In eastern England, the first few months of 1740 were dreadful. Everything froze-and stayed frozen for six long weeks. The price of food soared. People rioted. Some were hanged. On his estate outside Norwich, Robert Marsham was listening for the voice of the song thrush, one of the first signs of spring.
Six years later, as the King’s troops massacred Bonnie Prince Charlie’s Highlanders at Culloden, Marsham was waiting for the hawthorn to show its new green leaves. Thirty years on, when British redcoats were facing American rebels in the first battle of the War of Independence, Marsham was watching the rooks feed their newly hatched chicks.
Now, more than 200 years later, Marsham’s observations on some of the smaller events of the 18th century have become more significant than he could ever have imagined. They provide a unique record of how plants and animals respond to a changing climate.
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THAT winter was the worst anyone could remember. At The Hall in the Norfolk village of Stratton Strawless, Robert Marsham wrote a detailed account of just how bad the first few months of 1740 had been.
The gorse and heather died. The rabbits starved in their warrens. It wasn’t much warmer indoors. During the days, it was so cold his beer turned to ice. At night the piss in his chamber pot “froze to a cake”. When he tested the temperature outside by pouring water out of the window, he found it turned instantly to ice. It was so cold that in London the Thames froze.
He was about to put down his pen, when he remembered there had been some trouble. “With Ye high price of provision in general, the Weavers in Norwich, and some idle people in Ye Country, rose in riotous manner, and did some damage in Norwich and Ye neighbourhood, for which some were Hang’d at Ye next Assizes.” It was worth a sentence, but Marsham’s mind was occupied with something else-the spring.
As soon as the ice began to thaw, Marsham was out looking for the first signs of the new season. But it was March before he heard a song thrush sing-weeks later than usual. The hawthorn didn’t bloom until June-two months behind schedule.
Marsham had begun to keep a log of some of the key events of spring in 1736. Within a few years he was collecting dates for 27 “Indications of Spring”. He watched for the first snowdrop. He noted when buds burst on 13 species of tree. When the rooks began to build their nests, he jotted it down. The croaking of frogs, the first flutter of a brimstone butterfly-all duly recorded. Marsham listened and watched for the return of migrant birds-the first call of a cuckoo, the first sight of a swallow swooping in from the south. He kept this up for 61 years, noting how the timing of these regular spring events changed according to how warm or cold the weather had been.
Phenology-the study of the timing of natural events-was a popular pastime among 18th century country gentlemen. The best known was Gilbert White, the Hampshire clergyman who won fame with his book The Natural History of Selbourne. White was a keen amateur naturalist and an ardent spotter of nature’s “firsts”. Marsham, who lived at the same time, was more scientific and what he left is likely to prove far more useful.
Unlike other gentlemen phenologists, who gave up after a few years or kept tabs only on butterflies or birds, say, Marsham stuck to his 27 “indications” year after year until 1797, when he died at the age of 90. His family has continued to jot down the dates almost continuously since then, providing more than two centuries of records.
Marsham noticed that temperature made a big difference to some species. Cold weather delayed some of the symptoms of spring, while warm weather brought things forward. The leafing of the mountain ash, for instance, could be as early as 5 March or as late as 2 May-a difference of 58 days. He also noticed that the earlier a species normally made its appearance, the greater the effect of a change in the weather.
Marsham was lucky to reach a ripe old age. He didn’t feel ready to publish his “Indications of Spring” until he had notched up more than half a century of records. He also lived long enough to read A Natural History of Selbourne, which was published in 1789. The aged Marsham, then in his eighties, and White-nearing 70-began to swap observations and “first dates”.
They had a lot to learn from each other. When Marsham mentioned the antics of amorous toads he had seen, White politely put him straight. “If I might presume to say that what you see respecting the copulation of toads is, I think, a mistake, you will pardon my boldness: because the amours carryed on in pools and wet ditches in the spring time are performed by frogs…” Marsham admitted he might easily be wrong. “If I should live to another Spring, I will examine them with more care,” he replied.
Both men knew that their new-found friendship might be short. “O, that I had known you forty years ago!” lamented White. If a letter didn’t appear for a while, they suspected the worst. “My eyes water so much that I am forced to write by instalments, as bankrupts pay their debts,” grumbled Marsham. At the age of 85, he confessed to White that he might be missing a few “firsts”. “Perhaps my deafness might deprive my hearing of Spring Birds, but I have heard hardly any Thrushes this year.” White died in 1793; Marsham four years later.
White might have been more famous but Marsham established phenology as a respectable science. And so it remained until the 1940s, when scientists with increasingly sophisticated instruments began to dismiss it as imprecise and amateurish-something akin to trainspotting.
Today, however, phenology is back in favour. Over the past 30 years, spring in the northern hemisphere has been arriving sooner. Plants are blooming earlier and trees are coming into leaf weeks ahead of schedule. Butterflies, also, are emerging way ahead of time. In England, the red admiral is appearing 36 days earlier than in the mid-1970s. And swallows are arriving a week earlier than 25 years ago, while some migrant birds, such as blackcaps and chiffchaffs, no longer bother to leave the country at all.
The world is growing warmer and biologists are worried that they don’t fully understand how wildlife will respond to the changing climate. So to monitor what is happening, Tim Sparks at the Centre for Ecology and Hydrology in Cambridgeshire has set up a countrywide network of observers in partnership with the Woodland Trust. The volunteers of the UK Phenology Network have begun to log the dates of key events in spring and autumn, the times of the year when change is most marked.
It’s one thing to monitor the changes over coming years, but the only way to predict what might happen is by looking back to see how plants and animals responded to changes in the past. That’s where Marsham’s long stretch of records can help. If current climate models are right, says Sparks, then in the next century most if not all of Marsham’s indications of spring will begin to show two to three weeks earlier. Spring will be here before you know it.