What happens to bees when temperatures soar? Extreme heat can be highly challenging for many species of bees, as well as butterflies and birds.
Bee bodies, like human bodies, are made mostly of water. Fresh water is of critical importance to their survival in hot weather. They adapt to the heat by searching for and drinking lots of water in hot weather and foraging less for pollen.
When you consider that a honeybee hive can have anywhere from 20,000 to 80,000 bees living there, you can see the importance of keeping the hive cool. They need water not just for themselves to drink for survival, but these social insects collectively bring nearly a gallon of water back to their hive every day to keep the hive and larvae cool.
Honeybees perform an activity called ‘bearding’ in hot weather, where they get into groups outside the hive, making a shape that looks like a beard, to lower the interior hive temperature.
When bees collect water, they store it in their stomachs and then regurgitate it when they get back to the hive. There, they have different ways to use the water. Some lap the water up with their hairy tongues and spit it over the eggs to create a protective saliva membrane around them. Others use their wings to fan the water, so it evaporates and cools the air like our air conditioning units do.
This 1:53-minute video by Frederick Dunn explains honeybee bearding:
In contrast, bumblebees live in smaller underground colonies and there are usually only 50 to 500 bees in a colony depending on the species and habitat. These important pollinators don’t have the resources of large beehives to protect them from intense heat.
Persistent heat disrupts insect reproduction and feeding cycles. It is no wonder that according to a study from the University of Ottawa in 2020, extreme heat as well as habitat loss, pesticides, and diseases, is cited as a reason for bumblebee declines in Europe and North America.
Butterflies also need water access. Gardens with bird baths, fountains or shallow dishes of water are favored. Wine corks, leaves or twigs are ideal for perching in the water.
Birds sing during mating season, so once it ends, many birds go silent. Birds conserve their energy during heat waves, so they don’t move around or fly much. They seek shady spots in the trees to cool off. They reduce their inner body temperature by keeping their beaks open and panting, a vibrating of the throat called gular fluttering. Bird baths provide water for birds to drink and cool off their feathers and skin.
Excessive heat impacts hummingbirds. They must forage for food constantly to supply energy for survival, so they can’t avoid heat by sitting in the shade for long. Nighttime heat disrupts their ability to go into a deep rest state, or torpor, which reduces body temperature and conserves energy.
Place a hummingbird feeder in a shady area in your garden. Grow healthy nectar flowers for all pollinators. Most of all, place water in your garden daily and keep it fresh so pollinators can use it for the survival of themselves and their families.