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Wild Birds and Domesticated Cats

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Cat with bird in its mouth coming through cat flap.

Cats are remarkable animals and must be one of nature's most efficient designs. The domesticated cat could probably survive very well without humanity even after thousands of years living in intimate contact with our species. They may be fond of their humans but they're still independent - wild at heart. This is one of the many excellent qualities their human companions admire about them. A great many people adore cats and are, no doubt, amply rewarded for all their love and affection. Long may this relationship continue.

However, there is a quiet massacre taking place in Britain and other countries where cats have been introduced. The RSPB (Royal Society for the Protection of Birds) conservatively estimates that there are around 9,000,000 cats in this country and they kill in the region of 275,000,000 small animals each year. That figure of 275 million includes 55 million birds. That only works out at about 30 kills per cat per year. As many cat owners will testify, their cat may make two or three kills per day if it's a very good hunter. These numbers are astounding! It's difficult for people to visualise or otherwise comprehend just one million. The entire human population of Britain is less than 60 million and yet cats manage to kill almost that many birds in Britain alone, every year. Wow!

In a state of nature there is balance between the predator and the prey. This balance is completely non-existent in the case of domestic cats and their prey. Nature may be harsh from the point of view of the individual, but this balance is healthy for both predatory and prey species. If the number of prey animals falls, then the size of the predator population that depends on them will also diminish. The opposite happens when prey species numbers increase. However, because domestic cats do not depend on their prey for their own survival, prey species can fall to levels where the species is unable to recover and the number of cats continues to increase.

Almost all bird species and many small mammal and reptile species are in serious decline for a whole variety or reasons such as farming methods (using pesticides, mechanisation, ripping out trees and hedges, filling in ponds, draining wetlands) and loss of habitat (deforestation, building of houses, factories, supermarkets roads etc). It is unfair to blame cats for the problem when the causes are almost entirely human generated - even the cat problem is human generated.

How Cat Owners Can Help

Cat owners can help though, if they have the will. There are many ways they can help:

  • They could put a bell on their cat's collar. These may seem not to work because they don't jingle very much. Nevertheless, research by Glasgow University suggests bells on the collars of cats, reduce the number of kills made by as much as 50%. Even if the bell only jingles a bit as the cat launches itself for the kill, this gives the victim some small warning and provides a slim but significant chance of escape.

  • Birds are particularly vulnerable to cat attacks at dawn and dusk and especially between March and July. The RSPB suggests that cats should be kept indoors at these times.

  • There is some evidence to suggest that well-fed cats are somewhat more inclined to stay close to home and less inclined to hunt - or at least they don't hunt with so much determination.

  • Both the British RSPCA (Royal Society for the Prevention of Cruelty to Animals) and the New Zealand SPCA, promote a policy of neutering cats. The purpose of this policy is not just to help endangered indigenous species, though this is obviously a major consideration - it is also to benefit the cats. Because there are so many more cats than people willing or able to offer them homes, many towns have large feral cat populations. These cats are often poor pathetic creatures: diseased, malnourished and easy prey for the more cruel elements of humanity. Some cat owners may think it unkind to have their pet neutered. There is a commonly held belief that a cat should have at least one litter of kittens before being neutered. This belief is baseless. The result of this kind of thinking is that people who love cats often end up with more than they ever really wanted or are able to cope with and the rest of the cats that are 'surplus to requirements' have to face a harsh existence on the streets, posing a threat not only to wildlife, but to the more fortunate pet cats who can be attacked by them and catch diseases from them.

  • Another thing that many people who have cats may not have considered is feeding their garden birds (see below for tips on doing this). At first thought, it seems a cruel or insane idea to feed the birds in your garden when you have a cat. In fact, RSPB research indicates that well fed birds are far less likely to fall victim to cat predation. This is probably because they are not forced to search for scarce food on the ground.

Bird Feeding Tips for Cat Owners

There are several ways of feeding birds but not all are suitable for gardens with cats. It's not a good idea to scatter food on the ground or on bird tables where a fair amount of it will fall to the ground. It's not a good idea to site feeders near to cover where cats can lurk in wait or sneak up on the birds unnoticed. Birds do, however, like to feed within about 20 metres or so of trees and hedges, where they can quickly seek safety if threatened by predators.

There are two types of feeding device that are suitable for a cat's garden: the peanut feeder and the seed feeder.

The peanut feeder is a wire basket or tube. The gauge of the mesh is important: it has to be small enough not to allow a whole peanut through1, but big enough not to damage the birds' beaks. Most reputable bird food suppliers' feeders are of the correct gauge. Because the gauge is smaller than the peanuts, food doesn't spill out, so peanut feeders don't need to be fitted with a tray. Peanut feeders attract finches, tits, nuthatches, woodpeckers, sparrows and starlings.

The seed feeder is a clear, polycarbonate tube with top, bottom and feeding ports made of either plastic or metal. Metal ones are more expensive because they're squirrel-proof and can have accessories attached to their bases, such as trays, poles and hooks. Seed feeders, depending on the seed they contain, attract finches, tits and sparrows. Seed feeders are not suitable for peanuts because they tend to go mouldy rather quickly in the damp atmosphere of the polycarbonate tube. They are suitable for sunflower seeds and mixed seeds. The best kind of mixed seeds are the 'no-mess' varieties that contain a high proportion of sunflower hearts. Some of the cheaper mixes contain lots of wheat, split peas and corn which the birds just sling out of the way in their search for the seeds they actually like and are able to eat, such as sunflower seeds, hemp and millet. Even with a tray attached, the cheaper mixes will eventually result in wheat and corn hitting the ground where the pigeons and doves will try to eat it, just before the cat ambushes them.

Both types come in various sizes with capacities ranging from 200 grams to 4 kilograms. Prices (at time of writing) range from £3 to round about £40. If you just have a very small garden with, say, a washing line where you could hang a feeder, a small £3 wire basket would be quite adequate, provided the line is high enough and far enough from any feline launch pads, like walls and shed-roofs. (One enterprising cat owner reported that she had sited her nut feeder on a washing line, above a dense, woody shrub where her cat couldn't get close.) If the garden is bigger and you would like to provide more food and variety, you will need feeders that can be mounted on poles and, in the case of seed feeders, can have a tray attached. Small, tube, peanut and seed feeders that are pole mountable, cost about £7. They're sturdy, can be disassembled for washing and should last for years. Some are guaranteed for the purchaser's life-time.

The trays that should be attached to the bases of seed feeders cost about £5 to £9, depending on size. Some are very big and can be used like bird tables. These catch any seed spilled from the feeders so that the birds are not tempted to feed from the ground. They can feed in safety from the tray.

Poles cost £9 to £10, come in three or four sections and have a spike on one end so that they can be driven into the ground. You can buy extra sections for about £3. If you have a patio, you can buy a base for about £12, to stand the pole in. You can also buy pole hooks to attach to the poles to hang additional feeders so there's one feeder mounted at the top of the pole and up to four hanging from hooks attached to the pole.

Feeders should be washed from time to time, and any food that has remained uneaten for two or three weeks - especially peanuts, which can go mouldy - should be changed. It's a good idea to start by half-filling the feeders until the birds find them and get sufficient confidence to use them. That can take a week or two if there's a high cat population in the area.

Some Ugly Statistics

Here are some chilling facts to underline the need to do everything we can in order to help our wild birds. There are currently 36 bird species 'Red Listed' in the UK. This means that their numbers have declined by 50% or more during the course of the last 25 years. The well-loved Song Thrush is on that conservation red list. The Tree Sparrow population has declined by 90% in the last 25 years. Even the 'common' Starling's numbers have plummeted in recent years.


Cats would probably not cause any great problem to large, healthy bird populations, but when birds have so many other hardships to overcome, the impact of cats can be significant.

Awareness of the importance of biodiversity and concern about species extinctions is growing in Britain. It's estimated that, worldwide, three species of plant and animals are lost every single day. The loss of species of flightless birds in countries like New Zealand is even more worrying. These birds have very little chance of escape once they've been spotted by a cat. It won't help to mount feeders on poles for birds that have lost the ability to fly as a result of millennia without any serious predators. New Zealand's Forest and Bird Society recommends that cats should be kept indoors at night because cats catch more birds at dusk and dawn. Cats should be fed regular, balanced meals and provided with toys. They say proper provision should be made for the cats' care (and, by implication, control) when cat owners go on holiday. This advice also seems appropriate for cat owners anywhere else in the world, including Britain.

A small effort on the part of a large number of cat owners could make a real difference to the survival chances of our beautiful, feathered friends and, ultimately, benefit the cats.

1Birds can be a bit daft, like some human parents. If they feed a whole peanut to a chick, it might easily choke.

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