Marine Iguanas

On being a marine Iguana

If you’d rather watch a video than read this information, we’ve got you covered.  Click here to go to our YouTube video on marine iguanas.

Hi!  I’m Maverick, a marine iguana.  I’d love to tell you what my life is like while I’m warming myself in the sun!

Mom buried three eggs in the warm sand of our island—about 65 feet (20 meters) inland. After three months, I cracked my shell, clawed my way to the surface…and chaos! Dozens of hatchlings like me were scrambling across the beach while gulls, hawks, and herons circled. A snake slid through the dune grass. A cat watched from the shade. Yikes! Everyone wanted a tiny iguana snack. I was just a little guy about four inches (10 centimeters) long, so I bolted for the rocks by the water, where a few sturdy adults stood guard. Safe at last—what a first day!

I settled into a colony of several hundred marine iguanas of varying ages.  Our beach was wall-to-wall iguanas while we’d bask in the sun during the day.  After sunset, we huddled in clusters to conserve our heat.  With all this togetherness, it’s a good thing everyone was very friendly.

When I first arrived on the scene, I dined on iguana guano.  (Yes, that a fancy word for poop!)  After a year, I braved the shallow water and tide pools where, along with the lady iguanas and smaller males like me, we fed on red and green algae.  As I got older, I gradually became more able to forage for the algae underwater and could dive to get to it.

When I reached my adult-size of 22 inches (56 centimeters) plus a fabulous 33-inch (84-centimeter) tail, my larger body was able to hold heat a little longer so I could forage further.  I’d bask in the sun to raise my body temperature, then take a deep breath and submerge.  I could stay underwater for more than 30 minutes and dive up to 98 feet (30 meters) as I looked for tasty red and green algae to eat.  But within the hour, as my temperature began to drop back down, I’d head back to shore.  Sometimes, when I waited just a little too long, I’d have a hard time climbing out of the water, but I always made it.  Once I was back on land, I sneezed out the excess salt, found a good sunny spot, and basked again to recharge myself.  

When I was eight-years-old, I started noticing the ladies as breeding season approached.  While we males are normally black on Española Island, from January to March we add some red and turquoise to our coloring to help attract a mate.  (I’ve heard males turn different colors on the other islands, but no one else is dubbed a “Christmas iguana” like us.)  As I got older and larger, I also claimed a small territory during these months.  My turf was a patch about 200 square feet (20 square meters), hemmed in by boulders and crevices.  Ideally, it sat close to the water and gave me a sunny perch for long afternoon basking.

Inside my turf, my normally friendly façade fades to territorial posturing.  If another male tried to cross the line, I’d bob my head, open my mouth, and raise the spiny crest along my back.  Usually this was enough to drive the intruder away, but when it didn’t, I was ready to rumble.  As the battle heated up, we’d thrust our heads together to push the other away.  Sometimes we’d be entangled for hours, although we would take periodic breaks.  Eventually, the other male would assume a submissive posture and retreat.  Haha!  I win!

When a lady traipsed onto my territory, that was a different story.  I switched from “territorial guardian” to “smooth operator” – a few suave head-bobs, a tasteful jaw-gape, and a strong shuffle as I slowly walked sideways in her direction.  If she accepted my invitation, we’d court for a few minutes – blink and you’ll miss our epic romance.  Then she was off and a few months later she would lay our eggs.  I’d strike a basking pose and wait for the next lovely lady to appreciate my charms.    

During our two-month breeding season, I don’t abandon my territory.  As a result, I can’t forage so I lose some of my body weight.  Because it’s so hard on me physically, I only participate in these encounters every other year.  When I’m not holding down a territory, I’m hanging out with my colony.

I’m warmed up now so it’s time for my daily foraging expedition.  Maverick out!