The bush never gets stale thankfully, although I’m not going to ram home the cliché that every day is different, as it should be patently obvious to most.
The way to really get the most out of it however is to be curious. A wise man once told me that the secret to be universally interesting is to be universally interested, and nowhere is that more true than out in Africa’s wild places.
Continually asking questions – of oneself and of others – is how to keep stimulated, no matter how random they are.
So a couple of weeks ago I watched the Ximungwe female leopard sniffing around a boulder cluster and the thought came to me: How do female leopards know when they are about to give birth? More than that though; by what processes (if any) can the birth be delayed so that the female is able to deliver her young at a suitable den? While science still isn’t exactly sure about what triggers labour, one theory is that it is the release of a hormone by the foetus, but when it comes to leopards or lions, how long is it after the release of these hormones that the mother needs to be at a den?
Let’s take a few steps back here (and bear in mind from the start that I don’t really have answers for these questions, I’m merely trying to initiate a discussion). I’ll use a leopard as an example. Females that are heavily pregnant will start investigating potential dens as they become heavier and heavier with cubs. Den-sites need to be secluded, and the entrances ideally need to small enough for cubs to crawl into or the mother to place them in without allowing bigger predators to reach in and fish them out. I can’t get inside a female leopard’s mind, but it’s more than likely that there are a couple of potential sites identified by the mother during her pregnancy. The next step is actually getting to the den once labour is triggered. How long does the female have? In humans some babies can be delivered in an hour or two while others can take well over 24 hours. I doubt there is as much variation in the delivery time of a leopard, but there may well be cases where the mother, finding herself far from selected den-sites during a hunt, has to give birth in a less-than-suitable spot simply because she didn’t have time to get back to a pre-selected den.
I might be overthinking this completely, especially in the context of the Leopards of Londolozi. Territories here are amongst the smallest recorded in the world, in large part due to the abundance of suitable prey and adequate cover in which to stalk. Availability of den-sites may also be a factor in determining territory size, but the point is that in a small territory, it wouldn’t take very long for a female to get to a selected den to birth. Let’s take the now-deceased Tamboti female as an example.
She had probably the largest territory of any female on Londolozi during her tenure, although the area sadly didn’t feature too many great dens. This last bit aside, from one corner of her territory to the opposite one, as the crow flies (which is how she would cross it, not having to stick to roads) was probably a maximum of 6 kilometres. That’s not far. The average human walking speed is roughly 5km/h, and a four-legged mammal like a leopard would be able to match that without any problems. Roughly an hour – most likely – less – and the Tamboti female would be safely ensconced in a den if she felt even the slightest hint of labour.
Because their habits and gravitation towards cover can make them so hard to find, we tend to think of leopards as covering big distances. This is probably based on us covering big distances in our tracking efforts. But in actual fact, the females in the Sabi Sand don’t roam all that far. A leopard in the Kalahari is a different story, but we’ll leave that for another day.
Having mulled all this over while typing this post out, I’ve started to stick to the Parsimony Principle; the simplest explanation is probably the right one. Although considerations like how much time the females need from when labour is triggered, whether they can delay birth or not, or to what extent they are forced to choose a den based on where they are in their territory at the time, are grist to the mill in terms of discussion, I think it might simply be that the female leopards here have investigated all the potential sites, have a selected one in mind, and when they feel labour induced, simply walk there.