Wednesday, 14 April 2010

More Signs of Spring

Nightingales, terns, cuckoos and sedge warblers all arrived this week. Although birds are the dominant interest at this time of year, there is a lot more to see on the Reserve.

Among the plants, something new literally 'pops up' every day. Every year we find a new plant, or one that has not been seen for some time. Some years are brilliant for a particular plant which may appear in abundance, but not for another which may not show up at all.

This spring we have had an amazing show of yellow flowers such as coltsfoot and lesser celandine. I even found some leaves of greater celandine or King-cups in the Great Meadow ditches, but they are not flowering yet. In Paxton Meadow, near the Visitors' Centre, we have the best show of cowslips so far. They are just coming into flower now.

Soon we will be looking for mustards such as Lady's Smocks and Jack-by-the hedge (garlic mustard). Orange-tip butterflies, which lay their eggs on these plants, are already on the wing.

This is a very exciting time for anyone interested in insects. Unless you are a real expert, you can usually find an insect that you have not seen before. Once you spot one, you then go on to find hundreds of them. So it is with mining bees. Look for small holes with piles of soil around them, particularly in banks or the small cliffs behind fishing swims. Mining bees (I call them J C Bees) are very small, dark coloured bees. You can see the pollen sacs on their legs.

In the same areas you can find digger wasps, which are also very small, but have the typical ant-like, vespine body, in three obvious parts. Solitary bees, which typically look like dark bumble bees, are much larger, but make holes in the same cliffs.

A cliffside mixed colony of insects will attract predators and parasites, so half an hour's careful observation of a sunny bank can pay dividends.

Just now is a good time to see bee flies. These fuzzy creatures have a long proboscis so that they can feed on nectar from flowers, particularly primroses and cowslips. They look quite predatory, but they are harmless, unless you are a solitary bee. On Monday, I found a dozen or so bee flies in the meadow near the big steps. They were carefully quartering the ground like hover flies, but there was not a flower in sight, so they could not have been feeding. There were a few bumble bees in the same area and I came to realise that they were looking for holes made by solitary bees. They lay their eggs in the hole and the larvae parisitise the young bees.