In August 2006 a further grant was awarded for the continuation of this project.

With the discovery, in 1998, of a mixed colony of Royal Tern, Cayenne Tern and South American Tern on Isla Verde Island many questions arose about the population movements and their biology. During the 2005 breeding season, Sterna-Averaves Project studied this mixed colony of Royal Tern and Cayenne Tern on Isla Verde Island (Rocha), Uruguay.

Main results indicated that a high rate of interactions with Kelp Gull (Larus dominicanus) influenced the spatio-temporal dynamics and caused the failure of the colony with none reproductive success. This dynamic were mainly given by inter-specific competition for nest sites between terns and gulls and predation by gulls of eggs and chicks terns.

Anecdotic information suggests that Kelp Gull numbers had increased in the last decades in Uruguay. This fact could negatively affect the breeding of the tern colony in the medium-term. Also, Kelp Gulls takes advantage of artificial food sources, which could be the reason of its population expansion in Argentina. Therefore, the goal of this project is to evaluate in what extent Kelp Gull affects, and could affect in the future, the tern's breeding on Isla Verde Island.

During 2007 breeding season, we will study more deeply the interactions between Kelp Gull and breeding Terns, and evaluate those with human activities. The breeding population size and breeding success of Kelp Gull on Isla Verde will be determined. Also, we will continue studying the breeding ecology of the mixed tern colony monitoring their breeding success, spatio-temporal dynamics, population size and their regional movements.

Educational work and diffusion of our project will be carried out in "La Coronilla" and "Punta Del Diablo" Towns. This project will contribute substantially to determine the conservation status of Royal and Cayenne Tern in Uruguay and in the region. Results of this project will give information about the dynamics, life cycle, regional movements and threats of the tern breeding population on Isla Verde. Interactions between gulls and terns and the breeding biology of these species in Uruguay will be better known.

This project will be the beginning of a long term study program that will allow us to know the population trends of the breeding assemblage and their breeding biology, at an adequate timescale, that will be very important for our conservation work in the area.