have you SEEN a dik-dik?

A recent and actual G-chat transcript, between my sister and me.

Alix: Have you SEEN a Dik-dik?

Me: No. What is a Dik-dik?

Alix: A tiny tiny antelope.
             They are monogamous.

They can run 26 mph.

Can you imagine if a Dik-dik ran past you at 26 mph?

It would be amazing.

I wish lap giraffes were real.

Okay got to go. Love you bye.

Of course, I immediately Wikipedia’ed Dik-dik, and was faced with the cutest ungulate I’ve ever seen.

OH MY GOD. (wikicommons)

They are little antelopes that live in Africa. They eat small plants and shrubs, throw it back up, chew it some more, and eat it again. This would be gross, but they’re so tiny that it’s more funny than it is gross.

What really caught my eye in the Wikipedia article was the blurb referring to their monogamy. It reads:

“Monogamy in dik-diks may be an evolutionary response to predation; surrounded by predators, it is dangerous to explore, looking for new partners.”

Monogamy exists all throughout the animal kingdom. Selective pressures vary in each instance of it, but it is safe to make the sweeping statement that monogamy usually evolves as a means to protect highly vulnerable young. Take us, for example. The survival rate of babies (before the present-day civilization) must have been waaaaay higher if Dad stuck around to protect mom and child from saber-toothed tigers and to help provide food. On the other end of the spectrum, consider a housefly. Baby houseflies are ready to buzz off and start life as soon as they hatch. Mom and dad aren’t even around- they’re already off having irresponsible sex with new partners. Monogamy wouldn’t make sense for them.

Dik-dik being sassy. (pbase.com)

Never before had I seen monogamy explained as a response to predatory danger for the parents. No way this could be true, I thought to myself. I researched further, and lo and behold: a whole paper has been published on Dik-dik monogamy. And they found something pretty interesting.

It had been previously assumed that Dik-diks were facultatively monogamous. Facultative monogamy is monogamy that is the result of restrictions on resources. In other words, male Dik-diks could only defend enough territory to accommodate one female, and that’s why they only mated one female. If more resources were available, then the male Dik-diks could afford to pimp two or more females.

Researchers found evidence to the contrary of this model. Male Dik-diks routinely defend territory (and therefore resources) to accommodate several females! Why do they date just one lady, then?

Obviously, because they have the capacity to love. (Alix, you stop reading here. Life will be better if you do.)

No, that’s not true. Rather, it’s because the males are jealous little suckers and don’t want any other guys picking up their girlfriends. It’s formally called mate guarding- and is an evolved behavior that increases the likelihood that their genetic material is passed on to the next generation. If Dik-diks had the equivalent to “The Maury Show,” the audience would be sorely disappointed that Dik-diks rarely question the paternity of their fawns. Daddy Dik-diks keep close enough eyes on their ladies that they’re not too worried about it.

This being said, monogamy rarely occurs in nature without extra-pair copulation, aka “getting some on the side.” In Dik-diks, only males will engage in extra-pair copulation. Mated females are noted to rarely, almost never, engage in extra-pair copulation (go figure).

So, several components contribute to Dik-dik monogamy. It is safer for the tiny, herbivorous animals to stick to their territory instead of going down to the local drinking hole to try to meet new Dik-diks. Also, mated pairs spending almost all of their time together increases paternal fidelity. And even though males have the capacity to mate more females, they don’t- the lingering urge to mate guard has been passed down from earlier times when perhaps the Dik-dik male could only defend territory for one female.

My initial balking reaction to the explanation of Dik-dik monogamy was short-sited. It wouldn’t make sense for the natural world to be as diverse and multifarious if evolution followed a blueprint. Regardless of how many notes I took or outlines I made about monogamy as an evolved reproductive strategy while I was in college, I don’t know diddly squat.

When asking questions about the evolution of life, always remember to keep an open mind. If researchers hadn’t kept open minds about Dik-dik monogamy, we’d still be without the knowledge that males mate one female, even though they can mate more. And I prefer to live in a world where Dik-diks stick by each other's sides in a non-obligatory capacity. Don’t you?

Here's the paper:

Female dispersion and the evolution of monogamy in the dik-dik. Brotherton, PNM, and Manser, MB. Animal Behavior, 1997. Volume 54 (6), 1413-1424.