Many native wild plants which flower in spring are stimulated by increasing day-length but this is coupled with many other factors, including temperature. In 2006 many plants, but not all, flowered later than in 2005, as a result of the cold spring. To help monitor the effect of possible climate change on different plants and animals, why not log on to www.phenology.org.uk and see what you can do.
Look for bluebells and wood anemonies in the woodland. In 1843, the first spring after Darwin moved to Downe, he wrote:
"The first period of vegetation, and the banks are clothed with pale blue violets to an extent I have never seen equalled & with Primroses. A few days later some of the copses were beautifully enlivened by Ranunculus auricomus, wood Anemone & a white Stellaria. Again subsequently large areas were brilliantly blue with bluebells. The flowers here are very beautiful....." March 25th 1843 'General Aspect'
Primroses and Cowslips
Darwin studied these spring plants in great detail. It was well known that their flowers were of 2 types, called pin and thrum-eyed, and Darwin found that the most viable seed was produced when cross pollination occurred between the 2 different flower types. He also studied hybrids between them (false oxslips).
Primrose pollination diagram (Left: pin, right: thrum) from Darwin's book, "The different forms of flowers on plants of the same species" (1877).
Look for a greater variety of butterflies on the wing as the month progresses. Orange-tip butterflies hatch from their pupae in April and the butterflies which have been hibernating during the winter such as the brightly coloured small tortoiseshell, comma and peacock butterflies emerge to mate and lay eggs on plants such as nettle. The underside of their wings, unlike the top surface, is dull, resembling the bark of trees and making them difficult to spot when at rest with their wings closed together. In 'The Descent of Man', Darwin wrote:
"Butterflies would be particularly liable to be attacked by their enemies when at rest; and most kinds whilst resting raise their wings vertically over their backs, so that the lower surface alone is exposed to view. Hence it is this side which is often coloured so as to imitate the objects on which these insects commonly rest."
Greater and Lesser Spotted Woodpeckers
Listen for greater spotted woodpeckers drumming to assert territory. Darwin marvelled at how well they were adapted to their lives in the trees:
"Can a more striking instance of adaptation be given than that of a woodpecker for climbing trees and for seizing insects in the chinks of the bark?"
Before too many leaves clothe the trees, look for the smaller, quieter, lesser spotted woodpecker, about the size of a sparrow with similar colouring to the greater spotted woodpecker but with distinctive ladder like markings on the wings. According to the British Trust for Ornithology, this species has suffered a 50% decline since 1980. It has been suggested that this may be due to reductions in the area of mature broadleaved woodland, increased isolation of woodland and a reduction in the amount of dead trees left standing which support the insects they eat and provide their preferred nesting sites. (They make a new nest chamber each year in decayed wood). Please do let us know of any sightings of this bird within the nominated World Heritage Site, see the 'Record Your Sightings' page.