HARLINGEN, Texas (ValleyCentral) — At first glance, this tranquil South Texas pond, with palms gently swaying in the distance, looks quite peaceful, but danger lurks in the greenish slime-cloaked waters.

A closer look reveals the toothy countenance of the largest reptile in North America having just emerged from the primordial mire.

It’s that time of the year when the Rio Grande Valley alligator population begins appearing from the tepid waters of their wintery lair.

As temperatures climb, these cold-blooded creatures rise from tunnels they have inhabited during winter dormancy to soak up the sun.

Nobody knows how many alligators roam the Valley, but there is a thriving population at Laguna Atascosa Wildlife Refuge east of Rio Hondo and on adjoining ranches.

On sunny days, the imposing reptiles can be seen basking on banks, and some easily surpass 10 feet in length.

Females rarely exceed nine feet, but males can apparently attain lengths of 15 feet or more and weigh in excess of 1,000 pounds. An Arkansas gator recorded in 2012 measured 13 feet 3 inches and weighed a reported 1,380 pounds, while stories of even bigger gators persist.

These opportunistic carnivores will eat just about anything they can snatch from fish to fowl, turtles, and mammals.

Once on the verge of extinction, American alligators were protected as an endangered species in 1967, but have achieved a remarkable recovery and in 1987 were removed from the endangered species list.

There are now more than five million wild alligators roaming the southern coast of the United States with approximately half a million in Texas, and special permits are required to hunt them.

There are some impressive alligators patrolling the lower Valley’s interconnected waterways, and it is wise to be alert to their possible presence as they are becoming more active with warmer weather prevailing.