Nature Notes – May 2018

At this time of year, everything in the natural world seems to be changing particularly fast, with spring flowers appearing, insects emerging, and seasonal changes in bird life. By the end of April, most of our common migrant birds were arriving. Chiffchaffs and Blackcaps have been in song for several weeks, and others like Whitethroat and Lesser Whitethroat are here and will be singing in May. A few Swallows are here, but I hope there will be more. A good place to see early Swallows is always the Ladybird plant nursery at Gromford, where they nest in the potting sheds.

Cowslip

Along the verges the Primroses are still flowering, but are much less obvious now that other plants are growing higher and masking them. The Cowslips, which appeared a little later, have taller stems and so are now showing well. They seem to be commoner on the verges and field boundaries on the clay soil of our district, and less so on the sandy areas. Where they grow together, these two do sometimes hybridise, producing a cross with a multiple head of Primrose-like flowers, but on a taller stalk like a Cowslip. This, confusingly, resembles a third species, the Oxlip, which is much scarcer and in Suffolk confined to woodlands further to the west. The hybrid is called the ‘False Oxlip’, and I have seen the occasional specimen in woods in Sweffling. The spring flush of wildflowers in our hedgerows and verges also includes the brilliantly white Stitchwort, with its narrow, grass-shaped leaves, growing amongst the emerging young grasses. Also white, but with smaller less conspicuous flowers and broader leaves, is the so-called Garlic Mustard (alias Jack-by the-Hedge, Hedge Garlic and various other names). It is a member of the cress family, but its leaves, when crushed, do smell very strongly of garlic.

Stitchwort

Garlic Mustard is the chief food-plant of the caterpillars of the Orange Tip butterfly, which is conspicuously on the wing on sunny days at this time of year. A small white butterfly, it is the male which has the bright orange wing-tips. The female’s wings have grey tips, and both have grey-green and white marbled undersides. I rarely see the caterpillars, but they are long, thin, and pale green, matching very well the seed pods of the food plant. I also often mention in spring the Brimstone butterfly, the male with its bright butter-yellow colour, and the female a pale yellowish white. Camouflage here takes the form of the butterfly, when at rest with the wings closed, looking very like the underside of a pale green leaf. The caterpillar’s food plant is a shrub called Buckthorn. I have only found one specimen of this in Sweffling, in an old hedge, but Brimstones are known to travel very widely and are likely to be seen passing through any garden.

Listen out for the Cuckoo, which should have arrived by now. I have heard reports in late April, but not yet the actual bird. The Swifts will be here any day now – I always reckon the first week in May.