Scientists from National Audubon Society have printed a research highlighting the excessive conservation worth of California’s Central Valley and the Colorado River Delta for tens of tens of millions of migratory landbirds every year.
The research, led by Audubon’s new Migratory Bird Initiative and printed in Ornithological Applications, estimates that greater than 65 million birds use main parts of the Central Valley throughout fall migration, and about 17 million birds use the Colorado River Delta throughout spring migration. These areas are vital migratory routes on the inhabitants stage for dozens of species. Audubon scientists additionally discovered the Central Valley and Colorado River Delta to be migratory “bottlenecks,” as a result of these areas had extremely concentrated numbers of birds in comparison with equally sized geographies on the identical latitude. Protecting the Central Valley and the Colorado River Delta shall be essential in conserving the populations of North American migratory birds into the longer term.
“Spring and fall migration seasons could be probably the most harmful occasions of the yr for migratory birds. We now know greater than ever about chook migration, permitting us to take vital steps to guard them,” mentioned Bill DeLuca, PhD, migration ecologist with Audubon’s Migratory Bird Initiative and first writer of the research. “It’s arduous to overstate the significance of defending birds year-round, and never simply in breeding and wintering habitat, if we wish to safe their future.”
Anna’s Hummingbird, copyright Mark S Szantyr, from the surfbirds galleries
Using knowledge from the Cornell Lab of Ornithology’s eBird Status and Trends staff and inhabitants estimates from Partners in Flight, Audubon scientists summarized the abundance and spatial focus of 112 species of migratory landbirds, week by week throughout the research areas.
Audubon researchers highlighted three main findings:
1) California’s Central Valley and the Colorado River Delta alongside the United States-Mexico border are migration hotspots for tens of tens of millions of migratory birds as they fly up and down western North America.
2) The tens of tens of millions of birds that fly by these areas symbolize main proportions of many species’ world populations. For instance, within the spring, greater than 27 % of North America’s Tree Swallows migrate by the Colorado River Delta, and 80 % of Lawrence’s Goldfinches migrate by the Tulare area of the Central Valley. In the autumn, greater than 5 % of the Black-throated Gray Warblers migrate by the Colorado River Delta, and practically 40 % of Anna’s Hummingbirds migrate by the Central Valley. Full checklist of species and proportions accessible upon request.
3) The Valley and Delta act as migratory bottlenecks. As birds migrate by these latitudes, they funnel into these research areas. These excessive concentrations of birds makes them particularly weak to threats. Migratory chook conservation efforts and analysis ought to subsequently give attention to these key areas.
Audubon California, the state workplace of National Audubon Society, has labored on land and water conservation efforts within the Central Valley for many years.
“We’ve lengthy identified of the Valley’s significance to migrating waterfowl, however we have been astounded on the sheer variety of land-based birds who additionally depend upon the area – as an illustration, practically 40 % of all Anna’s Hummingbirds migrate by the Valley within the fall. This research places an exclamation level on what we have already got come to see because the Valley’s hemisphere-wide significance,” mentioned Meghan Hertel, director of land and water conservation for Audubon California.
The Central Valley and the Colorado River Delta will not be simply vital for regionally breeding birds, they’re additionally vital for widespread migratory birds that individuals take pleasure in of their backyards and parks up and down the Pacific Flyway.
“This research additional demonstrates the outsized significance of the Colorado River Delta, notably for the numerous birds that migrate by, together with 27 % of the worldwide inhabitants of Tree Swallows within the spring and greater than 5 % of breeding Black-throated Gray Warblers within the fall, in addition to many different land birds,” mentioned Jennifer Pitt, Audubon’s Colorado River Program Director. “And whereas the Delta is only a remnant of what it as soon as was—attributable to upstream water diversions, historic drought, and local weather change—we all know that focused and strategic restoration initiatives with our companions in Mexico will end in optimistic outcomes for each folks and birds.”
Many North American landbirds are declining at alarming charges, and we have to know the locations that they depend upon all year long. Audubon’s Migratory Bird Initiative is working with migration researchers and conservation practitioners to make use of the very best accessible migration science to assist steer conservation efforts to those essential landscapes.
To be taught extra about Audubon’s Migratory Bird Initiative, please go to www.audubon.org/migration.