Baby, it’s Cold Outside…

Trying to find enough food to keep going through the cold northern winter is so tough that many of the birds we think of as British don’t even try. They fly off to warmer regions where there is plenty of food, returning in the spring when conditions are more suitable: plants are growing and prey is in abundance.

For those that stay, the battle for survival really begins in earnest in December, by which time the autumn berries are long gone and the temperatures are getting low.  The winter cold forces birds to use up precious food and fat reserves to maintain their high (43°C) body temperature.  It’s no coincidence that the cheery robins on Christmas cards look like feathery tennis balls: they’re doing everything they can to reduce their rate of heat loss, fluffing their feathers to trap warm air next to their skin.

Providing supplementary food and water for your local birds at this difficult time of year can significantly improve their chances of survival.  You have probably heard this before, feeding birds is a popular pastime in Britain with regular campaigns organised by Animal Welfare charities.  There’s even a good chance that you are already be a regular and enthusiastic bird helper.  So, why am I writing about it?  Well, mainly because I think that bird feeding raises some interesting questions about birds and the state of our countryside, which are well worth a closer look.  Questions like:

Surely they can cope?

Think back in time, there haven’t always been humans around to feed the birds.  Any bird that has adapted to survive the winter did so long ago and has been doing fine for hundreds of thousands of years.  Why do they need help now?  The answer is actually in the question.  Humans have made, and continue to make huge changes to the countryside that affect wildlife.  Areas that were originally packed full of natural food are now given over to farmland that only provides food for us, planted with alien trees that don’t provide anything for British animals or covered in concrete.  We have destroyed vast areas of, once suitable, bird habitat in the name of progress.  This destruction continues as we continue to demand cheap food, out of town shopping centres and bigger motorways.

Feeding during the winter can’t be much help, why bother?

We can’t make up for the wholesale destruction of bird habitat such as occurs when hedgerows and woodlands are removed, land is given over to intensive farming, and towns are built.  Nationally, populations of many bird species are declining: starlings, sparrows, nightingales, skylarks… there is a long list of once common birds that are in decline.  We can only hope to reverse these declines if we make big changes to the way we treat the countryside.  In the meantime, there are lots of things we can do to help, and one of them is, you guessed it.  Feeding.  Even in city centres, there are quite large populations of birds and a variety of species do very well.  Sadly, urban areas provide plenty of feeding opportunities during the summer, but not many during the winter.  If you want to see lots of birds during the summer, you need to help out when there’s no natural food around.

If I feed my local birds, wont I be upsetting the balance of nature?

This is a concern for many people.  There is, after all, a chance that your local birds may come to depend on your feeding efforts and would starve if you stopped.  Surely, if the birds were left to fend for themselves,  nature will find its balance?  There have been a number of experiments that have attempted to answer this question.  In rural areas, where feed provided by humans is an easy alternative to naturally available food, it has been found that birds can switch back to natural food without any problem if the humans stop helping.  In urban areas it has been shown that supplemental feeding helps keep the bird population much higher than it would naturally be.  However, remember that the lack of food during the winter in urban areas is the result of human action in the first place.  Careful observation of urban birdfeeders has shown that birds rarely depend on a single feeding station but travel between a number of different feeders within their home range or territory.  This has two advantages: firstly, when you start feeding, it wont take the local birds long to find your feeder and provide you with a wonderful spectacle; secondly, if you stop for any reason, your garden wont suddenly be filled with starving birds, they’ll just switch their attention to another feeder down the road.

How do I start?

If I’ve convinced you to get feeding, great.  This is how you start.  First, you need to think about where you’re going to put your food.  If you’ve got the room (and the cash), a bird table is best as this can be used to serve a variety of food and will keep it off the ground where many birds, quite reasonably given the number of cats that roam the average street, fear to feed.  The best bird tables have a roof – to keep the food dry and are easy to wipe clean, wash and disinfect.  Avoid tables that are overly ornate as these are often difficult to fly onto or fly away from, great for the cats, not so great for birds.  Where you site a bird table is also important.  Birds that have just stuffed themselves full of tasty treats are slower to take to the air than hungry birds, so give them a head start by placing your table in the open – clear of trees and bushes.  This will allow your avian diners see approaching danger before it’s too late.

If a bird table is too big an investment, why not try using a simple peanut feeder or make fatballs (see below) that can easily be hung from trees, washing lines or a simple stand.  Once again, if you’re buying a feeder, try and think like a bird: avoid ornate and fiddly designs that are difficult to fly onto easily and difficult to get away from in a hurry.

What should I feed?

Although birds will eagerly scoff bread scraps, bread is more filling than it is nutritious and there are way better foods.  Try to stick to things with lots of fat in, like nuts and lard.  Different people report varying degrees of success with different foods: uncooked pastry, cheese, melon seeds, jacket potatoes, minced raw meat and stale cake are all popular.  Pretty much anything that isn’t too salty or spicy will do fine.

You need to be careful of salt, as it can kill small birds in excess.  Never put out bacon, salted peanuts or last night’s curry.  On the nut front, unsalted peanuts are a real winner, but rotten fruit, coconut (not desiccated, use only coconut in the shell) and Brazil nuts are also popular.

If you decide to buy some custom-made bird food, steer clear of brands that contain a large proportion of grain.  A recent experiment by my uncle involved switching between food made principally of a sunflower/peanut mix and a cheaper food that contained high levels of grain.  He found that all the birds except Bluetits and pigeons turned their noses (beaks) up at the grain.  He has gone back to the original mix, but will repeat the experiment when the birds get hungrier to see if that makes them less fussy.

Is it true that peanuts can be harmful?

Peanuts can pose a health hazard to your garden birds in two ways:

  1. Peanuts can become contaminated with alfatoxins, a highly toxic, cancer causing chemical produced by a common mould, Aspergillus flavus.  This mould is present everywhere, and grows on the peanuts whilst they’re in storage.  It is estimated that about 30,000 tonnes of aflatoxin-contaminated peanuts are in storage in Europe, most of which will end up in the bird food market. The majority contain aflatoxin levels up to 200ppb (parts per billion) (compared to the recommended limit for human consumption of 4ppb).  The peanuts that go to make your peanut butter are rigorously checked and passed fit for consumption.  The same is not true for most peanuts sold as bird food.  If you’re buying peanuts, check the packet, the best suppliers only use peanuts are fit for human consumption and will say this on the packet.  If these are too expensive, switch to sunflower seeds.
  2. If bluetits feed whole peanuts to their chicks this can kill them.  The chicks can’t cope with such large food items and they become stuck in their guts, causing starvation.  There are numerous reports of dead chicks that have been found, following a post mortem examination, to have died in this way.  If you place your peanuts in a mesh feeder that forces the birds to peck them apart to get them out, preventing the problem.  Alternatively, you guessed it, switch to sunflower seeds.

I want to know more?

Great.  Check out the birdfeeding links at or write to the RSPB, (The Lodge, Sandy, Bedfordshire) enclosing a stamped, self addressed envelope, and ask for information on feeding garden birds.

Funky Fatballs

Yes, that’s right…  Fat, the delightful, high-energy snack that gives garden birds their get up and go.  Fat has more energy per gram than protein or carbohydrate and it’s just what garden birds need on a bleak winter’s day.  Why not make a fatball as a treat for your local birds, and join in with a big experiment?

Members of Cymer Afan Comprehensive School science club, just up the road from me in South Wales, started this experiment with the help of a Wales Science Year grant.  They wanted to help out their garden birds, but they also wanted to see if there was a way of making their feeding stations extra tempting.

Because birds have excellent colour vision, which they use to find food (and each other), the students thought the colour of the food they left out might make a difference to the birds’ selection of feeding site.  To test this, they made fat balls of different colours and hung them in their gardens.  So that their test was fair, each student hung fat balls, identical in every respect but colour in their gardens for a week.  To see how popular each ball was, they were weighed at both the start and end of the week so that the difference in weight could be recorded.   All the results were combined to give an average.

As you can see from the table and chart, green fat balls were the top choice, followed by red and yellow, with blue proving least popular.  These results are interesting, and allow us to draw some tentative conclusions.

Blue food is clearly unpopular with the garden birds of South Wales.  This conclusion is supported by other research into bird feeding behaviour.  The bright blue colour of poisonous slug pellets is not, it seems, an accident.  In nature, blue is not a common colour, so it is likely that the majority of birds would not naturally associate it with food.

The popularity of the green food in this experiment surprised me.  It has been shown in other research that birds go for either red / yellow or green.  Gulls and pigeons, for example, go for red and yellow whilst pheasants, ducks, swans and their relatives go for green.  It is thought that this difference in preference between species reflects the normal feeding patterns of the birds.  Pigeons are very good at spotting and feeding on berries which are predominantly red and yellow.  Gulls are fed as chicks by parents with yellow and red beaks.  Pheasants, geese and swans feed on green plant material.

I would have expected that the birds taking most advantage of the fat balls would have been tree dwelling, berry feeding species with a preference for red and yellow.  Further investigation, with an attempt to identify the species eating the fatballs would certainly be useful.

The way birds select food is obviously important to the manufacturers of pesticides who wish to discourage birds from eating their products, but it’s also of interest to companies who want to attract birds.  I talked to Chris Whittle of CJ Wildbird foods about our experiment and he was very interested.  He told me that they’ve been doing similar work.

They had conducted an experiment to see if the colour of a garden birdfeeder made a difference to how many birds used it.  They used 12 different coloured bird feeders all the same size, filled with the same foods.  The feeders were placed in random positions in a garden and moved around once a week for a period of 18 months.  To be extra-sure their results were accurate, they then repeated the whole experiment three times in the UK and once each in Austria and Germany.  The results were as follows: red feeders attracted siskins only; green attracted Goldfinch only; blue was the most successful during the summer and in bright sunlight; silver was the most successful at all other times.  The performance of the blue feeder was a surprise, however, it was only popular in certain light conditions, possibly due to the way the feeders reflected Ultraviolet light in these conditions.  Their quest for the ultimate birdfeeder continues.

So, what next?  The experiment gave us some interesting results, but it also posed new questions.  There are certainly improvements that could be made in the method and it would be useful if we knew more about which birds were eating the food.  Also, in the initial experiment, no one thought to use an uncoloured fat ball as a control.  Finally we need to repeat the original experiment with a few improvements and we need to repeat it as many times and in as many different places as possible.  That way, we can be sure that the observed results are reliable and not the result of chance.  This is where you come in.  If you’d like to help out with the big experiment, and help your garden birds at the same time follow the recipe below.

Making a fatball is easy.  You need lard (a couple of packets will do fine), wild bird food, string and netting – net curtain material or “dress” netting – cut into squares measuring 30cm along each side.  If you’re going to have a go at the experiment, you also need four bottles of food colouring: red, yellow, green and blue.  An old newspaper, to prevent you staining your kitchen worktop is also a good idea.

Lard is solid at room temperature, so you need to chop it up into smaller blocks, stick it in a pan and heat it gently.  When it turns liquid, remove from the heat, add the wild bird seed and mix well.  You know you’ve added enough seed when you get a mixture that resembles a gross breakfast cereal.  For an ordinary fat ball (and for your control) you now need to leave the mixture to cool until it starts to go solid before you use a large spoon, or, even better, an ice cream scoop to transfer a fist sized dollop onto a square of netting.  Gather up the corners and tie together with the string to make a bundle.  Remember to use enough string to allow you to tie the fat ball to a feeder or tree outside.  For the coloured balls, take four bowls, old margarine cartons or similar and add a bottle of food colouring to each one.  Dip the net curtain squares in the colouring so they take on the colour.  Remove the net curtain squares and squeeze any excess colouring back into the bowls so you don’t drip food colouring all over the kitchen.  Place the netting to one side for a moment (on the newspaper!) and get the mixture in your pan nicely liquid.  Now, transfer the goo into the bowls with the food colouring and mix well.  You can guess the rest, add the coloured goo to the coloured net squares and tie up like before.  Don’t forget, before you put your balls outside, you need to record their weights.  You’re now ready to stick the whole lot outside in a suitable tree.

Good luck, merry Christmas to you (and your garden birds), see you in 2003.