The Demise of a Tropical Coastal Lagoon as Breeding Habitat for Ground-Nesting Waterbirds: Unintended, but Anticipated Consequences of Development

ABSTRACT

Laguna Cuyutlán (Colima, Mexico), an Important Bird Area, used to provide breeding habitat for ground-nesting waterbirds. During 2014 and 2015, nesting efforts of laughing gull, black skimmer, and royal, gull-billed and Forster's terns failed almost completely due to inundation, while least terns and snowy plovers fared the same during 2014. No anomalies in rainfall, tidal level, or coseismic subsidence explained such failure. Rather, the inundations were due to the enlarging of Canal Tepalcates that connects the lagoon with the sea, which was widened from 100 to 300 m and dredged to 17-m deep. Before this, the hydrodynamics were regulated by evaporation and runoff. Now, increased seawater volumes dominate the basin's hydrodynamics. The failure of Laguna Cuyutlán as a breeding habitat for these birds is an important threat for these species, as this lagoon held one of the < 20 colonies known for several of these species along the western coast of North and Central America. Documenting this demise of Laguna Cuyutlán for ground-nesting waterbirds transcends the regional scale as it emphasizes the little consideration still given to biodiversity vs. economic development, and is a warning for coastal projects in other developing areas of the world.

KEYWORDS:

• conservation
• Laguna Cuyutlán
• Laridae
• Mexico

Acknowledgments

We thank two anonymous reviewers for comments that helped to improve this article and Paolo Solano for providing important reports.

Funding

Field work was made possible by internal funds from the Centro de Investigación Científica y de Educación Superior de Ensenada and by personal resources of the authors.