There exist few hospitable places left on earth that can claim to be truly ‘untouched’ or ‘unspoilt’, but given its accessibility, the small ‘Isla Contoy’ off the coast from Cancun, gets pretty close.
Only just over five miles long, this narrow strip of rock, sand, and mangrove only just peeks up above the turquoise waters of the Carribbean sea.
Much is made of the unspoilt wild beauty of the island, and it is very beautiful, but all is not quite what it seems. The island has secrets, and one of them is quite deadly.
First of all, it is certainly not a pristine habitat, untouched by the meddling influence of man. The scene of tropical paradise below is perhaps somewhat tainted if you realise that the palm trees should not actually be there at all, but were planted or introduced by humans…

Introduced palm trees
In the foreground of the photo, and covering much of the island, is one of the four species of mangroves (more on them later as they are a clue to the island’s deadly secret).
The palms are not the only signs of the human touch. There are a few buildings, although literally only a few (in single digits), including a dock where visitors arrive, an observation tower where they look out, and a couple of habitations for the four or five rotating temporary conservation workers who are the only human residents. Aside from guides and scientists, only 200 tourists are permitted to visit a day, and must abide by a number of rules to protect the ecosystems (such as not wearing sun cream).

View from the highest point on the island with dock and observation tower visible
While the human presence is thankfully small, there are large numbers of birds. Frigate birds in their many thousands use the islands as a breeding ground.

Magnificent Frigatebird (Fregata magnificens)
The chicks perch precariously (frigatebirds don’t actually ever truly perch, they just sort of rest on something) in the mangroves above the lagoons while large fish swim around menacingly below. Sometimes the chicks fall in the water.

Frigatebird chick
Wading shorebirds visit the islands in large numbers as well. I stood on a small jetty photographing the Spoonbills (below) in the distance on a lagoon when a guide brought his tourists to look at them. He pointed at them and said in Spanish “Mira! Flamencos” (“Look! Flamingos”) – I didn’t embarrass him and, to be fair, they were quite far away and flamingos do apparently visit the island in large numbers, although I didn’t see any there.

Roseate Spoonbills (Platalea ajaja)
There are good numbers of ibis, herons, and all manner of waders, big and small, including the the ultimate ‘shorebird’…

(Ruddy Turnstone) Arenaria interpres
I photographed this chap on the beach as we boarded our boat home. The reason it fills the whole frame is I couldn’t step back far enough or change my lens fast enough to get a more pleasant aspect.
Terns and other sea-birds can also be found circling, or come on to the island to roost or breed. And that’s it. I mean, we are talking over 150 species, so not bad for such a small island, but there are no passerines whatsoever on the island.
The reason there are no resident perching/song-birds or anything similar, or any resident mammals, is the same reason why the island has never been been fully inhabited by humans. There is no freshwater. No rivers, no springs, or ponds, just very salty lagoons.

Lagoon and the ocean
Humans have visited the islands for hundreds, maybe thousands of years. Mayan pottery and carved shells have been found, but these were likely left by visiting sea-farers. The island has only ever been accessible by boat.
On approach and departure from the island, for miles, the sea is shallow and almost impossibly turquoise. We did some snorkelling, although the reefs in this area are not large or in great condition. More impressive is the odd dark circular shape that we saw as the boat moved through the sea. At certain points these rock-like shapes were really quite numerous – and sometimes almost the size of a small car. And they were moving. The island and the sea around it is an important breeding area for sea turtles. In fact all four of the major turtles breed on the island’s beaches: Loggerhead Turtle, Green Turtle, Hawksbill Turtle, and the largest turtle in the world, the Leatherback.
We saw other dark shapes in the sea. From a distance it appeared to be a small black island, and then a floating mat of some sort. We got closer to see a densely packed flock (or ‘gulp’) of several hundred, maybe thousands, of cormorants…

Double-crested cormorant (Phalacrocorax auritus)
As our boat powered alongside them, we all watched transfixed as the tightly packed gulp became a flight. The black shape, turned black and white by the splashing wings and feet, soon became an elongated cloud that stretched further than my camera lens could encompass and passed alongside and then out beyond the boat. It was a magnificent wild spectacle of the first order that is only poorly translated into pixels.

Cormorants in flight
Trip list
Having finally come to the end of this rather long, serialised trip report of my time in Mexico, I can now include the trip list of species positively identified while we were out there.
As I said in a previous post, the list is nowhere near as long as it should have been, but it includes a number of life-firsts (marked below by a star*), and there were an even greater number of fantastic memories. The double-crested cormorants above, were not rare or unusual, but seeing this huge flock on a turquoise sea was an incredible experience I shall never forget. If you have the opportunity to visit the Yucatan, I heartily recommend it.
- Spotted Sandpiper
- Wilson’s Plover*
- Willet*
- Mangrove Warbler*
- Red-winged Blackbird
- Groove-billed Ani
- Tropical Kingbird
- Least Tern*
- Great Egret
- Palm Warbler*
- Dunlin
- Greater Yellowlegs*
- Black-necked Stilt*
- Mangrove Swallow*
- Mangrove Vireo*
- Tropical Mockingbird*
- Tri-coloured Heron*
- American Flamingo
- Royal Tern*
- Brown Pelican
- White Pelican
- Laughing Gull
- Caspian Tern
- Turnstone
- Sandwich Tern
- Ring-billed Gull
- Ruddy Ground Dove
- Blue-grey Gnatcatcher*
- Yellow Warbler
- White-winged Dove*
- Golden-fronted Woodpecker*
- Osprey
- Green Heron
- Black Vulture
- Northern Jacana
- Anhinga
- Altimara Oriole*
- Social Flycatcher
- Magnolia Warbler*
- Cinnamon Hummingbird*
- Black-crowned Night Heron*
- Pygmy Kingfisher*
- Lesser Scaup
- Double-crested Cormorant
- Reddish Egret*
- Vermillion Flycatcher
- Lesser Yellowlegs*
- Blue-winged Teal
- White Ibis
- Great Blue Heron
- Wilson’s Phalarope
- Empidonax (sp?) Flycatcher
- Turquoise-browed Motmot*
- Hooded Oriole*
- Clay-coloured Thrush
- Yellow-olive Flatbill*
- Greyish Saltator*
- Chestnut-sided Warbler
- Lesser Greenlet*
- Spot-breasted Wren*
- Turkey Vulture
- Hawk (sp?)
- Brown Jay
- Great-tailed Grackle
- Bronzed Cowbird*
- Great Kiskadee
- Red-throated Ant Tanager*
- Rose-throated Becard*
- White-bellied Wren*
- Myiarchus (sp?) Flycatcher
- Plain Chachalaca*
- Roseate Spoonbill
- American Golden Plover*
- Cave Swallow*
- Euphonia (sp?)
- Barn Swallow
- Northern Cardinal
- Collared Dove
- Black-cowled Oriole*
- Common Ground Dove*
- Feral Pigeon
- Yucatan Jay*
- Snowy Egret
- Yucatan Wren* (heard only)
*= Life Tick.