Interior Least Terns: Preservation Through Innovation and Partnerships
The Interior Least Tern is the smallest of the North American terns and has been listed as an endangered species since June 27, 1985. These small shorebirds average 8-10 inches in length with a wingspan of 20 inches. Descriptive identifiers include a black crowned head with a snowy white underside and forehead. As shorebirds, the Interior Least Tern hover over, or dive into, standing or flowing water in order to catch small fish. Interior Least Terns do not breed until they are 2-3 years old. Typically, these birds breed in late summer between June and August. Their preferred habitat is barren to sparsely vegetated sand bars alongside rivers, or sand and gravel pits. They prefer open habitats and breed in isolated areas along the Missouri, Mississippi, Ohio, Red and Rio Grande Rivers. After migrating, this species winters in coastal areas in Central and South America.
Natural and anthropogenic factors have threatened the habitat of Interior Least Terns. This species prefers to live around wide river channels with sandbars, which are naturally created as sediment is deposited through river flow. The creations of dams and reservoirs and changes in river patterns and water flow have severely impacted suitable areas for Interior Least Tern habitat and breeding ground. Additional threats include nest disturbances by human recreational activities in rivers and along sandbars.
How We Are Helping
At Riverlands Migratory Bird Sanctuary a partnership has been created to help the Interior Least Tern population. The US Army Corps of Engineers, the National Great Rivers Research and Education Center and The Audubon Center at Riverlands work together to support the Interior Least Tern species in two ways: construction of a floating barge tern nesting habitat and educational awareness.
The US Army Corps of Engineers created a floating barge habitat for the Interior Least Terns in Ellis Bay (located within the Mississippi River) to provide ideal nesting conditions, create a potential sighting tool for future permanent habitat locations, and restore sandbar habitat to the stretch of the Mississippi River. For construction, they used two dredge pontoon barges and altered them to hold 5 feet of sand/gravel mix. They anchored the barges and attract birds with call boxes and decoys. This season, the floating habitat has been considered a success with 20 adults, 23 hatchlings, and 5 eggs remaining during the last count (updated 7/9/2012).
This year, a group of local high school students took a particular interest in the Interior Least Terns through the RiverVision Leadership Project (supported by The Audubon Center at Riverlands). Participants learned about the endangered status of the Interior Least Terns and visited Riverlands to help prepare the Floating Interior Least Tern Habitat Barge. They also created public service announcements (YouTube videos, art work, books, short stories, songs, and a replica of the barge) for their school and community to raise awareness about the Interior Least Tern and its endangered status.
Matthew Magoc has had a lifelong interest in nature and currently serves as Environmental Education Specialist at The Audubon Center at Riverlands in West Alton, MO. The Center is an excellent location from which to observe the terns in summer.
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