Galápagos: Santa Cruz Island and Puerto Ayora

August 19, 2023 • 9:30 am

Here’s a brief account of Thursday’s perambulations on Santa Cruz Island and its largest city, Puerta Ayora. This is the first time we’ve viewed inhabited areas of the island (the population of the city is around 12,000, roughly half the population of the archipelago:

The city harbors two important organizations that we visited. The first is the headquarters of the Galápagos National Park, founded in 1968. It comprises 97% of the archipelago, and is a World Heritage Site. They also have a captive breeding program of giant tortoises (all the subspecies), which they hatch and, when they’re older, release on the appropriate island.

The other is the Charles Darwin Research Station, which monitors and supports all scientific research that goes on in the Galapagos. It’s also in charge of the important work of conserving the islands, including restocking species that have gone locally extinct and eliminating invasive species. Finally, it helps educate islanders, and Ecuadorians in general, about the islands

An aerial photo of the Station (and the nearby harbor) from its site:

Two photos of lava lizards from the National Park Headquarters. I’m not sure if these are two different species or a male and female of the same species. There are seven species (Microlophus spp.) in the archipelago.

I suspect these are different species based on the back patterns, but perhaps a reader knows better.

This is the stuffed remnants of the famous “Lonesome George,” the last remaining individual of his subspecies, helonoidis niger abingdonii.  He was found on the island of Pinta in 1971, and the grazing of feral goats (now largely eliminated) had reduced the population of this subspecies to only a single male: George. He became a worldwide symbol of conservation, as he, being a male, was the end of the line.

George was introduced to several females of related subspecies in captivity, but failed to produce offspring. (They were trying to reconstruct his phenotype by backcrossing.) George died in 2012, aged 101 or 102—fairly young for a giant tortoise. As a symbol of potential loss of species and subspecies, his stuffed remains reside in a temperature-controlled room at Park headquarters:

But nearby are the breeding sites for the turtle restoration project. Here’s one ripe for release: a “saddleback” tortoise. The subspecies come in two types: “saddlebacks,” with an indentation at the front of the shell, and “domed”, with no indentation.

This is a saddleback, and you can see that the indentation allows it to extend its neck out and up. These subspecies are found on dry islands where they must lift up their heads to graze on bushes and cacti. The domes variety (see below) are found on wetter islands where they can simply put their heads down and graze. Thus the differentiation is an example of an “adaptive radiation” driven by natural selection based on the different ecology of the islands.

A baby tortoise of the domed variety, about the size of my hand. It’s marked to designate where its ancestors came from. This one will be released when it’s bigger. The babies are ineffably cute (and are subject to a reptile trade in the U.S., which is legal so long as they are bred in the U.S.), but if you get one, prepare for a monster that can grow up to 700 pounds!

A saddleback adult raising its head:

The National Park has a small Darwin-themed museum, and contains this whale skeleton whose vestigial rear legs (which I mentioned in my talk) are clearly visible. I’ve put a circle around them, and took care to point them out to my shipmates as one piece of evidence for evolution. Note that they are not connected to the rest of the skeleton, reside entirely within the body, and thus are useless signs of history. (Vestigial organs need not be without function though: consider the repurposed “wings” of penguins.)

There’s an overly spiffy statue of Darwin outside the museum, with too much hair and holding a book that looks too thin to be either the Voyage of the Beagle or The Origin, and too large in size to be one of his notebooks. His shoes, a pair of English brogues, also look too modern, but I don’t known much about Darwin’s sartorial propensities.

The town of Puerto Ayora, which is quite touristy around the stations, with lots of trinkets on offer, but elsewhere is a typical Ecuadorian town

Tee shirts for sale. The trinkets make much of the double entendre of “boobies,” as you can see from the “I love boobies” shirt below.

A large carved wooden statue of a tortoise in a park. The inhabitants are rightly proud of how well they’ve conserved their islands and the flora and fauna.

The fish vendor site is my favorite place in the town, as seals and birds frequent it, hoping for a handout. Nearby a guy checks his cellphone while a sea lion rests comfortably nearby. I love how nonchalantly the locals coexist with the wildlife.

The best part of Puerto Ayora: the place they sell fresh fish by the harbor. Dozens of animals congregate nearby, drawn by the vendors’ generous habit of tossing a scrap of fish or two to the. animals. Even a marine iguana found its way to the place, though I don’t think they eat meat.

And dozens of hungry Brown Pelicans (Pelecanus occidentalis, not endemic) crowd the fish vendor, preferring to wait for a handout than to go fishing in the sea.

An expectant bird:

It’s funny to watch the birds crowding the fish slicer. Every so often he tosses them an unwanted piece of fish, which they take off to the side and devour:

Even a brazen sea lion invades the stall; this one has put its head on the counter!

In the afternoon, after we had individual walks around town, we visited a local farm that grows cocoa, sugarcane, and coffee. We got to sample all of them, and all were excellent. Here’s a ripe cocoa pod, ready for extraction of the beans.

A still where the fermented sugar cane is distilled to make aguardiente, a potent (60% alcohol) form of  local moonshine. I had a small glass, and oy, was it strong! The still is very old, with the tub of water in the foreground used to cool the vapors containing ethanol

The pure spirit drips from the still:

The lunch stop was at a restaurant in the highlands called “El Manzanillo,” which is conveniently located next to a patch of grassland and forest that’s rife with giant tortoises. Look at all of them! These are not pets or residents; they are individuals who have come up to the highlands to graze and mate during the wet season. In a few months the females make the long trek down to the sea to mate and lay eggs. At their slow speed, it takes them weeks.

Each island has its own distinctive tortoise, with some bigger islands having two or three subspecies. My own view is that there are 15 subspecies in the endemic species Chelonoidis niger, but some of our naturalists think there are 11 living full species. As I said before, this is a judgement call given that most of them are geographically isolated from the others.

Lunch first, though I was eager to inspect the tortoises. It’s a pleasant, open-air restaurant.

This is probably the only time in my life that I was able to drink a sugarcane slush, made from pure sugarcane juice, which of course is very sweet.

And then a beer. I chose a local beer, “Boobies” porter. It was quite good. With it I had chicken, potatoes, and rice and beans.

On to the tortoises! This, as you can see, is one of the domed subspecies, and was estimated to be about 75 years old. (There’s no way of estimating age beyond size, though they are thought to live up to, or longer than, 150 years.) Now many of the turtles are marked by inserting chips in them, the same thing they do with cats and dogs.

It’s grazing. The dome prevents a big extension of the neck, but that’s not necessary as this subspecies simply lowers its head to eat the vegetation.

A head shot. They’re easily spooked, so you have to use a long focal length. Regulations stipulate that you must be at least two meters away from all animals.

As far as I can see, they ate every plant in the meadow. It must take a lot of vegetation to grow such a giant reptile!

A big ‘un with a little ‘un.

A fellow passenger trying to get a good head photo:

They were everywhere! It was a good day.

And one awaited us by our bus back to the port. The drivers are very careful to avoid them, as there are huge fines for running over one. There are also “tortoise crossing” signs along the roads, but I was unable to photograph one from a moving bus.

And a species I long wanted to see, the medium ground finch (Geospiza fortis) of The Beak of the Finch fame. This is the species in which Peter and Rosemary Grant and their colleagues demonstrated strong natural selection (a change in beak size of 10% over the years 1976-1977), due to a drought that eliminated small seeds, and with them individuals with small beaks who starved to death.

16 thoughts on “Galápagos: Santa Cruz Island and Puerto Ayora

  1. I presume that Darwin had a lot of hair as a young man. Nice to see the statue is not the clichéd portrait of him when he was older.

    As for brogues (internet research: approx 15 minutes), it seems they originated with Scottish and Irish farmers in the 19th century. The holes were originally a practical measure to let water out after walking through bogs.

    So, I’d say it is possible that the brogues are not anachronistic.

  2. I had no idea that tourism had become such a huge business on the Islands. The Runway on one Island is more than 7200 ft. long. Seymoure Airport it is called moving 300,000 people per year. I hope they continue to protect the wildlife.

    1. I am finding this series of posts, photos and written accounts endlessly fascinating and informative. Thank you so much for continuing to further our education!

      May I ask how your lectures are going down with your audience? I hope you have had some rewarding Q&A sessions afterwards.

      1. I think the lectures went well, but of course people aren’t going to tell you that they didn’t like your talk. There were a fair number of questions and a LOT of discussions about evolution with fellow passengers at meals and on hikes.

  3. Looks like a great trip – pretty sure we were looking at the same tortoises (and eating lunch in the same place) last year. But the Darwin Center and the Park HQ were unfortunately still closed to visitors post covid.
    A question, does the term “vestigial” designate a change of function or a loss of function? A penguins wings are clearly functional, although not for flight, while those of emus and ostriches (and indeed Galapagos cormorants) are markedly less useful, beyond perhaps, display. A whale’s legs, of course, are much further into the useless category.

    1. I think to most of evolutions “vestigial” means “a loss of the ORIGINAL function”. Such a trait can, as you note, still adopt a new function. Such features still constitute evidence for evolution because, for instance, it would be odd if the Deity just happened to make penguin flippers containing the exact same bones as flying birds (their ancestors).

  4. I’m really jealous of those who live surrounded by nature, while city dwellers like myself are stuck with cats ( who are wonderful, of course), d*gs, pigeons, and sparrows.

  5. I sent a photo to PCC(E) years ago of an ostrich standing over her very young chicks. Our guide said that she was looking out for eagles. She was holding her wings in a very purposeful way, possibly helping to hide her young.
    Edit: meant as a reply to Simon.

  6. In reference to ‘vestigial’ cetacean hip bones… My understanding is that these are generally hip rather than leg bones though I’m not sure which specific hip bone they are derived from (but I’ll make a guess at the end). Right whales and close relatives sometimes have remnants of leg bones. The pelvic bone remnants are present in all cetacean species except the pygmy and dwarf sperm whales. There are good indications that they are not ‘vestigial’ at least in males (the question remains open with respect to females).
    Male cetaceans of species with promiscuous mating systems tend to have large testes, long penises and comparatively large hip bones relative to body mass. They also exhibit extraordinary penile dexterity to achieve copulation with reluctant or choosy females in unusual positions (including apparently while airborne in the case of the Harbor Porpoise, think of the fairly spectacular ‘pink floyds’ of grey whales). Muscles (ischiocavernosus) that help to control penile movement originate on those pelvic bones (the same muscles connect to the clitoris in females) and thus those bones may be critical to successful mating which would make them not the least bit ‘vestigial’. (Yes these same muscles are present in most (all?) mammals including us, serving some of the same functions as well as others. Their bony anchor point is the ischia, the bones you sit on). The presence of these muscles inserting on these bones would suggest to me that the first bones I’d look to as the origin of the remaining cetacean hip bones would be the ischia.
    Aside: We once put the ‘gimme’ question “What marine mammal are you most like and why?” on an exam in Marine Mammals (a few students actually managed to get it wrong). Best answer: “A Blue Whale, because of the size of my penis”. Full credit for lightening the load while grading!

  7. I’ve been following your Galápagos posts with great interest and appreciation. TNX for taking the time to prepare these – particularly enjoyable for people like myself who will never get there but wish they could.

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