Nature 2015 April

So Where Do Swallows Go In Winter and Eels Go To Spawn?

The Reverend Gilbert White was one of the first, and probably remains one of the most highly regarded 18th century British pioneering naturalists. The principle work he is known for, ‘The Natural History and Antiquities of Selborne’, was published towards the end of his life in 1789. It took the form of correspondence from White to other well-regarded naturalists of the day.

White was born in Selborne Hampshire in 1720. He was the son of the local clergyman. He took holy orders, and on the death of his father in 1764 returned to Selborne, as curate. He remained there for the rest of his life, aside from brief sojourns in nearby Sussex. Along with Charles Darwin, David Attenborough, Richard Mabey and several other nature writers, he frequently provides me with inspiration for the themes of these monthly nature notes.

Gilbert White’s journal which recorded through letters his natural history observations around the parish of Selborne became a one model of nature writing for the next hundred years or so. The book has remained in continuous print to this day. His observations were drawn from experiences whilst riding around the Selborne area on parish duties, and whilst out fishing or shooting with his dogs. What was not made clear by the author or publishers at the time was that over half of the 110 letters were never sent to the reported correspondents, and many others were often largely re-edited before they were published. This may be one of the earliest examples where a sequence of largely contrived letters was used as a literary device.

I have more than once flicked through the pages reading a letter or two to get inspiration. This time I decided to spend some time browsing his journal in more detail and found some interesting extracts which are worth repeating here. The first modern zoological textbooks only began to appear towards the end of the 18th century. Naturalists of the day were still much influenced by the fundamental but progressively abandoned principles laid down in the 3rd century BC by Aristotle. In fact, at the time of Gilbert’s journal the foundations of taxonomy had only just been laid down by Carl Linnaeus. Unlike the term botanist which was well-established the term ‘zoologist’ was not in use. Those studying animal habits and anatomy were known as ‘fauners’.

Meanwhile, the study of insects was making greater progress, not least due to developments in microscopy and the fascination of gentlemen to assemble cabinets of curiosities which typically included draws full of beetles, dragonflies and lepidoptera. The antiquarians, who wrote the first books on the subject, were well-versed in the use of Greek and Latin prose and were not minded to include drawings with their imprecise descriptions. Gilbert criticised foreign taxonomies, and in particular those of the French fauners, for their verbosity.

The imprecision of these texts clearly had irked White who wrote these prophetic words in March 1771:

“As far as I can judge, nothing would recommend entomology more than some neat plates that should well express the generic distinctions of insects according to Linnaeus; for I am well assured that many people would study insects could they set out with a more adequate notion of those distinctions than can be conveyed at first by words alone.”

We take for granted the extent of our present-day knowledge on the habits of animals. Throughout his book there are observations illustrating the limits of understanding about the lifecycles of animals. One example illustrates a particular mystery of the time which remained hidden until the 20th century. On discovering an eel in September 1774, White records:

“The threads sometimes found in eels are perhaps their young. The generation of eels is dark and mysterious.”

It was only in 1905 that it became clear that eels travelled from rivers of Europe to the Sargasso Sea to spawn and that the juvenile elvers returned to the same river systems as their parents to mature.

Several of his anecdotes might be amusing to us but do show Gilbert’s approach is also questioning and scientific. For example, writing in 1771 he relates the story of his musical friend who has studied the calls of the local owls and using a ‘pitch-pipe’ had concluded they all hooted in B-flat. However, a neighbour of Gilbert’s ‘who is said to have a nice ear’ had remarked his owls hooted in A-flat, B-flat, F-sharp and G-flat. In the light of this Gilbert speculates to his friend that perhaps each species of owl hooted with its own unique note.

There was much controversy at the time over the habits of gregarious birds, why they flocked together, and why they sometimes disappeared for long periods. White mused over seeing a congregation of rooks ‘attended by a train of daws’ (jackdaws) and accompanied by ‘a flight of starlings for their satellites’ he speculated that rooks had a more discerning sense of smell useful in finding food and this was ‘understood’ by other birds.

A trip to Sussex in November 1772, and a chance encounter with a garden resident, may have provided Gilbert with evidence in support of Aristotle’s contention which had persisted and was summed up by the question: Where do swallows go in Winter?

Gilbert came across a tortoise digging itself a cavity underneath the shrubbery in which to overwinter. He wrote soon after:

‘I am more and induced to believe that many swallow kind do not depart from this Island; but lay themselves up in holes and caverns: and do insect-like and bat-like, come forth at mild times, and then retire again.’

Elsewhere, White quotes a local man’s story about swallows being found in a chalk cliff collapse as evidence that swallows in Hampshire reside in holes in the cliffs on the south coast. Sadly, Gilbert White died in 1793 just four years before evidence of bird migration was published describing multiple sightings of large flocks of swallows in the late Spring flying in great numbers northwards over the Mediterranean Sea.

In the 18th and 19th centuries investigating the natural history of one’s surroundings remained largely the preserve of gentlemen who had the time and wealth to enjoy their rural pursuits. Gilbert White’s writings over 200 years ago illustrate many of the generally held beliefs of the day about the wonders and purpose of nature, and the limits of understanding about the habits of animals. What though distinguishes Gilbert’s writings from most of his fellow naturalists is his rigorous approach to measurement and the recording of everyday minutia in a precise but flourishing style. It’s worth looking out for a copy as your efforts will be well-rewarded by discovering the richness of Gilbert Whites’ nature writing.

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