The bald eagle successfully recovered and was removed from the endangered species list in 2007. The recovery of the bald eagle is an American success story. Many other species are not so fortunate, and still need our help to save them from extinction.
Endangered species are animals and plants that are in danger of becoming extinct. Threatened species are animals and plants that are likely to become endangered in the foreseeable future. The US Fish and Wildlife Service determines which species should be listed as threatened or endangered in the United States. Individual states also list as threatened or endangered as populations may vary from state to state.
Here we highlight a few species that are listed as threatened or endangered at the state or federal level, or who are facing challenges to their survival.
photo: International Crane Foundation
The tallest bird in North America is also one of the most endangered. Standing nearly five feet tall, these birds inhabit marshes, shallow lakes, lagoons and estuaries.
The population hit a low of fewer than 20 individual birds in 1941 that migrated between breeding grounds in Canada and wintering grounds near Aransas, Texas. Conservation of habitat helped the flock increase, but still the flock was vulnerable.
Recovery efforts now include hand raising whooping crane chicks using puppets costumed to look like adult whooping cranes so that the young do not improperly imprint to humans. Some of these chicks are released directly (‘DAR’ or Direct Autumn Release) near flocks of adults so that they can learn to migrate from the existing flock. Some young whooping crane are taught to migrate by following an ultralight plane (with a costumed pilot).
Today there are more than 600 individual birds in North America in three flocks (in addition to birds in captivity as part of breeding and reintroduction programs). The natural migratory flock still migrates from Canada to Texas each year. A non-migratory flock was established in Florida and now numbers more than 20 birds. An introduced migratory flock of more than 100 birds winters in Florida and breeds in central Wisconsin.
This beautiful and unique turtle was once widespread across eastern portions of US and Canada. Today, it is found in just a few states, and then in only a few places. Minnesota may host one of the largest remaining populations of Blanding’s Turtles, though it is listed as threatened across Minnesota.
Weaver Dunes, an extensive area of Mississippi River backwaters, marshes and sand dunes, just south of Wabasha, MN is prime habitat for Blanding’s Turtles. However, these turtles face a challenge every year when they head upland to lay their eggs. The upland breeding areas are now separated from their backwater habitat by a highway. Road kill is a major threat and those that do lay eggs may face danger on their return to the river. Turtle eggs are left unattended by parents and are vulnerable to scavengers such as skunks and raccoons. Blanding’s Turtles late maturity (they don’t breed until about 12 years of age) and low reproductive success rate means it is difficult for this species to recover even in the best of circumstances.
Lampsili higginsii were once common in the Mississippi River but have been considered federally endangered since 1976. Higgin’s Eye mussels inhabit large rivers, and are found in areas of deep water with moderate current. They burrow into sand and gravel at the river bottom, opening their shell to siphon for food.
Habitat loss has played a part in the decline of Higgin’s Eye pearlymussels, but the biggest factor by far has been the introduction of the non-native, invasive zebra mussel. Brought to US waterways in ballast water from international shipping, zebra mussels colonize any available hard surface, including the shell of other mussels. Zebra mussels now infest many Minnesota lakes and rivers. When zebra mussels attach to a Higgin’s Eye pearlymussel, they prevent it from moving, burrowing or opening its shell to feed. Citizens can help many native species by following rules established for recreation on lakes and rivers to prevent the spread of this and other invasive and harmful species.
Danaus plexippus Monarch butterflies begin life as eggs which the adults lay on milkweed plants. When the eggs hatch as larvae they eat their eggshells and, subsequently, feed on the milkweed plants. Monarchs appear to lay their eggs exclusively on milkweed. Once common near agricultural fields and surrounding areas across the Midwest, milkweed is now in steep decline. Chemical applications on farm fields can kill all the ‘weeds’, and overspray impacts nearby areas. Mowing of roadside ditches has sharply limited the amount of available milkweed.
Critical habitats that monarchs rely on for food, reproduction, and overwintering are all declining. Pesticide use is also implicated in the decline of monarchs. Pesticides can also affect the adult monarch; the butterflies we love to see floating through the sky. When foraging for food, feeding on nectar and pollen, monarchs and other pollinators are exposed to neonicotinoids. Neonicotinoids are an insecticide that can exist in the nectar, pollen or leaves of a plant months after initial application. Monarchs and other pollinators can be exposed to lethal doses when feeding on these plants.
Status: The U.S. Fish and Wildlife Service initiated a Status Review of the Monarch Butterfly under the Endangered Species Act with a due date for information submission of March 3, 2015. They are working with partner organizations to engage Americans in protecting monarchs and restoring monarch habitat.