There are four general ways in which birds drink.
Most birds are unable to swallow by the "sucking" or "pumping" action
of peristalsis in their esophagus (as humans do), and drink by repeatedly raising their heads
after filling their mouths to allow the liquid to flow by gravity, a method usually described as "sipping" or
"tipping up". The notable exception is the Columbiformes; in fact, according to Konrad Lorenz in
- "one recognizes the order by the single behavioral characteristic, namely that in
drinking the water is pumped up by peristalsis of the esophagus which occurs without exception within the
order. The only other group, however, which shows the same behavior, the Pteroclidae, is placed near the doves just by this doubtlessly very
Although this general rule still stands, since that time, observations have been made of a
few exceptions in both directions.,
In addition, specialized nectar feeders like sunbirds (Nectariniidae) and
hummingbirds (Trochilidae) drink by using protrusible
grooved or trough-like tongues, and parrots (Psittacidae)
lap up water.
Many seabirds have glands near the eyes that allow them to drink seawater. Excess salt is
eliminated from the nostrils. Many desert birds get the water that they need entirely from their food.
The elimination of nitrogenous wastes as uric acid reduces
the physiological demand for water.
Birds have a four-chambered heart, in common with humans, most mammals, and some reptiles (namely the crocodilia). This adaptation allows for an efficient nutrient and oxygen
transport throughout the body, providing birds with energy to fly and maintain high levels of activity. A
Ruby-throated Hummingbird's heart beats up to 1200 times per
minute (about 20 beats per second).
(Click on image to enlarge)