Monday, May 18, 2015

The Pigeon Guillemots of Montaña de Oro

Of all my favorite birds, the Pigeon Guillemot (Cepphus columba) is number one.  During the breeding season, their rounded body is very black with brilliant white wing patches (photo by Mike Baird).  Their legs, feet, and mouth lining a brilliant orange-red; the feet are so red they look like they have been photoshopped.

Montaña de Oro's rocky shoreline with all its nooks and crannies provides the Pigeon Guillemot with ample areas to nest.  Like clockwork, every March, these hardy little sea birds arrive in Montaña de Oro.
 The Pigeon Guillemot uses its short strong wings to swim while searching for food, diving to depths of 150 ft.  When not feeding, they often rest on cliff edges (above photo).  By vigorous flapping of their wings, combined with the use of sharp claws on webbed feet, the Guillemot is able to climb the steep, rocky cliffs. 

A few days ago, from the Bluff Trail, I observed several pairs of Guillemots acting very frisky, with much splashing, wing stretching, and shallow dives.  I focused on a pair that was the easiest to view. For the ease of explanation I will call them Frank and Doris.  I would describe their antics as a pre-mating ritual.  Like some males Frank was the aggressor.  Doris was enjoying the attention but was rather standoffish, not ready for the grand finale.  Frank would close in, and Doris would scoot out of reach.  They participated in this behavior repeatedly.  Twice they flew to and from a nesting hole in the cliff. 

 As Frank (above photo, lower right) chased Doris he was constantly chatting.  Unable to understand the high pitched sounds, I made an unscientific assumption.  Frank was telling Doris that time was of the essence, as they must return to sea mid August.  He was reminding her that incubation takes at least 30 - 32 days, and then there is the intense 35 - 50 days of feeding the little darling; two eggs may be laid, but only one chick will fledge. (below photo - Doris checking out a nesting area)
Both parents incubate the egg and bring small fish to their chick.  Success raising a chick to maturity depends on the weather, the impact of human activity, and the warming ocean and its disastrous affect on the food chain.  Hopefully, Doris and Frank will incubate an egg, produce a healthy, well adjusted nestling which will one day return to the rocky cliffs of Montaña de Oro.