SPCA Otago wants whoever drugged more than 100 birds in Mosgiel to admit to the cold and inhumane act.
Otago SPCA inspector Julie Richardson said several members of the public had telephoned the animal shelter about more than 100 poisoned birds, including a plover, blackbird, starlings, sparrows and pigeons.
About 30 of the birds were dead and another 74 found dying were collected from the Mosgiel area.
Some of the birds were lying upside down and others were being eaten by hawks and magpies, she said.
Some of the rescued birds died on the way to the shelter; three died overnight and another was put down yesterday.
Yesterday, 62 birds were recovering in the heated isolation facility at the animal shelter in Opoho.
The drugged birds had eaten a commercial bait, ''a narcotic poison which works on the central nervous system, producing a hypnotic and anaesthetic effect on the birds - it basically induces hypothermia,'' she said.
Although it was legal to poison birds, it was concerning that many of the birds were barely alive.
The bait-layer should have waited 30 minutes and then humanely killed the dazed birds, she said.
Instead, the birds had been left to die.
''I'm not sure where the birds have ingested this bait. All I saw was the aftermath.''
The person responsible could be prosecuted under the Animal Welfare Act, she said.
''We understand these animals are a pest but you still have an obligation to ensure they are not suffering.''
She wanted the bait to be used responsibly.
''Be vigilant and pick up the dead birds. They should be disposed of because cats and dogs can eat them and suffer.''
A poisoned bird could be placed in a box in a warm place, such as a hot water cupboard, until it recovered.
Anyone who handled poisoned birds should wash their hands thoroughly, she said.
Once the birds at the shelter had recovered, they would be released, she said.
Anyone with any information on the poisoning should contact Otago SPCA, she said.
