Three years ago I heard about an interesting project at Lake Atotonilco – a RAMSAR (protected) wetland located alongside the town of Villa Corona, located 30 kilometers west of Lake Chapala.
An organization called Eco Kaban was working there to study Charadrius nivosus, the endangered snowy plover, known as el chorlito nevado in Spanish.
Several of Jalisco’s most active bird watchers invited me join them for a visit to the lagoon. To my surprise I discovered that the snowy plover makes its nest not among bushes or rocks, but out on the flattest, most exposed spot it can find on beach. “Nest,” however, is just a euphemism, as there is nothing to it but a slight depression in the sand. Naturally, this means the plover’s eggs are constantly being eaten by predators, stepped on by cows, and driven over by ATV enthusiasts.
“Cabezas de chorlito!” I couldn’t help exclaiming. “Why do these birds lay their eggs out in the open?” I asked the leader of the project, biologist Said Felix, whom I found bending over a cluster of three little eggs, with a caliper in one hand and a clipboard in the other.
“Believe it or not,” he told me, “the reason is that plovers have to perform a little ritual for choosing a nesting site, and it can only be done on soft sand or mud, in a flat, open spot. Here the male uses his feet to dig three slight depressions. The female then inspects each spot for quality, chooses whichever she considers the best and then drops little pebbles – or pieces of colored glass, if she can find them – all around the winning depression, and that is where she lays her eggs, whether or not we think it’s logical.”