WASHINGTON (CN) - The rufa red knot, a small world-ranging shorebird, has been listed as a threatened species under the Endangered Species Act. The U.S. Fish and Wildlife Service noted in Thursday's final rule that poorly-funded conservation efforts are not enough to protect the long-distance flyers.
The action resulted from a 2011 settlement agreement between the USFWS and the Center for Biological Diversity (CBD). Environmental groups petitioned the agency in 2005 on behalf of the red knots. The agency agreed the birds warranted protection but no action was taken due to other listing priorities. The historic settlement agreement created a workplan to speed listing decisions for hundreds of species, including the knots.
The rufa red knot is a robin-sized bird that makes an annual 18,000 mile round trip between the tip of South America and the Arctic. Though the birds have other minor migration routes, the primary route for the largest concentration of the red knots includes an important stop-over in the Delaware Bay, on the northeast seaboard of the United States. There, thousands of birds gather to feast on horseshoe crab eggs, nearly doubling their weight for the flight to the Arctic, where they nest.
Eel and conch fisheries in the mid-Atlantic area have traditionally used horseshoe crabs as bait, and the biomedical industry uses the crabs' blood in medical testing due to the blood's unique properties. The overfishing and overharvest of horseshoe crabs contributed to a steep decline in the red knots' most important refueling resource, which in turn led to the birds' 75 percent decline since the 1980s.
Conservation efforts have curbed the use of the crabs for bait, and the medical industry has modified its approach to use catch and release methods for crab blood harvesting, but these changes have been inconsistently applied. "Monitoring necessary for the implementation of the management framework was not conducted in 2013 or 2014 due to lack of funding; thus, the framework is not currently being implemented as it was intended to function," the USFWS noted in the regulation. In addition, horseshoe crabs take up to 10 years to reach maturity, resulting in a "biological time lag" in rebuilding the crab stock.
Meanwhile, climate change has caused timing mismatches that affect the birds throughout their migration and breeding areas. The birds must arrive in Delaware Bay at the time the crabs are laying eggs, for example. In the Arctic, the lemming cycle affects the degree of predation on bird eggs. In years when lemmings are plentiful, the foxes and other predators do not prey as heavily on the birds' eggs and chicks. Both of these natural cycles have been affected by climate change, the agency said.
"Although historic threats in the Delaware Bay area have been ameliorated thanks to the actions of federal and state partners, our changing climate is posing new and complex challenges to the red knot's habitat and food supply," USFWS Director Dan Ashe was quoted as saying in the agency's press release. "It has never been more critical that we take positive action to save this bird."
Sea-level rise, coastal development, oil spills and wind farms also threatened the birds, causing damaging changes and reductions in their habitats, according to the action.
"With today's decision to protect the red knot, our children and grandchildren just may have the chance to marvel at one of nature's greatest spectacles, the marathon migration of the red knot," the CBD's senior scientist Mollie Matteson was quoted as saying in the group's response to the listing action.
There were only minor changes from the listing proposal published in September 2013. The agency is planning to designate critical habitat for the birds next year.
The final listing is effective Jan. 12, 2015.