The farmer, from the Richmond district in the Northern Cape, allegedly poisoned the birds over a period of three years since 2012.

While his reasons for the alleged poisonings are still unclear, the birds were apparently attracted to newly planted fields and pivots on his farm, which is designated as a sheep and cattle farm, further raising the possible contravention of land use and irrigation development laws by the farmer.

Neighbours on Monday said the “illegal” irrigation pivot went into operation in 2012, when the first carcasses were found. It now appears as if the poisoning continued until recently.

According to reports, farm workers were instructed to dip corn in a poison called Temic, also known as “Two Step” or Aldicarb, to deliberately poison the birds. The workers then had to collect the carcasses of the dead birds and bury them in porcupine and aardvark holes.

While the total number of carcasses found is believed to be around 200, sources on Monday revealed that the number might be closer to a thousand.

The owner of the farm could face a myriad of charges if found guilty of deliberate poisoning, including contravening animal protection, nature conservation, environmental management, land use and poison management legislation, which includes the Northern Cape Provincial Conservation Act and the National Environmental Management Biodiversity Act.

Dr Gerhard Verdoorn, who was on Monday busy with the investigation into the alleged “mass murders” of the national bird, said he would be conducting toxicology reports on some of the carcasses to determine what poison was used to kill the birds.

“I don’t want to believe that this is true but all evidence so far points to the fact that hundreds of blue cranes were deliberately poisoned,” Verdoorn said.

He said that the misuse of any form of Aldicarb (registered in South Africa by Bayer Crop Science until 2012) was a serious crime under the Fertilizers, Farm Feeds, Agricultural Remedies and Stock Remedies Act.

“It is prohibited to use any insecticide for any other use than what is indicated on the label. On the label there is no indication for its use on birds and such action therefore makes it a criminal offence,” Verdoorn said.

He further stated that the poisoning of any animal without a permit was in contravention of nature conservation laws in all provinces.

He requested that any information that could assist in the investigation be relayed to him on 082 446 8946.

Various agricultural and environmental groups on Monday condemned the alleged incident and expressed disappointment at the “cruel and deliberate mass murder” of the blue cranes.

Agri Northern Cape on Monday said it regretted the unfortunate loss of the blue cranes and “condemned in the strongest terms possible the illegal killing of any wildlife”.

A concerned resident from the Richmond area said on Monday that the incident impacted “substantially” on the conservation of blue cranes in the Northern Cape because the area had one of the largest number of blue cranes in their natural habitat in the world.

“This grouping was one of the largest in a single area. It is a serious blow to the blue crane population as there are less blue cranes left than there are rhinos. Around 20 years ago there were about 100 000 and today there are less than 20 000,” the resident said.

The blue crane (Anthropoides paradiseus) is currently listed as vulnerable in the Eskom Red Data Book of South Africa, Lesotho and Swaziland and the 2010 International Union for the Conservation of Nature and Natural Resources (IUCN)’s Red List.

The central Karoo population of the south-eastern region of the Northern Cape is one of South Africa’s three blue crane strongholds.