Three lions die in zoo as Japan battles extreme heat
Autopsies show that the lions suffered from dehydration and multiple organ failure.
Three female lions at Tokyo's Tama Zoological Park have succumbed to suspected heat-related illnesses, as Japan grapples with extreme summer temperatures. The deaths occurred within a week, with autopsies indicating dehydration and multiple organ failure in the lions, aged three to 15, strongly suggesting heat as the cause, according to the zoo.
Miwa Kosaka, a zoo representative, informed the BBC, "This is the first time we've experienced anything like this. Last year was also hot, but none of our lions fell ill like this." Japan's summers are becoming increasingly severe, with some cities experiencing "cruelly hot days," defined as temperatures exceeding 40C.
Mugi, a three-year-old female lion, exhibited a loss of appetite on July 19 and was unable to stand the following day. Despite zoo staff providing ventilation, water for cooling, subcutaneous fluids, liver tonics, and vitamins, she died on July 28. Ichigo, an 11-year-old female lion, passed away on July 31, followed by Luena, a 15-year-old female lion, on Sunday.
Autopsies confirmed systemic dehydration and multiple organ failure in all three lions, pointing to heat stress as a contributing factor. The zoo stated that definitive causes of death await further test results.
As of Monday, three other lions—two males and one female—remain "unwell and unable to stand," receiving fluids, medication, and vitamins from zoo staff. Kosaka noted to the BBC that "some of the lions are showing signs of improvement." Four lions have begun to recover, while six were in good health from the outset. These healthy and recovering lions will be moved to a private enclosure equipped with portable air-conditioners and industrial fans.
Hideaki Karaki, a professor of veterinary medicine at the University of Tokyo, explained to local media that high humidity hinders lions' ability to regulate their body temperatures. Unlike sweating, lions expel moisture from their airways through deep breaths, which typically lowers body temperature as the moisture evaporates. However, in high humidity, this process becomes less effective. Karaki also suggested that a sudden temperature spike in mid-July might have prevented the animals from acclimating to the heat.
Tama Zoo, home to approximately 260 animal species, has featured lions since 1964, offering a safari-style bus service for visitors to view them. Last month, the zoo announced the suspension of its lion exhibit and bus service due to the "sudden heatwave" affecting the lions' health.
Nationwide, at least 18,000 people were hospitalized for heatstroke in the week of July 20 alone, according to government data. The government has issued heat warnings, urging residents to stay cool and encouraging office workers to adopt breezier attire.