Weather-wise, 2012 was a strange year. At the start of spring, conservation organisations were predicting that wading birds such as the lapwing would not be able to find enough food for their chicks, because of a lengthy drought.

Wetland Bird Survey reveals wading birds in decline – in pictures Read more

A few months later, at the end of July, Britain had suffered one of the most prolonged spells of heavy rainfall in recorded history. The spell from April to July 2012 was the wettest period since weather records for England and Wales began in 1766, and for the country as a whole, the summer – defined as the three months from June to August – was the wettest for exactly a century.

The effect of this weather on wetland birds was disastrous. In one flooded field in Somerset, a pair of black-winged stilts – rare visitors from mainland Europe – attempted to breed, but their eggs became soaked and did not hatch. Farmers, who had initially welcomed the rain, lost whole fields to flooding, and were unable to cut silage or make hay.

The unusually wet weather was the result of a shift in the Atlantic jet stream, which tracked more southerly than usual, bringing low-pressure systems from the Atlantic and dumping vast amounts of rain on southern Britain.