If you sift back through the catalog of parental admonitions that were meant to ensure you a long and happy life – you know, “don’t stick your tongue on frozen metal”, “don’t eat yellow snow”, “don’t drink your father’s last bottle of beer” – somewhere buried in there your mother must surely have added “and oh yes dear, don’t swim with sharks”.
Very sound advice to be sure but swimming with sharks – whale sharks that is – in the Sea of Cortez is truly one of life’s great (and, sadly for you danger junkies, very safe) adventures. While whale sharks have thousands of teeth in hundreds of rows in their enormous mouths (imagine armed shark mouths 4 to 5 feet wide), they can neither bite nor chew. That’s right, they are happy to forego all human body parts in favor of plankton, krill and small fish. Go figure!
Whale Shark Mouth! Photo by Deni Ramirez
So now you feel safe but even if you were on the varsity swim team you’re probably wondering how you could actually keep pace with a shark in the water. Well, the whale shark got its moniker because it is the only fish that is literally as big as a whale; mature adults can reach 60 feet in length and 50 tons in weight. Reaching these proportions requires an immense amount of energy, which the whale shark gets by consuming huge volumes of plankton-rich water, then straining it out through its gills. In fact, to get the food it needs it is not unusual for a whale shark to filter 400,000 gallons of water anhour. To conserve this hard-won strength – and continue eating – whale sharks tend to do a lot of hanging about in the water, or, if moving, doing so at a very slow pace. This lollygagging is what makes it possible for non-bait types like humans to jump in and swim alongside them for a bit. Of course, when they want to put on the speed they certainly can so when a whale shark tires of your company all you will see is a swishing tail receding into the distance.
Now you’d think it’d be a relatively simple matter to learn about a mammoth fish the size of a school bus dawdling through the water eating up everything in its path. But the fact is that scientists still know relatively little about the whale shark, and La Paz resident Dení Ramirez of Whale Shark Mexico is trying to change all that. Originally from Mexico City, Dení has been studying whale sharks in La Paz since 2001, and completed her Ph.D. in marine biology last year. The whale shark’s skin is covered in a pattern of pale yellow spots and stripes that is unique to each animal, a type of fingerprint if you will, so Dení has been able to track some of the inhabitants of La Paz Bay. In fact, she has been tracking the young sharks Flavio, Tikki Tikki and Tango for almost a decade now, and has determined that they are true Baja residents. While whale sharks have been spotted across the globe from Australia to Djibouti, from the Philippines to Mozambique, Dení’s juveniles appear to travel only in the Sea of Cortez, from the Bay of La Paz to Bahia de Los Angeles – roughly 600 miles. We asked Dení why we seem to be seeing the whale sharks around La Paz so much more over the last couple of years than we ever did before.
Whale Shark Feeding in the Sea of Cortez: Photo by Deni Ramirez
“It’s really just a question of food. Over the last two to three years the conditions in the Bay of La Paz have been just right to produce an enormous amount of plankton for the whale sharks to feed on. The wind, currents, mangrove conditions – all these have combined to create an excellent environment for plankton growth that we just didn’t have for such extended periods in earlier years. Also, in the Bay of La Paz the plankton is rich in the coastal waters, and these relatively shallow waters give the young sharks in my group a certain amount of protection.” Dení is happy to take visitors with her on her research trips and share some of her extensive knowledge of whale sharks and research methodology.
Dení is currently doing a lot of work with the pregnant females who inhabit the deeper waters around Espiritu Santo Island and have found that they have much larger migrations than the young sharks due to their different needs as mothers, mothers who surely will work to ensure the long life and happiness of their offspring by admonishing “and dear, don’t try to eat the humans. They’ll just clog up your gills.”
TOSEA guest Mary Winzig recounts her whale shark adventure:
“Swimming with whales sharks is the most amazing thing I have ever done in my life. They are such magnificent animals and I felt so lucky to be in their presence. I was scared—to see something so large and to know you are jumping in the water with them made me pause for a moment. My heart seemed to be almost leaping through my wetsuit – I asked the guide to make sure they were whale sharks because their dorsal fins were so huge! But after watching them and seeing their polka dots, I realized I had to swim with them. You can’t be afraid of anything with polka dots! Jumping in and seeing them through the snorkel was magical. Once I was in the water, I wasn’t afraid. I have no idea how long I was in the water with them, 2 minutes? 15 minutes? I was transfixed. Their mouths look like the grill of a ‘57 Chevy. I have never felt so small or insignificant, but also so powerful. I have decided I have to do everything in my power to help save these magnificent creatures. Thank you Todos Santos Eco Adventures for this wonderful opportunity. I look forward to swimming with the sharks again!”
What do scorpions have in common with humans? Unlike most of their fellow arachnids and invertebrates but very much like humans, scorpions are viviparous, i.e., they give birth to live young one by one. The scorpion babies look like miniature adults, except that they are very light in color (adults are dark) and cannot sting. This lack of stinging ability may help promote family harmony as almost immediately after birth baby scorpions climb onto their mother’s back, a perch they enjoy for several days until their first molt (longer for some species). The mother scorpion does not feed her babies, but she does carry and protect them until they are able to hunt for themselves. Unless, of course, she gets too hungry in which case she no longer recognizes the small arachnids are her babies and eats them! Some time after the first molt young scorpions leave the (relative) safety of their mother’s back to establish their own territories.
Mama Scorpion with Babies on Her Back
The body of a scorpion is divided into two parts: the cephalothorax (also called the prosoma) and the abdomen (opisthosoma). The cephalothorax is the scorpion’s “head”, comprising the carapace, eyes, chelicerae (mouth parts), pedipalps (claws) and four pairs of walking legs. The scorpion’s exoskeleton is thick and durable, providing good protection from predators. Scorpions have two eyes on the top of the head, and usually two to five pairs of eyes along the front corners of the head. In the summers in Baja scorpions can be seen raising their bodies off the ground to cool their undersides.
Scorpion Family Photo
Scorpions play an important role in the ecosystem of Baja by helping to keep the insect population under control. They also like to eat spiders, small mice and lizards. But they don’t eat every day; in fact scorpions have been known to go without food for up to 12 months if they have sufficient water. Typically though scorpions will have a meal at least once every 2 to 3 weeks. They are quite resourceful in going after these meals. Some stalk their prey and some will even dig a trap in the sand for their prey to fall into.
Others take a more relaxed approach and just wait by their burrow with their pincers open and stingers raised until unsuspecting prey wanders by. Once prey is within reach the scorpion grabs it and crushes it with their pincers. Scorpions try not to use their venomous sting unless absolutely necessary as it takes a great deal of body energy to produce more venom. Younger and smaller scorpions tend to use their stingers more often than larger and older ones. Scorpions have very small mouths and can only take in liquid, so captured prey is crushed and injected with enzymes that dissolve the insides. Scorpions are remarkable survivors. If necessary, they can slow their metabolism to as little as one-third the typical rate for arthropods. In this way the scorpion greatly reduces its intake of oxygen and can live on as little as a single insect per year. But unlike most hibernating species, even with lowered metabolism the scorpion has the ability to spring quickly to the hunt when the opportunity presents itself.
Scott Taylor, founder of the Australia-based Cetacean Studies Institute, wrote a magnificent book in 2003 titled Souls in the Sea: Dolphins, Whales and Human Destiny. Anyone who has interacted with the (free and wild) whales at Magdalena Bay, or swum with the (free and wild) dolphins in the Sea of Cortez, is aware on some level of the enormous intelligence of these beings, mammals who have inhabited the planet much longer than we have and, as Taylor argues, “possess a deep wisdom about how to live sustainably and joyfully.” In his book Taylor ponders why, after centuries of abuse, whales and dolphins continue to engage with humans. Is there something they are trying to tell us? Are they trying to change our perceptions of them? Taylor provides quotes from different writers who ponder the intelligence and messages of cetaceans:
It is an important and popular fact that things are not always what they seem. For instance, on the planet Earth, man had always assumed that he was more intelligent than dolphins because he had achieved so much – the wheel, New York, wars and so on – whilst all the dolphins had ever done was muck about in the waves having a good time. But conversely, the dolphins had always believed that they were far more intelligent than man – for precisely the same reason. — Douglas Adams, The Hitchhiker’s Guide to the Galaxy
Cetaceans unquestionably have big brains, and the frequency with which they use them in patterns that can only be described as play suggests that they frolic with their minds as readily as they do with their bodies. This tendency towards mental playfulness may in itself have been partly responsible for the enlargement of their brains.
— Lyall Watson and Tom Ritchie, Whales of the World
The brain of a dolphin prepared for microscopic examination reveals these things at the cellular level:
The dolphin’s cell count is just as high per cubic millimeter as is that of a human.
The connectivity, or number of cells connected to one another, is the same as that of a human brain.
There is the same number of layers in the cortex of a dolphin as there is in a human brain.
In other words, this brain is as advanced as the human brain on a microscopic structural basis.
— Dr. John Lilly, Man and Dolphin
The cetacea hold an important lesson for us. The lesson is not about whales and dolphins, but about ourselves. There is at least moderately convincing evidence that there is another class of intelligent being on Earth beside ourselves. They have acted benignly and in many cases affectionately toward us. We have systematically slaughtered them.
— Carl Sagan, The Cosmic Connection
The dolphins had long known of the impending destruction of planet Earth and had made many attempts to alert humankind to the danger; but most of their communications were misinterpreted as amusing attempts to punch footballs or whistle for tidbits, so they eventually gave up and left Earth by their own means. The last-ever dolphin message was misinterpreted as a surprisingly sophisticated attempt to do a double-backward somersault through a hoop while whistling “The Star-Spangled Banner” – but, in fact, the message was this: “So long… And Thanks For All The Fish!”
— Douglas Adams, The Hitchhiker’s Guide to the Galaxy
The California Sea Lion (Zalophus californianus) is one of the most sociable and fun-loving marine mammals around, and they love to congregate in large colonies of one thousand or more along the Pacific coastline. They are called the lions of the sea because of the loud roars they can produce. The males of some sea lion species also grow thick manes around their necks. From Todos Santos you can visit and interact with sea lions at the famous sea lion colony of Los Islotes in the Sea of Cortez.
Baby sea lions are usually born in late June and are fairly well-developed from day one. Just after birth they can swim a little bit, call for their mothers, and open their eyes. Several days after birth the sea lion mothers leave their youngsters in the rookery and head into the ocean in search of food. When they return they call for their babies with a loud trumpeting noise and the babies reply in a series of bleats. This goes on until mother and pup are reunited. The mother’s final test to determine that she has found her pup is to sniff the pup all over.
Getting to Know the Neighbors: Snorkeler & Sea Lion
Sea lion males are quite impressive in size (and seem especially so when you’re snorkeling nearby), growing up to 8 feet long and 660 pounds. Females are much smaller although they are still the size of a large man, growing up to 6.5 feet long and weighing in at over 200 pounds. As they mature, males grow a crest of bone on the top of their heads, and it is this crest that gives the sea lion its generic name: loph is forehead and za in an emphatic, so Zalophus californianus means “Californian big-head”.
The main difference between a sea lion and a seal in appearance is that sea lions actually have ears, while seals do not. Sea lions are also built to move on both land and water, although they definitely look more graceful in the ocean! The sea lion’s front flippers have a bone structure that is quite similar to that of a human arm and hand. These front flippers propel a sea lion forward while it is swimming, while the rear flippers control steering. The sea lions use both pairs of flippers to walk (waddle) on land.
California sea lions enjoy a wide variety of seafood and feed mainly on squid and fish. Adult females forage for food anywhere between 10 and 3,000 kilometers from the rookery and can dive as deep as 274 meters, with average dives of 31 to 98 meters. Sea lions can stay underwater for up to 15 minutes by sealing their noses shut. The Californian big-head lives to be about 17 in the wild, somewhat longer in captivity.
A wonderful bird is a pelican,
His bill will hold more than his belican.
He can take in his beak
Food enough for a week;
But I’m damned if I see how the helican.
By Dixon Lanire Merritt, 1910
The brown pelican is one of the best fishermen in Baja and watching these prehistoric-looking birds in action is pretty incredible. It is the only pelican species to dive for prey, zooming in from a height of 30 feet and streamlining its body and wings as it flings itself into the ocean like an arrow. The big beak pouch for which the pelican is so famous is used as a dip net to catch fish. But fish don’t stay there long – they are quickly transferred to the stomach (the center of gravity) so that the pelican can maintain balance while flying. Quick transference also helps prevent the likelihood that a gull will steal the fish, something that can happen if the pelican doesn’t swallow quickly enough. The brown pelican’s beak is capable of holding up to 3 gallons of water – about 3 times more than its belly can!
The Brown Pelican (Pelecanus occidentalis) is the smallest of the eight species of pelican, although it is a large bird in nearly every other regard. It is 106-137 cm (42-54 in) in length, weighs from 2.75 to 5.5 kg (6-12 lb) and has a wingspan from 1.83 to 2.5 m (6 to 8.2 ft). The brown pelican’s habit of diving for fish from the air distinguishes it from other pelican species that engage in cooperative fishing from the surface. Watching a flock of brown pelicans flying low over the ocean in V-formation is one of the majestic sights of Baja. They can fly at speed upwards of 30 miles per hour.
Fossil evidence tells us that pelicans have changed very little over the last 30 to 40 million years, perhaps accounting for their rather prehistoric look. Brown pelicans are hatched in broods of 2 to 3, and eat about 150 pounds of fish in the 8-10 month period they are cared for by their parents. Pelicans can live for up to 30 years.
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