Puffin Along (On the Crest of a Wave)

Yet another story about scientists being 'baffled' about there being 'fewer than there should be' (what is the right number?) Puffins in the Farne Islands and elsewhere in the UK (http://news.bbc.co.uk/1/hi/sci/tech/8126331.stm) and their attempts to determine the causes by tagging the birds. Just two comments. Firstly, I thought it was pretty well established that a major reason for the reduced success of the 'sea parrot' in breeding was the decline in sand eels that they feed to their chicks (I seem to remember stories of chicks choking on more bony fish). Secondly, although one can learn a lot by tagging birds (with tags that are becoming progressively smaller and more sophisticated), there is little doubt that being tagged applies an additional penalty to these animals making it even less likely that they can efficiently feed their chicks. So I just wonder whether a further study is really needed at this stage.