Of all the predators in the Highlands, the ones that do more damage to small prey across a wide range of wildlife are the crows. This means the carrion crow and the hooded crow that occupy different ranges in the Highlands. The hooded crow is essentially a western bird and that includes the Western and the Northern Isles. It has a black head, wings and tail with a pinkish grey body. In contrast the carrion crow is found to the east and they are all black with a very slightly bluish sheen. What is interesting is that in a line from just north of Inverness and south down the Great Glen there is a hybrid zone where both hooded and carrion crow interbreed. The offspring are fertile and this gives rise to varying amounts of grey feathers on some birds. In some cases there are just a few patches of grey feathers and the bird looks rather incongruous.
Part of the reputation of these crows is how cautious and clever they are. For example, if you want to use a hide to photograph them the normal routine just does not work. With other birds the photographer will take a companion to the hide, slip inside and then one person goes off whilst the photographer stays inside to take the photographs. The bird is fooled into thinking the danger has past. With both the hooded crow and the carrion crow you need to take three people to the hide and two walk away before the bird will accept that the danger has gone.
Both the crows will take a very wide range of prey and one of their specialties is the eggs or chicks of ground nesting birds such as the waders and smaller birds. Lapwings, oystercatchers, snipe, redshank and even the larger curlew will fall prey of them. They have developed a routine to take this prey as one bird will distract a sitting bird away from the nest, then the other bird slips in and helps itself to the eggs or chicks. The camouflage of the eggs does not fool them and not even the camouflage of the chicks when they have left the nest. The chick camouflage is clever as it relies on the birds just looking like two pebbles. This is achieved by wader chicks having dark feathers all over but with a pale line of feathers around the neck. These light feathers means the two parts of the chick, the head and the body look like two separate pebbles so that most predators are fooled – but not the carrion and hooded crows!
The very wide range of food that both these birds will take is also part of their success. They will scavenge along the seashore and such was the case last week with a pair I saw on Nairn harbour/beach. They were two typical hooded crows and had spent some time along the shore picking at various dead prey from crabs to limpets. Then they came to rest on the seawall where I took the photograph from a distance of about six yards and they were completely unconcerned. Typical hooded crows with the pinkish grey feathers very conspicuous. In contrast they will patrol the high tops of the Cairngorms searching for ptarmigan eggs or chicks or they will pick at a dead salmon along riversides. Watching them scavenge along roadsides for casualties is almost an art form. One worrying aspect is that they are now invading gardens, even small ones, and they can do a great of harm to nesting birds and their eggs/chicks. These crows produce emotive thoughts from such people as farmers and gamekeepers and yet despite the constant “war” against them they continue to flourish and their future seems more than assured.
Tags: highland birds