Late April welcomes three of my favourite entries in the wildlife calendar, namely bluebirds, bluebells and butterflies.

Yes our bluebirds, or swallows are arriving having completed their epic flight from Capetown where they spent the winter.

For many years I have enjoyed watching them along Kingston riverside where they nest under the boardwalks just above the surface of the Thames.

Opening now are bluebells and a welcome sight in our woodlands. Unfortunately the invasive Spanish variety which opens first and is far less attractive having paler non-pendulous flowers is seen more and more in gardens and rough places nowadays.

Already flying are all the spring butterflies including holly blue, peacock (very common), red admiral, brimstone, comma, tortoiseshell (scarce) , small and green-veined whites, speckled wood and orange tip. The photograph shows a male orange tip feeding from a bluebell, making a striking colour combination. Bluebells are among the favourite nectar plants for brimstone and orange tip butterflies . Badgers living in bluebell woods use the thick green leaves to line their setts for bedding.

The female orange tip lacks the orange wing patches, somewhat resembling a small white and lays single eggs on cuckoo flower, garlic mustard and related plants.

If a second female arrives to lay an egg she can detect if one has already been laid and moves on. This is because the first caterpillar to hatch turns cannabilistic if another one is present and this is nature's way of ensuring there is enough food plant to go round.