My passion: Protecting the giant tortoises of Cerro El Fatal (“Chelonoidis donfaustoi”)

January 29, 2018

By guest author Wilman Valle, Galapagos National Park ranger.

giant tortoise

My name is Wilman Valle. I am 47 years old. When I was 20, I became a park ranger for the Galapagos National Park. I was born and raised on Santa Cruz Island in the farming sector El Camote. Since I was very young, I have been familiar with the giant tortoises — especially those that inhabit the eastern side of Santa Cruz, because they always came up to my farm. Whenever I went goat and pig hunting in the sector known as Cerro El Fatal, I encountered them. The trails they opened made it easier for me to walk around looking for pigs.

These close encounters with giant tortoises throughout my life led me to become a park ranger. Prior to working in eastern Santa Cruz, I was part of the goat and pig hunting group on Santiago Island. In 2001, when I left the hunting group, one of my main tasks has been the protection of giant tortoise nests to prevent them from being preyed on by feral pigs — thanks in part to my deep knowledge of the eastern sector of Santa Cruz Island. This work involves several visits during the annual tortoise nesting season, something I have done at least 40 times each year.

protecting tortoise nests

I’ve always enjoyed this job and I know almost all the giant tortoises in El Fatal. Since 2015, when genetic studies confirmed that this tortoise is a separate species from the tortoises that inhabit the western side of Santa Cruz, it has become even more important to protect this population. In addition to protecting their nests, we need to study them more to establish new management measures, given that this unique species has so few individuals. In the past many tortoises from this site were slaughtered by humans and many nests have been preyed upon by pigs.

A few years ago, the trampling of the nesting areas by wild donkeys became a serious problem limiting the reproduction of the giant tortoises of El Fatal. This was in addition to competition for food with feral goats. Park rangers have been working hard to control these introduced species, and have achieved near eradication of them in this area, although a few remain. But now there are new problems.

Plant control

Controlling introduced plants in a tortoise nesting area.

In the last year, a group of five companions dedicated several days to controlling supirrosa or multi-colored Lantana (Lantana camara), an introduced plant that is invading the nesting area. If this aggressive species manages to cover the area, it would be very serious for tortoises, because it is one of the few places that has the appropriate conditions for the females to dig their nests and lay their eggs.

Since 2016, Galapagos has undergone a long period of drought with very low temperatures. This caused the 2017 nesting season to be delayed. In November, which usually marks the end of the nesting season, we found newly dug nests. The low temperatures also caused the incubation period of the eggs of the previous season to last longer.

Hatchling tortoises

Hatchling tortoises from a natural nest in El Fatal.

That gave us the opportunity to find 60 hatchlings emerging from their nests. These tortoises were transferred to the Fausto Llerena Tortoise Center, where they are cared for until they are old enough not to be attacked by introduced predators, particularly rats and fire ants (Solenopsis geminata), one of the more recent arrivals in the tortoise areas, particularly the nesting zone, of El Fatal.

As a galapaqueño and park ranger, I hope to continue having the opportunity to contribute to the conservation of this unique species of tortoises that has always been a part of my life.

Wilman ValleWilman Valle has been a park ranger for the Galapagos National Park for 26 years. He has been collaborating with the Giant Tortoise Restoration Initiative in recent years, with his efforts to preserve and protect the tortoises of Santa Cruz Island – both the Eastern Santa Cruz Tortoise and the Western Santa Cruz Tortoise.

All photos © Wilman Valle.

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