TOKYO: Three lions from a Tokyo zoo have died from suspected heatstroke, and others are under treatment, a spokeswoman said on Tuesday (Aug 4), with the big cats struggling with high levels of humidity. Ten of the 16 lions in Tama Zoological Park have suffered symptoms such as "loss of appetite and decreased activity" since mid-July, and three lionesses died, the zoo said in a statement. "According to our veterinarian, the cause of the deaths is suspected to be heatstroke", as dehydration and multiple organ failure were observed, a spokeswoman told AFP. "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. Scientists say human-induced climate change is increasing the frequency and intensity of extreme heat events in Japan and elsewhere.