Breckland Birder

Breckland Birder
Water Rail at Thompson Water, Norfolk Photo by Paul Newport

Thursday, 19 December 2013

Crossbills

One of the species which is always associated with the Breckland area is the Common Crossbill, this is often a target bird for birders visiting our unique area.  As well as this species, a much rarer form occurs, the Two-barred Crossbill, whose nearest usual range to the UK is Finland.  At the time of writing, Two-barred Crossbills are present at Lynford Arboretum in Norfolk.

Croxton Heath, Norfolk
At dawn today I visited East Wretham and Croxton Heaths, these large areas of Breckland heath and forest often support wintering Great Grey Shrike, however, I did not seen one today despite searching suitable habitats.  This species is very wide ranging, therefore, it will be worth checking frequently throughout the winter months.
The main focus this morning was on a party of 30+ Crossbills which I found in a single tree alone within a large clearing.  These birds would often fly around together before coming to rest again in the same tree, they would also visit bushes in the clearing.  Due to Crossbills dry diet, water is important to the species, and I noticed this tree was close to a track with lots of puddles, it was therefore very likely that these Crossbills were here to drink.

Crossbills Croxton Heath, Norfolk 19/12/13
Birders are often attracted by the sound of the Crossbills harsh, repeated "chup" flight call, again, a very distinctive sound of Breckland.
Pine trees, especially Larch, are the species to search for this bird. They will often feed silently, however, if you are lucky enough to be close to a tree where Crossbills are feeding, dropping cone debris is a sure sign of their presence.

Crossbill (male) Croxton Heath 19/12/13
Male and female Crossbills are very different in their appearance, males are highly distinctive as they are a striking brick-red whilst females are a dull green.


Juvenile  Crossbills are similar to females but are heavily streaked.
Young Crossbills are born with 'normal' bills, it is not until they grow that the mandibles cross at the tip to form the highly distinctive bill which has evolved to prize open pine cones in order to extract seeds.  

The picture here shows a male Crossbill, it is just possible to see that highly strong, specialised bill crossing at the tip, a fantastic tool for the job it was designed for.






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