Top 10 Mexican Biodiversity Hotspots

A UNESCO World Heritage Site in Michoacán and State of Mexico where 300 million monarch butterflies winter in oyamel fir forests at altitudes above 3,000 metres, creating one of the world's most spectacular wildlife phenomena as the trees turn entirely orange with the weight of resting butterflies. The migration — 4,000 kilometres from Canada and the northeastern United States — is the longest insect migration on Earth.

UNESCO-listed as both a natural and cultural World Heritage Site, Calakmul in Campeche contains the Maya ruins of a city that once rivaled Tikal in political power within an 1.8-million-hectare tropical forest that hosts jaguars, tapirs, spider monkeys, and the largest population of scarlet macaws in Mexico. The site's dual heritage status is unique in the Americas.

UNESCO-listed as the "Aquarium of the World," the Sea of Cortez between Baja California and mainland Mexico contains 695 vascular plant species, 891 fish species, and is the most important breeding and feeding ground for blue whales, fin whales, and whale sharks in the Pacific Ocean. Jacques Cousteau's famous description of the Gulf of California as the world's aquarium reflects its extraordinary vertebrate and invertebrate species density.

The Jalisco highlands reserve where researchers discovered in 1977 that the ancestor of all cultivated corn — Zea diploperennis, or wild perennial teosinte — still grows in the wild is one of the most scientifically significant plant discoveries of the 20th century and fundamentally altered the direction of corn breeding research globally. The reserve's cloud forest ecosystem harbors over 2,600 vascular plant species.

A dramatic 30-kilometre gorge carved by the Grijalva River through Chiapas, Sumidero's 1,000-metre walls harbour nesting colonies of great egrets, boat-billed herons, and swifts, while crocodiles sun on the river banks and spider monkeys inhabit the canyon forest. The boat tour from Chiapa de Corzo through the canyon, surrounded by walls so high the sky is reduced to a stripe, is one of the most dramatic wildlife experiences in Mexico.

A UNESCO World Heritage Site in Puebla and Oaxaca that protects the world's most diverse assemblage of columnar cacti — 81 species including the cardon, which grows to 15 metres — in a Sonoran-Chihuahuan transitional desert ecosystem. The reserve also protects the earliest evidence of the domestication of maize, squash, and chiles by pre-agricultural Mexican peoples.

A Veracruz rainforest reserve at the northernmost limit of the Mesoamerican tropical forest that contains the highest density of endemic plant species in Mexico and is one of the last refuges for howler monkeys in eastern Mexico. The reserve's three volcanic lakes — Catemaco, Chalchoapan, and Sontecomapan — support lacustrine ecosystems found nowhere else in the country.

The largest wetland system in Mexico and Central America, the Centla Marshes in Tabasco support the largest population of West Indian manatees in the Gulf of Mexico alongside jabiru storks, roseate spoonbills, and the critically endangered Morelet's crocodile. The floating meadows of water hyacinth and aquatic grasses form a habitat that changes entirely between wet and dry seasons.

A Chihuahuan Desert reserve shared between Chihuahua, Coahuila, and Durango protecting the Bolsón de Mapimí ancient lakebeds, home to the endemic bolson tortoise — one of the largest terrestrial tortoises in North America — and to the remarkable flora of the Chihuahuan desert that contains 20% of the world's cactus species. The local legend of a "Zone of Silence" where radio signals fail, created by a 1970 US rocket crash, has made the reserve famous in Mexican popular culture.

A UNESCO World Heritage Site in Michoacán and State of Mexico where 300 million monarch butterflies winter in oyamel fir forests at altitudes above 3,000 metres, creating one of the world's most spectacular wildlife phenomena as the trees turn entirely orange with the weight of resting butterflies. The migration — 4,000 kilometres from Canada and the northeastern United States — is the longest insect migration on Earth.

UNESCO-listed as both a natural and cultural World Heritage Site, Calakmul in Campeche contains the Maya ruins of a city that once rivaled Tikal in political power within an 1.8-million-hectare tropical forest that hosts jaguars, tapirs, spider monkeys, and the largest population of scarlet macaws in Mexico. The site's dual heritage status is unique in the Americas.

UNESCO-listed as the "Aquarium of the World," the Sea of Cortez between Baja California and mainland Mexico contains 695 vascular plant species, 891 fish species, and is the most important breeding and feeding ground for blue whales, fin whales, and whale sharks in the Pacific Ocean. Jacques Cousteau's famous description of the Gulf of California as the world's aquarium reflects its extraordinary vertebrate and invertebrate species density.

The Jalisco highlands reserve where researchers discovered in 1977 that the ancestor of all cultivated corn — Zea diploperennis, or wild perennial teosinte — still grows in the wild is one of the most scientifically significant plant discoveries of the 20th century and fundamentally altered the direction of corn breeding research globally. The reserve's cloud forest ecosystem harbors over 2,600 vascular plant species.

A dramatic 30-kilometre gorge carved by the Grijalva River through Chiapas, Sumidero's 1,000-metre walls harbour nesting colonies of great egrets, boat-billed herons, and swifts, while crocodiles sun on the river banks and spider monkeys inhabit the canyon forest. The boat tour from Chiapa de Corzo through the canyon, surrounded by walls so high the sky is reduced to a stripe, is one of the most dramatic wildlife experiences in Mexico.

A UNESCO World Heritage Site in Puebla and Oaxaca that protects the world's most diverse assemblage of columnar cacti — 81 species including the cardon, which grows to 15 metres — in a Sonoran-Chihuahuan transitional desert ecosystem. The reserve also protects the earliest evidence of the domestication of maize, squash, and chiles by pre-agricultural Mexican peoples.

A Veracruz rainforest reserve at the northernmost limit of the Mesoamerican tropical forest that contains the highest density of endemic plant species in Mexico and is one of the last refuges for howler monkeys in eastern Mexico. The reserve's three volcanic lakes — Catemaco, Chalchoapan, and Sontecomapan — support lacustrine ecosystems found nowhere else in the country.

The largest wetland system in Mexico and Central America, the Centla Marshes in Tabasco support the largest population of West Indian manatees in the Gulf of Mexico alongside jabiru storks, roseate spoonbills, and the critically endangered Morelet's crocodile. The floating meadows of water hyacinth and aquatic grasses form a habitat that changes entirely between wet and dry seasons.

A Chihuahuan Desert reserve shared between Chihuahua, Coahuila, and Durango protecting the Bolsón de Mapimí ancient lakebeds, home to the endemic bolson tortoise — one of the largest terrestrial tortoises in North America — and to the remarkable flora of the Chihuahuan desert that contains 20% of the world's cactus species. The local legend of a "Zone of Silence" where radio signals fail, created by a 1970 US rocket crash, has made the reserve famous in Mexican popular culture.