Eating and drinking
Some birds, like Green Herons, jays, shrikes, crows, owls, and gulls, swallow part or all of their prey whole. Strong stomach juices digest the soft parts. The remaining parts—bones, teeth, fur, feathers, claws, etc.—are formed into pellets that are regurgitated later. Some birds routinely vomit in the same location, leaving piles of pellets.
Owls are one of many bird species that swallow their prey whole. This photo shows pellets from a Long-eared Owl, Asio otus, some intact and some pulled apart to show their bits of matter, including bones.
The amazing photo above shows two birds of prey clasping each other; neither will let go! Why? Hunger! Great-horned Owls, Bubo virginianus, routinely prey on hawks. The Red-tailed Hawk, Buteo jamaicensis, is trying to save itself but also wants to make a meal of the owl. They may have been hungrier than usual—when it’s frigid and snowy, prey for them can be harder to find.
Great-horned Owls also prey on hares, rabbits, rodents, opossums, woodchucks, bats, weasels, other owls, and even skunks. Sometimes domestic cats, too. They’re pretty ferocious and sometimes kill more than they can eat, but they don’t let it go to waste—they cache the extra to eat later.
(About the photo: Ken Lockwood, a raptor rehabilitator, was called to the scene by a bystander, to separate the birds, which appeared injured. Except for ruffled feathers, the owl was fine. The hawk had leg injuries and was cared for until healed, then successfully released.)
Birds don’t have teeth to pulverize their food, so their digestive system has a specialized way of breaking it down. After food is swallowed it goes into their “crop,” an enlarged pouch in the esophagus. From there, it goes into a stomach that has strong digestive juices and from there into their gizzard, which has strong musculature for grinding. Once it’s sufficiently converted into a digestible mash, it flows into their intestines. Sometimes, birds swallow small stones or grit to help in the grinding process.
Do you leave your hummingbird feeder out in winter? Especially if you live in a more northern climate, it might help a late migrant or even supplement the diet of other winter visitors. Use 1 part sugar to 4 parts water. As in summer, keep the solution fresh and the feeder clean. In the winter the solution ferments slower, so the feeder will need cleaning only every week or two. The nectar won’t freeze unless the air temperature drops to around 29°F (-1°C). You may want to use two feeders and rotate them in and out to prevent freezing in colder weather. If you have to bring the feeder indoors overnight, put it out as early as possible in the morning.
Birds expend more energy in the winter and are often forced to spend all day looking for enough calories to carry them through the night. When we offer them seeds, nuts, and suet, we grant them an opportunity to spend part of their daytime hours resting and conserving energy.
Do you feed bread to birds? They’ll eat it, but experts say other kitchen scraps are better, as bread doesn’t contain any of the vital nutrients birds need. Instead, augment birdseed and nuts with beef fat trimmings, bacon rinds, apples, grapes, potatoes, peas. And, cheese, as this bird is eating. You can also offer moistened pet food. Don’t allow foods to spoil and don’t leave leftovers out overnight if you want to avoid unwanted nocturnal critters. Be sure to grate or cut food into tiny pieces. No junk food!
Have you heard the one about the drunk bird? It sounds like a joke’s coming next, but there really are birds that get drunk from eating too many fermenting berries. That seems funny; only sometimes, it isn’t.
Like many DUI drivers, “FUI” birds are just too drunk to fly right, and many die from crashing into things. They also behave like inebriated humans in other ways: They walk in circles, topple over, lean against things for support or bring their wings to the ground to hold themselves upright. They vomit. And, they probably suffer morning-after headaches, too! Here’s a good story about a drunk Cedar Waxwing, including useful tips about how to care for an intoxicated bird, and lots of good photos, too.
Where did they go? Why do birds sometimes disappear (or mostly so) from our feeders? Well, it’s because nothing beats fresh food, like berries on a bush and seeds still clinging to flower heads. So even in winter, the number of visitors at feeders may be low as long as fresh foods are available. No matter how elaborate and well-filled our feeders may be, birds may scarcely give them a glance when there’s plenty of food available at its natural source.
Sleeping and resting
Where do birds go to sleep? Usually, they go where they’ll feel safest within the same area they spend their waking hours. Some that nest on the ground also sleep there in dense cover. Others sleep hidden in trees, where they can feel the vibrations of climbing predators in time to escape. Cavity-nesting birds sleep in tree holes, chimneys or birdhouses. Many water birds sleep on or close to water.
Some birds sleep while standing on both legs or, like Flamingos and other water birds, on one leg. Why just one leg (especially in winter)? Theories abound, but a commonly accepted one is that it conserves body heat. A bird’s legs receive three times as much blood per heartbeat than their major muscles do. So, that’s a lot of warmth they can hold close to their body.
Some birds are thought to take short naps while flying. Laysan Albatrosses spend almost their entire lives in flight, and that includes sleeping up there, too. Another example is Swifts, which mate, eat, and bathe while flying, and likely sleep up there, as radar planes have detected them several thousands of feet high at night.
Birds must stay alert to survive, so how do they get any rest? They do it in short bits—sometimes only a few seconds long—whether napping by day or settling in for the night. Some switch between sleep and drowsing with their eyes half-closed so they can still see. Some birds that migrate long stretches rest in flight by allowing half their brain to sleep, while the other half keeps its eye open to stay alert—and aloft!
Singing, calling, behavior
Most diurnal (daytime) birds sing only when the sun’s up. But British researchers studying city-dwelling European Robins discovered they’re singing at night. Scientists have long thought streetlights confuse birds into thinking it’s daytime, but it turns out that noise has a more significant impact. As the daytime noise level in cities rises, the number of birds singing at night increases. It seems the birds are trying to be heard.
Birds sing and call for many reasons: To define territory, attract mates, warn of predators, stay in touch with one another, announce the finding of food or to beg to be fed. Tiny Winter Wrens sing at ten times the power of a crowing rooster. Brown Thrashers may know more than 1,100 distinct songs. The male Western Sandpiper sings while performing courtship-display flying. The single Red-eyed Vireo sings up to twenty thousand songs a day!
Birds sing more in the early morning and at dusk. There’s an important reason: That’s when the air is typically still, and the way it carries sound waves makes them clearer. There are also fewer competing background noises. Even birds that are heard singing during the day will tend to sing more at dawn and dusk.
Do birds abandon their babies if we touch them? Experts say no—once eggs have hatched, the parents’ drive to nurture their offspring outweighs their fear of human scent. Unless the nest is repeatedly disturbed, that is. So, if you’re watching nestlings, it’s best to peek at them only when the parents are away.
Do you see frenzied activity at your bird feeders before a storm? That’s because birds have a special receptor in their middle ear telling them to hurry up and take shelter. Called the Vitali organ or Paratympanic organ, it helps with their hearing and balance, but it’s also a built-in barometer. When air pressure starts falling, signaling a storm ahead, birds change their foraging patterns, social interactions, and times of activity. As for mammals, bats are the only ones with a Vitali organ (named after its discoverer, Giovanni Vitali, an anatomist). Although we humans can detect some pressure changes, birds can do it to a remarkable extent.
We’ve all seen birds perched like this, sometimes by the hundreds. Scientists think they do it because overhead lines are good resting places and offer a good view. Sitting close together also makes for easy communication. Have you noticed that, too, that except for the occasional nonconformist, they sit facing the same direction? They face the wind, probably because sitting with their backs to it would ruffle their feathers, and it’s also easier for them to take off into the wind.
Different birds have different “domestic” lifestyles. Some pair up only through the current nesting season. Some are polygamous and mate with several partners to ensure they spread their genes around. Others are monogamous and stay together until one dies. The health of its mate is important to a bird, and some species may part company if one becomes frail. Blue Jays, Barn Owls, Bald Eagles, Canada Geese, and Pileated Woodpeckers are some of the birds that mate for life.
Birds cool off by evaporating moisture through their skin and by panting. A study of desert birds shows that a summer temperature rise of just 2°F above normal can double the rate of water loss in small birds. Excessive water loss increases a bird’s body temperature and can lead to heat stroke and death. Unusual mass bird deaths have been reported across the United States in ultra-hot summers.
Anatomy, feathers, grooming
“Just washed my feathers and can’t do a thing with ’em.” Many birds bath regularly, even in winter! They do it to keep their feathers clean, wash off parasites, and cool their bodies on hot days. After bathing, they use their beaks to coat their feathers with a waterproof oil from a gland located under their tail feathers.
Some owls have long feathers sticking up on their ears. Called ear tufts, they make the shape of the owl’s head look distinctively different from the usual, but have nothing to do with the ears or hearing. Scientists think ear tufts are used for subtle communication, signaling, or recognition. About fifty species of owls have them.
Birds and other wildlife suffer in winter if they don’t have access to water—it can be more vital than food. This Mourning Dove looks like it needed a long, satisfying drink, but what it found was ice. A birdbath with a heater can change that by giving birds access to liquid water when it’s freezing outside. (Heated birdbaths placed close to the ground will give all animals a drink—but thread the electric cord through a PVC pipe to keep it protected from chewing rodents.
When snow covers the ground, how do birds find food? Ground-feeding birds look for bare spots and mine them thoroughly for seeds and insects. Birds also explore crevices in woodpiles and rock piles, and cling to old flowers and pick at the heads. If necessary, they try to scratch through the snow. Their situation can grow dire when snow is deep and long-lasting.
No, this woodpecker isn’t dead! He’s crouched down, trying to eat snow. It’s a struggle for birds to find liquid water when everything’s frozen. Covered with layers of fluffy, insulating down, they’re pretty prepared for winter’s cold temperatures. But finding water and fatty foods for energy—and plenty of it—is key to their survival. Small birds can’t peck through frozen ground and ice. Birds’ ability to fly farther south helps them out, and we sometimes see unexpected species at our feeders.
Birds and cats don’t mix
Are cats poaching at your bird feeders? Place feeders in the open, away from shrubs and other hiding places. You can also try putting a wide circle of short wire fencing around feeders. That works well, even when feeders are near shrubs: By placing the fencing just in front of the shrubs, cats may hide, but must jump over the fence to get at the birds, which rustles the foliage and alerts them.
Cats can hide very well—sometimes by remaining motionless in plain sight. Millions of birds are killed each year by cats that have a good home and plenty of food, but they’re just doing what cats do. Hanging a bell on its collar doesn’t help—a stalking cat moves too slowly for it to ring, and when he pounces, the ringing comes too late.
If a neighbor’s cat is a problem, the solution may be as simple as asking them to keep their cat indoors. It’s not only safer for birds, but for cats, too: Cats who go outdoors have shorter lives, falling prey to cars, dogs, coyotes, and other animals, and diseases, such as feline distemper. They can get lost, stolen, or poisoned.