Rocks & Shoals

In 1989, TILT received a grant to study the undeveloped islands in the river. The study indicated that “When people and boat traffic are present, some birds no longer use the islands for nesting (Common Terns, loons), loafing and feeding areas are lost, and changes occur in the types of vegetation due to soil disturbance, trampling and introduction of alien species…The loss of native vegetation which accompanies island development affects the visual quality, stability of the soil and other ecological relationships. Problems with sewage disposal on rocky islands can result in health and water quality hazards.”

TILT had purchased a number of small rocks and shoals and was given several more, but there still remained many unowned and undeveloped shoals that could be developed. TILT acquired all undeveloped shoals under one-half acre in size by quitclaim deed, and has protected them.

The Eagle Wings Shoals in Clayton were purchased by TILT in 1991. At the time, the islands were of critical importance as the only productive nesting site for the Common Tern in the western Thousand Islands. The Common Tern is designated as a Threatened Species by NYS and a Species of Concern by the US Fish & Wildlife Service. This is primarily due to a loss of nesting habitat and competition with gulls. The Eagle Wings are premier tern habitat, except that gulls eat eggs and chicks.

Dr. Lee Harper helped TILT and Save The River! install a gull exclusion grid on the Eagle Wings which has been maintained since 1992. The grid is made of filament line that is spaced in such a way that terns can fly in and under it while gulls cannot. The grid is installed in April before the terns start nesting, and is removed in August (on a TILTrek) after the chicks have fledged. While other factors may play a role in whether the colony has a successful hatching year (weather, water level, other predators) it is clear that the grid does protect the colony from gull predation.

In 2009, Save The River! and TILT installed another gull exclusion grid on Tidd Island, a small islet near Thousand Island Park. This island was donated to TILT in 2005, and is also perfect tern nesting habitat. We will keep you posted as to its success.

Click here for more information about the Common Tern Project.