July 2010 - The Cuckoo

 

The Common CuckooThe call of the cuckoo has sadly been missing this year.  I have heard them occasionally in the distance but they have been absent from the pines bordering the field in front of our home, where they have been every year since we moved to Bawburgh. Their decline is nationwide since the early 1980s numbers have dropped by 65%. Only time will tell the real reasons for the decline but some likely causes revolve around diminished food source (largely caterpillars), loss of habitat (moor land, waste ground, reed beds, and woodland edges) and suitable bird nests (commonest host species quoted as dunnock, pied wagtaiL meadow pipit, and reed warbler) in which to lay their eggs. Host species appear to be shifting their breeding times forward by nearly a week, so when the cuckoo appears she may well have missed her chance. Another theory revolves around the cuckoos’ habitat in West Africa where they over winter. Due to a growing global demand for food, timber and bio- energy, there is significant loss of habitat caused by increases in agriculture and forest clearance. I suspect the reason for the decline may be complex. The cuckoo is on the conservation status ‘red’. Further information may be found on the British Trust for Ornithology website.

Unlike the cuckoo, one of its host species, the dunnock, is increasing in numbers - certainly confirmed by sightings in our own garden. This bird used to be called the hedge sparrow, although it is totally unrelated to the sparrow as can be seen by the differences in the beak. The beak of the dunnock is fine, enabling feeding on small seeds. The sparrows’ beak is heavier and better for dealing with grain and larger seeds. The dunnock is shy, brown and nondescript (dunnock literally means ‘little brown job’) and easily goes unnoticed as it rummages under and around bushes for insects and other invertebrates, seeds and berries. It reluctantly ventures out into the open and is rarely seen on bird tables, although it may rummage underneath. One of the most striking aspects of dunnock behaviour is its complex social system. There are usually more female than male birds, so females may accept and mate with more than one partner. The second or ‘beta’ male will help with maintaining the territory and feeding young. On the other hand, dominant or ‘alpha’ males may take on more than one territory and have more than one mate. DNA studies have shown that chicks in the same brood can have different fathers. In the winter, dunnocks will lead largely solitary existences, although they may come together to feed in small groups if food supplies warrant this. We had a dunnock that over wintered under our car port. We often saw it flying at night triggering the sensor on the security light, where it used to settle to get some warmth and maybe the odd insect or spider. Not such a daft bird!

lingibson@bawburghvillage.co.uk

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