Birds and bees suffer in this heat, too
“It was surprisingly noisy in the botanical garden. Birds were yelling their heads off, bees were buzzing around in bee fashion, and butterflies were flapping about, swearing and jostling one another for the good flowers.”
— Abbi Waxman, “The Garden of Small Beginnings,” 2017
During the second gardening class at the L.A. Botanical Garden in Waxman’s novel, Lili and her two daughters were paying close attention to different sounds in the garden.
Five-year-old Clare observed, “The birds are much louder here than they are at home; why is that?” Her studious manner was in stark contrast to the red and white polka-dotted Minnie Mouse dress she had worn that day in honor of all the ladybugs in the garden, which, unlike the birds, bees and butterflies, were going about their business quietly.
Annabel, her 7-year-old sister, answered her like big sisters will do: “I don’t think they’re any louder. I just think everything else is quieter here.”
My experience while sitting in the shade of my front yard yesterday was quite different. I didn’t hear any birds singing, the bees had seemingly disappeared, and if the butterflies were swearing, they were doing it in sign language.
The silence got me wondering how our pollinator friends are coping with the extreme heat. Here’s what I learned about bees, butterflies and birds:
Bees’ bodies are made up mostly of water, just like humans’, so they need plenty of water to drink during hot weather, too. When temperatures soar, bees adapt to the heat by reducing or completely stopping their foraging for pollen and, instead, they focus on finding water. Not only do the bees need water for themselves to survive, but social bees bring as much as nearly a gallon of water back to their hive every day to keep the eggs and the interior of the hive cool and moist.
After collecting water in their stomachs, bees regurgitate it once they return to the hive. Some bees fan the water with their wings so it evaporates and cools the air, similar to central A/C. Other bees lap up the water with their hairy tongue and then spit it on the eggs, creating a protective membrane around them with their saliva.
Honeybees also engage in an activity called bearding more often during hot weather. Some of the bees leave their hive and gather in groups outside, which can take on the shape of a beard. Scientists believe the bees work collaboratively this way mostly to prevent the interior temperature of the hive from becoming too hot and killing the larvae and other members of the colony. However, bearding sometimes occurs before a swarm, so look out!
Honeybees are transplants from Europe, and they live in perennial colonies with populations that can reach 20,000 in wild habitats and 80,000 or more in managed beehives. Bumblebees, including Oregon’s 16 native species of bumblebees, live in much smaller, underground colonies that range from 50 to 500, depending on the species and habitat. Bumblebees are also important pollinators, but they don’t have the resources of large beehives to protect themselves from extreme heat.
That may be why a 2020 study from the University of Ottawa cited extreme heat as one reason for bumblebee declines in North America and Europe, along with habitat loss, pesticide use, and disease. In fact, extremely hot temperatures are causing a decline in many insect species, including beneficial insects, because the heat disrupts their feeding and reproduction cycles.
Butterflies, on the other hand, are well suited to warm temperatures because their wings consist of thermodynamic panels that determine the intensity and direction of sunlight. Lepidoptera use this information to angle their wings to reflect the sun’s heat either away from their body or toward their body in order to regulate their body temperature. Butterflies need a body temperature of around 86 degrees before they are able to flutter about (or swear).
However, extended periods of excessive heat increase the mortality rate of butterfly larvae, and plant die-off from the heat reduces food and shelter for butterflies. Like bees, butterflies need consistent access to water, so they appreciate gardens equipped with bird baths, fountains or shallow dishes of water. Place wine corks or stones in the water for landing pads.
The primary reason birds sing is to announce their territory and to attract a mate, so now that mating season is over, that’s one reason I don’t hear as many birds singing these days. Another reason is that birds conserve their energy during heat waves, so they don’t move about or fly as much, instead seeking out shady spots in the trees to cool off.
Birds don’t have sweat glands, so they reduce their internal body temperature by keeping their beak open and panting, a vibrating of the throat called gular fluttering. Bird baths and other water sources provide water for birds to drink and to cool off their feathers and skin.
Extended periods of excessive heat can have the most impact on some of our smallest avian friends — hummingbirds. They have to forage for food almost constantly in order to supply the energy they need to survive, so they can’t afford to sit out the heat in the shade for long.
Warmer nighttime temperatures may disrupt the hummingbird’s ability to enter into a state of deep rest called torpor, which the birds need to reduce their body temperature and to conserve energy. Growing nectar flowers or placing a hummingbird feeder close to or in a shady area helps keep hummingbirds healthy during extremely hot weather.
Back to “The Garden of Small Beginnings,” where young Clare in her Minnie Mouse dress is finding out that birds are “always singing this hard, we just can’t hear them properly.”
“That must be annoying for them. I don’t like it when I’m trying to say something and no one is listening.” Clare clearly empathizes with the underdog — or underbird. After considering this for a moment, she adds: “No wonder they poop on cars all the time. I would too.”
Sure do love that Clare!
Rhonda Nowak is a Rogue Valley gardener, teacher and writer. Email her at Rnowak39@gmail.com. For more about gardening, check out her podcasts and videos at https://mailtribune.com/podcasts/the-literary-gardener.
My gardening to-do list for this week
Wash the bird poop off the car, and then make sure there’s water available for the birds, bees and butterflies in the garden.
Sit in the shade on the porch with my mouth open and try gular fluttering to feel what’s it’s like to be a bird in hot weather.
Wear a red and white polka-dotted Minnie Mouse dress in honor of all the ladybugs in the garden.