Saturday, 1 January 2011

Survival of the fittest.

If you've been following Birds2blog you'll know very well these photographs are - in my view - unique and it is hard to believe they depict a Stonechat engaged in the act of a fight for survival, it was eventually established it was catching and feeding on Common Backswimmer notonecta glauca a type of water boatman, so called because of its habit of swimming upside down.

This one is even harder to believe, it is the same Stonechat well on the way to submerging itself in water. As can be seen this individual is 'fishing' through an ice-hole as an ultimate act in order it may survive until its main diet of insects and other small invertebrates becomes available after the thaw which eventually follows such harsh weather conditions though not soon enough for many birds and other wildlife, take a look at 'Sad end for a film star' in the photo section on the LDBWS website for an example of just one bird which sadly didn't make it.

Over the years I've discovered a mass of interesting and often intriguing facts about one of our most complex bird species which is the Stonechat and whilst concentrating on the birds diet during the recent harsh weather the UK has experienced I am reminded of one or two of the more interesting facts about the species.

Even in the more average winter months the Stonechats choice of invertebrate is restricted, but in the harsh weather of late the birds food is - where available - supplemented by seeds and a variety of small fruits/berries. During observations the Stonechat has been seen to 'hammer' snails on a stone in winter, and on another occasion - during a week long freeze with snow cover in 2000 - to take hibernating caterpillars from the base of grass clumps.

Other interesting studies of feeding habits further afield and not related to weather conditions have shown two male European Stonechats in Israel which preyed together on a Scorpion measuring between 16-17mm which is at least 10mm above the average size of prey, on one occasion the Scorpion was seized and thrown against a stone by one of the birds which then retrieved it and repeated the process, it was eventually eaten by both birds though not including the claw.

In finding a Stonechat on Wednesday 29 December at Conder Green I was prompted to post this brief article. Initially I was quite amazed to find this bird and had been thinking of a date in March to be the first chance I'd have of finding one on passage. But my amazement was a little subdued when I gave myself the time to realise how complex,resilient, and adaptable the Stonechat really is.

Birds....they amaze me in a thousand ways!

Thanks to Brian Rafferty for these amazing images which - along with some accompanying text - were quite rightly published in an issue of British Birds

1 comment:

Warren Baker said...

It is amazing just how reilient the birds are Pete, you're quite right.

I would expect them to be though, why should they be any different from us, after all we would eat each other in order to survive!!

Enjoy the chats :-)