A very dry early summer has given me very little to report, with no unusual sightings during the migration season. There were a good number of Orange Tip butterflies in May but surprisingly the midsummer butterflies have been in short supply without last year’s huge influx of migrant Painted Ladies.

The appearances are that our resident breeding birds have done well with good numbers of young Tits in feeding parties and some extremely tame young Robins. Blackcaps and Chiffchaffs which migrate relatively short distances have come in to breed satisfactorily with a few Whitethroats on areas of rough ground such as the velodrome surround. However the anxiety has been the welfare of the long distance migrants, namely the House Martins and Swifts.

The House Martins arrived late and did not establish themselves into their nesting sites until well into the second week of May, and then into less than half their usual numbers. Their actual wintering ground in Africa is not well known as there have been very few ringing recoveries but the suspicion is that there is a problem either in their winter territory or their migration route.

Swifts on the other hand may have a problem finding sufficient breeding sites. They require crevices rather than holes for access which means penetrating defects in brickwork or roof tiling in tall houses, which many householders for obvious reasons are correcting. The RSPB is encouraging us to acquire Swift boxes which have an aperture suitable for entry, but it will be important to place these at a height equivalent to the second storey of a house. A young Swift on leaving the nest has to be able to get enough momentum to thrust itself into the air. It is unable to take off from the ground as its legs are too short and too far back on its body. We occasionally find one on the ground and if it is still alive the advice is to take to the highest available point and launch it. Unfortunately these young birds are often found too late and will not have survived. Readers may have noted that the screaming parties of July Swifts have increased the numbers and this will be due to the inflation of the young which are learning their flight technique. Hopefully we will be able to maintain our small population.

I shall be interested to hear if readers have any further observations.

Peter Roseveare Wildlife Recorder (tel: 020 7274 4567)

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