In 1867, Canterbury released 40 house sparrows to feed on crop pests; Within 15 years, New Zealand was poisoning birds and paying bounties after they began cutting down grain crops.

The house sparrow was brought to New Zealand in 1867 to help farmers deal with insects that feed on crops, but the small bird soon became a problem in itself. Within a few years, as it grew in number, it also began to damage crops, leading farmers and authorities to turn against the species.Introducing familiar European birds to New Zealand was not uncommon. According to the Teara government encyclopedia, European settlers brought many species of birds to the country. Both because they missed the birds they knew from Britain and because they hoped some of them would help agriculture. In total, 130 bird species were brought to New Zealand, of which 41 eventually established wild populations.The Canterbury Acclimatization Society released 40 sparrows in 1867. The birds were expected to help control agricultural pests, particularly insects that damaged crops. But the sparrows didn’t just focus on insects. Although they fed their young caterpillars, beetles, flies and spiders during the first week after hatching, at other times they were more interested in grains and fruits.That made the bird a serious concern for farmers. Sparrows damaged wheat, barley and corn crops, and their ability to reproduce quickly meant their numbers could increase rapidly. The same qualities that made them attractive as a potential pest control species eventually made them difficult to control.

Introduction of foreign birds.

The introduction of birds accelerated as agriculture expanded across New Zealand. By the early 1850s, moths, caterpillars, beetles, and grasshoppers had become major problems in agricultural areas. Some insect outbreaks were so large that they disrupted normal activity.Native birds ate insects, but their ability to control pests on farmland was limited. They generally foraged in agricultural areas when nearby bushes provided suitable habitat. As more land was cleared for agriculture, the edge of the forest was pushed back and native birds had even less influence over farmland pest populations.Therefore, farmers looked towards the birds of Europe. Species such as blackbirds, thrushes, starlings, sparrows and magpies were introduced in the hope that they would feed on insects and reduce damage to crops.Beginning in the 1860s, acclimatization societies began to organize these introductions more systematically. They selected birds in part for their ability to survive in New Zealand and reproduce in large numbers. Some societies also wanted birds that could eat insects during the summer but switch to other foods, such as seeds or grains, during the winter.

The rapid rise of sparrows led to organized efforts to control them. (Photo: Teara)

The sparrow boom

Only 100 house sparrows were released in New Zealand between 1866 and 1871, while the Canterbury Acclimatization Society released 40 in 1867.Their reproductive success was high. Te Ara says this was probably due to abundant food, little competition, a mild climate and few predators at the time. The birds were also very efficient breeders.Early observers noted that female sparrows could lay another clutch of eggs while their previous young were still in the nest. Apparently, the young birds helped incubate the eggs.The naturalist Thomas Kirk highlighted the potential scale of this growth in 1878. He calculated that, in theory, a pair of house sparrows could produce a population of 322,000 in five years.

A new plague emerges

The introduction of the sparrow was intended to reduce insect pests, but the birds themselves began to be seen as a threat to agriculture. However, the problem was not limited to the sparrows. Other small introduced birds also multiplied and damaged crops.Within 15 years of its introduction, there was a coordinated effort to control small European birds. Sparrow clubs were formed in the 1880s to reduce what was described as the “sparrow plague”. The clubs were modeled on similar organizations established in England from the 1850s.Methods included poisoned grain, shooting, and financial rewards for collecting sparrow eggs. Rewards were also offered for eggs and heads of small introduced birds. The system encouraged children to collect sparrow eggs, and young children collected hundreds of thousands of them.