A Wildlife Tip Sheet from Jacobi Jayne & Company
by ornithologists Chris Mead and David Tomlinson
Magpies are the birds that everyone loves to hate. It is difficult to find anyone who has a good word to say about these handsome rogues: in many peoples' eyes, magpies are the avian equivalents of the football hooligan. Once regarded with superstitious awe, today the unfortunate magpie has become an object of hate. It is not unusual to hear mild-mannered old ladies insisting that magpies should be shot, or to read indignant letters in papers, suggesting that the Royal Society of the Protection of Birds (RSPB) should do something about magpies.
Short of supplying its million members with shotguns, there is little the RSPB can do about them. Alas, there is not a lot the private individual with a small, magpie-ravaged garden can do, either. Magpies are instinctive killers, and in the breeding season they will systematically hunt hedgerows and gardens in search of eggs and nestlings to feed their young. There are few more upsetting sights than watching a magpie killing defenceless young thrushes or blackbirds.
Quite how much impact magpies have on garden-bird populations is debatable, as no detailed research has been done. It is often argued that magpies have little or no affect on the overall population, as the young birds they kill would die of other causes anyway. However, it can also be argued that garden birds face so many threats that magpies are one they could well do without.
Part of the problem with magpies, and the reason for their current unpopularity, is their huge increase in numbers over the last 30 years. Numbers have tripled, and they now occur commonly in areas where they were once absent. There are a number of reasons for this. One of the most significant has been the decline in traditional gamekeeping. Modern keepers are more concerned with rearing and releasing pheasants than controlling so-called vermin, so magpies are allowed to flourish in areas where once they would have been shot.
Historical confirmation of this fact comes from Simon Holloway, author of The Historical Atlas of Breeding Birds in Britain and Ireland. A century ago, the magpie "endured systematic and concerted persecution at the hands of many people that resulted in a dramatic reduction of the population in Britain. The reduction in numbers was so severe that late 19th century writers were contemplating its extinction in some areas."
Surprisingly, the car, rather than the gamekeeper, may well be the real reason behind the magpie's recent population explosion. Until relatively recently, numbers were probably kept in check by lack of food during the winter and early spring. (During the winter months the magpie's diet is mainly a mixture of vegetable matter and invertebrates.) The increase in the number of cars on the roads has led to a corresponding increase in wildlife road casualties, something the scavenging magpie appreciates. It is this new abundance of food that has allowed magpie numbers to grow so quickly.
Magpies are among the most intelligent of birds, so are quick to make use of new food supplies, such as car kills. What's more, they are adept at avoiding being run over themselves. Small numbers of young magpies may be killed by cars, but relatively few adults meet such an end.
Magpies may be shot or trapped legally under general licence, but for most of us, these two methods are impractical. Though magpies may become tame and confiding in certain areas, they are quick to disappear at the sight of a gun, and are notoriously difficult to shoot.
Trapping is the most effective way of controlling numbers, and the most successful method is live-trapping with a Larsen trap. The Larsen is a cage with two compartments, each with a spring door. One compartment holds the decoy bird, the second has its door held open by a split perch. In order to enter the trap, a magpie will invariably drop onto the perch, which then gives way, and the door springs shut.
The Larsen trap was developed in Denmark, and many thousands are in use in Britain today. Catching the decoy magpie can be the biggest problem - it is illegal to buy live, wild-caught magpies for traps. Once you have a call bird, it must be provided with food, clean water and shelter, and similar provisions must be made for any birds that are caught. As with all live traps, it is essential that it is checked at least twice a day.
It is not unusual for a Larsen trap to catch as many as 20 or 30 birds in a season, from April through to July. Quite how much impact this has on the local magpie population depends on the area you are in. If your neighbours are also controlling magpies, then it is possible to make a significant reduction in the local population. If, on the other hand, no-one else in your area is doing so, then you are simply creating a vacuum that magpies from the surrounding countryside will soon fill. The Game Conservancy Ltd (Fordingbridge, Hampshire SP6 1EF, tel: 01425 651003) produces an excellent leaflet on hints for using Larsen traps, and also supplies the traps themselves. The cost for a lightweight model is around £60. The use of Larsen traps is approved by the RSPB, which uses Larsens on some of its reserves.
If you are not in a position to trap or shoot magpies, then the best way to help the survival of the small birds in your garden is with the provision of good habitat. The greater the number of potential sites there are, then the more successful nesting attempts there are likely to be.
This may be difficult if you only have a small garden. It is a good idea to encourage birds to nest in places that are not vulnerable to the marauding magpie. How about leaving a shed window ajar? Robins, wrens, blackbirds and song thrushes will often nest inside, where they will appreciate the relative security. Magpies are unlikely to follow them in. If you do have a vulnerable open nest, then it is possible to protect it with an enveloping ball of wire netting. Use a mesh size that will let in the nesting bird, but exclude the magpie. If you erect open nesting boxes, then defend them with wire as soon as you put them up. Better still, use the Schwegler nest box that is designed to get the bird nesting in an enclosed space that the magpie cannot reach.
In some areas, magpies may even attack free-flying adult birds, not just defenceless nestlings. This is quite unusual, and the best solution is shooting the culprits, so long as this can be done safely by an expert.
If you feel that your garden feeding is attracting too many unwanted magpies, the secret is to feed within a wire-netting cage with a mesh size that excludes the magpies. It is easy to protect a bird-table in this way, and to feed on the ground inside a movable 'ark' (as used for poultry). Fortunately, it is rare to have problems with magpies taking food from hanging feeders.
Research by the British Trust for Ornithology has not, so far, revealed any connection between the increase in magpies and the overall decline in song birds. However, the Allerton Project, run by the Game Conservancy Trust, has shown a marked increase in nesting success by song thrushes, blackbirds and chaffinches on the 824-acre Loddington Estate in Leicestershire. Here magpies (and crows) are controlled, using Larsen Traps.
Chris Mead and David Tomlinson
Magpie Facts & Useful References
- Magpies occur throughout the British Isles, but are absent from the Highlands, and almost all the Scottish Islands.
- Experts believe that there are more than 600,000 magpie territories in Britain.
- Magpies were absent from Ireland until the end of the 17th century. There are now an estimated 320,000 territories there.
- The magpie is a cosmopolitan bird, its range extending from Portugal to Korea. It also occurs in North Africa, and in parts of western USA and Canada.
- In some areas in Europe, large numbers of magpies are killed by goshawks.
- In southern Europe, great spotted cuckoos lay their eggs in magpie nests, and reduce the magpies' breeding success.
- It takes a pair of magpies around 40 days to build their large, domed nest.
- A typical magpie clutch is six eggs.
- Only the female magpie incubates the eggs - it takes 24 days for them to hatch.
- Young magpies leave the nest around 27 days after hatching.
- Magpies are omnivorous, eating a wide variety of food, ranging from grain and fruit to carrion.
- Magpies have been recorded catching and killing frogs, lizards, snakes, bats, mice, voles and even rabbits, as well as small birds.
- Magpies will cache surplus food during times of plenty.
- The Magpies, by T.R.Birkhead (Poyser, 1991) is a detailed monograph about the magpie's biology.