Bird of the Month: Peruvian Booby

The Peruvian Booby (Sula variegata) is endemic of the cold current along the west coast of South America, from Ecuador to Chile.  However, under abnormal conditions, they wander north, up to Panama.  In fact, we are experiencing an "invasion" of this species at our country.

Peruvian Boobies in Peñón de San José, august 9th

Everything started last june 22nd, when one individual was found weakened in Panama City's Amador causeway.  This bird was taken to the Summit Gardens where a veterinarian examined it; however, the bird died the next day.  This report passed unnoticed until it was published in this article.  More than one month later, Panama Audubon's Society (PAS) Executive Director, Rosabel Miró, received an intriguing email from a 13 years-old girl with photos attached showing a Peruvian Booby.  The girl took the photos from the balcony of her apartment in an exclusive development in Panama City.  The next day, august 2nd, Rosabel and other PAS members visited the site, finding the Peruvian Booby (photo in this Xenornis report).  Another PAS member, Rafael Lau, managed to visit the actual balcony where the booby was found.  This individual appeared in june 22nd (thus matching the date of the first record) and was sleeping in the site each night since then.  The owner of the balcony refers that she fed the bird the first weeks because it looked "sick", accepting water and bred until it got better (report with photos here).

Peruvian Booby over Peñón de San José, august 9th

Rosabel insistence paid off when, while scoping the rocky islet Peñón de San José, 1600 meters away of Flamenco island (linked to the city by the Amador's causeway) on august 3rd, she spotted a Peruvian Booby among dozens Blue-footed Boobies.  It was late in the afternoon and the next day a group of birders scoped no less than five Peruvian Boobies in the islet.  Since then, many observers have reported the Peruvian Boobies from the islet.  The highest count was made on august 9th, with no less than 38 adults counted from a boat circumnavigating the islet.  The last time I personally check this group of birds was on august 31st, when I spotted 4 of them from the ferry to the Pearl Islands.

Peruvian Booby in Pachequilla Island, august 31st

So far, the Peruvian Boobies were reported only from or near Panama City (Amador's causeway, Punta Pacífica in Panama City, Peñón de San José and unpublished sightings of birds feeding at sea in front of Costa del Este, in Panama City).  However, during my last trip to the Pearl Islands, we found 7 Peruvian Boobies resting in Pachequilla Island close to Contadora Island.  This is an important record since other observers found none in previous visits.  Also, we should remember that, during "El Niño" of 1983-84, the Peruvian Boobies were reported from the Pearl Islands as well in impressive numbers (3490 birds were counted in Pacheca Island on june 17th, 1983).

Peruvian Booby over Pachequilla Island, august 31st

There is only one report of a Peruvian Booby in Panamanian waters apart from these invasions, an individual resting at sea in front of Juan Hombrón beach, Coclé province by Carlos Bethancourth (report in Xenornis).  These invasions are quite rare, and we must make every effort to document them in detail.  There are few published papers about the 1983-84 invasion, and only one report in eBird of a Peruvian Booby in Bona Island (Upper Bay of Panama) by Chuck Aid on april 3rd, 1983.  For these, and many other reasons is why we chose the Peruvian Booby as our Bird of the Month!

Blue-footed and Peruvian Boobies in Peñón de San José, august 9th.  Can you tell them apart?

Literature consulted:
1.  Ridgely R, Gwynne J. A Guide to the Birds of Panama. Princeton University Press 1989.
2.  XENORNIS. At http://www.xenornis.com/