Nowak, J. Bosco

English

Aquatic Commons

ISLA DE LA PLATA AND THE GALAPAGOS 
by 
J. Bosco Nowak 
According to legend, Isla de la Plate (Silver Island) was so named because it was there that Francis Drake 
divided up the huge booty from the Spanish treasure ship he had captured in 1579. It lies close to the coast of 
mainland Ecuador and does not form part of the Galapagos which lie a thousand kilometres deeper into the 
Pacific. Nevertheless, as it also lies near the equatorial line, its wildlife has many features in common with that 
of the archipelago. J. Bosco Nowak, who held a scholarship to study at the Darwin Research Station and is a 
Galapagos naturalist guide, has visited this somewhat forgotten island and has written this disturbing report 
on present conditions there. Ed. 
In October 1985, Maria del Carmen Marcillo and I visited La Plata Island. At Punta Machete we were 
surprised to hear the very familiar roar of a bull Galapagos sea lion. At the foot of the cliffs there was a 
complete colony: a territorial male, five adult females, two sub-adult females, a juvenile and, at a certain 
distance from the harem, three not fully grown males. The bull was patrolling the beach. All five adult 
females seemed close to giving birth. A sight strange to us was a female repeatedly chasing away some red-
headed vultures, which were probably trying to feed on sea lion excrement. There are no vultures in the 
Galapagos. 
This would seem to be the first record of a colony of Galapagos sea lions, Zalphus caJifornianus wolJebecki, 
outside the archipelago. From my years of experience as a Galapagos naturalist guide, I feel quite sure of 
my identification; this was definitely not a colony of the South American sea lion, Otaria byronia. Sr. 
Zaccarias Intriago, the caretaker of the island, which he has known for over 35 years, told us that for as 
long as he could remember these "perros del agua" (literally "water dogs") had been there, but that it was 
only in recent years that they had established a permanent colony. Previously they arrived during the hot 
season and left again when it grew colder, and this was still true of some but not all of them. During recent 
EI Nino years (when the ocean temperature is higher than normal) Sr. Intriago estimated that the 
population had been well over 50. On these occasions the fishermen would drive them off the beach or 
even kill them. They disliked them because they eat a fish called corrina and because the bulls sometimes 
attacked them in their canoes, often at great distances from the island. The sea lions' best protection is the 
steepness of the cliffs and the danger oflanding on their beach from the sea because of the big waves and 
the submerged lava flows. 
The other Galapagos species which has colonized Isla de la Plata is the Waved Albatros, Diomedea 
irrorata, but its numbers have recently been sadly reduced and in two days of searching we found only two 
pairs. In 1975 the population was estimated at somewhere between ten and fifty pairs. We found a dead 
adult which had clearly been killed by the fishermen who go on shore to hunt for feathers: its head had 
been torn off and its breast stripped. 
It was interesting to establish that the breeding seasons of the albatrosses and of the sea lions synchronize 
with those in the Galapagos. There were other similarities that reminded us of the archipelago: the 
Masked and Blue-footed Boobies, Red-billed Tropic Birds, Magnificent Frigatebirds, Brown Pelicans 
and White-vented Storm Petrels. Then there are the familiar Palo Santo trees and plants like Croton, 
May tenus and the beautiful Cordia lutea. We were so impressed by the similarities that we ended up 
searching for giant tortoise fossils in the secondary sediments. But there are also differences from the 
Galapagos. I thought I was watching a carpenter bee but it turned out to be a tiny, dark hummingbird. 
There are no hummers in the Galapagos and the La Plata mockingbirds belonged to the mainland coastal 
species, not to any of the four endemic Galapagos species. 
The Galapagos suffered their greatest threat when human beings arrived, began destroying the 
environment and introduced alien animals and plants; something similar is happening on La Plata. 
Fishermen hunting for feathers could exterminate the albatrosses and reduce the boobies which have 
already become so shy that one cannot approach them closer than 30 meters. A goat population which we 
estimated at 300 is destroying the vegetation and leaving the fragile soil exposed to erosion. 
Let us give thought to how this island, which is officially part of the Ecuadorian national park system, can 
be given efficient protection. It took me a long time to decide to publish this report but, if nothing is done 
to save Isla de la Plata, I should feel I was in some way responsible for the continuing destruction of this 
unique ecosystem. 
17 
Noticias de Galapagos, vol. 44 1986


Isla de la Plata and the Galapagos

http://aquaticcommons.org/5784/1/NG_44_1986_Nowak_Isla_de_la_Plata.pdf

Isla de la Plata and the Galapagos

Abstract

Similar works

Full text

Available Versions

Aquatic Commons