Scops owls are colored in various brownish hues, sometimes with a lighter underside and/or face, which helps to camouflage them against the bark of trees.

For most of the 20th century, this genus included the American screech owls, which are now again separated in Megascops based on a range of behavioral, biogeographical, morphological and DNA sequence data.

In 1988 it was attempted to resolve this by re-establishing all those genera split some 140 years earlier at subgenus rank inside Otus.

[8] Still, the diversity and distinctness of the group failed to come together in a good evolutionary and phylogenetic picture, and it was not until the availability of DNA sequence data that this could be resolved.

In 1999, a preliminary study of mtDNA cytochrome b across a wide range of owls found that even the treatment as subgenera was probably unsustainable and suggested that most of the genera proposed around 1850 should be accepted.

What is certain is that they are very closely related; they may be considered sister lineages which fill essentially the same ecological niche in their allopatric ranges.

A screech-owl fossil from the Late Pliocene of Kansas[18] – which is almost identical to eastern and western screech owls – indicate a long-standing presence of these birds in the Americas, while coeval scops owl fossils very similar to the Eurasian scops-owl have been found at S'Onix on the Spanish island Majorca.

Note that there is no reliable estimate of divergence time, as Otus and Megascops are osteologically very similar, as is to be expected from a group that has apparently conserved its ecomorphology since before its evolutionary radiation.

[9][20] While late 19th-century ornithologists knew little of the variation of these cryptic birds which often live in far-off places, with every new taxon being described a few differences between the Old and New World "scops" owls became more and more prominent.

They also have a kind of song, which is a short sequence of varying calls given by the males when they try to attract females to their nests, or between members of a pair.

They also possess well-developed raptorial claws and a curved bill, both of which are used for tearing their prey into pieces small enough to swallow easily.

Some, like the recently described Serendib scops owl (Otus thilohoffmanni), were discovered because their vocalizations were unfamiliar to experts in birdcalls.