Around 400 endangered reptiles and amphibians have died from improper shipping and dehydration in South Africa, according to animal inspectors.
More than 1,600 animals were discovered crammed into two crates at the OR Tambo International Airport, with the survivors being treated at Johannesburg Zoo.
It is thought the animals came from Madagascar and were part of a legal shipment headed for the exotic pet trade in the US.
A routine inspection uncovered the animals after a bad smell had been detected.
The zoo's vet, Brett Gardener, told the BBC: "A substantial number have stabilised, eating and drinking, there are about over 1,200 that have survived - others with irreparable damage."
He said the fact the flight was delayed could have been connected to the high level of deaths.
He added: "The boxes arrived on Tuesday morning and were scheduled to connect on a flight that evening. The flight was delayed indefinitely due to bad weather and attempts to put them in another flight failed."
But the animals, which included 30 differed species of frogs, chameleons, lizard, toads, and geckos, had been placed in two crates, being packed in plastic boxes with barely any room to move.
The National Society for the Prevention of Cruelty to Animals (NSPCA) said the creatures had been kept in the tubs and bags for five days before they were found on 29 January.
AFP reports that Ainsley Hay, the manager of the NSPCA's Wildlife Protection Unit, said: "Many animals could not move or turn around in their containers. None had been provided with water.
"People who have exotic animals as pets must realise that they are causing this cruelty. Without the demand for these animals as pets, there would be no market and these animals would not be stolen from the wild."
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