Showing posts with label tits. Show all posts
Showing posts with label tits. Show all posts

30 Dec 2017

Tits and Beaks

Photo: Dennis van de Water


It is, I suppose, another sign of advancing middle-age when one starts to be more interested in tits and beaks than what the Americans crudely refer to as t and a.

Thus I was intrigued to hear that the British obsession with feeding birds seems to be causing a rapid evolution in the rostrums of certain species, including tits, as they physically adapt to the garden environment.      

In fact, researchers at Oxford who have been studying the great tit population in Wytham Woods for over 70 years, have found that the beaks of UK birds in comparison to their Continental cousins are up to 0.3 mm longer. This may not sound like a big deal, but it's actually an astonishing development and even such a tiny advantage can mean the difference between life and death.  

Further, in conjunction with colleagues in the Netherlands, they have also discovered that, due to natural selection, genes determining beak length are now significantly different in British tits; in other words, Dutch birds not only have shorter beaks, but different DNA sequences. 

Apparently, the British spend about £200 million each year feeding their feathered friends; that's twice as much as the rest of Europe. And they have been doing so for many years now. Thus, whilst researchers can't definitively say that bird feeders are responsible, it certainly seems reasonable to suggest that the longer beaks are a result of this interspecies generosity.

However, whilst it's interesting to note that the number of species of birds that now rely upon supplementary food supplied by householders has risen to around 130 (up from just 18 forty years ago), one does worry about dependency and what would happen if, for whatever reason, people decided to hang up less feeders and more anti-bird spikes in the trees - like those sons of bitches in Bristol worried about protecting their precious BMWs. 


Notes 

For further details, see 'British birds adapt their beaks to birdfeeders' (20 Oct 2017) on the Oxford University News and Events page: click here. Most of the factual information above was gleaned from this source. 

The actual study referred to - 'Recent natural selection causes adaptive evolution of an avian polygenic trait', by Mirte Bosse, Lewis G. Spurgin et al - was published in Science, Vol. 358, Issue 6361, (Oct 2017), pp. 365-68. 

The case of residents in Clifton - the affluent Bristol suburb - fixing spikes to trees in their neighbourhood in an attempt to prevent birds from perching and shitting on the expensive cars parked below, was widely reported in the press earlier this month. I refrained from commenting here on Torpedo the Ark, as I didn't want to be seen to be inciting vandalism in response to this grotesque act of selfish and spiteful stupidity. Click here to read a report in the local paper, the Bristol Post.