Bracken is common on the more acid soils in the site, most noticeably at Keston. This very intrusive fern mainly reproduces vegetatively and by spores. In parts of Britain its spores have been implicated in increased rates of cancer in sheep which graze extensively in moorland where it is dominant. In the past it was often used as animal bedding.
Growing in grassland, the purple flowers of knapweed are a rich source of nectar for butterflies and other insects this month.
The characteristic sickle shape and screaming cry of the high flying swifts has been very noticeable above the Down House Estate this summer, but during August they will leave for Africa where they will spend the winter.
These shy, nocturnal lizards can be found in many parts of the site. They hide away during the day under stones or logs and eat slugs, snails, soft bodied invertebrates and slow moving garden pests. Female slow worms mate about once every 2 years in May and June (see photo). The live young are born this month (about 8 per mated female) and will not be fully grown for 6-8 years. They may live for up to 54 years.
Moths commonly fly indoors during the summer and there are numerous different species living within the proposed World Heritage Site, many of them very beautiful. Darwin wrote about moths in 'The Descent of Man', discussing how most moths,
"...rest motionless during the whole or greater part of the day with their wings depressed; and the whole upper surface is often shaded and coloured in an admirable way, as Mr Wallace has remarked, for escaping detection. The front-wings of the Bombycidae and Noctuidae, when at rest, generally overlap and conceal the hind-wings; so that the latter might be brightly coloured without much risk…the following fact shows how cautious we ought to be in drawing conclusions on this head. The common Yellow Underwings… often fly ..during the day or early evening, and are then conspicuous from the colour of their hind-wings. It would naturally be thought that this would be a source of danger; but Mr J. Jenner Weir believes that it actually serves them as a means of escape, for birds strike at these brightly coloured and fragile surfaces, instead of at the body."
Grasshoppers and Crickets
Grasshoppers and crickets can be heard in many parts of the Site now. They can be distinguished from each other because crickets have much longer antennae. The young of both hatched from eggs in the spring looking like minature adults but unable to fly. As they grew and developed they shed their skin about 5 times before finally emerging as adults. Adult male grasshoppers attract females with their chirping song which they make by rubbing their back legs against their forewings during the day. Crickets, who make a higher pitched sound, rub one wing over the other and generally 'sing' in the evening and at night, apart from the great green bush cricket which can be heard throughout the day. After mating, grasshoppers lay their eggs on soil amongst grasses, while female crickets have a large ovipositor with which they insert eggs into soil, rotting wood or bark crevices.