Sian Ka’an Biosphere Reserve

More than seven million birds of prey of more than 20 species fill the air

Spotted jaguars, ocelots, margays, and stealthy panther-like jaguarundis steal warily through rain forests ruled 1,000 years ago by Mayan civilizations. Mayans looking out then over this seamless vista of sea and sky called it Sian Ka’an, “where the sky is born” or “gateway to heaven.”

Now 2,040-square-mile (5,282-km2) Sian Ka’an Biosphere Reserve, U.N. World Heritage Site on the Yucatan Peninsula, bounded on one side by pristine beaches, coastal lagoons and 70 miles (113 km) of the world’s second longest coral reef and on the other by marshes and dense tropical rain forest, has treasures from both worlds. Pyramids, canals, temples, and entire Mayan cities rise from the jungle at dozens of significant archeological sites.

Manatees, once mistaken by long-at-sea sailors for plump mermaids, loaf in shallows protected by reef homes of spiny lobsters, changeably-hued octopi and dozens of species of bright tropical fish. Endangered green, hawksbill, leatherback, and loggerhead sea turtles lay eggs on white sand beaches. Primitive tapirs, close kin of rhinoceros but looking more like elephants, browse, swim, and forage on aquatic vegetation with their tiny white-striped babies.

Howler monkeys expand furry black throat pouches emitting other-worldly howls.

Prehensile-tailed kinkajous and tribes of 70 or so black-handed spider monkeys compete for the same fruits, screaming shrilly on spotting a puma (or mountain lion) or one of the spotted felines, well concealed by their beautifully patterned fur.

Collared anteaters and peccaries snuffle through understories. Tiny red brocket deer, 14 inches (35 cm) high, forage on savannah grasses. Tayras, alert little South American martens, are omnivorous. So are handsome small pacas—red-and-white patterned beaver-like rodents— among 103 mammal species, the smaller ones prey for ornate hawk eagles.

Flame-feathered flamingos and toucans holding up colorful ponderous-looking bills (actually almost weightless) are among some 350 spectacular bird species, including orioles, tanagers, and other wintering northern songbirds. Iridescent turquoise-browed motmots pluck lacy patterns in tail feathers. Red-crested woodpeckers hammer tree trunks. Pygmy-owls whistle at night.

Thousands of wading birds nest, some on offshore keys, including roseate spoonbills, wood storks, magnificent frigate birds, broad-billed herons, and rare jabiru storks. Great curassows and brilliantly-plumaged ocellated turkeys pick through forest litter.

Sian Ka’an, funded in part by World Wide Fund for Nature, is 85 miles (136 km) south of Cancun. A range of lodging is available nearby.

Threats include plans that have been discussed for an international airport near Tulum, just 10 miles (16 km) from important nesting areas.