Hi All
Been away working for a few days in Chichester and stayed with friends who are daft on birds too. They have loads of bird feeders around the place and I saw lots of their Blue Tits which were all smaller than ours here in Wales, and I was wondering why? Anyone got any ideas?
Chez
You have no control over what life & people throw at you - but you have full control over how you deal with it!
Hi,
bird species do tend to vary in size geographically ; as they move north subspecies often become larger- note Greenland wheatears. Occasional runts occur but not in any numbers. However Blue Tits in Britain only vary a little on an individual basis. Remember that different light, surroundings and vegetation can make birds appear larger or smaller .
The annals of birding are full of well- seen birds that 'appeared' to be bigger or smaller than they should be and caused much confusion.....
:)
S
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The geographical variation of blue tits is marked with two distinct groups.. the differences tend to relate to very slight variations to the pluamge more than actual size though. The blue tit we are all highly familiar with (Cyanistes caeruleus) occurs across Europe and the Middle-east, with the "classic" blue crown and head stripes, greenish upperparts and short thick bill - within this group the variation is...clinical ..to say the least! so there really isn't anything in way of regional variation within the UK to note. The other distinct group is referred to as C.teneriffae , from North Africa and the Canary Islands, with mainly blue/black crowns and head stripes, slate-blue upperparts and a longer thinner bill.
To split hairs further - within the caeruleus group are 7-8 races recognised (mostly through genetic profiling) mainly reflecting darker plumages in the more humid west and increasingly paler towards the north and north-east of Europe and Scandinavia.
Within teneriffae are 6 races, between north Africa and slight variation between each of the Canary Islands.
Hope that helps to clarify!
L