There has been quite a lot in the press about the decline in the Cuckoo population, down 37% over 15 years. This overall UK figure masks what is happening regionally where the Cuckoo is down 55% in the South East but up 37% in Scotland. It would appear that climate change is a factor in its decline in England, though in North West England it is down by a significant 45%. Cuckoos breed right across Europe with the UK at the edge of its range in the North West part of the continent so it should be expected to adapt to a warmer climate in England quite easily. Therefore there must be other reasons. What about the Cuckoo’s host species? The three most common host species are Dunnock, Reed Warbler and Meadow Pipit and all three species are relatively abundant and are unlikely to be the cause of decline in Cuckoo numbers. The Cuckoo’s primary food source is hairy caterpillars and perhaps there is a clue there, I have no idea however on the populations of hairy caterpillars. Perhaps the problem lies in the migration routes and/or wintering areas. Cuckoos winter south of the equator in Africa but exactly where the birds from the UK winter is unknown. The birds are not easily caught as there are no nests. Finding young Cuckoos in host nests is extremely difficult and as a result very few birds are ringed. There has been one recovery to date, and that one being in the Cameroons. Their migration routes are down through central Europe where they feed up along the Med before crossing North Africa and the Sahara in big hop of 3500Km. This fact has been surmised as there are virtually no records of Cuckoos in North Africa. Getting to the bottom of why Cuckoos are in decline is going to be a challenge for any researcher. Now that many birds can have satellite tracking devices fitted, I would think the Cuckoo must be a very obvious future candidate, provided the difficulty of catching one can be overcome!

Last month I mentioned that we had a pair of late Swallows prospecting our watermill site but sadly they did not stay so it looks like another Swallow-free year. However I am pleased to say we had a surprise breeder return to the site after many years absence in the form of a Spotted Flycatcher. This is very welcome news as, like the Cuckoo, the Spotted Flycatcher numbers are significantly down having dropped by 59% since 1994. Until I accidentally flushed it from its nest in an implement shed I was not even aware of its arrival.. The nest already has four eggs. Of the few nests that I have monitored over the years none has been successful so lets hope there is a better outcome this time.

As we are often reminded, small changes in the way we do things can have a profound effect on the bigger environmental picture and this is certainly true for our garden birds. Throughout the summer months young birds will be leaving their nests for the first time. These fledglings are particularly vulnerable during the first few hours of life beyond the nest as they discover and strengthen their wings, doing “circuits and bumps”. Most baby birds leave the nest at dawn or soon after, which in these latitudes is very early, so the simple expedient of keeping our pet cats and dogs confined over night and into the early hours of the morning can tip the balance of survival for hundreds of young birds.