What a difference a nipple makes

We've mentioned several times that sibling rivalry in spotted hyenas is fierce. You might recall from my long-ago post on the dominance hierarchy that if a female has two cubs, one becomes dominant almost immediately, and reaps the benefits of this. It has easier access to the mother's milk, gets cuddled while nursing, and develops faster. In fact, we think that one of our older females, Moon Pie, actually has a bum nipple—all females have two teats—so in this case the difference is especially drastic. When Moon Pie has twins, the dominant cub tends to develop at a much faster rate than its subordinate sibling.

Anyway, here are a couple photos that highlight some of these differences. Remember Falafel, who had newborns back at the end of July? (She was the one who drooled all over one of them.) Here's a chance for you to check in on the progress of her cubs, Tilt and Jordache. It is difficult to see the difference in size because they aren't in the same photo, but you are able to see the difference in development. Notice how Tilt, the dominant cub (top photo), is already getting its spots, whereas Jordache, the subordinate cub (bottom photo), is still mostly black:




But it gets better. Perhaps you also recall that there's not only a difference between dominant and subordinate siblings...there's also a difference between high-ranking and low-ranking cubs. High-ranking cubs develop much more quickly than their low-ranking counterparts, because their moms have better access to food. Here's a picture of two cubs, Jordache (left) and Monopoly (right), that were born within two days of one another, and look at the tremendous size difference between them:



Monopoly is the granddaughter of Murphy, our alpha female, whereas Jordache is the granddaughter of a low-ranking female in a different matriline. You can see we're not messing around when we say this whole rank thing is pretty important. The last photo is also of Monopoly, and I'm including it just to give you a better idea of how quickly Monopoly's spots have come in compared to those of Tilt or Jordache.