Although by the time this article is read it will be early Autumn. At the time of writing it is high summer in a season of mixed weather with the trend being towards drought in spite of patches of heavy rain, just sufficient to give temporary protection for our gardens. Fortunately we have been spared the “Beast From The East” this year which apparently damaged both Spring migration and breeding in 2018.
We have had few spring passage migrant records. A Cuckoo was heard on one day in May in Sydenham woods. Cuckoos do use Dunnocks as hosts but with not enough large caterpillars here to feed the young they cannot be expected to try and breed in Dulwich, so migrants will move on.
The good news is that a pair of Little Grebes have once more bred in Dulwich park lake and we have had our summer breeding population of Blackcaps and Chiffchaffs. Although we have lost the Burbage Road House Martin colony, I have been informed that there is a colony breeding in the Anerley end of Crystal Palace and I have seen a few flying over Dulwich.
Historically Swifts nested in holes in trees and in the northern end of their breeding range they still do, but have adapted to utilise holes in houses to which they owe their sizable numbers that presumably grew over the past few hundred years. Houses now have fewer holes these days, but it is possible with new builds to incorporate bricks with holes for the Swifts, which a neighbour of Dave Clark in East Dulwich has done, and with successful Swift colonisation. Alas the lack of nest sites is not their only problem and a reduced number of aphids in the air, essential for nestling food means that the adults have to travel further to get enough to bring back. to feed their young. Steven’s latest photo shows just one nestling in his box whereas two or three might have been expected.
Food for nestlings has become a problem in the times of climate change and a mismatch between availability of such items as small caterpillars and times of hatching is a potent cause of failure. A friend of mine with a camera inside a nest box described to me the unedifying experience of watching his baby Blue Tits die one by one of what appeared to be starvation. Hopefully this will prove to be an exception and there will be better luck next year.
Butterflies seem to be doing better this year with Red Admirals and Painted Ladies coming in as visa free migrants from the continent. The good news is that a Marbled White butterfly usually found on chalk downland but has been noted to be expanding its range. The so called Grass Butterflies ( Meadow Browns, Gatekeepers and Skippers ) are now on the wing with a plentiful number in Green Dale where there is an uncut field, and once more we have Stag Beetles. Southern Hawker Dragon Flies and azure Damsel Flies featured in an article last year are once more abundant. We are grateful for your records and photographs so do keep them coming.
Peter Roseveare Wildlife Recorder
020 7274 4567