The Galápagos: North Seymour Island

August 14, 2023 • 9:15 am

We had a 2½-hour walk on North Seymour Island this morning. The weather was lovely: not too hot, overcast (best for pictures), and with a cooling bit of wind. And the animals were all out and on display.

First the ship, National Geographic’s Endeavour II, photographed from shore. It’s not large (26 staterooms), making for a pleasant, uncrowded existence.

The breakfast buffet, only a small part of it shown. I have to restrain myself because in Chicago I eat only one meal a day, and the food is great aboard. Yogurt, fresh fruit, pancakes, omelettes to order, all kinds of muffins and breadstuffs, fruit juice, fried eggs on crispy tortillas con queso. I must restrain myself, and have decided to have a smallish breakfast (I usually have only coffee), a large lunch, and a very small dinner. The food is excellent.

Here’s North Seymour Island, a tiny (1.9 km2 !), scrubby islet just north of Santa Cruz. It’s small, but absolutely overflowing with lizards, iguanas, birds, pinnipeds, and finches:

Animals. First, the endemic swallow-tailed gull, according to Wikipedia “the only fully nocturnal gull (and seabird) in the world.” (I may get some of these wrong, as I’m going by what the guide said, and I may have forgotten. I welcome corrections.)

A male blue-footed booby; an endemic species.

Two views of a young blue-footed booby:

An older father booby sitting atop his chick. Note the ring of feces around the nest. Can you see the chick in front?

A booby family, mother atop egg. The male and female switch incubation while they take turns getting fish in the ocean:

The blue feet of the male booby. Only the males have the coloration, and of course it’s a product of sexual selection, used in luring females. The males “tap dance” slowly while displaying their feet and also extending their wings and calling. The females are looking for. . . . well, we don’t exactly know.

Another booby with two chicks (the number varies from 1-4 or so). We thought the chicks were dead, but the guide assured us that no, they just rest like that. They were right by the trail, showing the remarkable tameness of the animals on the Galápagos—something noted by Darwin.

A closeup of one of the chicks, probably about two weeks old, we were told:

The magnificent frigatebird, a species native to the archipelago but not endemic. Again showing sexual selection, the male has an inflatable red pouch that he blows up during the breeding season, comme ça:

A frigatebird chick:

My first finch!  I think the naturalist said it was a medium ground finch, made famous by the work of the Grants (see below). Sadly, it’s backlit, and you can’t get too close to these puppies:

Two views of the Galápagos land iguana, one sister species of the marine iguana (there are three species of endemic land iguana in the archipelago, but the number is disputed):

One of seven endemic species of lava lizard in the archipelago. Don’t ask me which one, but perhaps Greg will know:

A Galápagos sea lion, another endemic species; this one has a young pup. You can tell this is a sea lion rather than a seal (there’s one endemic of each) because it has external ears. (A convenient mnemonic is that “sea lion” is longer than “seal” and thus has an extra feature: the ears.)

An endemic cactus, Opuntia galapageia (there are several subspecies). It serves as food the for the land iguanas, and you can see where it’s been nommed by them. On other islands the giant tortoises eat them:

One thing that impressed me when I first came here over a decade ago was how much life there is on these barren, lava islands. It all comes from the fact that in this area the sea is rich in nutrients and fish.  Look at all the signs of birds:

More signs of life, with a famous island in the background. Can you name it?

Yes, it’s Daphne Major, famous among biologists as the place where Peter and Rosemary Grant, along with their students, studied the finches and provided the paradigmatic case of natural selection: selection for beak size in the medium ground finch over a year of drought (1976-1977). This remarkably rapid instance of selection was described in a Pulitzer-Prize-winning book by Jonathan Weiner, The Beak of the Finch

Here’s Daphne Major to the left and Daphne Minor to the right:

Finally, a rat trap on the island, designed to removed a dangerous predator. The Galápagos National Park is a kindly place, and they do not kill the rats, which are trapped with pheromones. When the traps have accumulated a few rats, they take them to mainland Ecuador and let them go (or so I’m told).

That’s a lot of stuff to see in a bit over two hours!

24 thoughts on “The Galápagos: North Seymour Island

  1. This is an exciting post to see. I love the booby family. Especially Mrs. Booby. I was wondering if they looked like the male and I see they don’t. I’m glad the booby babies are just resting.
    What a great collection of creatures. Very exciting indeed!

  2. It’s interesting that the young boobies rest that way. I would imagine it might be protective from some predators that don’t want to eat already-dead prey, but I don’t know if that could work. Maybe it’s just the comfortable way to lie around.

  3. The blue feet of the male booby. Only the males have the coloration, and of course it’s a product of sexual selection, used in luring females. The males “tap dance” slowly while displaying their feet and also extending their wings and calling.

    So I reckon Carl Perkins’s Blue Suede Shoes constitutes convergent evolution, after a fashion? 🙂

    1. Actually they are probably the common rat now seen in cities and ships worldwide, not native to either the Galapagos nor mainland South America. The should really be euthanized.

  4. This is utterly wonderful – to simply walk around and see such riches of Nature – a precious, special experience.

  5. Seems like there would be a great photograph anywhere you look! Spiffy looking boat…looks to have a lot of neat gadgets and instrumentation; maybe they’ll let people on the bridge? Thanks for the photos and information.

  6. The mnemonic about seals and sea lions doesn’t really work here since ‘fur seals’ are not ‘true’ seals, or phocids. Its a confusing name. Fur seals are otariids just like sea lions and have external ear flaps, can rotate their rear flippers underneath their hips to ‘walk or run’ on land, and are primarily front flipper drive while swimming, sort of like flying underwater. Phocids have no external ear flap, hump along on land dragging their rear flippers behind them and are primarily rear flipper drive while swimming, using side to side sweeps. There are no phocids resident on the Galapogos. The Galapagos fur seals tend to be more secretive and harder to observe.

  7. Thank you for the close-up of life in the islands. I’d love to see a blue-footed booby in the wild. I hope you are really enjoying yourself and that your lecture was well received. What an adventure!

  8. No I realize they are presumably btown rats, but brown rats are not native outside Asia. Also yhey could potentially spreaddisease from the islands, to the mainland, though that eould be more likely the other way around I admit. It seems very strange to me.
    As an invasive species I am sure tge rats do a lot of damage. Manh islands have full eradication programmes.
    Or are they Pacific rats? See Pitcairn, Henderson Island…

    PS nice – you are very lucky…🤓

  9. Wow, those boobies are fantastic! And the babies laying like that in the path…and yet what I’m really wondering is how Jerry always picks ships with such great food.

  10. Outstanding post. I think the finches got written up in Scientific American years ago back when we all read it. Was the title “Darwin’s Finches”?

    Surely they don’t really let the rats emigrate to the mainland. Some are likely pregnant and they aren’t necessarily native or endemic to Ecuador, either. They could have come from anywhere in the world, ships being ships. Maybe the Islanders are too kindly to kill them even humanely. But somebody surely does.

    Keeping rats from disembarking from ships is probably as important a task for Ecuador’s mainland port authority as it is on the Islands. I’d hate to be the master of the rat ship. He’d be as popular as Typhoid Mary.

  11. Jerry, lovely photos. I wish I were there. One small correction, the Blue-footed Booby is not endemic to the islands. It is found as far north as California and as far south as Peru. But a handsome bird nevertheless.

  12. Thank you for these never-seen-before-closeup photos of the resident birds and iguanas. The feet and hands of the latter are remarkably like ours,

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