Summary of Interior Least Tern Research and Monitoring Workshop

ERDC TN-DOER-E17

September 2004

Summary of Interior Least Tern Research

and Monitoring Workshop

PURPOSE: This technical note summarizes the

results of a national workshop on the federally

endangered Interior Least Tern (ILT) (Sterna

antillarum athalassos) (Figure 1) held April 15-

16, 2004, in South Sioux City, Nebraska. The

purpose of the workshop was to assemble an

interagency group of ILT experts that could pro-

vide input to the development of a range-wide

monitoring protocol to assess the status, distribu-

tion, and abundance of the species. The informa-

tion presented herein is derived from presenta-

tions made during the workshop by representa- Figure 1. The Endangered Interior Least Tern

tives of the U.S. Army Corps of Engineers (Sterna antillarum athalassos) breeds primarily

(Corps), U.S. Fish and Wildlife Service on sandbars associated with river systems

(USFWS), U.S. Geological Survey (USGS)

(Biological Resources Division), American Bird Conservancy (ABC), and various state agencies

and universities.

BACKGROUND: The U.S. Army Corps of Engineers (Corps) is responsible for managing and

maintaining navigable coastal and inland waterways of the United States. Activities associated

with waterways maintenance, including dredging, dike construction, dredged material disposal

operations, beach nourishment, and variable dam discharge actions, often conflict with federal

and interagency mandates to protect populations of the endangered Interior Least Tern. These

conflicts often result in a lack of flexibility and increased costs in waterways maintenance. The

specific impacts of Corps operations on ILT populations are poorly understood. Without this

information, management options to mediate Corps impacts are severely limited, and efforts to

meet recovery goals for the ILT are compromised.

In December 2002, representatives from three Corps Divisions (Northwestern, Southwestern,

and Mississippi Valley), Corps Headquarters, and seven Corps Districts attended a meeting in

Tulsa, OK, and identified several actions to facilitate the ability of Corps managers to resolve

conflicts of waterways operations while protecting ILT populations. One major concern noted

during the 2002 meeting was the current lack of coordination and infrastructure that hampers

efforts to effectively monitor and assess the status of ILT populations.

The current status of the ILT population, relative to recovery goals published in the ILT Recov-

ery Plan (Sidle and Harrison 1990), is of considerable concern to the Corps. Currently, the total

numbers of birds range-wide may exceed recovery goals established in 1990, although goals for