Wednesday, 7 March 2018

Duck Tales and Paradise

Who's a pretty boy den?
Sexual selection: now there's a thing. Most higher animals and some lower animals too (definition Flaxen?) are subject to this phenomenon. Simply put, it involves mate selection and preference for reproduction. Almost exclusively this is practised by the female of the species. This makes good biological and evolutionary sense as the female is responsible for harbouring the foetus within her body, supplying nutrients and in many cases continuing to nurture the offspring after they are born. In species where the male's only contribution to the effort is supplying the seed of life, it behoves the female to be picky. Therefore, the female will choose a mate she considers genetically 'fit'. This does not occur at the conscious level but is ingrained within. She is apt to pick the healthy and strongest of males as a visible demonstration of good genes. Even where the domestic arrangement favours male involvement in bringing up the brood, it still makes good sense for the female to pick a good healthy mate. In some species, especially mammalian species, the males contend amongst themselves for sexual access to the females. This often takes the form of violence and the winner, if he is able, will gain a harem. This is a very brutal but effective way to demonstrate your fitness and ability to sire strong healthy brats which in their turn will be able to pass on their genes to the next generation. In other species, the selection process can seem bizarre resulting in some strange male attributes, well at least to the untrained eye.

Consider the humble peacock. The female is the dowdiest of birds. The male, in contrast, is bedecked and bejewelled with a plumage reminiscent of a rich scintillating tapestry. It appears that the female has a preference for males with the most ornate feather arrangements. This may seem frivolous and even dangerous for the male as a great deal of energy investment is necessary to maintain an elaborate display. Furthermore, the heavy gaudy feathers make escape difficult and detection by predators easy. However, biology is never frivolous, or more importantly, evolution is never flippant with the bestowal of her gifts. An ostentatious male signals his health and fitness by his display. In other words, the magnificent plumage is a marker for more important traits controlled by underlying genetic factors.

Sex amongst animals is not always consensual. Bird species, in particular, may engage in rape in order to sow their seed into the next generation. How is the prudent female able to cope under such circumstances? It benefits her not at all if her children are fathered by a relatively weak, and soon to be eaten, male. But the wily female has a highly sophisticated adaptive solution......

Consider the very unassuming, duck. Female ducks have evolved a rather ingenious reproductive system. The vagina is a labyrinth, with twists and turns ending in semen traps. There is only one true path to the promised land and this guarded by a muscular spasm. The drake is generally not a sensitive lover and will engage in rape and often gang rape. By constricting her vaginal muscles the female is able to guide the drake’s penis and hence the semen to a place not conducive to conception. Thus the female can exert control over who father’s her ducklings. The highly motivated males also come under the influence of evolutionary adaptation. In turn, they have evolved a rather large penis with a distinctive corkscrew appearance. Hence the male is able to better navigate the contortions and convolutions of the female’s vaginal anatomy. Selection for a specialised vagina has acted as a spur for the evolution of countermeasures. The advantage, however, is with the female as they are able to influence conception in 93% of cases. Only 3% of avian species are endowed with a penis. Therefore drakes are extremely privileged in this regard. Although on the flip side they have to suffer the indignity of the organ sloughing off once a year. But despair not gentle reader, and do not pity the penisless (not a real word) male, for he has the ability to grow another just in time for the next raping/mating season.  

Isn’t the rich poetry of life, beautiful, brutal and strangely fascinating?

Who's a big boy den?


  1. 'Tis indeed a good job that the peacock approach never caught on amongst primates: imagine the howls of anguish from those delectable young ladies who had coquettishly set their hat at Liberace, Elton John, Boy George &c.

    1. Wasn't Elton Bog married at some point?

    2. Still is:- except first time was to a Kraut woman, second time to a Canadian bloke.

      Must be a few Saturday night renderings of The Lumberjack Song chez Elton.

  2. I seem to recall something about baboons.... However, If this link works..

    Hopefully you will find a fascinating tale of the breeding habits of guppies. And how the females select their partners..

    1. The link worked fine. An interesting interplay between sexual selection and predation pressure. Another fine tome by the good Professor.