October 2022

As their name suggests, shorebirds spend the majority of their annual cycle foraging, nesting and migrating along coastal habitats. This guild consists of plovers, sandpipers, oystercatchers, godwits and others. Most species in this group are known to undergo lengthy migrations and whether they stop periodically along migratory routes to refuel or fly nonstop between their breeding and nonbreeding habitats, the importance of high-quality fuel cannot be overstated. Highly productive shoreline habitat supplies the requisite food items that propel these birds successfully along their journeys. Habitat modification, human development and climate change have altered coastal habitats and their capacity to provide for shorebirds and, as a result, this guild has experienced significant declines over the past 4 decades. An unfortunate 10 species are considered “Tipping Point” species and include birds such as Lesser Yellowlegs (Tringa flavipes) and Whimbrel (Numenius phaeopus). Sanderling image by Ben Gorman.

Grassland habitats have declined in both extent and quality throughout North America as a result of shifting agricultural regimes, habitat conversion and the rampant use of pesticides. As a result, no other terrestrial bird guild has declined more than grassland birds. In the last 50-years, two thirds of all species contained in this guild have experienced declines, and 6 species are considered “Tipping Point” species, including Bobolink (Dolichonyx oryzivorus) and Henslow’s Sparrow (Centronyx henslowii). Bobolink image by Allen Schenck.

The arid habitats (desert and sagebrush) found throughout the mid-West and Western North America are home to a large but shrinking bird population. While long-term declines have been experienced by all 32 species in this guild, 4 species are considered “Tipping Point” birds, including the Greater Sage-Grouse (Centrocercus urophasianus) and Bendire’s Thrasher (Toxostoma bendirei). The principle drivers of decline include drought, persistent and extensive fire activity and human development. Greater Sage-Grouse image by Kerry Hargrove.

The forests of Western North America have fared better than most other guilds over the past 50-years. Although this sounds optimistic, since the 1990’s the 46 bird species within this guild have declined by 20% and 3 species are considered “Tipping Point” species, including the Rufous Hummingbird (Selasphorus rufus). Scientists are currently hard at work trying to identify the major contributing factors to the declines seen in this guild of birds, but it is believed that a long history of fire suppression in the west is at least partially responsible. Rufous Hummingbird image by Malissa Kelly.

The birds of our Eastern Forests are beginning to show signs of stabilization after long-term decline. While this is encouraging news, there is still much work to be done. Collectively, Eastern Forest birds have declined by 30% over the past 50-years, but this decline has leveled off since the early 2000s. This stabilization is believed to be in large part due to forest restoration and dedicated conservation efforts. The three “Tipping Point” species in this group have also shown signs of improvement. The Cerulean Warbler (Setophaga cerulea) and Wood Thrush (Hylocichla mustelina) are two species that appear to be responding well to dedicated forest restoration projects. Hermit Thrush image by Gail Kahover.

Of all the guilds, that of the waterfowl (ducks, geese and swans) and waterbirds (pelicans, cormorants and allies) has done remarkably well. Long-term, targeted conservation programs and U.S. policy aimed at creating and maintaining wetland habitat are largely to credit for an increase of as much as 1,000% for some species. Despite this increase, the news isn’t all good. When looking at specific groups within the guild as a whole, dabbling ducks, diving ducks and sea ducks have all declined over recent years and 4 species are considered “Tipping Point” species projected to lose another 50% of their population over the next 50-years. Major threats to this guild include climate change, habitat loss and changing wildlife communities. White-winged Scoter image by Tom Younkin.

Why do these 73 species appear in their own guild? Their unique evolutionary history has a great deal to do with the answer. The endemism of birds on the island of Hawaii is incredibly impressive and represents a tremendous amount of biological diversity that needs to be conserved, as once it is lost, it is gone for good. Almost half of all Hawaiian species are already extinct or presumed extinct and 20% of those remaining are on the U.S Endangered Species List. Mosquito borne illness, habitat loss and climate change are to blame for much of this decline. Captive breeding programs and conservation projects are underway to help the most at-risk species, but the future is not bright for Hawaiian’s endemic birds. The conservation hill is steep, but the goal of bringing these species back is essential. Scarlett Honeycreeper image by Nancy Strohm.

Seabirds have been declining for decades and currently, 22% of species within the guild are considered “Tipping Point” species. Climate change is largely responsible for the largest drivers of decline: drowning nesting habitat, changes in prey distribution due to warming seas and increased storm activity. Pollution and invasive species have also been identified as stressors to global seabird populations. The report does not mention the current strain of Avian Influenza that has decimated populations of nesting seabirds in the northern Atlantic during the 2022 breeding season. The combined effects of these factors on long-lived seabirds may very well drive long-term and irreversible changes to populations unless immediate conservation action is taken.