Two species of freshwater mussels and the rufa red knot shorebird are among the latest considered for protection under the Endangered Species Act.
The US Fish and WIldlife Service (FWS) announced plans to list the Neosho mucket mussel as endangered and the rabbitsfoot mussel as threatened Sept. 17, with protection going into effect 30 days after the new rules are published in the Federal Register.
According to the FWS, the former is found in Missouri, Arkansas, Oklahoma and Kansas; however, only one population has been identified as reproducing at a rate that can sustain the species.
"We estimate the Neosho mucket has been lost from about 62 percent of its historical range with only 9 of 16 historical populations remaining," a FWS release states. "This mussel is declining throughout its range with only one of the remaining nine populations considered a large, viable population."
Though found in 15 states, wildlife officials estimate the rabbitsfoot mussel has undergone a 64 percent reduction in its historical range, with only 51 of 140 populations left -- 11 of which are considered viable.
The rufa red knot shorebird, meanwhile, lives in 25 countries and 40 states. The FWS cites climate change and direct human interference as significant threats to the animal's continued existence.
"The rufa red knot is an extraordinary bird that each year migrates thousands of miles from the Arctic to the tip of South America and back, but -- like many shorebirds -- it is vulnerable to climate and other environmental changes," Service Director Dan Ashe said in a statement. "In some areas, knot populations have declined by about 75 percent since the 1980s, with the steepest declines happening after 2000."
Loss of habitat due to sea level rise and shoreline projects as well as reduced food supplies as a result of commercial harvesting of horseshoe crabs are among the challenges facing the bird, according to the FWS.
The proposed rule is available for public comment through Nov. 29.