Spring brings a feeling of hope and promise which is almost tangible when you watch the vigour with which the local wildlife gets stuck into the new breeding season.
And yet there is one bird, ironically the very bird that is considered the true harbinger of spring, whose breeding habits undermine the promise of new beginnings.
The call of the cuckoo is said to be a sure sign that warmer days are on their way.
But this bird is notoriously parasitic, finding foster nests for its eggs and tricking other birds into raising its chicks.
Favourite hosts include meadow pipits, dunnocks, pied wagtails and reed warblers.
Remarkably, different female cuckoos will target different species. One will focus on tricking dunnocks each year and lay matching bright blue eggs.
Another will lay green-ey blue eggs, speckled with brown - a perfect match to trick the reed warbler.
Like a burglar staking out a potential hit, the female will carry out lengthy and detailed investigations into the comings and goings of her chosen ‘host' species.
I once watched a female whose speciality was a reed warbler's nest. She flew down into the reed beds to search out their hidden nest sites several times before making her move.
Timing is of course essential for a successful deception. To avoid detection, the cuckoo needs to remove an egg from her host's nest and lay her own matching egg, all without arousing suspicion.
I found the nest that this cuckoo had chosen and in it was the egg she laid: a perfect match, just fractionally larger than the others.
I was lucky enough to see the chick shortly after it had hatched, in true style well before the others.
I put up a hide six feet away so that I could watch what happened. An unusually large chick, its instincts kicked in immediately. Though still blind, it set about using its specially hollowed back to flip its competitors overboard into the boggy water below.
There would not be enough food or space for anyone else.
The duped foster parents then cared for the cuckoo chick, assuming it to be their own, and put in an extraordinary 16 hours a day to raise it.
The cuckoo chick has a special tactic to drive its adopted parents on. Rapid shrilling calls trick its surrogate parents into thinking their nest contains a whole brood of chicks and their instinct to feed these young is unstoppable.
Cuckoo chicks leave the nest after three weeks of birth and are fed by their surrogate parents for a further two weeks outside the nest.
Three weeks after that the clumsy chick will follow its true cuckoo parents on their 3,000 mile migration to Africa .
Reed warblers normally have two broods of four or five chicks per year. But will only be able to raise one cuckoo chick in that time.
Cuckoos are nature's favourite cheats and also one of our shortest visiting migratory birds as they leave our shores in August. For reed warblers, at least, it is maybe just as well.
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Wildlife Diary -
