Three female lions at Tokyo’s Tama Zoological Park have died from suspected heatstroke amid an intense heatwave impacting the region. The deaths mark the first heat-related fatalities among the zoo’s lion population in its 62-year history.

The lions, aged three, 11, and 15, were all born at the zoo and exhibited symptoms including severe dehydration and multiple organ failure, according to post-mortem examinations. The exact cause of death remains under investigation, but zoo officials attributed the fatalities to the sudden arrival of extremely hot and humid weather.

Since mid-July, 10 of the 16 lions at Tama Zoological Park have shown signs of distress, including loss of appetite and lethargy, prompting medical treatment for several of the animals. While some lions have begun to recover, others continued to deteriorate, leading to three deaths over a week: one lioness last Tuesday, another on Friday, and the most recent on Sunday. In response, the zoo suspended public viewing of the lions on July 23.

Staff at the zoo have intensified countermeasures to protect the animals from the high temperatures, which include spraying water, improving ventilation, and installing spot air conditioners. A zoo spokesperson noted that while lions are generally considered heat-resistant, the combination of heat with Japan’s characteristic high humidity presents a unique challenge compared to lions’ native dry climates in Africa.

The extreme weather conditions are part of a broader pattern affecting Japan this summer. Temperatures reached nearly 39 degrees Celsius in the Tokyo area in mid- to late July, with some parts of the country surpassing 40 degrees Celsius. This follows Japan's hottest summer on record last year, which included a peak temperature of 41.8 degrees Celsius in Isesaki, north of Tokyo.

Heat-related illnesses have placed a significant strain on public health nationwide. From July 20 to 26, approximately 18,600 people were hospitalized for heatstroke, and 45 individuals were pronounced dead on arrival, according to Japan’s fire and disaster management agency. Heat-related deaths in Japan typically number around 1,300 annually, with the government aiming to reduce that figure by half by 2030.

While the lion deaths have drawn attention to the impacts of extreme heat on wildlife, zoo officials reported that no other animals at Tama Zoological Park have shown signs of heat-related illness. The situation underscores growing concerns over the effects of escalating temperatures and humidity on both human and animal populations amid shifting climate patterns.