The Urban Alligator – Part 1
~Written by Mark Kramer
More than any other local species, the American alligator is an animal sure to stimulate discussion, emotion, and passion. It certainly does for me. In fact, I had to repeatedly remind myself not to turn this episode into a novella (I failed). This is in part driven by the fact that they are large powerful predators capable of eating you. Learning to safely appreciate and accept predators in your neighborhood is an act that we are still cultivating. Fortunately, unlike lions, cobras, or elephants, the alligator’s habitat is in the water. Those gators seen on the six o’clock news are on their way to a neighboring pond (or newest gator love interest-or both), not on their way to make a meal of your backyard chihuahua.
My high school explorations of Armand Bayou began with my wilderness running buddy Ray. Even at fourteen, it seemed like we had been friends forever. We accepted that our mission in life was to get further into the wilderness, or be planning for our next adventure into it. Ray’s Dad had a canoe which he would haul to the bayou and leave us for the day. As we got old enough to drive, we would meet at the newly opened Bay Area Park in our cars and swim to the rope swing (located where the current boathouse is now). Alligators were then listed as an Endangered Species, which was troubling to the young mind of a developing naturalist. We spent many a summer’s day swimming the half mile with our bellies sliding across the soft slick mud bottom to the rope swing (hoping barefoot high school girls were already there). With only our eyes and nose above the water, we jokingly suggested this is the life of an alligator.
That was then. Now, things have changed. In a testament to the effectiveness of a positive federal regulation (the Endangered Species Act), the apex predator of the Bayou City has returned. I encourage Houstonians to expect the likelihood of an alligator being in every bayou, stream, pond, and lake. Bayous are biological arteries that run through the massive human population of our area. Bayous are conduits of water, but they are also the conduits of wildlife. Bayous have enabled gators to travel and disperse into any suitable waters of the Houston area. Just because there was no alligator in that pond yesterday, that doesn’t mean there won’t be an alligator there tomorrow.
This episode of Urban Alligators originated by discussion of alligators in ABNC ponds. ABNC is the prime local destination for gator viewing. Whether it’s from the Boardwalk or guided pontoon eco-tour, there is no better place to see and learn about alligators in Harris County. Doing it safely means keeping a safe distance, never feeding them, and no more swimming.
The biology of Armand Bayou alligators follows a predicable seasonal pattern. In early Spring (March-April) the animals awaken from a long winter’s nap. The first order of business is getting warm. Warming of the entire body core temperature is a difficult task for a five-hundred-pound reptile (the largest reptile in North America). On sunny days, gators will haul out and bask to raise their body temperature. Raising body temperature also speeds reptilian metabolism, enabling the first gator meal of Spring. It’s a powerful hunger considering the last supper was probably consumed in October/November.
After awakening and warming, alligators are hungry. Basking primes the body for the first meal. Exactly what you eat is driven by your size. That means anything from dragonflies to white-tailed deer are on the menu – depending on how big you are. A gator’s life is best described as a sluggish slow-motion lifestyle punctuated by lightning-fast strikes. To witness this predator at work is memorable. Predators help to keep wildlife populations in balance. They are also sometimes responsible for unexpected beneficial ecological outcomes. The establishment of colonial nesting waterbirds at ABNC occurred unexpectedly and spontaneously after nesting alligators appeared in the Rookery pond. Alligators found suitable nesting habitat on the pond’s island and herons and egrets nested in the trees above! These bird Rookeries are commonly associated with the protection of a nesting female alligator serving as an unintentional guardian.
After a good meal or two, alligators begin to think about mating. Alligator behavior is amongst the most elaborate in the reptile world. Courtship begins in April/May with a male bellowing or vocalizing with a sub-sonic roar that may make the bayou waters dance around his body. A dominate male and female will partner and mate for several days. These Gator Love Fest’s alternate with aquatic reproduction time and pair bonding/basking sessions on land.
Female alligators begin nest building about now (May-June). She collects material to build what is essentially a compost pile. Grass, twigs, and mud are shaped into a three-foot diameter pile into which 30-60 eggs are deposited. The temperature of the nest determines if each egg will be born male or female. The warmer the temperature the more males born. Several reptile species exhibit this reproductive phenomenon known as temperature dependent sexual determination. Then the mother gator waits close to the nest for the remainder of the incubation period (approximately two months). In fact, female alligators are such fiercely protective mothers that this is perhaps the most dangerous time for people to approach an alligator. I have a vivid memory of an eight-foot long nesting female gator hissing at the 32’ long pontoon boat as we passed her nest! Sometimes on the Bayou Ranger tour boat as we enter Alligator Alley and approach one of these nests, it’s like traveling upstream on an ancient river with a secret source. It’s like looking back in deep time to see the evolutionary beginnings of motherhood. Many evolutionary biologists suggest that alligators (and all crocodilians) may be a “missing link” in the evolution from the dinosaur to modern birds. This early maternal drive of nest building, egg protection, and care for offspring is carried into the birds of today. These are similar behavioral adaptations carried from one evolutionary lineage to another (in theory).
Today, top predators worldwide are challenged to coexist with humans. Alligators are that apex predator in the Bayou City and only exist where we make space for them to survive. Their superior design and lifestyle have enabled them to survive unchanged since the time of the dinosaur, until humans nearly pushed them out entirely and for good. As I swam towards that rope swing, I never imagined that forty-five years later Armand Bayou would be alive with alligators once more.
Stay Tuned for Urban Alligators Part 2 – Late August When The Hatchlings Are Born!