Spring of 1976...

Fifty years ago, the great butterfly season of 1976 was brewing. I was there, big time: having had the previous eight summers wrecked by the examination system*, I took a self-funded sabbatical, and butterflyed on over a hundred days between mid-April and early September – playing cricket on most of the others. This was low budget stuff, my main form of transport was a three-speed bicycle – and the tarmac melted. I was living near Selborne in East Hampshire, a top butterfly hotspot, but thought nothing of cycling to Chiddingfold Forest. Crucially, I kept detailed diaries.

The previous summer had been hot and dry, and 1974 had been reasonable too. Butterfly populations were on a high. Truly great butterfly summers are the second or, better, third in a sequence of hot summers. ’76 was the third. Incidentally, we have not had a hot summer sequence this century...

The 1976 butterfly season did not begin unduly early, like modern seasons. Here’s some first and last dates, from the Selborne & Alice Holt Forest district:-

Orange Tip                     April 16^th        June 12^th

Speckled Wood              April 19^th            -

Green-veined White       April 20^th       June 18^th

Dingy Skipper                 May 6^th         June 22^nd

Duke of Burgundy          May 7^th          June 10^th

Pearl-bordered Frit         May 6^th          June 6^th  

Small Pearl-bordered      May 23^rd       June 24^th

 

Those are typical start and end dates for central southern England from that era. Butterflies, that summer, didn’t start emerging early until the start of June. Then, Large Skipper commenced on June 1^st and Meadow Brown on the 2^nd (my earliest Meadow Brown of the 20^th century).

The Holly Blue was staging one of its periodic revivals, having been scarce since 1970. The Pearl-bordered Fritillary had an astounding year, with colonies in most young conifer plantations (there were at least ten colonies in Alice Holt Forest that summer, and the butterfly truly abounded in Chiddingfold Forest). 

But Butterfly of the Spring / early Summer 1976 was the Wall Brown, which was almost omni-present – not just on the downs and grassy heaths, but in open woodland rides, along road verges and on garden banks. My diaries record some 250 Wall Browns, between May 10^th and June 18^th, but I didn’t diarise roadside and garden sightings. I saw over 50 in Lodge Inclosure of Alice Holt Forest on May 23^rd. This abundance occurred after a massive 3^rd brood during the sublime autumn of 1975, blowing a hole in the theory that a 3^rd brood depletes populations and is responsible for the current decline. Common Blue and Small Copper were comparably numerous.

The spring weather wasn’t too extreme. April was dry and merely pleasant, and May started and ended rather poorly, though it included a couple of strong anticyclones. The heat and the drought were to come later. This meant that spring butterflies were not unduly stressed, laid a lot of eggs, and had lengthy flight seasons. It was also a great time for larval development. All the while, the Purple Emperor season was brewing...

Next Time: June & July '76.

*Rant: why oh why didn’t we reset the academic year during the Covid pandemic, so that exams take place in the autumn, and we allow our young folk to experience spring and early summer? Rant over.