Cuckoos start to arrive in good numbers in April and in May are at their peak of singing and so at their most noticeable. They are shy birds, much more often heard than seen. It is not that they sing from deep within vegetation, often preferring to use exposed perches on the top of trees or on telegraph poles and lines and along fence lines. It is just that they are very wary of humans. Also, they are, by nature, rather individual birds, usually seen singly, which helps make seeing a Cuckoo a far from everyday occurrence. Many people, even birdwatchers, are not always aware that they have seen a Cuckoo, when one flies by. They look like something between a Kestrel and a skinny dove, whizzing along on flapping wings which don’t appear to rise above the horizontal. Sexes are similar, but there is an uncommon red-morph of the female; like a speckled juvenile but in a glorious rufous colour.