Nature most definitely is the ultimate tinkerer. She seems never to be satisfied by what is and seems to rather have made the decision to constantly try and upgrade the performance of everything on earth simultaneously. Well, maybe not exactly; crocodiles (and I’m sure some others) seem to have been left as is for a while now.
But I digress, the point I was trying to get at is that nature has come up with some very inventive ways around problems. And one of the millions of these is the mating process in large felids. The mechanisms involved in the feline mating ritual are fascinating, if not somewhat bizarre. Random side note here: these mechanisms are not solely applicable to felines but are also found in hares, rabbits, and some rodents.
Let’s start with the female. The large cats differ from their domestic cousins in that they do not have a seasonal oestrus cycle that is governed by day length e.g. as summer arrives and the day length increases the pituitary gland takes note of this and signals to the hypothalamus that it needs to tell the gonads to stop being so lazy and get back to work! This is what happens to many other animals like impala, wildebeest and warthogs.
Leopards and lions have a more regular cycle. They will come into “heat” every 5 – 13 days every 2 – 3 months. In an environment like Londolozi with an extremely high density of leopards, it really is quite unlikely that a male will not encounter a female while she is in oestrus but that is not a given. The same applies to lions, where the dominant male or coalition (group of males) will almost certainly locate an oestrus female in any pride that they are dominant over. So, in essence, a female has about four shots at falling pregnant per year. A point to note however is that a female may fall back into oestrus only two weeks after losing a litter, an unfortunate but very real possibility.
Enter the male. Male and female territories overlap (for obvious reasons) but a male’s territory may be three, four or even five times that of a female. Now, a male patrols his territory for a number of reasons but one of them is to scout about for any potential mating opportunities. In leopards, he will come across a bush, shrub, or tree that a female has marked against and will pick up her scent. In lions, where the females do not necessarily mark territory, they may just encounter the female whilst on patrol or when meeting up to hunt/feed. He’ll inhale the marking/urine/scat deeply and pass it through a highly specialised Jacobsen or Vomeronasal Organ which is able to, amongst other things, tell whether a female is in oestrus. From there, he’s got pretty much one thing on his mind!
Fast forward through the many kilometres walked trying to locate this female and to the meeting of the pair. The two meet and, in leopards at least, after the initial shock, will come together. The female is none-too-shy about presenting herself to the male, weaving back and forth in front of him, her tail swishing and wrapping about the male’s face before dropping down and presenting her rump; this behaviour is called lordosis.
But this is where it gets really interesting. At this point, the female is not actually ovulating! Big cats seem to be very conservative with their eggs and will not release one unless actually mating. The act of mating is what stimulates ovulation. But the mechanism that triggers the release is even more bizarre, it’s pain. The barbed penis of the male means that extraction is painful for the female, potentially for both parties judging from all the snarling, biting, and swatting that accompanies each 10-second-long mating bout. But this release of an ovum is not immediate, it will occur three to five days later after some 200+ mating bouts!
But let’s say that a female has been mating with one male for the last three days. During that time, they’ve been making quite the fuss, potentially drawing the attention of another male whose territory borders that of the current male. In lions, the same would apply but just with another member of the dominant coalition. He’s either caught the scent of the female or heard the fuss and has also been attracted by the very exciting prospect of furthering his lineage. Now he arrives on the scene and much to his chagrin has been beaten to it! So, he launches himself into the fray and battles with the other male to decide who will retain the attention of the female.
And this is where ‘Nature the Tinkerer’ got really clever. Delayed ovulation means that only the winner of the fight, the stronger male, will be present during the ovulation and successfully conceive, and that means that only the strongest genes are passed on. And that suits the female just fine as that means her offspring have stronger genes and are more likely to survive and further perpetuate her DNA codes. It’s all about the genes!
Another crazy upshot of all of this for the female is that now both males are invested in the protection of the cub! She has confused the paternity and where one male, knowing that he had not mated with the female would kill the offspring, thereby knocking the female back into oestrus two weeks later and allowing himself the opportunity to procreate, now both males may think the cubs are theirs and therefore both ensure the cub’s survival.
This is just one example of a huge number of weird and wonderful mechanisms that have developed over the aeons that life has been flitting about on our beautiful planet. What’s your favourite random animal fact?