THE marina where I keep my boat is owned by a pair of magpies. At least, they seem convinced they are the proprietors of the harbour and a certain amount of the surrounding land. They hop confidently on and off the boats and jetties searching along the water’s edge for dead fish or anything else edible.
When parents bring their children down to feed the ducks, and swans, the magpies are in attendance to pick up any dropped crumbs. Of course the swan family – mother, father and five adolescent cygnets – are also convinced they own the marina and a considerable stretch of the river on each side of it. But this doesn’t worry the magpies because the vegetarian swans offer no real competition.
However, it does worry me slightly because when I paddle out in my canoe the male swan attacks me. It has never pressed home an attack and I don’t believe it would – swans are bluffers. But it’s more than capable of capsising my little craft so I don’t like turning my back on it when it’s in an aggressive mood.
The one real problem the magpies face is a pair of hooded crows. These birds, normally called grey crows in rural Ireland, are closely related to magpies and, although they have larger territories, they eat similar things.
The natural diet of both species consists of things such as earthworms, beetles and slugs. But they are also great eaters of carrion, filling the niche occupied by vultures in many other parts of the world.
Early in the morning they will fly along roads, looking for animals that have been run over during the night and they will search shorelines for victims of drowning or fish that have not survived an angler’s keep-net. Also, and controversially, both species rob eggs and young from other bird’s nests during the breeding season.
So the grey crows are in direct competition with the magpies for the rich pickings around the marina and there is continual tension – a sort of phoney war. The larger crows have the upper hand and they repeatedly demonstrate this by mounting surprise attacks on the magpies.
They dive out of the sky while the magpies are on the ground. The attack never results in bloodshed but does cause a huge loss of dignity to the magpie which has been singled out. It makes a wild dash for cover then re-emerges, twitching with anger and grumbling loudly for several minutes.
The effect of nest predation by both species is a controversial topic. There are studies which show no significant impact on populations of song birds and ground nesting birds, and others which show the complete opposite. Many bird conservation bodies prefer the ones that exonerate the crows and magpies. Other ornithologists are not so sure.
You really have to take your pick.
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