In the summer of 1897, the call of a mysterious bird sparked a brief but thorough quest whose hand-sized outcome is a curious testament to the speed of change in our world.

A retired engineer called Charles Louis Hett heard the bird near his home in Brigg, a small town in Lincolnshire in the north of England. Certain he had seen the bird’s call described in print a few days earlier, Hett scoured his books — but he couldn’t find the paragraph so he couldn’t identify the bird.

What followed was a six-month burst of research and writing. Hett scavenged scraps of information from books. He corresponded with strangers around the country. He walked in the wilds with his ear to the sky. His aim was to build consensus around a definitive descriptive list of the calls of nearly 400 bird species. By January 1898, his small ‘bird dictionary’ was on sale.

A few years ago, my mum found a copy of it in a second-hand bookshop and gave it to me. It still amazes me as I hold it in my hands. Among the calls Hett listed are the Red-throated Diver’s “ak-ak-kakara-kakera“, the Whimbrel’s “tetty-tetty-tet” and the “tst-tst-tsook-tsook” of the Red-backed Shrike. Just like the French-English/English-French dictionaries I remember from secondary school, Hett’s book first lists the hundreds of calls and the birds that make them; it then lists the bird species and the calls that each makes.

But it is what comes next that interests me most — a list of 1,300 local and old-fashioned names for British birds*. There you can find the Stanepecker (for Turnstone) and the Scawrie (for Herring Gull), the Rusty Crackle (for Blackbird) and the Teapot (for Goldcrest) — each one is a name that is rarely, if ever, uttered today.

It’s hard to imagine how Hett managed to compile so much information in just six months, working from a tiny town about 100 years before the Internet entered public life. What’s more striking is that an effort to replicate Hett’s mission today would likely fail. Many of the names will have slipped out of use. Gone extinct.

Many of the birds have gone too. The new State of British Birds report [PDF] shows that populations of many British birds are in steep decline. In the past three decades alone, several species have declined by more than 80 percent. Extinction beckons. “Since 1966, we’ve lost 44 million individual birds from our countryside at an average rate of 19 birds every 10 minutes,” says a joint statement from the organisations behind the report.

We don’t know what populations were like when Hett heard his mystery bird but we do know that modern threats — pesticides, habitat loss, climatic change — had yet to make themselves known.  The only danger that Hett himself noted was from people who killed birds so they could identify the corpse — something that helped motivate him to publish his dictionary. “The destruction of an uncommon bird for the purpose of identification, is a barbarism,” wrote Hett, who hoped his book might prove an “aid to identification without slaughter.”

It is easy to dismiss Hett’s world as a long-forgotten yesterday. But, given that the oldest person alive today was born some months before Hett heard his mystery bird, the dictionary shows just how much the world can change in a lifetime. And it seems likely that some of the species Hett listed will have fallen forever silent —  in Britain at least — by the time I pass my copy of his book on to my own child.

*[By 1902 Hett had published an updated list [PDF] that more than doubled the number of synonyms to nearly 3,000 names — an average of more than seven for each real species.]