Wintering Plovers

Effective conservation management needs to consider all life cycle stages of a threatened species and protect sufficient habitat. To improve Snowy Plover conservation it is  important to know where they breed but we also need information about where they spend the rest of the year.

Snowy Plover populations are either migratory or resident. Whereas many populations from the US have to migrate because of cold winters the climate in Mexico is good for them all year. The migratory plovers might move hundreds or thousands of kilometers. But particularly where the Inland Snowy Plovers overwinter is poorly known.

In Mexico Snowy Plover conservation and research is slowly picking up but still in its infancy. At Bahía de Ceuta  have marked hundreds of adults and chicks since starting the project years ago. Despite these efforts only a handful of color banded individuals from Ceuta have been resighted elsewhere. Other teams from Mexico have similar experiences. By contrast, we often see new usually unmarked immigrants and have no idea where they come from, especially in winter. Or how long they stay. Or where they stop. We suspect that many of these unknown plover are just staying for the winter and use this and other Mexican wetlands as wintering site.  Remarkably, one plover female marked breeding at Texcoco Lake, Mexico City, was recently resighted in Oklahoma traveling more than 1000 miles in between the two sites. 

In Utah Snowy Plovers are regular summer guests. But nobody knows where they spend their winter. We are currently trying to figure out to what extent the Utah Snowy Plovers overwinter in Mexico. For this we teamed up with Snowy Plover biologists from Baja California, Mexico City, Nayarit and Utah and the project got funding from Tracy Aviary Conservation Fund (if you like this project you can make a donation here by selecting 'Snowy Plover' when asked for your inspiration). Since beginning of 2013 we have visited monthly the beaches and wetlands at four sites in Mexico and have looked for banded plovers. 

The first two winter monitorings were very successful. Overall the Mexican teams made more than 5000 sightings of Snowy Plovers. Most of these plovers didn't have color bands. Moreover, light conditions are often difficults and color bands are muddy and therefore cannot be identified. This means that for the vast majority of the Snowy Plovers we don't know where they came from. But for about every tenth sighting the biologists were able to read the full band combination. From this we learned that most Snow Plovers had  been marked at (or near) the re-sighting location during previous breeding seasons. In 2013 we got very excited about fourteen banded Snowy Plovers seen in Baja California. They had band combination unknown to us and we were able to trace them back to coming from California and even one Snowy Plover male who had been breeding in Utah the year before. In 2014 we then found even more evidence that interior Snowy Plovers overwinter in Mexico. In February 2014 we banded a male Snowy Plover in Ceuta and this male was found nesting three months later in Utah. This means that there is definitely some contact between Pacific and interior Snowy Plovers. This fits to what we see at the breeding grounds and the result of genetic studies but needs further careful exploration/monitoring and more banding efforts. 

A concentrated cross border banding and resighting effort will increase the chances that we can establish origin of wintering guests and movements of this migratory species. In January 2014 we held a re-sighting and wintering workshop in San Quintin, Baja California. At this place we had previously struggled to capture wintering plovers and we managed to band 17 Snowy Plovers. A few of them since then have been seen in California.

We are very happy that the conservationists from Tracy Aviary were as excited as we about the progress. They have decided to continue their support of our project and we will be able to run the winter monitoring.

This male Snowy Plover was nesting in May 2012 at Great Salt Lake, Utah and resighted in January 2013 near San Quintin, Baja California. We hope he'll make it back this year to breed in Utah again. Daniel also spotted several wintering plovers from California at his site.  Photos by Jonathan Vargas and Daniel Galindo.


Another male Snowy Plover making the journey from Mexico to Utah in 2014.
The male was caught in February 2014 at Bahía de Ceuta and then captured again on a nest at Fish Springs, Utah in June. This male even managed two hatch two chicks. Photos by Medardo Cruz and Kristen Ellis.