Bon Homme County, South Dakota
Note: This information is provided for reference purposes only. Although the information provided here was accurate and current when first created, it is now outdated.
Pesticide Table | About the Least Tern | About the Piping Plover
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Table of Pesticide Active Ingredients
|3s||Within the shaded area shown on the map and 2 miles up all streams that join the shaded area, do not apply this pesticide within 100 yards from the edge of water for ground applications, nor within 1/4 mile for aerial applications.|
Least tern [Sterna antillarum antillarum] (interior population)
Least terns are among the smallest of the terns, measuring 8 to 9 inches in length. Both sexes have a black cap and nape, white forehead, grayish back and wings, white belly, orange legs, and a black-tipped yellow bill. Immature birds have darker plumage, a dark bill, dark eye stripes, and white heads. A special characteristic of the least tern is the "fish flight" the male performs during courtship. This high-flying aerial display with one or two other terns is done while carrying a fish in his bill that the female takes and eats. Female terns usually lay one to four eggs around late May to early August in colonies of about 20 small ground nests.
Least terns occur along coastal areas and along rivers with sufficient breeding sites; only the "interior" populations (more than 50 miles from coasts) are considered endangered. Preferred river systems for the interior least tern are those with bare or nearly bare alluvial islands or sandbars, favorable water levels during the nesting season, and food availability. Historically, interior Least terns bred along the Colorado, Red, Rio Grande, Arkansas, Missouri, Ohio, and Mississippi Rivers. Current studies indicate that this tern is extremely limited in both numbers and distribution. It is now considered rare throughout most of its interior range but recent studies have documented significant increases along the Mississippi River. The exact wintering area for the tern is unknown; however populations have been known to winter along the Central American coast and the northern coast of South America from Venezuala to northeastern Brazil.
The main reason for this species' decline is the reduction in suitable nesting habitat throughout the central and western United States. This is largely due to increased vegetation brought by man-made changes in river flow. Other disturbances, such as recreational activities that disturb nest sites, housing construction and development, continue to threaten tern populations.
The U.S. Fish and Wildlife Service has developed a recovery plan that describes the actions considered necessary to conserve this species. Research is being conducted into the tern's habitat requirements, breeding patterns, lifespan, and winter residence. Increased public awareness and habitat protection are also projects that are currently being undertaken to help prevent this species from becoming extinct.
Matthews, J.R (ed.), The Official World Wildlife Fund Guide to Endangered Species Vol. II, Beacham Publishing Inc, Washington, DC. pp. 697-697.
Piping plover [Charadrius melodus]
The Piping plover is a stocky, short-billed shorebird, approximately 7 inches long. It has sand colored wings, a black chestband and crown patch, a white underside, and an orange bill and legs. The plover feeds primarily by probing in the sand to catch small crustaceans, mollusks, and worms. Some insects are taken opportunistically.
The breeding season for the Piping plover is from late March to August. During this time, distinct black stripes appear on the bird's breast and forehead. Also at this time the Piping plover calls melodiously, hence the description "piping" and the species name melodus. During the courtship ritual the male flies in figure-eights and struts, whistles and puffs up its feathers around the female. The female lays four eggs at a time in a small, shallow nest lined with pebbles or broken shells.
The Piping plover historically bred in the Northern Great Plains of the United States and Canada, the Great Lakes beaches, and the Atlantic Coast beaches. Currently, the species' range remains similar to its historic range, except that very few birds remain at any of these sites. For the most part, the Piping plover has begun to retreat northward into Canada and along the northern Great Lakes. The Lake Michigan shoreline in Illinois, Long Point, Ontario, and other habitats in Michigan were also once common habitats for the plover, but it now rarely resides or breeds in these locations. In the fall, the plover migrates south and winters along the Gulf Coast, the southern Atlantic Coast from North Carolina to Florida, and some Carribean Islands. Population estimates of Piping plovers indicate that this species has experienced a serious population decline throughout the United States.
Much of the decline of this ground nesting bird has been caused by human disturbance of its habitat. The plover is extremely sensitive to the presence of people and is easily scared off its nest, which makes it easier for predators (such as gulls, skunks, foxes, dogs, or cats) to attack the nestlings, or for the young to be separated from their parents. Off-road vehicles and recreational activities have destrupted nesting habitat and continues to be a problem for plover reproduction. Along rivers and beachfronts, human interference with natural water flows for development has allowed vegetation to take over riverbanks, making them unsuitable for nesting. There is also some potential for pesticide exposure when plovers are feeding in or near agricultural fields.
The U.S. Fish and Wildlife Service has devised a recovery plan that sets a goal of 1,200 breeding pairs, a number suitable for delisting consideration. In order to achieve this goal, the FWS has made efforts to reduce nest disturbance by pedestrians, off-road vehicles, and predators. These include fencing, rerouting off-road vehicles, enforcing pet leash rules, removing litter and removing predators. In addition, an existing public information program is being expanded to alert beach dwellers and recreational users to possible harm they can cause the Piping plover.
Matthews, J.R (ed.), The Official World Wildlife Fund Guide to Endangered Species Vol. II, Beacham Publishing Inc, Washington, DC. pp. 590-593.