Of iguanas, sea lions and other beasts

Animals of the Galápagos

Land iguana on North Seymour

The Galápagos Islands are located 600 miles from the Ecuadorian coast in the Pacific Ocean. There are 14 large islands and 120 smaller islets and rocks. Their isolation from any other place has resulted in the evolution of many unique species of flora and fauna, endemic to the archipelago or even to just one island within it.

The islands have been formed through volcanic activity, due to a “hot spot” just the west of the group (under Fernandina). Eruptions here cause an island to form from the lava and rock emitted from beneath the sea bed. But rather than create one ever-growing island, made larger by each new eruption, the slow south-eastward movement of the tectonic plate on which they sit means that by the time of a subsequent eruption the island created by the previous one is some miles to the east, and instead a new one forms. Thus each island is on a slow journey south and east (moving at a rate of seven cm/year); those furthest on that journey, such as San Cristobal and Espanola, are the oldest, and those in the west, such as Fernandina and Isabela, much younger (in geological terms).

A keen geologist will be fascinated by the details, but for the rest of us the attraction lies in the vivid scenery that results from all this activity, and for me, above all the colours. A jumble of black lava boulders, the backdrop to a white coral beach. Or a black lava beach washed by a turquoise sea. Or again, on Rabida, dark red cliffs with dusty green opuntia clinging to them.

And this dramatic scenery is the set for a multitude of living dramas, as the various animal species play out their lives under the gaze of mesmerised visitors. For the islands’ isolation has not only led to the large number of endemic species being present, but also to their tame and inquisitive nature. The Galápagos were never attached to any continent and the island chain's remote location made it impossible for large land mammals that usually dominate the food chain to make the journey to the here. The giant tortoise became the dominate animal on the land, and he is a herbivore, so no threat to the others. With this lack of natural predators, the wildlife of the Galápagos thrived in an Eden-like environment and never learned to be fearful of other species – even our own. Meeting these animals and interacting with them in their own environment is the true joy of a Galápagos holiday, so this blog entry is devoted to a description of the main ones we saw on a lot of the islands, while more about the most memorable of these encounters will follow in future entries describing the individual islands we visited.

Galápagos sea lion

Sea lions at Gardner Bay, Isla Espanola

The first animals to greet us on almost every island were the sea lions. And I do mean “greet”. It often seemed that they had been lolling around on the beach or even the landing jetty just waiting for our arrival! This isn’t a scientific distinction, but for me they fell into four groups – adorable pups, languid and photogenic females, lively bachelor males, and the occasional bolshie alpha male throwing his weight about. The latter are best avoided, but all the others will allow you to come pretty close, and will often come closer still to you.

The Galápagos sea lion is a distinct species, but closely related to the California sea lion. They are found on all the islands and number in the ten thousands. The females usually have just the one pup a year, though Fabian said twins are not unusual and he has once seen triplets! We saw several newborn pups, for example on Sombrero Chino and Española. The babies are nursed by their mother for about six months until old enough to fish for themselves, and most of those we saw were still at this stage, so stayed quite close to mum. Some were more adventurous though and were venturing along the beach or across the rocks. One such followed a few of us for some time at Gardenr Bay on Española, apparently mistaking us for family – so cute!

In addition to these large nursery groups we saw several of bachelor males (including on Isla Rabida and South Plaza). Male Sea Lions sometimes retreat to these so-called bachelor colonies to take a rest from the aggro of the alpha male. Once refreshed they may try themselves to take on one of the latter and to try to establish their own beach territory with several females, which they will then have to defend continuously from other bulls. These fights take their toll – most alpha males we saw were battle-scarred, and Fabian told us that their reign is often short (sometimes only a few weeks) as they grow weaker with each fight and are then more easily vanquished.

Galápagos fur seal

In addition to the Galápagos sea lions, which are everywhere in the islands, there are a smaller number of Galápagos fur seals. These too are an endemic species, and live mainly on the rockiest shores. They are smaller than the sea lions, and their fur made them a target for poachers in the past, although they are of course now protected and their numbers are growing again. They live in the greatest numbers in the western islands, Fernandina and Isabela, which we didn’t visit. They also tend to be shyer than their cousins! But although we weren’t lucky enough to see any while on any of the islands, we did see some on a couple of our panga rides, most notably off Genovesa when on our way to the dry landing at Prince Philip Steps.

The sea was quite rough here and it was difficult to hold the camera steady, so my photos were not as clear as I would have liked, but they do show the thick fur and distinctive whiskers.

Fur seals are part of the same “eared seals” family as sea lions, and differ from true seals in having small external ear-flaps. Their hind flippers can be turned to face forwards, and, together with strong front flippers, this gives them extra mobility on land – an adult fur seal can move extremely quickly if it has to. They also use their front flippers for swimming, whereas true seals use their hind flippers. Their scientific name is Arctocephalus, which comes from Greek words meaning “bear headed”, and it’s easy to see how they got this name.

Land iguanas

Land iguana on Plaza Sur

One of the largest animals you can see in the Galápagos are the land iguanas, which on some islands can reach over a metre in length. There are actually two species to be found here – Conolophus subcristatus on six of the islands, and Conolophus pallidus only on Santa Fe. The latter is often a paler yellow than the main species (hence the name, “pallidus”), and has more spines on its back. Charles Darwin described the land iguanas as “ugly animals, of a yellowish orange beneath, and of a brownish-red colour above: from their low facial angle they have a singularly stupid appearance.” however I have to say that I disagree with the famous naturalist, as I found them sort of cute, although probably only their mothers would find them beautiful!

All the marine and land iguana species in the Galápagos are thought to be descendants of a single species, the green iguana, which is native on the South American continent. Arriving probably on vegetation rafts to the isles, the green iguana, in order to survive, had to adapt to a new and different environment by evolving into two very distinct new species.

One of these, the land iguana, adapted to feed on the vegetation of the islands. Surprisingly perhaps, they prefer the prickly pear cactus or opuntia. This in turn has evolved, growing much taller than elsewhere in the world to be out of reach of the iguanas, but the latter simply stand on their hind legs to reach the pads and fruit. They have a leathery, tough tongue and don't need to remove the spines from the cactus before eating. The cactus forms about 80% of their diet and ensures that they get plenty of water even in the arid dry season such as when we visited.

Marine iguanas

Marine iguana on Isla Espanola

The other main species of iguana that you will see on many of the islands are the marine iguanas, of which there are in fact seven sub-species, varying in size and colour. Most are black or dark grey but some have red colouring too, most notably on Española where the males have not only red but often green colouring too, which becomes brighter during the mating season – giving them the nickname of Christmas iguana!

When the green iguana arrived here, some found themselves on islands where vegetation was sparse, and turned, through necessity, to the plant-life beneath the sea, and thus became the world's only sea-going lizard. They have developed a flattened snout and sharp teeth in order to feed on the algae on the underwater rocks. Their tail is flattened vertically like a rudder to help them swim and they have long claws to grip the rocks while feeding so that they don’t drift away.

Marine iguanas can stay submerged for up to ten minutes, before having to come up for air. When not feeding they are usually found sunning themselves on lava rocks, often in large groups and, as we saw in several places, even piled up on top of one another! Sometimes you will see them appear to sneeze, but in fact they are snorting to get rid of any excess sea salt with the help of special glands in their nostrils.

Lava lizards

The smallest of the reptiles we saw regularly on the islands were the lava lizards. There are seven species, and there is only ever one species on each island. All but the Galápagos Lava Lizard is found only on the island whose name they bear, whereas the former is found on many islands.

Lava lizards are smaller than the iguanas but nevertheless can grow to up to 30 cm in length (males – females are shorter), although the average is considerably less than that. They are found on all the major islands apart from Genovesa, and are the most abundant reptile on the islands. In all the species the females tend to be more colourful, with a red throat, but on Española the whole head is often bright red. Only the males have spines along their backs, and their colouring and patterns vary quite a bit between species, according to the landscape and environment of the islands, as they have evolved to blend in with their surroundings. They don’t blend in that well however!

Sally Lightfoot crabs

These distinctive crabs can be seen all over the Galápagos, especially on the dark lava rocks, and they really catch the eye with their vivid orange and blue colouring. They are not endemic to the islands, being also found all along the Pacific coast of South and Central America. Nevertheless they seem to be one of the animals most associated with the Galápagos.

They are quite large (adults can grow to about 20 cm) and really stand out against those dark rocks, so you will spot them easily. They are harder to photograph than some of the other animals though, as they can move quite quickly at times. If you spot one that appears to be blowing bubbles from under the shell, as in my second photo, it’s an indication that it will soon be discarding its shell. The crabs have to do this periodically as they grow, because the shell doesn’t grow with them and becomes too small. So they shed the old shell and then have to stay in a sheltered, hidden spot such as a crevice in the rocks until the soft new one beneath it, now exposed, can harden. During this time they are very vulnerable and would make a tasty meal for a sea bird, hence the need to hide.

Also known more prosaically as red rock crabs, these are among the most beautiful of crabs. The colour can vary but is always bright, although the young are dark brown (for camouflage on the rocks). John Steinbeck, one of my favourite authors, wrote about them:

Sea turtles

As well as all the wildlife on the islands and in the air above, there is lots to see in the surrounding waters. You will some marine life from the boat and panga, but to see it at its best it is necessary to get into the sea with them – I loved our snorkelling sessions here.

The Galápagos Green Sea Turtle (Chelonia mydas agassisi) is a subspecies of the Pacific Green Sea Turtle (Chelonia mydas), and is the only turtle to breed on the islands. Nesting is between the months of December and June, and we were there in November – too early, although Fabian did point out one nest on the beach of Bartolomé, where we also saw a turtle swimming in the sea very close to the shore, his head poked above the waves. We saw several on our last morning too, on a panga ride in Black Turtle Cove, Santa Cruz. But the best place to see them is, as I said, in the water. There were several at our snorkelling site off the beach of Santiago, while my clearest encounter was in Gardner Bay, Española.

The Pacific Green Sea Turtle is listed as an endangered species and is protected from exploitation in most countries, including Ecuador. The Galapagos National Park authorities close certain beaches in the islands when it is nesting season for the Green Sea Turtles to protect the nests from tourist activity. However, the turtles are still in danger because of several human practices. Water pollution indirectly harms them as it threatens their food supplies, and many green sea turtles die caught in fishing nets. If you do find yourself on a beach with a turtle nest, as we did, your guide will point it out – be sure not to walk on it.

Some other animals, seen on only one or two of the islands, will feature in my future entries about our visits to those. Meanwhile though I will continue this overview of the wildlife of the Galápagos in my next entry, with a look at the islands’ birds …