It is well known that the sexes of many species of birds migrate at different times – usually the male birds ahead of the females. Conventional scientific thought has suggested that this is because males need to arrive earlier in order to set out and defend a territory prior to the females’ arrival. This late snow storm suggests another possibility:
Eons ago the sexes migrated together. Usually the missus would be just behind her man lazing in his slipstream. This position was physically beneficial for her as the long flight didn’t require as much energy thus leaving her with ample reserves that she could invest in breeding. This was a pretty good trade-off from the male’s point of view. However, this position also made it possible for the female to give the male a running commentary on where he should be going, how fast he was going, what he was doing, etc. This detracted from the trade-off somewhat but energy for breeding still tipped the scales in favour of this strategy. Every now and again though the pair would run into a late snow storm. Then the s@%t hit the fan: “I told you it was too early to leave but ooohhh nnooooo, you knew better. You and your ‘let’s get going babe so we can see Spring come upon the land and we can sample those first juicy catepillars’. If you’d just done what I suggested – wait a few more days, you can never be too sure about the conditions. But nnnooooo, you had to push on ahead…blah, blah, blah.” Well, it was this sort of interchange that tipped the scales the other way. After this sort of onslaught who felt like breeding anyway. Once the species had experienced enough storms, the males began to take off together looking to experience the coming of the Spring to the land while the females lingered; this also gave them someone to chat to about even the most inconsequential things while enroute.
And so you see, this storm has shed new light on an old theory.
Here are some pictures Rick took on March 10th, 2008 at Ruthven. Click the thumbnails for a larger image.