WATCHING OWLS
Most birdwatchers see owls on daytime roost or nest site known locally. However, owls can be fruitfully found and observed independently. There is no need to disturb the same known birds, and casual encounters at night can be identified.
DAYTIME OBSERVATIONS
Most owls roost during day, camouflaged, in tree hollow, rock crack, dense tree foliage, or pressed against tree trunk. The perch is usually hidden from above. Be very careful not to disturb them. Especially nests are easily abandoned or predated by corvids when parent owls are scared. Keep distance, be quiet and move calmly. A roosting owl may stay immobile, but sees well at daytime.
Roosts are sometimes discovered by alarm of songbirds or corvids – check such unexpected noise. One can also narrow down a place where owls are heard at night. Old, possibly hollow tree or a patch of dense conifers are good candidates to scan patiently from distance to locate a camouflaged owl. Search for guano and pellets – balls of fur and bones spat out by owls (and many other birds). Owl species can be identified from pellet. Zoologists studying small mammal fauna often check bones in pellets.
NIGHT WALKS
Best chance of success is, however, finding owls at sunset by calls. Be aware of variation of calls of each species. Remember also that owl at night is usually afraid of man. Easiest to watch are grown chicks after leaving the nest in late spring or summer. They are not shy and often call continuously from before the sunset. However, keep observations short as adults will stop feeding chicks in human presence. When using a lamp, shine to the side and bring it slowly to the perching owl. This makes it less likely to flush. Avoid shining at your fingers or any part of human body. Keep noise to minimum, especially don't talk and stay away from shuffling on dry leaves or bushes.
CASUAL OBSERVATIONS
During casual observation of an owl in darkness, note at least size, shape of head and wings and mode of flight. Try seeing at least eye color, barring, and basic wing pattern. Note that owl in bright light can look surprisingly pale with distorted contrasts.
Day birds flushed at night have slow, cautious flight and can be mistaken for an owl, eg. Buzzard for a large species or Lapwing for a small owl. Coots, rails, woodcock, many other waders, ducks, herons and nightjars are frequently active at night. They and their calls, as well as sounds of martens, foxes and deer can be mistaken for an owl.
WARNING:
Some owls, especially Hawk and Ural Owls, dangerously attack man near nest or grown chicks. They can fly noiselessly and hit the head or face with talons. Keep eyes fixed on parents and don't prolong observations. Also, usual caution against getting lost or tripping over at night is helpful.