Partners in Flight
One of the things I like about living in Missouri is that I can see many different kinds of birds throughout the year. Spring brings the shorebirds, followed by warblers and tanagers in the summer. Juncos and eagles arrive in winter. Together, they offer a seemingly endless flight of viewing opportunities. I often marvel at these feathered gifts of nature and know our world would be much less interesting without them.
In the early 1990s, studies began to show that many of the birds that we now take for granted had been declining due to widespread habitat loss and degradation. To counter this trend, a group of concerned biologists formed Partners in Flight (PIF), a voluntary conservation organization that works to protect declining species of birds before their numbers fall so low that they face extinction.
In a nutshell, PIF seeks to keep common birds common and off the Endangered Species List Participants include government, academic and industry professionals whose combined efforts expand "on-the-ground" bird conservation.
Across the country, Partners in Flight is developing scientific bird conservation plans for physiographic areas, or "eco-regions." Within this framework, a Missouri working group has helped develop plans for each of the five eco-regions that comprise our state.
About 700 species of birds breed in North America, but not all are in trouble. To determine which ones require the most urgent attention, Partners in Flight considers a combination of seven factors. They are as follows:
- Relative Abundance - Species with many individuals are less vulnerable than those with fewer individuals.
- Breeding Distribution - Species that breed over a wide geographic range are less vulnerable than those with limited ranges.
- Non-breeding Distribution - Species whose wintering and migration habitats cover a wide geographic range are less vulnerable than those with limited ranges.
- Threats Non-Breeding assesses threats to a species and its habitat during migration and on wintering grounds.
- Threats Breeding assesses threats to the species and its habitat on breeding grounds.
- Area Importance indicates the importance of an area to the general range of a species. For example, more than 15 percent of the world’s summer tanagers, and more than 30 percent of the world’s whip-poor-wills, breed in the Ozark and Ouachita mountains of Missouri, Arkansas and Oklahoma. Severe declines in such large populations would have dire consequence to the global population of those species.
- Population Trend evaluates whether a species is increasing, declining or stable. For most species, this score is based on 30 years of data from the North American Breeding Bird Surveys, a network of roadside censuses conducted annually by accomplished birdwatchers across North America. Even declines as small as 1.6 percent per year for 30 years (the percentage of decline for the dickcissel over its range) can have profound consequences. Look at it this way. If, 30 years ago, you had invested $100,000 and suffered a similar loss, you would have less than $62,000 today.
The highest priority species are those with limited ranges, declining trends and threats to their habitats and populations. In Missouri, some of the highest priority species include the greater prairie chicken, cerulean warbler and Henslow’s sparrow. Dickcissel, prairie warbler, and field sparrow are among those considered moderately high priority.
In the Partners in Flight planning process, species needing conservation attention are grouped into "suites" by habitat type. For example, birds that use grasslands are in a common group, as are birds that need mature or early successional forest habitat.
The needs of each species in a given habitat are then evaluated so that managers can know what kinds of conditions birds require at a given site. The various species in a suite of mature forest birds may nest or forage in different parts of the canopy, in shrubs or on the ground. Therefore, the forest must have these layers of vegetation to provide habitat for them all.
Once habitat needs are identified, Partners in Flight planners look for species within the suite that have the largest spatial requirements. Greater prairie chickens, for example, have home ranges of roughly 2,000 acres, but cerulean warblers only inhabit areas with thousands of acres of contiguous forest. The species with the largest minimum area requirement serves as a gauge to identify the lowest size limit of habitat that will support the entire suite.
Another important consideration in planning for bird conservation is whether or not a population is able to produce enough offspring to remain viable. If the habitat contains too many nest predators or nest parasites, nesting success may be too low to perpetuate the species at that locale.
Perhaps the largest threat to many breeding birds in the Midwest is the brown-headed cowbird, a parasitic species that lays its eggs in the nests of other species. Female cowbirds can lay one egg a day during their early summer breeding season and can travel as far as three miles between feeding areas and breeding sites.
The "hosts" incubate the cowbird eggs along with their own, and then raise the faster growing cowbird chicks to the detriment of their own offspring. Parts of the Midwest where grasslands and forests are relatively small and isolated are so saturated with cowbirds that songbirds produce very few of their own species.
Without immigration from other areas where a host species’ reproduction is high, cowbird parasitism could cause songbird populations to become locally extinct. Because both cowbird parasitism and nest predation are largely related to the condition and types of land use surrounding suitable habitat, Partners in Flight considers the condition of the landscape surrounding managed areas when making recommendations for on-the-ground bird conservation.
Luckily for our forest birds, much of the Missouri Ozarks is still heavily forested, and forest songbirds in those areas appear to be producing enough young to export individuals to parts of the Midwest where reproductive success is low.
Grassland birds, on the other hand, appear to be declining throughout much of the state because of ongoing habitat loss and fragmentation. Partners in Flight seeks to reverse this trend by working with landowners and grassland conservation groups to restore grassland landscapes on a voluntary basis.
Partners in Flight recommendations for improving and restoring habitat at both the site and landscape scale mark the beginning of a new approach to conservation. Successfully implementing PIF plans will continue to rely on the voluntary and combined efforts of government and academic conservation biologists, as well as the commitment of private landowners who want to benefit birds.
Stabilizing bird populations won’t be easy, quick or cheap, but the reward for these efforts will be a diversity of beautiful birds that will continue to enrich our lives.