Flying is arduous, particularly for large birds which have less muscle power per unit weight than small birds. However, little birds cannot soar, big birds can.
If any bird stops flapping its wings, it will glide to a lower elevation — unless there is an updraft in the air that counteracts its descent. Then it can stay aloft for hours. After days of rain, some days of sunshine have provided these big birds with thermals. Thermals are large bubbles of buoyant air that rise from the sun-warmed surface. While soaring in a thermal, birds fly in circles so as to stay within the ascending air of the thermal. Below, three birds soar in the thermals of recent days.
Although a passerine, the raven often soars. Its cousin, the crow, only manages it for short stints.
In addition to hunting from a perch, a Red-tailed Hawk often hunts while soaring.
A frequent sight is that of a soaring Bald Eagle. This is a juvenile.
