The dry season lingers on here at Mpala, with megafauna wandering in search of water and arthropods awaiting an outburst. Last week we experienced a brief but strong rain, stimulating some insect eclosion as well as tortoise activity. On my morning walk, a leopard tortoise (Geochelone pardalis) lay comfortably in the tall grasses, sporting its lustrous spotted carapace. Later in the day two more tortoises ambled by, munching away fiercely on the desiccated grasses. One of them had a drastically different shell pattern, almost uniformly mahogany brown with some remnants of splotches along the edges of its scutes. Older individuals such as the darker tortoise lose their vibrant juvenile colors as they age. Unlike many other large tortoises, leopard tortoises do not make burrows. However, they will sometimes utilize pre-existing holes constructed by other animals. Two nights ago we were lucky to witness an aardvark at night, digging fiercely to create massive cavities and underground burrows. For a mature leopard tortoise, an unoccupied burrow like an aardvark’s would be an ideal refuge during suboptimal environmental conditions.
After several days of stormy skies (but no rain!), chilly winds and a five minute drizzle brought about another leopard tortoise. A friend spotted it strolling along, and I later happened upon the tortoise poking out on top of termite mounds. When I approached, it retracted back into its shell, cautiously waiting for me to move along. Hoping to see the tortoise up close, I laid down next to it quietly. After 15 minutes, the tortoise didn’t seem to perceive me as bringing imminent danger, and it brought out its head, inflating its throat and glancing to the side every few minutes. Occasionally it would smack its jaws and produce a hollow faint sound of expelled air, showing me bits of grasses it had recently chewed on. Eventually it made a gaping yawn for about four seconds while blinking its eyes slowly (this photo is not a defensive behavior). What was so interesting to see up close was an amber-like liquid that drooped down from its left eye which was exposed to direct sunlight. Chelonians do not have tear ducts and instead secrete a mucous discharge to lubricate the eyes and expel particles of dust. In sea turtles, these “tears” also function in releasing excess salt. I have never observed this behavior before, and the quantity of liquid excreted really surprised me.
Chameleon update! After being unable to spot our resident chameleon for many days, Clayton managed to find the little fella moving along the tall grasses just a couple of feet away from its usual perch. We were particularly worried because we also found a chameleon pancake (roadkill) not too far away. Fortunately, he is still thriving and awaiting the rain gods to grant him water and insects!
Photographed after slight disturbance [2], both during its slow maneuvers towards a nearby trunk.
