02 March 2012

Another Curlew Tit is spotted

The life of a wild bird is not an easy one. The BTO get quite a few reports of 'unusual' looking birds with abnormal plumages and deformities. The types of deformity vary widely but the most commonly reported are of the legs and especially the beak.

The most common bill deformities reported by Garden BirdWatch members are:
  • Upper mandible over grown
  • Upper and lower mandible crossed over
  • Upper and lower mandible elongated together
  • Lower mandible over grown
  • Bill fractured
Ringers are in the unique position of being able to record abnormalities by measuring and by taking photographs. John Griffin from Devon recently caught this adult Blue Tit with an 18mm long bill! The cause behind this abnormality is unknown but this bird was at a healthy weight so was able to feed and take care of its plumage to some extent.


Ringers have reported ringing birds (Blue Tits in particular) with normal beaks and then, on re-catching these birds again months later, they have varying abnormalities. This proves that the abnormalities in birds can occur at any time in their lives. The most common bill deformities in Blackbirds are fractured bills, however this is rarely reported in Blue Tit, Great Tit or Starling. More information can be found on the Garden Birdwatch pages.

Thanks to John Griffin for letting us know and the photo.

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