Mexico is one the most biologically diverse countries on earth. It's home to 1041 bird species, 439 mammals, 989 amphibians and reptiles, and about 26,000 plants – in each case, about 10% of the total number of species on the planet, on just 1.4% of the earth's land. Just a dozen or so tropical countries harbor two-thirds of the earth's plant and animal species, and Mexico is among them.

Many Mexican species are endemic, including more than half of its reptiles and amphibians, and 139 of its mammals. Over 1/3 of all the world's marine mammals have been found in the Sea of Cortez. The southern state of Chiapas alone has some 10,000 plant species, more than 600 birds (twice as many as the USA) and 1200 butterflies (more than twice as many as the USA and Canada combined).