Why you should make a date with nature as spring approaches in Norfolk

I’m sure, like me, you look for the first swallow of the year, for the bluebird beloved of poets is one of our favourite harbingers of spring.

It is perhaps unlikely you make a written note of the date each year, but if you do, you could be a phenologist.

Phenology is the recording and study of the timings of natural events, and the ‘father of British phenology’ was a Norfolk man.

From 1736, Robert Marsham recorded, from around his home in Stratton Strawless, 27 indicators of spring.

These included the first cuckoo calling, nest-building rooks, flowering wood anemones, and of course the first swallow to arrive back from Africa.

Following his death in 1797, successive generations of his family continued to record these signs of spring right up to 1958.

At the time nobody realised how important these records would become.

Today, with concern over climate change and its impact on wildlife, these records are the longest running and one of the best sets of data that link climate and the natural world.

Common frogs are first spotted in the middle of March (Image: Mark Hamblin)

For example, Marsham’s records have shown how a 1 degree rise in temperature results in hawthorn coming into leaf 10 days earlier.

This spring Norfolk Wildlife Trust invites you to take part in our own phenology survey and share your first sightings of three species: swallows, orange-tip butterflies and common frogs.

Whether you are lucky enough to have them visit your garden, or you see them on your local patch, you can help us map sightings within our county so we can build a picture of where – and when – they appear.

The common frog is the most likely candidate for the ‘first show’. Depending on the weather frogs usually emerge from their hibernation in late February and March, and immediately set off for their breeding ponds.

The average date for clumps of frogspawn to be seen in Norfolk is March 10, but this is also dependent on the weather.

You may be lucky enough to find toads in your pond also; once you are familiar with both, they are easy to tell apart.

Toads are brown, warty with stumpy legs and a blunt grumpy face.

Frogs are smooth, green and yellow with longer legs, they will only hop rather than crawl.

Robert Morgan of Norfolk Wildlife Trust (Image: NWT)

Frog spawn is always in clumps, rather than strung out around the pondweed as toads prefer to do.

There is no mistaking the male orange-tip butterfly: it is the only species in the UK to sport bright orange-tips to its white wings.

The female orange-tip is not as easy to identify, and closely resembles the other common white butterfly species. It can best be separated when at rest by its green-mottled underside; this forms excellent camouflage when nectaring on cow parsley.

The butterflies emerge from their over-wintering chrysalis from early April through to early July. The caterpillars feed on cuckooflower or garlic mustard. In gardens they will also lay their eggs on dame’s violet and honesty.

Swallows are small birds with glossy blue/black plumage and deeply forked tails.

When perched you may see their creamy-buff underparts, they also have a red throat and forehead.

The swallow can be distinguished from the house martin by the lack of a white rump and from the swift by the long, forked tail.

Swallows also tend to fly close to the ground when feeding, this is when they can show grace and agility in swooping low over meadows in search of insect prey. They are migratory birds with spring migration taking place from mid-March through to mid-May.

The average date of arrival in southern England is March 20, although this date maybe slightly later in Norfolk.

Submit your sightings online at www.norfolkwildlifetrust.org.uk/spotter or email wild@norfolkwildlifetrust.org.uk with what you saw, and when and where you saw it.