How a severe drought in Africa caused whitethroat population to drop

By Paul Homewood

h/t Paul Weldon

Even by the Guardian’s lowly standards, this is down there with the worst:

More than 50 years ago, in the spring of 1969, Britain’s birders noticed that something was amiss. Whitethroats – which until then had been one of the commonest migrant visitors to the country – were missing from their usual hedgerow haunts.

The reason for their absence turned out to be a severe drought. This took place during the autumn and winter of 1968, in Africa’s Sahel zone, a narrow strip of land south of the Sahara where many British whitethroats spend the winter.

The drought led to a major shortage of insect food, which resulted in the deaths of millions of whitethroats – perhaps as many as four out of five. The following spring these birds failed to return north; hence the title of a seminal paper, Where Have All the Whitethroats Gone?, in the British Trust for Ornithology’s journal Bird Study.

The good news is that, since then, this engaging little warbler has made a partial comeback. This spring, whitethroats have returned in force, and are singing their scratchy song from almost every hedgerow around my Somerset home.

The bad news is that this was one of the very first indications that the world’s climate was changing; and that droughts in Africa may become more regular as a result. What a pity that we didn’t heed that early warning from the whitethroats, all those years ago.;amp;amp

The Sahel drought he refers to lasted from the late 1960s to the early 1980s, and was by far the worst drought there in recorded history. It occurred as a direct result of global cooling.

Since then, as global temperatures have recovered, the rainfall has returned to the region, and the desert has greened:

Recent “greening” of the Sahel: The results of trend analyses of time series over the Sahel region of seasonally integrated NDVI using NOAA AVHRR NDVI-data from 1982 to 1999. Areas with trends of <95% probability in white.

In spite of Stephen Moss’ assertions, The Sahel has long experienced a series of historic droughts, dating back to at least the 17th century. They have nothing to do with his “changing climate”

But at least the Whitethroat will be grateful for a warmer climate!


JUNE 30, 2022