Some readers have contacted me to try and explain why they have suddenly been inundated with crows invading their gardens, often in large numbers. “Crows” mean members of the “Corvid” family and covers four very common birds, namely rooks, carrion crows, hooded crows and jackdaws. The odd ones out of these are the carrion crows and hooded crows as for a very long time they were thought to be a variation of the same bird. Now it has been finalised that they are two different types of birds. However, a further complication is that where their ranges overlap they freely hybridise The carrion crows base is to the east of Inverness going right over to the east coast. The hooded crows base is to the west from Inverness and extending to the west coast and into the Outer Isles. Where they overlap, on a broad zone based north and south of Inverness, they freely hybridise and you can get all sorts of variations in the amount of black or grey feathering.
These are the three crows that cause the main problems in the gardens namely the rook, jackdaw and hooded/carrion crow, the latter depending where you live. The problem seems to be the lack of food on farmland at this time of the year. The biggest culprits are the rooks and jackdaws and once they start visiting gardens for food there seems little to stop them. What tends to happen in my garden is that once any food has been put out the ever present jackdaws start calling and it is as if they just attract large numbers of jackdaws and rooks from afar. The main problems are just the amount of food they take and how aggressive they are to other birds. At first the birds just ate large amounts of mixed grain put out for various birds from chaffinches to robins and yellowhammers to blackbirds. Many of these birds are now actively feeding young that hop around begging for food from the adults. The grain can be on the ground or on the bird table, it makes little difference to the crows.
Recently these crows have changed their tactics and, as I cut down on the amount of grain, they have started going for the other food. One favourite is the suet balls in a special feeder and they just cling to the side and peck away. They will also go for the peanut holders and to see jackdaws or rooks clinging to the side trying to get at the nuts is almost comical with the antics they get up to. The main problem is not the aggression to other birds but the sheer amount of food they are taking. Bills for such a mixture of feed is bad enough without the wholesale plundering by these large numbers of crows. The only answer would seem to be to cut out the use of the mixed grain altogether but the worry is what this would do to the other smaller birds.
The books indicate it is easy to identify these crows and to a certain extent this is true. The photograph for example, taken in my garden, shows the much larger rook and a jackdaw feeding together and the differences are readily apparent. There is obviously no problem with the hooded crow with the varied combination of grey and black feathering. The problem lies in the carrion crows and immature rooks, particularly at this time of the year as with the absence of white at the base of the beak on the rook confusion can arise.
Tags: highland wildlife