Being a man is tough, and being a manly man is even tougher,
particularly in the animal world.
In the animal world, you have two goals in life: to survive and to reproduce.
The second goal actually trumps the first one, since you really, really want your
genetic material to be passed on.
It's therefore no surprise that animals will go to great lengths to find
themselves a mate.
Some species practise what is called a 'polygynous mating system', where a single
male will copulate with many females,
and by doing so, he makes sure that he is the father of the highest possible number of babies.
In polygynous species, males tend to be very big and impressive.
Think of gorillas, lions, elephant seals...
It's not just to impress the ladies though, but also to fend off any other
competing males.
It can even be a matter of life or death. For example, between five and 20
per cent of red deer stags die each year because of the fighting injuries during the rut.
On top of that, if you do manage to obtain a harem, maintaining it can be
very costly – at least energetically speaking. During mating season, male
Galapagos marine iguanas try to secure beach sites with a prime location.
The best territories will attract the highest number of females, and guarantee
the most matings.
Unfortunately, defending your real estate takes up so much time that you can't
afford to eat. A marine iguana securing the best site for his girlfriends may fast
for as long as 49 days and lose a quarter of his body weight.
OK, so it's a trade-off: you put in a lot of effort, but you secure more mating opportunities
Surely it pays off – at least the manly males get all the ladies, right?
Well, not necessarily.
Apart from the testosterone-filled machos
there are also males who are not particularly big, impressive or
aggressive; frankly, they wouldn't stand a chance against the alpha males, who
wouldn't even consider them worthy competition.
Interestingly, however, it turns out that they sometimes do better with the ladies.
Take red deer stags, for example: while two huge, powerful stags fight over their
harems in a dangerous antler battle,
the females are being fertilised by the unimpressive,
runty-looking young males. Who would have suspected that?
The technical term for this phenomenon of stealing mates is 'kleptogamy', but the evolutionary
biologist, John Maynard Smith, who came up with the concept, prefered to call it
the 'sneaky f***er strategy'. And it turns out that these sneaky males do quite well
for themselves.
For instance, among grey seals, a staggering 36 per cent of the
offspring from the females the alpha guarded were fathered by other males.
For some animals, kleptogamy is just a temporary strategy, employed until they
get bigger and have a chance at securing their own territory and mates. But some
choose to make a lifestyle out of it. In blue gill sunfish, males can actually
adopt two alternative lifestyles:
either they slowly wait to mature, get bigger, secure territory, build a nest and
become a good dad. Or they mature quickly while they're still small, and sneakily
fertilise the eggs that the good fathers are guarding. These sneaky males actually
put on feminine color patterns and mimic the behavior of females, so that they can
slip into the guarded nest, past the big, fiercely territorial daddies.
Cross-dressing can pay off.
In fact, across fish species the sneaky strategy seems to be a rule
rather than an exception; and throughout the animal kingdom, sneaker males can be
found across all taxonomic groups, from marine isopods to orangutans.
After all, why risk life and limb to prove your masculinity to the world
when you can just stick around,
look very feminine, and sneak in at the last moment.