Hundreds of bats have died as sweltering heat continues to spread across Australia.

Hordes of flying foxes have effectively “boiled” to death, campaigners have said, as temperatures exceeded 44°C in the Sydney suburb of Campbelltown over the weekend.

Groups of the animals were found “dead on the ground” or “hanging in trees”, with many of those that perished believed to be baby bats.

Campbelltown colony manager Kate Ryan told the Camden Narellan Advertiser: “They basically boil. It affects their brain – their brain just fries and they become incoherent.

“It would be like standing in the middle of a sandpit with no shade.”

The Australian heatwave has been so extreme over the past few days, that roads have melted and dozens of bushfires were reported across the country. Firefighters issued warnings as the heat reached near record temperatures in parts of the country.

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The extreme heat can affect young bats particularly badly, with many unable to withstand temperatures much above 40°C. While most adult bats found their way to shade, many younger individuals were left behind.

Campaign group, Help Save the Wildlife and Bushlands in Campbelltown, described the “heart-breaking” situation on their Facebook page. “So many little lives lost due to the extreme heat and not enough canopy cover to shade them or keep them cool,” they said.

“As the dead bodies were recovered and placed in a pile for a head count the numbers had reached 200, not including the many hundreds that were still left in trees being unreachable. Sadly a few adults were also included in the body count.”

Volunteers and animal rescue reams attempted to save as many of the animals as they could by cooling them down with water, but many were “on the last breaths” before help came their way.

The post added: “It’s devastating when a colony like our local one goes down like this due to heat. This colony needs more canopy cover and shaded areas to help with our ever rising hot summers because this episode will surely not be the last.”