Crocodiles have had one of their most spectacular evolutionary developments in the American continent, and especially in ancient New Spain, heir to the traditions, myths and legends of the Old World. They all follow a defined morphological structure that has allowed them to survive over millions of years: a snout with sharp teeth adapted for a carnivorous diet - fish, birds and mammals, although the main food for the young is insects and other invertebrates-, a body protected by an armored but flexible skin, and a powerful tail to propel its navigation.
Crocodiles have had one of their most spectacular evolutionary developments in the American continent, and especially in ancient New Spain, heir to the traditions, myths and legends of the Old World. They all follow a defined morphological structure that has allowed them to survive over millions of years: a snout with sharp teeth adapted for a carnivorous diet - fish, birds and mammals, although the main food for the young is insects and other invertebrates-, a body protected by an armored but flexible skin, and a powerful tail to propel its navigation.
When the Spanish conquerors arrived in America and called the current territories of Mexico, Guatemala, El Salvador, Nicaragua, Honduras, Costa Rica and the western United States, they recognized in these lands the effigy of their mythical dragons in the figure of the crocodiles that swarmed everywhere, and which they chose to call fierce lizards.
Regarding crocodilians and alligators, they both have a pair of large teeth near the front of the lower jaw. In the former, these two teeth fit into indentations in the upper jaw and are visible when the muzzle is closed, while in the latter they penetrate into bony cavities in the upper jaw, so when the muzzle is closed they are hidden. For its part, the muzzle of the gulls is extremely long and thin.
Crocodilians inhabit all tropical areas of the planet. With the exception of the Chinese caiman -Alligator sinensis-, the remaining seven species of alligators are found only in America and mostly in South America. The gulls have a representative, the gharial of India-Cavialis gangeticus-, which spans southern Asia, from the Indus to the Irawadi rivers, but is absent throughout southern India.
These reptiles are called cold-blooded, because they cannot keep their body temperature free from wide variations, as mammals and birds do. Thus, they need to lie in the sun to warm themselves or go under water or in the shade of a tree to cool down. Their senses of sight, smell, touch and hearing are highly developed.
THE SPECIES OF NEW SPAIN
As the conquerors did, it is still possible to contemplate four species of crocodiles within what was the New Spain, while in the current Mexican territory there are only three: the river crocodile-Crocodylus acutus-, the swamp-Crocodylus moreletii-, the caiman-Caiman crocodilus-. Fortunately, since the closures of more than thirty years ago and thanks to the efforts of researchers, conservationists and businessmen, their population situation has improved remarkably, although they were on the verge of extinction.
THE RIVER CROCODILE
It is the largest, as it ranges between five and seven meters in length. Its muzzle is remarkably sharp and long, and it has a subtle bulge in front of the eyes. Its general coloration is pale gray, with a greenish or yellow tint.
It inhabits coastal lagoons and rivers, although it can also occupy bodies of water in golf courses and urban areas. Sometimes he is seen sailing the waters of the sea or sunbathing on the beach. It is the only American crocodile with a wide distribution, as it is found from southern Florida, the Pacific coast to the Yucatan Peninsula in Mexico, Central America, the Caribbean islands and the northern portion of South America.
The females of this species lay up to 60 eggs in holes dug in sand or mud mixed with litter. Adults, especially females, develop maternal care behaviors, such as protection and monitoring of the nest, as well as the transport of the young in the snout to the water.
The nesting season varies according to the locality, between January and February, or until March and May. On the other hand, it is estimated that their wild populations range between ten and twenty thousand specimens; however, according to the accumulation of information generated to date, these figures appear to be underestimated. Regardless of this, the loss of natural habitats due to the urban development of the coast is one of its main problems to survive.
THE SWAMP CROCODILE
It is a little smaller than the river one, as it reaches an average of three meters in length and is brown with yellowish spots. The snout is somewhat shorter and wider than that of a river, in addition to having large, bulging golden brown eyes. The skin is quite thin, which is why it has been highly sought after for the trade.
It has a restricted distribution and is found from the center of the Mexican states of Tamaulipas, through San Luis Potosí, Veracruz, Tabasco, Campeche, the Yucatan peninsula and in the northern zone of Chiapas, as well as in Belize and the region of the Petén in Guatemala. This species prefers to live in the waters of rivers, lakes and swamps with vast vegetation or within forests.
On the other hand, the swamp crocodile, like the alligator, does not dig its nest, but accumulates litter until it forms a mound. The female lays between 20 to 49 eggs during the reproductive season that begins with the construction of the nest at the beginning of the rainy season -from April to July- and ends with the birth of the young from September to October. Likewise, like alligators, both the female and the male provide care for the nest and the young. Furthermore, the outstanding feature of this species is its formidable recovery, since according to recent research in Mexico there is a potential population of around 120,000 sexually mature specimens. In the same way, its reproduction in captivity is a success in the two specialized farms of the country.
THE ALLIGATOR
In Oaxaca and Chiapas, all of Central America and a large part of South America, the caiman is located, the smallest of the four species of crocodiles that inhabit ancient New Spain. males reach a length of two meters and females 1.20 m. Its color is yellow or dark with numerous black spots and it has a shorter and wider snout than that of other crocodiles, as well as a kind of horns over the eyes, for which it is also called calman of spectacles.
This species usually takes shelter in caves and cavities under the roots of trees. It inhabits lakes, rivers, streams and swamps, as well as in brackish environments. The nesting season occurs between the months of April to August or until September, while the female can deposit between 20 to 30 eggs in the nest.
In Mexico, caiman farming has been successful. However, given their restricted habitat, they are still threatened by poaching and the loss of their natural environments.
A SEPARATE CASE, THE MISSISSIPPI CAYMAN
It has been very effectively protected by US laws, which is why its wild populations currently register one million specimens. It is widely studied, both in captivity and in the wild. Therefore, it is considered a species with low risk of extinction.
Its habitat is made up of swamps, wetlands, rivers, lakes and small bodies of water in the North American southeast. Despite living in areas with fresh water, it can live in brackish environments such as mangroves. In addition, it is common for it to try to colonize urban areas such as golf courses and residential areas.
This alligator has a strikingly flat snout, shaped like a parabola, the length of which is one and a half times the width of its base. The eyes are yellowish and the pupil in light appears as a vertical elliptical opening. The adult specimens reach a length of four to five meters. During the reproductive stage, the female lays 20 to 50 eggs in a monticular nest made of sludge and litter.
KNOWLEDGE AND RESPECT
Finally, various researchers have come to the conclusion that the decline in reptile populations, including crocodiles, is the result of six important factors: habitat loss and degradation, introduction of exotic species that displace natural ones, pollution , diseases, disorderly use of resources and climate change. To these six is added one more: ignorance, which causes us to make bad decisions regarding the use and exploitation of resources, or to judge the species by their “good” or “bad” appearance.
Source: Unknown Mexico No. 325 / March 2004
