Zoo director Wuthichai Muangman and his staff held a news conference on Saturday (Sept 24) to respond to photos and messages posted on Thursday by a Twitter user with over 1.3 million followers. The name of the Twitter account was not given, reports Bangkok Post.
The posts prompted harsh criticism of the zoo as they showed some animals in an apparent malnourished state and habitats in disrepair.
Discussing a photo of an apparently underweight tiger vomiting into a polluted pond, Mr Wuthichai said the animal, named Khao Pun, currently weighs 38 kilogrammes, within the 30-40kg range appropriate for its age. Tigers are typically sleek creatures and may appear gaunt, he said.
Vomiting is normal behaviour for felines including tigers when they groom themselves and then cough up any fur, he added.
Addressing the pictures of the green pond, the zoo head pointed out the growth was green plankton, a normal occurrence in fresh water that does not signify rot or danger.
He also assured that other concerns were being addressed, including reports of bird carcasses, which have already been confirmed to be the offspring of migrating birds passing through the zoo. Officials had inspected the carcasses to check for diseases and had incinerated them
In response to comments that sections of the Chiang Mai Zoo Aquarium were overly warm due to poor air conditioning, Mr Wuthichai said repairs had been commissioned to begin in October.
Any moss seen on fish tanks was normal as the zoo maintains the most natural environment possible for its aquatic animals, he added.