By Kristen Currie
What to watch for in August: Hot and Thirsty Birds
People can retreat into air conditioned comfort in hot weather, but what do birds do? Just like us they have to maintain their body temperature regardless of the outside temperature or risk heat-related complications. Watch carefully, and you’ll see birds using various strategies to stay cool.
Birds don’t sweat, but birds can pant. As they speed up their breathing they move more air across moist areas of the lungs, throat and mouth. The moist air absorbs body heat and as it evaporates and is exhaled, birds cool down. Birds also droop their wings and hold them away from their bodies. They fluff their feathers to expose more skin, which releases heat too. Birds are most active in the cooler parts of the day and seek shade in the heat of the afternoon.
Some species including herons, cormorants, owls, doves and roadrunners have a unique behavior called gular fluttering. They open their mouths and visibly vibrate their throats, which increases air flow across moist membranes in the throat area. This dissipates heat more effectively than panting. Sometimes they both pant and gular flutter simultaneously.
Arguably the most bizarre cooling off behavior is used by vultures, which excrete waste onto their legs to stay cool. This highly acidic excrement also helps kill bacteria that vultures are exposed to in their role as nature’s janitors.
Help Thirsty Birds
You can help overheated and thirsty birds by providing clean, fresh and shallow water.
Providing water is easy – in a pinch you can use an upside-down garbage can lid or shallow plant saucer. If cats are a problem you can hang a bird bath in a tree. No matter which bird bath you choose, change the water frequently so it remains fresh and mosquito-free.
What is considered shallow water? A common bird that visits Austin bird baths is the Lesser Goldfinch. The entire bird is 4.5 inches in length. Its tarsus, which is the bone between its toes and ankle, is only ½ inch long. Birds usually only want to get water up to their belly when taking a bath, so for a goldfinch very shallow water is key. Think of hummingbirds and the water needs to be shallower still! If your bird bath is a little too deep, put a stone in it so small birds can use it safely. Or just don’t fill it up too high. Yes, it requires more frequent filling, but that means fresher water.
Just like people, birds need a little traction so they don’t slip, so birdbaths with a rough surface are desirable. Unfortunately algae has more places to grow, so a stiff brush comes in handy. Concrete bird baths have a lot of grip, and one way to beat back algae in them is to pour boiling water in periodically and let it sit a few minutes to loosen the algae before you scrub it off. It’s easy to change ground-level bird baths — just sweep them out.
To make your water feature more appealing to birds, provide a perch close by. Once a bird wets its feathers it can’t fly well and is more vulnerable to predators. It will use the perch to dry out and preen its feathers, and you get a great photo op.
Some birds really like moving water. You can get commercial drips and misters, or make a drip cheaply by hanging a plastic milk jug above a bird bath. Punch a small hole in it so it drips slowly. A drip also helps replenish a bird bath that gets a lot of use. You can also make your own bubbler bird bath, with a water reservoir, aquarium pump, tubing, and a plant saucer. If you have a larger budget or inclination streams and ponds are tremendous bird pleasers too. Where to put your bird bath? A shaded spot is good, with an eye to minimizing ambushes by cats, so place it several feet away from shrubs where they can hide.
A way almost guaranteed to attract songbirds, especially on a hot afternoon in August, is to spray leaves of shrubs or leafy tree branches with water. (Under current water conservation restrictions in Austin, using a hand-held hose is permitted any time of day and any day of the week.) If you can get one bird’s attention its excited chatter may draw others in. The birds rub up against the droplets until they are thoroughly drenched, and then find a place to sit and preen their feathers. One observer who lives in endangered Golden-cheeked Warbler habitat in west Austin successfully attracts those birds with this method. If you enjoy going for a walk in the morning or evening you may see lots of bird activity where sprinklers are creating the same desirable conditions – wet leaves that the birds take advantage of. They will leaf-bathe during and after rain showers too.
Deck-mounted bird baths, concrete bird baths, hanging bird baths, backyard ponds and streams, creating leaf bathing opportunities – pick one or several ways to provide water. You’ll give our resident and migrating songbirds something to sing about.
Keep in mind that water will also attract other wildlife like ring-tailed cats, raccoons, and squirrels. Some folks enjoy putting out a wildlife game camera to document all the visitors to their water features, especially the nocturnal ones.
Compiled by Jane Tillman, Travis Audubon Volunteer for KXAN Weather Blog