Tiburon’s Treasures

April 24-26, 2019

24 April: Between the tides and mountains blue,

lapped by rose-waters and a breath of dew


Waking up at 5 on a cold, damp morning, a few early birds piled into the van towards Santa Cruz estuary, looking for other early birds. We were armed with scopes, telephoto lenses and handy field guides, all ready to see what shore and seabirds would be out on the estuary that we had been so amazed by just a few days before.

We saw white egrets and ibises astride each other in the middle of the estuary, probing the ground with their beaks in search of small invertebrates or fish to eat. Little willets and godwits stuck closer to the river banks, navigating between mangrove pneumatophores doing the same.

Further downstream, the river began to deepen, mud slowly giving way to sand and shells. Here, elegant terns took turns to dive into the water to spear fish, while pelicans and cormorants glided overhead. Never failing to entertain, little grebes bobbed along in the water in every direction we looked. Propelled by their webbed feet, they too dove down into the water, fifteen to twenty seconds at a time, foraging for little crustaceans or fish to eat.

The night herons roosting in a nearby tree had begun stirring as the sun rose and the air warmed, possibly awoken by the extremely loud cawing of two particularly boisterous yellow-footed gulls. The pair of gulls ran in step up and down the beach, cawing in unison for reasons we hadn’t yet figured out.

As we drove out, we spotted a large osprey perched on a fencepost right next to the road, with a fish that it just caught gripped tightly with its long, curved talons. It stayed put to observed us just long enough for us to get off a few shots, before beating down powerfully with its six-foot wings and heading back to its nest.

The species diversity that we managed to observe (which included a few invertebrates such as two sea hares) was testament to the richness of the waters that supported it, one that definitely attracted the attention of the fleet of fishing boats around us. As we walked towards the boats, we spotted one headed towards a large sand flat on the horizon, with 3 men harvesting what could have been clams or pen shells at low tide. Unfortunately, this sand flat happened to be where large flocks of terns and cormorants were resting. They soon took flight, hundreds of individuals flying southwards past us in a single long line.

We then returned and got ready for an interesting lecture on island biogeography. After Xavier ran us through the general geography and natural history of the Gulf, one of the TAs from Prescott College came in to share some basics of island biogeography. This was based first on MacArthur and Wilson’s theory and then taken further to include various other factors like oceanic vs continental islands and substrata type to explain variations from the species richness trend. Placing some of the midriff islands on the chart also allowed us to visualize what some of the places we would be seeing were going to be like.

The lecture concluded with a friendly challenge from Sam for us to play against them in beach volleyball, which unfortunately only a few of us were up for. We cobbled together a mixed team, but after the first 30 seconds Colyer had to hobble off as he had jammed his toe in the wrong spot. Sounds like Duke alright, except this time Nike wasn’t involved. Thankfully, just as the sun set our resident volleyball pro Xavier came in to revitalize the team and we soon found our groove, carving out a strong 7-point lead but being pipped to the post 22-20 by a Prescott + Greg team.

We spent the rest of the day touching up our journals from the previous trip, washing out our clothes now peppered with little flecks of blue paint that would forever remind us of our time on Omar’s panga, and preparing boxes/coolers/backpacks for another exciting adventure ahead.


25 April: Reaching out with the touch of a hand,

Where there’re stars in the sea and clouds in the land


Piling everything we had onto Prescott’s super-panga, we soon met our new friends for the trip:

Cosmé, our captain and resident Chuck Norris, a fisherman and free diver who knew everything about anything when it came to fishing.

Manuelito, the Seri elder who’d be helping to take care of the camp along with

Elena, a middle-aged Seri lady who made various jewelry and handicrafts and would help care for the camp and Manuelito.

Gaby, Elena’s niece, a young Seri girl and student who would be coming along to join our excursions.

Abi and Danny who we’d met before, fellow students interested in the environment. Danny spoke some English which turned out to be really helpful.

Max, in his mid 20s, was in the process of being trained as a guide and seemed really well-equipped for the trip.

As if that wasn’t enough, we saw another tall dorsal fin in the distance, one that wasn’t porpoising up and down like the rest. Cosmé moved us in for a closer look, and the fin belonged to a hammerhead shark that none of us were expecting to see. It was relatively calm and we jumped onto the bow to get a better look, Katie O and Meredith leading the charge. Soon though, the dolphins that had followed us noticed the shark and rushed towards it in a large group, scaring the shark off in a huge megafauna interaction that we were so lucky to have seen.

The excitement continued as we made our long and winding way to our campsite at Los Corralitos, named after the enclosures that had been used there to catch sea turtles. The Cmiîque Iitom name for the camp was even more interesting: Inóohcö Quiixaz (pronounced Ee-noke-quee-hush), which referred to the sound that the water makes on the rocks. Indeed, the rounded pebbles gently tumbled over each other with the ebb and flow of the waves, producing soothing whooshes like nature’s windchime (or wave-chime).

We set up our luxurious shelters, larger than our previous ones and now with tables as well for food preparations, and were now greatly appreciative of the sheltered nature of the bay after our previous battles with strong winds. On the southeast tip of Isla Tiburon, Inóohcö Quiixaz was protected from both the northern and southern winds.

We headed on a hike up a nearby mountain, being extra careful not to step through the many thin sand bridges formed by the erosion of little caves into the side of the mountain. The yellow-brown sandstone along with greyish brown brush provided the perfect cover for the mountain’s residents: coyotes. Having spotted one on a spur far off in the distance, we tried to get as close as possible with a telephoto lens and have this photo of a coyote’s hindquarters to show for it. We would have other brown encounters with coyotes later on at the Groover, but for now back to the story.

Once at/near the top, we settled in and took in the beauty of our surroundings, sheer cliffs looking out past glassy calm waters towards islands in the distance. Xavier pointed out Isla Rasa, our destination for the next day, along with peregrine falcons that zoomed past below us. Alejandro took a keen interest in some little butterflies that were flitting between large bees to pollinate the yellow flowers on the tree that you can see just behind Max and Xavier in the group photo below. I tried to get some shots of both the bird and the butterflies too, a little blurry but enough for the biologists among us to use for identification.

We came back to a filling dinner (which means a lot coming from me) of Thai-inspired spicy peanut butter noodles and watched what must be Isla Tiburon’s idea of end credits to the beautiful day we’d just had: a stunning sunset, with the sun slowly slipping behind the mountains we had just climbed, bathing the clear blue sky in orange wash.

We thought that was all, but Xavier, Cosmé and a whole bunch of dinoflagellates had some other ideas. We went out on the boat once more once it was dark at 8pm and immediately bent over double, everyone leaning out of the boat to touch the water that was shimmering blue-green. Little sparkles merged into glowing waves at the stern of the boat, peppered with streaks of green fireworks that turned out to be fish, likely needlefish, scared off by the boat from their rest on the water’s surface. The cover photo for today is a picture that I was glad to have captured: a slightly blurry long exposure shot of Katie reaching into the water. While nothing could even come close to doing justice to this beautiful moment, this was at least a freeze frame of what truly was a magical end to our first day.


April 26: A home, a nest, a sanctuary,

why, why can’t we leave it be?


Awaking for the first time in our new campsite, we enjoyed hot coffee and oatmeal before making our way to the famed Isla Rasa. There, we met with Enriquetta, a most passionate and dedicated ornithologist who’d been studying the birds during the nesting season for 3 months every year over the past 41 years!

She showed us the valley in which 35,000 Hermann’s gulls and 175,000 Elegant terns were nesting, with the royal terns just off to the side closer to the water’s edge. The scale of the nesting was immense, birds as far as the eye could see, packed so tightly that their white bodies and black caps blended into a moving sea of static. In order to pack so many birds into this space, we learned about the honeycomb arrangement: nature’s most efficient way of packing the maximum number of approximately circular objects together in a given area, with up to 15 elegant tern nests per square metre.

It was interesting to learn about the interaction between the Elegant terns and the Hermann’s gulls, where the much larger sizes and aggressiveness of the Hermann’s gulls encouraged the terns to build their nests right next to gull nests, such that the gulls could act as protection against predation from the even larger yellow-footed gulls. This behavior essentially displaced many Hermann’s gulls from where they should be, and formed a large circle of tern nests surrounded by a narrow perimeter of gull nests.

During this whole time, a seemingly endless blanket of bobito flies materialized out of nowhere and covered us, crawling all over our skin (and especially faces)! It made it a little hard to focus but various adaptations including wearing our shirts and jackets over our faces helped a lot. Oddly, no insectivores had yet reached this particular oceanic island, if not I’m sure that it would have a great time feasting on bobito clouds.

We learned about the natural history of the island, how it had to deal with wave after wave of human exploitation: for guano in the 18th century and for eggs later on, and as of today fishing fleets that trawl nearby waters drastically affect food sources for the birds. Enriquetta shared about her struggles in communicating important scientific discoveries to fishermen – she had noticed patterns in fish consumption of the bird colonies in terms of quantity and species. Given that the birds hunt the smaller recruits that the following year’s fishing fleets would target when they had grown to an appropriate size, she had essentially found a way to predict the composition and likely catch rate per unit of effort for fishers! Unfortunately, as a reflection of the importance of science communication and the need for greater synthesis of knowledge across complex policy landscapes, it seemed that more support perhaps from the government or NGOs might be needed to bridge this gap.

Other highlights included spotting a family of Craven’s Murrelets with their chicks, relatives of the penguins that one might not expect to see so far North in such warm climates. Perhaps this should’ve been a warning to us about how cold the water would be, and I for one was definitely very cold even in a thick wetsuit.

That said, we continued on to Isla Salsipueda for a snorkel, spotting stingrays, large pufferfish, various sea stars, sponges and lots of little fish in and among the dense seaweed forests. Moving through the seaweed, I felt like a sealion, albeit a much smaller and slower one. To complete our sealion transformation, Andie, Katie and I had found a conveniently placed rock in the middle of the bay where we were snorkeling, one that had been warmed by the sun, gratefully basking and escaping the cold for a few brief moments before plunging back into the water.

We returned to camp and prepared a hearty, warming dinner, one that was wiped out a little too quickly by lots of hungry snorkelers. Unfortunately, our Seri friends were a little too late and there wasn’t much left in the pot for them. Hearing about all this, I came over as fast as I could and together with a few others split what we had in our bowls with Gaby, Danny and Max, a gesture which they appreciated. Some tuna salad that Abi managed to whip up came to the rescue, almost doubling the amount we had and making sure everyone had enough to eat. As dinner ended I tried to communicate that no one should have to go hungry, which came out as “no hambre” thanks to my limited Spanish vocabulary. Everyone seemed to understand however, and we headed over to the fire, now full and happy.

The night ended with people sharing stories around the campfire and talking about life, one of my favorite things to do. Something about flickering flames enraptures not just one’s attention but one’s soul, creating an atmosphere of warmth and friendship in which stories flow much more naturally.

Looking back at the few days we’d had so far on Isla Tiburon, I’m absolutely stunned by the treasures that we had been so fortunate to see, and thankful for the beautiful people from whom I had learned so much. Our Tiburon adventures continue in the next blog by Katie! 🙂