Is spring getting earlier (despite the snow we've seen)?

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

It is unlikely you make a written note of its arrival 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, Robert Marsham. Starting in the spring of 1736 he recorded, from around his home in Stratton Strawless, 27 indications of spring.

This 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 historical sets of data that link climate and the natural world.

Robert Marsham’s records may indicate that a one degree rise in temperature can result in significant changes in wildlife behaviour and natural development.

Hawthorn in Norfolk, for example, comes into leaf on average ten days earlier than when Marsham recorded it. 

On the face of it, why should earlier spring weather be an issue for wildlife? One would think they would prosper from it, and some most likely do.

Blue tits, like many cavity nesting birds, can struggle to find suitable nest holes, so an early start is a bonus.

Birds will often start nesting based on the clemency of the weather, however, the insects on which their chicks are fed may not be around in sufficient numbers.

Insects are ruled by their body clock, and need to properly develop at the pupae stage before emerging or, in respect to the blue tits’ favourite small green caterpillars, hatch from dormant eggs.

This can lead to a mismatch between the need for extra food, and availability - the consequences being far less chicks reaching the fledgling stage.

Flowering spring plants can be caught out in a similar way, with fewer pollinating insects being available.

The ‘Fool’s Spring’ we seem to regularly enjoy in February brings out the blossom on my cherry plum tree, only for it to be wilted by frost during a cold spell in March.

Peacock and brimstone butterflies emerging from hibernation can be caught out in a similar way.

A creature that appears significantly earlier than the dates recorded by Robert Marsham is the common frog.

Depending on the weather, frogs will now emerge from hibernation any time between late February and early March, and then immediately set off for their breeding ponds.

The mean date for clumps of frogspawn to be seen in Norfolk ponds is now March 10, at least two weeks earlier than in Marsham’s time.

The animal I look for each spring is its cousin, the common toad, and it is often the mostly likely candidate for the ‘first show’.

I’m in good company in looking to the toad as my proclaimer of spring, for George Orwell, better known for his dystopian novels, was a keen phenologist and kept many natural history records.

He wrote a poetic essay celebrating the first spring to follow the ending of World War Two.

Within it, he chose to discard the sentimentality of Wordsworth or Shelley and instead picked the toad as the season’s harbinger.

‘Before the swallow, before the daffodil, and not much later than the snowdrop, the common toad salutes the coming of spring…’  

I have to agree with Orwell, the toad is to be admired, and despite its skin of warts the creature is strangely alluring, with its gleaming gemstone eyes sitting in contrast to a blunt expression.

The toad, I feel, is a symbol of hope, defiance and strong will.

It can live for many years, always remaining loyal to the pond of its tadpole beginnings.

And with great vigour, will travel across roads, railways and housing estates to get back to its ancestral pool each spring.

The seasons may be shifting in character, but we know our wildlife can adapt.

However, to do so, adequate space and connected habitats are needed across our landscape, to ensure suitably healthy, numerous and robust populations that are able to cope with changing climate patterns. 

NWT is working hard, along with other landowners and alongside our communities, to provide vital corridors that link nature reserves and other important green spaces for wildlife.

The great news is that we can all play a part - anything from a garden pond, or even a small wildflower patch, can form an important stepping stone for Norfolk’s wildlife.  

Why not record the arrival of spring this year?

Phenology is a great way to engage children with nature by noting the emergence or arrival of spring wildlife – and you may be lucky enough to find toads and frogs in a local pond.

Once you are familiar with both, they are very 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.

Frogs will only hop, but toads prefer to crawl.

Frog spawn is always found in clumps in a shallow, sunny part of the pond and toads will string their spawn around the pond, entwining it through the pondweed.  

Why not share your spring sightings with us on social media?

Facebook: @NorfolkWildlifeTrust

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Twitter: @NorfolkWT