Day 15 |
Oct 26, 2008

Islas Pescadores, Peru

By JJ Apéstegui

Noon Position: 11° 46.1’ S, 077° 15.7’ W

Weather: Overcast morning with comfortable temperatures, a brisk breeze at sea in the afternoon with clear skies

This morning found us at the Islas Pescadores archipelago with the intention of doing an outing on our Zodiacs. The seas were calm, facilitating the disembarkation, and the islands were literally covered in birds. And guano, or bird droppings.

We started around 9 AM, going into the Zodiacs for a tour around this small group of islands that are basically a set of big rocks jutting out of the sea with steep cliffs all around them. The biggest one of them has a small group of buildings used by the guano collectors during the years when this is allowed, making us wonder how they ever managed to build them, given the geography of the island; in order to access this small ‘guano station’ they had built a series of metal ladders leading to a hanging pier, but the last part of the ladders had rusted away and was no more, so that now the access is using a rope ladder, also known as a ‘monkey ladder’ (named so maybe because you would need the dexterity of a monkey to be able to climb up there) dangling directly from the overhanging pier some ten meters above.

Much to our surprise, it turned out that there were people there, two ‘island rangers’ taking care of the buildings and patrolling during these years when the guano mining is suspended to let the colonies ‘rest’. The guano is collected for up to two years, while the supplies last, and then the collection is stopped for some five years to let the deposits build up again, given that the bird colonies are huge (an estimated 400,000 birds nest in this group alone).

The word “guano” derived from “huanu” a native Quechua language word for manure. It is a natural fertilizer, rich in nitrogen, phosphorus and potassium that has been exploited since pre-Inca cultures. Millions of marine birds have left layers of bird droppings covering the rocky islands and cliffs off the Peruvian coast. Historically, these layers reached a thickness of up to fifty meters. 170 years ago the world became aware of the guano and demand increased explosively causing an economic boom.

Guano is still harvested. There are about 26 islands and 13 headlands that are forming the so-called guano system in Peru and are exploited for their guano every 5 to 7 years during the non-breeding season, depending on the amount of guano and number of birds in the colonies. This guano is used in crops in Peru, and small amounts are exported to the United States and Europe as organic fertilizer. There are many different marine birds breeding on the islands and headlands of the guano system. However there are three species recognized as the most important guano birds because of their sheer numbers:

The Guanay cormorant (Phalacrocorax bougainvilii)

The Peruvian booby (Sula variegata)

The Peruvian pelican (Pelecanus thagus)

All of these species we saw on our excursion, some of them in the thousands, as well as other species of birds, like the Red-legged Cormorant, the Blackish Oystercatcher, Surf Cinclodes, the beautiful Inca Tern and the always funny Humboldt Penguins. Besides these birds, we found also a small colony of South American Sea Lions hauled out on one of the smaller rocky islets, and some people saw a Marine Otter. Almost all of the guests joined the excursion and most of the boats went all around the archipelago and stayed out for a good two to three hours, as we were all very exited by what we were seeing.

In the afternoon, the plan called for another stop and Zodiac tour, but the conditions in the area chosen for this were not very good and we decided that it would not be better than what we had seen in the morning, so instead we sailed by the Hormigas de Afuera group, seeking more wildlife sightings from the ship.