By: Medardo Cruz-López, Mexican Snowy Plover monitoring network (CHORLNEV).
I saw my first Snowy Plover (Charadrius nivosus), one of the most threatened shorebirds in the Americas, in 2006. However, my first meeting with this charismatic species was not wholly positive. I was part of a group of biology students visiting Playa Ceuta in Sinaloa, México to work on our projects. During the night, a British doctoral student approached us to tell us that he was working with the Snowy Plover and their chicks at the Salina de Ceuta. He informed us that a few of us had entered into the nesting zone without realizing, and had nearly crushed some of the nests! I became so enamored with this species and the work that was being done with it that a year later, I too became part of the Bahía de Ceuta Snowy Plover Project. Little by little, I became intimately acquainted with the species, and began to understand why biologists and researchers across the world study it.
Panoramic view of Bahía de Ceuta. Photo: M. Cruz-López.
Both Snowy Plover parents incubate the eggs for around 25 days, with the females sitting by day and the males by night. After the chicks hatch, the females often abandon them to look for another mate to breed again, leaving the male to look after the chicks until they reach independence at about 25 days. As we were learning about these behaviors, we observed that the population at Ceuta was changing, and we saw an alarming decline in their abundance. Researchers at other sites in Mexico began to monitor other populations of the species, discovering that the majority of other populations were also in decline. Because of this data-gathering effort, the Snowy Plover was declared a threatened species under the Mexican legislature in 2010.
Male incubating eggs. Photo: L. Eberhart-Hertel.
With a large number of colleagues interested in the population trends of the Snowy Plover in the country, they formed a monitoring network for the Snowy Plover in Mexico (“CHORLNEV” – after the Mexican name Chorlito Nevado). Snowy Plover monitoring programs were started in four of the most important populations: Complejo lagunar San Quintín in Baja California, Playa Ceuta in Sinaloa, Marismas Nacionales in Nayarit and Lago Texcoco in the State of México, all of these WHSRN sites. As the years have passed, new sites have joined the monitoring effort. Unfortunately, other populations have been lost, such as that at Texcoco, which fell due to the construction associated with an airport that was to be built at the site. Threats that the species faces in Mexico include habitat loss, human disturbance, and hydrological changes of coastal wetlands, and continental lagoons caused by landscape alteration (aquaculture farms, reduction in flow to continental lagoons and agriculture).
Left: Training workshop for the standardization of monitoring methods for Snowy Plover and attachment of GPS receptors. Right: One of our collaborators putting GPS receptors on reproductive adults at Laguna de Atotonilco in Jalisco. Photos: M. Cruz-López.
This collaborative network develop several cooperative projects. Currently, in the Bahía de Todos Santos and Playa Ceuta, two projects are being implemented as part of the Coastal Solutions Fellows Program of the Cornell University Ornithological Laboratory. Both projects look to protect and improve the breeding and wintering habitat of the Snowy Plover, in the process bettering the habitat for dozens of other species that also make use of them throughout the year.
So thanks to the collaboration and continued support of that doctoral student, Dr. Clemens Küpper and Dr. Luke Eberhart-Hertel (members of the Max-Planck Institute for Ornithology), we are now working on a project to learn about the movement of the species between populations and the habitat use of the Snowy Plover during the breeding season, by placing GPS-receptors on adults at five of the seven populations in the CHORLNEV network (San Quintín, Bahía de Todos Santos, Alto Golfo de California y Delta del Río Colorado in Baja California-Sonora, Playa Ceuta, Atotonilco in Jalisco, Laguna del Carmen Puebla, and San Crisanto in Yucatán).
Left: Fences to protect the nests of the Snowy Plover at Bahía Todos Santos. Photo: J. Vargas. Right: Information sign and fence (in collaboration with Pronatura Noroeste) to control access to the Old Saltworks at Bahía de Ceuta. Photo: M. Cruz-López.
CHORLNEV has grown in the last few years and there are a pair of potential new sites that could soon be incorporated into the network. We hope that it keeps growing and becoming stronger, as it has allowed us to join forces and work together for the common good of one the most interesting shorebird species that inhabits the beaches, coastal wetlands and continental lagoons of Mexico.
For more information visit the webpage of the Ceuta Snowy Plover Project (www.chorlito.org) or contact Medardo Cruz-López (mc2657@cornell.edu), coordinator of the Mexican Snowy Plover monitoring network (CHORLNEV).
Cover Photo: Male Snowy Plover at the nest with a recently hatched chick (note the GPS-receptor antenna). Photo: L. Eberhart-Hertel.
