Equipped with adaptations for keeping cool, birds still can use some help from humans during the long, hot summer
07-28-2014 // Melissa Mayntz
SUMMER IS A HOT SEASON, not just for bird-watching but for birds themselves, and the heat can take a toll on the animals. Just like birders who venture into the field without adequate water during summer, birds can suffer from heatstroke and overexertion—but bird lovers who provide cool, refreshing sanctuaries in their yards will be able to chill out with their feathered friends all season long.
From tanagers to buntings to hummingbirds, birds have evolved many physiological adaptations to keep cool. While birds do not sweat, bare skin on their faces and legs radiates body heat, and a higher respiration rate supports efficient panting. Many species can even control blood flow to their bills, which facilitates heat loss on hot days.
Behavior also helps birds beat the heat. Soaring high in cooler air can provide relief, while wing flutters or lifting feathers increases air circulation to keep skin cool. Many birds seek out shaded roosts on hot afternoons, doing most of their foraging during mornings and evenings. Some birds also use evaporative cooling: bathing or urinating on their legs, then allowing the liquid to evaporate and take away body heat.
As temperatures climb, however, birds’ physiological and behavioral adaptations may not be enough. Providing water and shade in your yard are easy and effective ways to attract as well as help out the animals.
Provide Plenty of Water
Water is the key to keeping backyard birds cool, but a basic birdbath is only the first step. Ideally, summer water features should include movement created by a dripper, mister or fountain because splashing sounds and glittering reflections attract birds. “The sound of moving water like a stream or even water slowly dripping into a basin or against a rock or foliage will attract many species of birds,” says Mark Kiser, Great Florida Birding and Wildlife Trail coordinator. “A mister device attached to a garden hose works wonderfully; the mister creates a fine spray that birds will either fly through to bathe in, or they will rub against the wet foliage.”
Moving water does more than bring in birds. Flowing and splashing slows bacterial and algal growth and discourages mosquitoes from breeding, minimizing the risk of mosquito-borne illnesses for birds and backyard birders alike.
When choosing a birdbath or other water feature, opt for one with different depths to accommodate both large and small species. A deep basin will discourage small birds from bathing, while a very shallow one will dry out quickly on hot days, particularly when birds bathe vigorously. “If the water is too deep, many songbirds and other small species won’t be able to use it,” Kiser says. “The right depth will depend on the size of the basin or container; one-half inch to one inch may suffice in many cases. Sloping sides allow birds of various sizes to access the depth they prefer.”
To keep a birdbath cool and full even in extreme heat, add a large chunk of ice to the bath each morning (freeze water in a plastic bowl the night before). As it melts, the ice will refill and refresh the bath. Proper hygiene is also essential. “Poorly maintained water features can spread disease, and pathogens thrive in summer heat,” says Sheri Williamson, co-director of the Southeastern Arizona Bird Observatory and author of the Peterson Field Guide to Hummingbirds of North America. Clean your baths at least once a week and more often if the water becomes discolored or contains algae or mold. Daily rinsing also will help keep a bath cleaner
Don't Forget Shade
As temperatures climb, shade is just as valuable to birds as water. To provide cool, shaded areas in your yard, create deeply tiered landscaping with broad-leafed native plants, adding vegetation around tree trunks or alongside buildings for even more shelter. “Native trees, shrubs and vines are particularly useful in the landscape to provide shade, shelter and food for birds,” Kiser says. “A dense, fruiting shrub, for example, can provide all three at the same time—protection from the heat and protection from predators as well as a food source.”
Place feeders in shaded areas during summer, which not only will help keep birds cooler but will keep oily seeds from spoiling as quickly. Similarly, bird houses should be mounted in shaded locations and have wide ventilation slits or holes under the eaves to provide cooling air circulation for nestlings. Place both houses and feeders in areas with gentle breezes for even more cooling, but keep them separate, as birds may be less comfortable in a house close to a busy feeding station.
Offer Reliable, Healthy Foods
No matter what the temperature, birds need to forage and stay alert for predators, and those activities generate a lot of body heat. Just as birders avoid strenuous hikes during the hottest part of the day, birds adjust their activity schedules during summer. You can help them by providing a healthy, reliable food source so the animals do not need to fly as far as frequently. “Birds that have a ready supply of healthy food can spend less time foraging and more time resting and bathing,” Williamson says. Good summer foods include sunflower seeds, fruit and nectar as well as no-melt suet. “High-quality food items will help keep birds healthy and their metabolism running smoothly so they are better equipped to deal with stressors such as periods of extreme temperature,” Kiser says.
To help hot birds rest safely, deter cats and other predators. Use baffles around bird feeders and houses, repair fencing and choose thorny landscaping that dissuades marauding predators. Birds that are safe will be less stressed by the heat and more comfortable visiting your feeders and baths.
For many of us, an ideal summer afternoon includes enjoying a refreshing drink on a cool, shaded patio. If you provide similar amenities in your yard, you won’t be disappointed by your feathered summer guests, even on the hottest days.
NWF’s Garden for Wildlife™ program provides gardeners with tips about native plants and other elements needed to create nurturing habitats for birds and other wildlife.
Become a NWF Wildlife Gardener. It's free and you will receive great gardening tips and learn how to certify your yard as a Certified Wildlife Habitat® site.
Melissa Mayntz is a Utah-based writer who covers wild birds and birding for About.com (birding.about.com).