Tuesday, August 5, 2014

Seeing the effects of "El Niño"

El Niño Southern Oscillation (ENSO) is, as its name suggests, an oscillation of the ocean-atmosphere system and is characterized by unusually warm ocean temperatures in the Equatorial Pacific.  The fishermen in northern Peru noticed that these phenomena usually occurred during the last months of the year, associating it with Christmas and with the niño Jesus, hence the name.  During strong El Niño events, the birds populations along the Humboldt Current disperse looking for reachable source of food.
Peruvian Boobies resting in a rocky island off the coast of Lima (Peru)
One particularly susceptible species is the Peruvian Booby.  They specialized in capturing anchovies by bomb-diving in rich waters of upwellings; however, when the water temperature rise, these anchovies schools move to deeper waters or migrate to other latitudes, out of reach for the boobies.  So, the presence of several Peruvian Boobies in the coast of Panama City is not exactly a good new.  The last time we saw such numbers of Peruvian Boobies (during the 1982-83 El Niño) at our coasts, the population collapsed in their usual range... from 3 to only 0.2 millions of birds!
Peñón de San José
The first Peruvian Booby recorded this season was found weakened in the Amador Causeway, in Panama City.  Its story appears in this article and in this Xenornis report.  Then, more than one month later, more Peruvian Boobies were seen in Panama City, specifically at a rocky islet known as Peñón de San José, 1.6 km to the south of the Flamenco marina at the end of the Amador Causeway (except for a photogenic individual found in private property in Punta Pacifica).  Yesterday, I joined Rosabel Miró (who photographed the Punta Pacifica bird and found the first Peruvian Booby at the islet), Michele Caballero and Andrea Carrillo to the Amador Causeway in order to aim the scopes towards the islet.  Leslie and Cindy Lieurance were already scoping the islet and, after a while, Darien Montañez and Osvaldo Quintero joined us as well.
Soon, several Peruvian Boobies started to appeared; both resting and flying.  They were too far away for our DSLR cameras, and my poor attempts to digiscope these birds produced the marginal photo I'm showing next:
Peruvian Booby (yes... in the center of the picture)
I know it is not too much... but the clean-white head and neck, contrasting with the dark and slightly checkered back is evident.  These birds (at least five different individuals... surely more) were mixed with Blue-footed Boobies.  A large flock offshore of boobies floating in the ocean may have had more individual.  I'm sure this is only the tip of the iceberg, and that we will have more and more Peruvian Boobies at our coasts, so stay alert!

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