The first osprey eggs are expected to hatch in the coming days - with one set of parents having a relationship that would be frowned upon if they were human.
This year's chicks could start hatching as soon as Tuesday. However, cooler weather in recent weeks mean that it's not certain, with Joanna Dailey, Kielder osprey observer saying that there is not an "exact science" to knowing when they hatch.
The birds of prey, which return to nest and mate at Kielder in Northumberland after wintering in warmer climes, tend to mate for life, but if one's partner dies, they will mate with a new one. And one of this year's mating pairs, who have already produced an egg, are mother and son.
