Stumpy and Kiawah, resident alligators at the Savannah River Ecology Laboratory, sneak a smooch one day in their enclosure on the SREL campus in Aiken, S.C.

The two reptiles have been a bonded pair since 1984, when Kiawah (on the left) arrived from Kiawah Island off the South Carolina coast. She measures in at 9 feet long and upwards of 300 pounds, while her beau Stumpy is 12.5 feet long and about 630 pounds. The pair have produced hundreds of juvenile alligators that have been relocated as “youthful outreach ambassadors” across both South Carolina and Georgia, and have contributed to areas with declining gator populations in the Southeast.

Both Stumpy and Kiawah came to SREL in the early 1980s as nuisance alligators—Stumpy had bitten a swimmer in southeastern Alabama that was harassing him. If an alligator did that today, it would likely be euthanized. That’s because—with the modest assistance of Stumpy and Kiawah—American alligators have come roaring back since being placed on the endangered species list in 1967. The reptile now enjoys a conservation status of “least concern,” according to the National Wildlife Federation.

Last year, the two alligators moved into a new pond and out of the enclosure Stumpy had called home for 37 years. Their residence at SREL allows for up-close observation of behaviors that herpetologists typically can only glimpse in the wild.