Japan’s oppressive summer heat has claimed three lions at a Tokyo zoo, with several more receiving treatment after showing signs of suspected heatstroke, a spokeswoman said.
The big cats have struggled with the country’s punishing combination of extreme temperatures and heavy humidity. Japan recorded its hottest summer on record last year, while temperatures in parts of the country have reached 40C in recent weeks, prompting the introduction of the new “cruelly hot day” designation.
Since mid-July, 10 of the 16 lions at Tama Zoological Park have displayed symptoms including “loss of appetite and decreased activity”, according to a statement from the zoo. Three lionesses have since died.
The zoo said one died today, another on Friday and the third on Sunday.
“Even though lions are thought to be resistant to heat, zookeepers have been strengthening countermeasures to cope with Japan’s summer heat in recent years. Heat here comes with high humidity; that is different from heat with dry air in Africa,” the spokeswoman said.
One of the lions, named Ichigo, which died at the park (Image: Tokyo Zoological Park Society)
She said the danger intensified after the rainy season ended in late July, when “heat arrived suddenly”.
In response, staff are stepping up precautions by sprinkling water, improving ventilation and installing spot air conditioners, she said.
Several lions remain under treatment, the spokeswoman added.
Japan’s heat is also taking a heavy toll on people. Nearly 18,600 were taken to hospital for heatstroke between 20-26 July, while 45 were pronounced dead on arrival, according to the fire and disaster management agency.
The country records about 1,300 heat-related deaths each year and has set a goal of cutting that figure by half by 2030.
Scientists have warned that human-induced climate change is making extreme heat events more frequent and more intense in Japan and around the world.
Japan’s highest recorded temperature was measured on 5 August 2025, when the mercury reached 41.8C in Isesaki, north of Tokyo.
The heat has also forced authorities to alter the schedules of cultural and sporting events in recent years. Among them is the World Cosplay Summit in Nagoya, which staged its latest summer edition last weekend.
