OLD BONES - SVP'S BLOG

Definitions - Describing Diet

I learned a new word at the annual meeting of the Society of Vertebrate Paleontology a few weeks ago: teuthophagy, which means “squid-eating.” It was used in a presentation about sperm whales (family Physeteridae), which frequently prey on squid and thus, can be described as teuthophagous. You can also describe yourself as teuthophagous when you are consuming calamari, so you may want to file that term away for the next time you want to impress someone with your verbal acumen.

Admittedly, there are few other contexts in which to use the word teuthophagy. But that delicious word got me thinking about mammal diets in general and the lengthy lexicon used to describe them. Most of these terms are based on the suffix -phagous, which comes from the Greek verb “to eat,” or -vor, its Latin equivalent. Knowledge of these terms is essential for detailed discussions of the ecology of living and extinct mammals, and I define a smorgasbord of some of the more compelling ones below. 

In teaching my mammal diversity and evolution course, my favorite mammal group for illustrating dietary variation is the family Phyllostomidae, the New World leaf-nosed bats, which take advantage of a surprising range of foods. Like many bats, some phyllostomids are insectivorous (insect-eating). This widely-used term can be a misnomer, though, as these and other insect-eating mammals can also prey on other small invertebrates. Describing them as arthropodivores (arthropod-eaters) or invertivores (invertebrate-eaters) would be more accurate, but for some reason these terms lag far behind insectivore in popularity. Some so-called insectivorous mammals, such as long-nosed echidnas (Zaglossus spp.), are vermivores that feed primarily on earthworms. Large-bodied insectivores such as aardvarks (Orycteropus afer) eat ants and termites almost exclusively. They are virtually always described as myrmecophagous (ant-eating) mammals, though I have seen the aardwolf (Proteles cristata) referred to as a termitivore (termite-eater).


A myrmecophagous aardvark (Orycterpus afer). Photo by D. Croft. Reuse permitted under CC BY-NC-SA 2.0.

Some phyllostomids prey on vertebrates, even other bats. Thus, they can be described as carnivores or, more generally, animalivores (feeding on both vertebrates and invertebrates). In addition to mammals, they can consume frogs (ranivory) and birds (avivory). Since birds are living dinosaurs, it follows that one could consider some phyllostomids to be dinosaurivores, which is a pretty cool thought. This term has not caught on yet, but I think it should. Try it out on your friends and family when you carve your Thanksgiving turkey in a few weeks.

Of course, most of us eat a lot more than just turkey at Thanksgiving, which makes us omnivores (eaters of everything). And if your turkey and other foods were produced nearby, you are also a locavore, an exclusively human dietary category. If you prefer to characterize your culinary preferences with a more novel term than omnivore, try hypercarnivore (if you eat almost exclusively meat), mesocarnivore (if you just mostly eat meat), or hypocarnivore (if meat is only a treat and veggies are more your style). According to the Urban Dictionary, you are a pescatarian if you dine on fish and seafood rather than beef, chicken, and pork. No other mammals are pescatarians, but there are piscivores that feed only on fish.


Hypocarnivorous meerkats (Suricata suricatta). Photo by D. Croft. Reuse permitted under CC BY-NC-SA 2.0.

Many phyllostomids are herbivores in the broad sense, meaning that they eat plants or plant parts. Most of these herbivorous bats are fruit-eaters (frugivores) or nectar-eaters (nectivores), though a few eat leaves (folivory) - a behavior usually restricted to larger-bodied mammals for physiological reasons. No sap- or gum-eating bats have yet been discovered, but marmosets (Callithrix spp.) are specialized gummivorous primates. Other primates such as saki monkeys (Pithecia spp.) are adapted for eating hard fruits and are described as durophagous (feeding on hard objects). Many small, herbivorous rodents sustain themselves on seeds, a diet known as granivory.


A gummivorous common marmoset (Callithrix jacchus). Photo by D. Croft. Reuse permitted under CC BY-NC-SA 2.0.

Vampire bats are members of the family Phyllostomidae and are the only mammals (or vertebrates for that matter) that feed exclusively on blood: sanguivory. This is an excellent term to use around Halloween or at your next Twilight book discussion. For me, it brings back fond childhood memories of watching late night “Creature Feature” movies hosted by Dr. San Guinary.


Sanguivorous vampire bats (Desmodus rotundus). Photo by D. Croft. Reuse permitted under CC BY-NC-SA 2.0.

Locavory may be the latest “green” diet, but the ultimate in recycling is coprophagy, eating feces. While not a pleasant visual, it turns out to be a very effective strategy for maximizing the nutritional value of leaves, which are notoriously difficult to digest. Coprophagy is practiced by a variety of folivorous mammals including rabbits (family Leporidae), sportive lemurs (family Lepilemuridae), certain possums (family Pseudocheiridae), and many rodents. Ruminating mammals like cattle do essentially the same thing by regurgitating partially digested food (cud) and then sending it back down the digestive tract. But there is no specific term for cud-eating.

So whether you are a teuthophagous omnivore or a frugivorous hypocarnivore, I hope this gives you a few things to ruminate on during your next dinner!

-Dr. Darin Croft is an Associate Professor at Case Western Reserve University in Cleveland, Ohio
Posted: 11/3/2015 12:00:00 AM by croftdarinadmin | with 0 comments
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