The park is blessed with some large and presumably old (if not ancient) oak trees. Most look healthy, but today I found out that some are infested with the oak processionary moth.
It was in spring, around 5am, that local residents were awoken by a strange noise outside in the park. I quickly dressed and went to investigate. A large vehicle armed with a very long spraying arm and a high pressure spray was coating all the trees with an insecticide, generating this odd sound. Now in August, those trees where this did not protect them are being harvested for the nests of the moth. As you can see below, from just a few oak trees, around 100 nests had already been gathered. And they are not small! If left untreated this can cause damage not only to the trees but to passers by as well. The moths shed hairs and these can cause severe allergic reactions in some people. The chap collecting the nests was wearing protective clothing, but already he was starting to feel the effects. He warned me not to linger around this particular tree, photos of which you see below.
It turns out that west London, along the route of the Central line, is particularly badly affected.
I go into the park and walk past the oak trees often. But I had never bothered to look up into the branches and really notice what was happening. From now on, I will!