A while ago I received an email from a blog reader asking for an update on the baby Eastern Black rhino (Diceros bicornis michaeli) Akili living in the Zoo Berlin. Is she well? Is she growing? Has she grown proper horns yet?
Yes, Akili is growing, and while she is still quite small compared to her mother….
…she has started to lose that cute baby look a bit, and is becoming a real, big and strong rhino! That’s mostly the fault of the two horns – still small, but quite clearly horns. What’s rather funny-looking is the head-on perspective, especially when she adopts that rhino-typical hanging-down head posture: the small skin bulge on the top of the head and the two big bulges between the skin folds on the neck mimic the horns, seeming to form an entire row of “bumps” – in side view this effect disappears.
As you can see, Akili is (as all rhinos are) a rather broad-shouldered and sturdy affair, and quite muscular as well. Often, rhinos look rather sluggish and, well, fat, especially the Indian species with their knobbly skin with big folds. Babies quickly nix that notion, because at their size we can compare with animals we know well, and immediately see that they move quickly and powerfully. In huge animals such as adult rhinos, elephants and even giraffes it is often hard to gauge how fast they are really moving a body part, simply because their size throws off our perception. Add to that the high threshold such animals typically have for reacting violently (who’s really going to pose a serious threat, after all? And moving rapidly costs absurd amounts of energy, so they do so sparingly) and they seem to be in constant slow motion. But even if, say, the angular velocity of a limb is low, the great length means that the foot may move surprisingly fast, and can deliver a hefty kick, with the large mass resulting in a stunning impulse to transfer.
And that’s certainly also true of large dinosaurs: even those that look dinky next to a sauropods, such as prosauropods or hadrosaurs, may be multi-ton animals with all the OOMPF in their tails or limbs of heads that we see in rhinos or elephants today when they “get hasty“. That’s one of the reasons I love studying huge mammals. Another is that they live under the same mass-induced constraints as other huge animals, including dinosaurs. Thus, expect more rhinos on this blog in the future.