Birding: Study details significant declines in many bird populations - Press Herald

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Grassland birds are suffering the declines and most are on the eastern Great Plains, but one of the six tipping-point species – the bobolink – occurs in Maine and is declining. E. Jason Wambsgans/Chicago Tribune

An important assessment of the bird populations in the United States has just been published. “State of the Birds of Report: United States of America 2022” was produced by a consortium of governmental agencies, non-government conservation organizations and professional ornithological societies. I am pleased to see that one of the participating organizations is the Biodiversity Research Institute based in Gorham.

As you no doubt suspect, this report is alarming. Since 1970, the United States and Canada have lost three billion breeding birds, a loss of 25%.

Seventy species are at a tipping point. Without significant intervention, the risk of extinction of these species looms large. For the purposes of this report, a tipping-point species is on a trajectory to lose 50% of its population in the next 50 years.

Declines of our bird populations are pervasive, and they are showing declines in every habitat except wetlands. Grassland birds are suffering the greatest declines. Most of these 24 species are on the eastern Great Plains, but one of the six tipping-point species – the bobolink – occurs in Maine and is declining here.

Eastern forest birds show a 30% loss since 1970, but the curve has leveled off since 2009. Stopping the decline is great, but we need to get the curve on an upward trajectory. The tipping-point species in this habitat (including Bicknell’s thrush evening grosbeak) have declined by 63% since 1970, but the rate of their decline has slowed a bit.

Two species of concern in the eastern forest are the wood thrush and cerulean warbler. The former can be found in Maine. A partnership called the Appalachian Mountains Joint Venture involving over 50 organizations from Alabama to New York has helped to stabilize the cerulean warbler populations and increased the growth of the wood thrush populations.

Seabirds are declining around the world. One study showed a 70% decline in seabirds since 1950. In the Gulf of Maine, Atlantic puffins are at the mercy of climate change. Since 2012, the Gulf of Maine has experienced four periods of marine heatwaves. The preferred fish prey for the puffins has declined due to the warmer temperatures, and the puffins cannot find sufficient food to feed their chicks. The summer of 2013 was particularly severe, with a nearly 90% reduction in fledged young.

Shorebirds show dramatic losses in the past 30 years. Ten of the 29 species considered are tipping-point species, including regular Maine migrants like American golden-plover, lesser yellowlegs, pectoral sandpiper, ruddy turnstone, semipalmated sandpiper, short-billed dowitcher and whimbrel. Protecting these species is daunting because these birds are long-distance migrants. Habitat destruction on their arctic breeding grounds, their southern wintering grounds and their migratory stop-over areas represent a multi-pronged threat.

Wetlands give us cause for hope. Many species of waterfowl have bounced back, thanks to conservation programs, wetlands restoration and funding provided by duck stamps. The 22 species of dabbling ducks and diving ducks have increased by nearly 50% since 1990. Seven species of geese and swans are currently near historic population levels, increasing six-fold since 1970. This increase is primarily due to their use of agricultural fields and urban habitats. Think Canada geese.

The Endangered Species Act (ESA) is an important tool for conservation of species under threat of extinction. The ESA has been the fulcrum for recovery of some bird species, including brown pelicans, bald eagles and peregrine falcons devastated by the DDT crisis. But we need to act to maintain our bird populations before they reach threatened or endangered status.

Just as a rising tide lifts all boats, conservation measures to protect and sustain birds benefit other wildlife as well. A diverse biological community is a stronger and more stable community. Bird conservation promotes environmental justice, ameliorating environmental inequities by improving habitats that have been particularly harmed by human activities.

Herb Wilson taught ornithology and other biology courses at Colby College. He welcomes reader comments and questions at [email protected]

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