The broad-snouted caiman may look terrifying, but that mouth full of bloody, unevenly protruding dagger-teeth is actually a multifaceted parenting tool. Females of the species, known to scientists as Caiman latirostris, use their maws not only to shred through thick vegetation and unwitting prey, but to guard the mounded nests of soil and plants where they lay dozens of eggs each rainy season. When the babies begin pecking at the insides of their eggs with a small egg tooth on top of their snouts, the mother caiman uses her jaws to gently crack the shells. And when her brood is ready, she carries each hatchling to the water inside her mouth.

Despite the moms’ toothy efforts, only 30 to 40 percent of eggs hatch, and the survival rate for caimans born in the wild is just 10 percent in the first year. That posed a problem until relatively recently, because people hunted the species for its skin, and otherwise persecuted it to near-extinction throughout its range in Argentina, Brazil, Bolivia, Paraguay, and Uruguay. The broad-snouted caiman and other crocodilian species around the globe declined sharply through the 1950s, ’60s, and ’70s, as demand for products made from crocodile leather ramped up in the economic resurgence after World War II.

Through the ’70s and ’80s, though, farming became a key strategy to support both the recovery of wild crocodilians and the croc-skin industry. The practice has successfully incentivized conservation of various crocodile species and their habitats by giving them tangible value to their human neighbors in places like Zimbabwe, Australia, Papua New Guinea, the United States, and Venezuela. As a result, the International Union for Conservation of Nature’s Crocodile Specialist Group considers 19 species “secure” from extinction, including the broad-snouted caiman in the Argentina and Brazil portions of its range.

Today, some 500,000 broad-snouted caimans swim in freshwater swamps, as well mangroves, and even stock ponds and drainage ditches, thanks in part to “ranching” that began in Santa Fe, Argentina in 1990 and spread. The program trains gauchos working on vast cattle ranches to locate wild caiman nests, protect wild adults, and aid research projects.

The work is painstaking. Gauchos visit nests when unattended, carefully marking the tops of eggs with colored pencil, because changing their orientation can kill the embryos inside. Then, they pack a portion of the clutch in nest material inside plastic boxes, and transport them as far as 10 miles by horse to a vehicle that will take them to a rearing center. When the eggs hatch, staff at the center cut the caimans’ tail scales for identification. Some caimans go to the commercial market for slaughter, but a percentage are also released back into the wild.

Both caiman populations and people benefit. The gauchos are paid $1 per egg, so in a particularly productive area, they might make an extra $1,000 to $2,000 per year over their typical monthly salary of $400. At the Santa Fe rearing center, members of the public are now allowed to look on while the caimans hatch to learn about the species’ natural history, while students have access to study the creatures long-term in a controlled environment. Meanwhile, broad-snouted caiman populations have increased 1,500 percent in some places. As of 2006, surveys of breeding females in the wild revealed that half had been raised in captivity.

And each year, those mothers put their gnarly mouths to work just as wild-reared caiman mothers do: defending their nests, helping their young hatch, and delivering them safely into their home waters.