Those animals just look like magnificent birds underwater. They are graceful, majestic and shy at the same time. But they have one common thing with us: their “fingerprints”. Theirs are situated on their back. Even if in English they are called “eagle”, in some other countries, they have different names, like “leopard” in France or even “painted back” in Ecuador. Their specific black and white pattern is unique to each specimen. With more than 500 different species around the world, they are quite common.
I have been diving for most of my life. I received my first diving license (Open Water Diver) at the age of 8 in my home country, France. Since then, my life has been closely connected to the ocean. I have lived in over 10 countries across 5 continents, but it’s Mexico, specifically Cozumel, that has captured my heart. I arrived in 2016 and in 2017 I could launch my own Dive Operator in the island, Olalasub.
Cozumel is a truly special place, not only can you dive all year round, but you also encounter exceptional biodiversity such as vibrant fish, sea turtles, nurse sharks, and of course, Eagle rays. Cozumel is a famous spot during winter to get an encounter with those rays. In that way, a few years ago, a non-profit organization called Cozumel Ocean Research (COR) was created by a few passionate people.They are using a special database, entering a picture of an eagle ray back and just like a police system would recognize a registered fingerprint, the database recognizes a back pattern and identifies the animal. Thanks to this system, and the help of local divers, COR has been collecting thousands of data in order to know more about those marine birds. We still know little about them.
So far, they have collected information about 1000 specimens on Cozumel Island, some staying around all year round and some just traveling through. Apart from their back helping them to camouflage from shark attacks while swimming over the reef, they also have an interesting nose and mouth. Eagle rays combine their capacities. While its nose has electro-sensory pores, making it like a radar, it can also change in size and form in order to look for food in the sand or even move some rocks. Then, they will use its powerful jaws and teeth to smash the hardest shells, just like a can opener. Generally, a scuba diver observing an eagle ray underwater could guess when the animal is going to look for dinner, as their lips are getting bigger and its nose is moving like a radar. They will look for shells, clams, mollusks in the sand. This is also the best moment to get closer. Staying as close as possible to the bottom, slowing movements, and approaching by the side in order for them to look at you, are keys to enjoy a magic encounter.
On some rare occasions, eagle rays have been found while sleeping in the sand. Until a few months ago, we didn’t even know it was possible. They normally need to be in permanent movement, just like sharks, to get enough oxygen in order to breathe. They just pause their brain while swimming in the safest area possible. However, we have different videos in Cozumel of eagle rays laying on a sandy bottom, looking like they are asleep. I have, myself, been in this situation, face to face, by myself, with what looked like a sleepy eagle ray. We don’t know much about it, but different theories are expressed; they could be resting, they could get cleaned, they could be in a kind of trance, or even trying to give birth. But most of the time, eagle rays give birth in a lagoon. They find the perfectly protected shallow waters looking like a paradisiac lagoon. Baby eagle rays are then all by themselves trying to survive. They generally stay a bit in this protected area, getting bigger and strong enough to swim fast in case of a predator attack and being able to escape from it.
When they enter the open waters, it is not uncommon for some eagle rays to engage in mimicry. In fact, they find an adult and become their shadow for a while, in order to learn the best spots of food, the best currents, and all the tips they could catch. Or in other cases, they find a group of rays and become part of it. In some places of strong current, in the north part of Cozumel, we observe this phenomenon of grouping. They just group, face the current and swim against it. We currently think they are looping around the island to get food and rest, and that they would like to group in this part of the strong current. Are they exchanging information? Communicating? Nesting? We don’t really know for the moment. They are still quite a lot of a mystery and every year we try to know more about it. We are awaiting to get trackers on some specimens in order to know more about their activities. In the meanwhile, the next eagle ray season is starting soon, and we hope with the help of each diver to report pictures, videos or any element about them. Also, more missions will be done around Cancun and Puerto Morelos where a lot of eagle rays are also seen. Are they crossing from those different places? Are they communicating? Are they different groups? We are still missing a lot of information about it and that’s why any help is appreciated.
