As temperatures across Australia soar, Melbourne Zoo's primates are being treated to what staff call their version of summer relief: frozen fruit popsicles, misting fans and careful monitoring during the hottest parts of the day.
The management of great apes and other primates through heatwaves has become part of the annual routine at Melbourne Zoo in Parkville. Unlike humans who sweat to cool down, primates rely on different physiological mechanisms to manage extreme heat, making the preparation particularly important.
Primates might prefer licking fruit-filled ice blocks over other cooling methods, according to enrichment programmes used across major zoos. Western lowland gorillas and Asian elephants are offered vegetarian fruitsicles, which are ice cakes filled with frozen fruit and diluted fruit juice, as documented by the Smithsonian's National Zoo.
The strategy serves multiple purposes beyond simple cooling. Enrichment using water and ice counteracts heat stress by encouraging natural behaviours like foraging, swimming, and playing while providing relief from the heat. At Adelaide Zoo in South Australia, keepers use the same principle; during heatwaves, the zoo provides icy treats filled with fruits and vegetables to baboons, and these frozen blocks not only cool the animals but also encourage foraging and problem-solving behaviours.
At Melbourne Zoo, where the facility is located within Royal Park in Parkville, approximately 4 kilometres north of the centre of Melbourne, the management of heat stress reflects a broader understanding of primate physiology. All primate areas have constant access to water, whether it be lixit nozzles or water bowls in smaller habitats, similar to practices at Zoo Atlanta. Additional cooling methods include misting systems and pools where apes can access water for relief.
The importance of these measures becomes clear when considering how primates handle heat. Animals radiate heat through skin regions with many blood vessels, such as ears; sweat or spread saliva on the skin to aid evaporative cooling; or pant; however, when air temperature exceeds body temperature, birds and mammals can only cool themselves using evaporative water loss, which puts them at risk of dehydration and hyperthermia.
Research highlights why primates face particular challenges. Primate habitats are predicted to experience 10 per cent more warming than the global mean increase in temperature, with 86 per cent of primate species likely to experience increases of over 3°C in maximum temperatures by 2050. This makes current heat management strategies increasingly critical for both wild populations and captive animals.
Zoo keepers follow temperature and weather guidelines carefully during extreme heat events. The combination of enrichment, water access, shade provision and climate-controlled indoor spaces allows primates to choose their environment based on their comfort level. All of the lemurs and apes have a choice to be in their indoor or outdoor enclosures depending on the time of day and weather conditions.
For the public, these preparations are often invisible. Behind the scenes, staff monitor animals closely for signs of heat stress, adjust feeding and activity schedules, and ensure that cooling measures are available throughout the hottest parts of the day. The measures at Melbourne Zoo reflect practices now standard at major zoos worldwide as extreme temperatures become an increasing concern for animal welfare.