As you can see, our primary research involves the big stuff: large carnivores, giant antelope, ungulates that could run you down. The camera trap grid is set up to record the movement patterns of these organisms… Which isn’t to say that other types of creatures which traverse the Serengeti don’t get captured in the net as well. I’m sure that many of you who actively identify have spotted the occasional bird, sighted a wildcat, or perhaps even happened upon a basking reptile. Spatial and temporal data is being gathered on these guys too, and for a small side project, I decided to delve into some of the less well-explored information.
I’m tackling a particular guild of small mammals. The questions I’m asking involve occupancy patterns and coexistence among organisms that compete for a common resource — sort of like that Ali does with large carnivores, but applied to other groups. Right now, I’m looking at data on spatial partitioning among myrmecophagous (there’s your buzzword for the day) animals: animals that eat ants and termites. The Serengeti landscape is littered with termite mounds – giant mud constructions held together by termite spit and seething with social insects. Termites are highly important to serengeti ecosystem functioning, breaking down dead plant matter and churning soil. Furthermore, they form over 80% of the diets of three mammals, the aardwolf (Proteles cristata), the bat-eared fox (Otocyon megalotis), and the aardvark (Orycteropus afer). Let’s meet them, shall we?
Sometimes I still can’t manage to convince even other scientists in our department that I’m not making the aardwolf up. Not an wolf (not an “aard” either), looking suspiciously like some sort of pygmy hyena, and eating primarily insects. I’m sure you can see my problem. Well, at least it is in the hyena family – one of the smallest, coming in at a very slender 7-10 kg. These guys produce saliva that is particularly sticky for licking up ants and termites off of the soil surface. While they can’t break into the giant termite mounds, they are the only African ant-eater to be able to tolerate the chemical defense secretions of the Trinervitermes termite soldier cast.
Best true fact about aardwolves: Aardwolves apparently “roar” when chasing off intruders. Kind of adorable right? Don’t melt too much: if that doesn’t work, they proceed to emit foul-smelling liquid from their anal glands. Delightful.
The Bat-eared fox:
These guys are the only canid to have given up almost entirely on mammals to prey on insects. Although small (only 2-5 kg), a bat-eared fox can scarf up over one million termites per year. In fact, they don’t even need to drink because they fulfill the majority of their water intake needs from all of the insects they consume.
Best true fact about bat-eared foxed: Their ears are sensitive enough toe detect the sound of termites chewing on grass, or, better yet, hear beetle larvae chewing their way out of an underground ball of dung.
Definitely the heftiest member of the bunch, at twice the weight of a labrador retriever even though they only stand about 2 feet tall. These guys are solitary and nocturnal, shuffling around at night in search of termite mounds which they tear open with their powerful digging claws. The fox and the aardwolf are unable to break through the thick crust of dirt, and there are intriguing reports of these other guild members trailing aardvarks during seasons when termites are most scarce – perhaps hoping to snatch up some of the termite-crumbs? Having breached a nest, the aardvark slobbers up hundreds and hundreds of insects with its 12 inch tongue. Rather than masticating this mouthful with its teeth, grinds up the ants using the powerful muscles of its gizzard. They’re the sole surviving representative of an obscure mammalian order called the “Tubulidentata” — everyone else in the order kicked the bucket before the end of the Pleistocene.
Best true fact about aardvarks: Although their diet contains mostly ants and termites, they are known to consume a fruit charming called an “aardvark cucumber”.
The diets of all these creatures is composed of exactly the same resource, which can become limiting during particular times of year. No information yet on what kind of partitioning we may find – do the bigger guild members exclude the smaller ones? Is there commensalism (a relationship where one member benefits without affecting the other) between aardvarks and the other mammals? Are some members forced to forage during times when predators are most active?
I admit I had a similarly skeptical reaction when I first discovered the aardwolf (and I read about it in an encyclopedia, so it’s not like it was a source that would be messing with me!). I think it’s mostly the name — it just sounds so bizarre.