Richard Collins: Sparrow - survivor of Mao’s great purge

Although Mao’s crude attack didn’t succeed, tree sparrows are vulnerable, as their roller-coaster history in Ireland shows, writes Richard Collins

This year marks the sixtieth anniversary of Mao Zedong’s ‘Kill a Sparrow’ campaign. It’s also 20 years since the death of the biologist who persuaded him to halt it.

As part of China’s ‘Great Leap Forward’, rats flies mosquitoes and sparrows were declared ‘capitalist public enemies’. Each sparrow, it was claimed, consumed several kilos of grain a year. The birds were also accused of spreading disease. ‘No warrior shall be withdrawn until the battle is won’ declared the Peking People’s Daily. From 1958 to 1962, nests were destroyed, chicks killed and adult sparrows shot on sight. Chinese Health Service reports claimed that a billion of them died. A history of China, published in Poland in 1999, describes birds seeking political asylum in the grounds of foreign embassies. Staff at the Polish mission refused to allow the sparrow-killers to enter, so a mob formed outside, beating drums continuously until the terrified birds dropped dead from stress and exhaustion.

Tso-hsin Cheng, who died in 1998, was China’s leading ornithologist. Criticising the ‘four pests’ jihad, he reminded the authorities that sparrows help control harmful insects. Eliminating the birds, he argued, was madness. Denounced as a ‘reactionary’, he was forced to clean toilets and endure six months solitary confinement in a cowshed.

But Cheng’s advice proved prophetic. Insect numbers exploded in China and crop yields fell. When the campaign was renewed, sparrows were quietly dropped from the list of public enemies, replaced by cockroaches.

Such an assault on sparrows was unlikely to succeed. Small birds are equipped to deal with disasters, natural or man-made, because their breeding success is ‘density dependent’. Starting to nest when just a year old, a female sparrow produces two or three clutches annually. A pair might fledge ten youngsters in a season. If all the chicks were to survive and breed, the pair would have over 120 million descendants within ten years. Sparrows can live to fourteen but, in practice, only two young, on average, reach breeding age, such is the fierce competition they face for resources. However, when the population is reduced by severe weather, or Chinese mobs, there is less competition and more chicks survive, making good the previous losses. The occasional hard winter in Ireland decimates small bird populations, but they bounce back in a year or two.

Mao’s extermination campaign had little long-term effect. On a visit to Beijing and other Chinese cities, some years ago, I encountered many sparrows. They were not the familiar ‘house’ ones of Irish gardens and parks but tree sparrows, immediately recognisable by their brown crowns.

Although Mao’s crude attack didn’t succeed, tree sparrows are vulnerable, as their roller-coaster history in Ireland shows. ‘The first Irish (tree sparrow) specimen was exhibited by Montgomery before the Dublin Natural History Society in 1852’ wrote Richard Ussher and Robert Warren. Numbers then increased ‘between Dublin Bay and the Malahide estuary’. The species soon had a widespread, but patchy, distribution throughout Ireland. Then, for reasons unknown, the population collapsed; the tree sparrow was virtually extinct here by 1950.

But the species recovered and became fairly common, at least in Leinster. One morning in February 1981, I ringed no less than 46 of them in Malahide. But the bonanza didn’t last; true to form, numbers then declined. The Atlas survey results suggest that the bird’s fortunes are now rising yet again. Something threatens our tree sparrows from time to time, but it hasn’t defeated this survivor of Mao’s great purge.