Charles Darwin Research Centre, Isla Santa Cruz

 After lunch back on the Nemo, and a short siesta, Diego took us around the Darwin Research Centre's tortoise breeding program. The research centre was set in a garden of native plants with names tags that A and I found interesting.

 

 

Its main aim is to breed the different giant tortoise species from all the various islands, especially those with depauperate populations. Sadly some species have already gone extinct.

 

 

 

 

 All tortoise eggs are incubated at 27^o or 29^oC to produce males or females respectively. The baby tortoises are reared i captivity until about five years old, when they are large enough not to be killed by rats when released into the wild.

 

One-year-old babies

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

We saw young and old tortoises from at least three islands, with different shaped shells. The Governor of the Islands told Darwin that he could tell which island the tortoises came from by the shape of their shell. Islands where the tortoises had to graze on tall shrubs favoured saddle-shaped shells that allowed the tortoises to crane their necks up high (see below).

 

Early seafarers used to catch thousands of the slow tortoises as a source of fresh meat,since they could survive for up to a year stored upside down in the hold of their ship - no animal ethics in those days! 

 

One big enclosure was a retirement home for old tortoises from private captivity.

 

 

 

 

There was a memorial to Lonesome George, the last of the Pinta Island species, who died in July 2012. He was probably over 100 years old and would not breed with any females from other islands.

 

 

 

 

 

His taxidermied remains are due to be returned to the Centre this year.

 

 

 

Galapagos giant tortoises have been sent to zoos all around the world in the past but no longer. Apparently Sydney zoo has a very old tortoise, and we recently saw some in Melbourne zoo.

 

We also had our first good view of a mockingbird (Santa Cruz species).

In addition to the variations in tortoise shell shape, and the finchs' bills, it was also the small variations in mockingbird plumage on different islands that got Darwin thinking about natural variations in populations and survival of those best adapted to their environment. 

 

 

 

 

 

 

And the little lava lizards were basking on the rocks (about 15 cm long), like our skinks. This one is a female who is shedding her skin. For a change, the females are brighter coloured than the males: females have an orange head and neck while the males are dull grey. 

 

 

Santa Cruz is one of the older Galápagos Islands.  It is an extinct shield volcano, whose shape reminded Drew of Cheju Island in Korea, and its extinct Halla-San volcano. The southern side of Santa Cruz is relatively well vegetated.  After passing two small craters near the summit, the north side is very dry, with vegetation dominated by a prickly-pear type of cactus and Palo Santo trees (which exude incense.

 

We were left to our own devices for the rest of the afternoon, our only chance for the week to go shopping (window shopping for Jenny and me while Andrew checked onto the Internet). Later we learned it was also the only chance between weekly voyages for the crew to have some shore-time. At about 9:30 the crew returned to the ship and we headed south west to the southern tip of Isabela Island. We motored off into a lovely moonlit night and ‘navigated’ overnight for nine hours to Isabella Island.