Population Status of American Oystercatchers (Haematopus palliatus frazari) Breeding in Northwest Mexico

Abstract. The western race of the American Oystercatcher (Haematopus palliatus frazari) is a resident and endangered shorebird of western Mexico. Its breeding population and conservation concerns are poorly known, but recent information indicates extremely low numbers and a discrete breeding distribution. Because of loss and degradation of sandy beaches by coastal development and disturbance from human recreational activities, the American Oystercatcher is a priority species in the Shorebird Conservation Plans of the United States and Mexico. Research on its distribution and abundance during the 2009 breeding season resulted in the identification of 2,286 adults in northwest Mexico. Although the population is higher than previous estimates, its distribution is more restricted than expected. It is distributed almost exclusively in northwest Mexico, and 80% of the total breeding population is found on the islands of Sinaloa and Baja California Sur. Based on these results, this species was officially federal...