, suggests that residential development in riparian areas may have numerous negative landscape-level effects on breeding bird populations, including an overall decline in species richness and diversity, an increase in avian nest predators, and increase in food generalist (i.e. robin, magpie) at the expense of more vulnerable specialist species (i.e. MacGillivray's warbler, yellow-billed cuckoo). Therefore, increased residential development in the cottonwood forest of the South Fork has the potential of causing habitat degradation not just on private lands but also on adjacent protected public lands. Neotropical migrants are likely most sensitive to habitat fragmentation from residential development and are most negatively impacted by these effects1.

Recognizing that residential development within riparian forest along the South Fork Snake River would fragment and degrade some of the best songbird habitat in Idaho, Teton Regional Land Trust, the Bureau of Land Management, The Conservation Fund and The Nature Conservancy have cooperatively protected 24 properties along the South Fork ranging in size from 10 acres to 2,500 acres by fee title or conservation easement. The resulting mosaic of public land and conservation easement properties maintains the continuity of important riparian habitats and greatly reduces the potential for habitat fragmentation due to residential development. TRLT is applying this model of riparian corridor conservation within priority landscapes along the Teton and Henry's Fork Rivers where songbirds are also a high priority natural resource.

Every spring from early May to early June TRLT celebrates community-based conservation and explores regional bird diversity by hosting bird walks on selected conservation easement properties. The focus of these trips is to better understand the ecology of local birds and the importance of private lands to conservation of regional bird populations.