Australia is currently experiencing an extreme heatwave, with temperatures projected to exceed 45°C for multiple consecutive days across various regions. Heatwaves pose a significant threat to human health, particularly affecting older individuals and those with lower incomes. Beyond human populations, numerous animal species also face challenges from these conditions.
Wildlife Responses to Extreme Heat
Many animals exhibit behavioral responses to high temperatures. For example, dogs pant to cool down, and koalas seek cooler parts of trees. However, prolonged periods of extreme heat can overwhelm these coping mechanisms. Previous heatwave events in Australia have resulted in the deaths of tens of thousands of bats. Some bird species can succumb to extreme heat within a single day.
Even cold-blooded animals, such as insects, are affected. Despite common assumptions that insects thrive in heat, prolonged extreme temperatures can be detrimental. However, various insect species, including ants, bees, and beetles, possess specific adaptations to manage heat.
Insect Adaptations
- Ants: While ant activity typically increases in warmer conditions, prolonged extreme heat causes them to reduce foraging, remaining in shaded areas or inside cooler nests. This can lead to increased presence of ants inside houses, which offer cooler, shadier foraging environments.
- Western Honeybees: These introduced bees, better suited to cooler climates, have developed heat management strategies. They engage in "bearding," where large numbers of workers gather on the exterior of the hive to enhance internal airflow. Bees also "fan" the hive by flapping their wings to circulate air and cool the interior, and collect water for evaporative cooling within the nest.
- Native Australian Stingless Bees: These bees can tolerate temperatures up to 40°C but struggle with extended periods at such highs. For artificial hives, cooling methods such as wet towels or temporary indoor relocation may be necessary.
- Beetles: Summer generally marks the emergence of beetles like Christmas beetles from underground, with high temperatures often triggering their appearance. During heatwaves, beetles tend to be less active, seeking out shadier locations. Hot and dry conditions can also diminish their food sources. Christmas beetles have developed methods to prevent overheating, including reflective hardened wings (elytra) and the ability to trap and then expel heat by flapping their wings.
Assisting Insects During Heatwaves
To support insects during heatwaves, several measures can be implemented. Adding rocks to birdbaths provides safe landing and drinking spots for flying insects, though regular cleaning is essential to prevent mosquito breeding. Gardens with extensive canopy cover offer shade for insects. Furthermore, insects found indoors during heatwaves may be seeking respite from the heat, and their removal may not always be necessary.