WHEN was the last time you saw a greenfinch in your garden?

They are stunning birds. The male is a dark green, with a greyish face and bright canary yellow wings patches. Their familiar trilling song is heard less and less.

Not so long ago there were nearly 5 million pairs of this stunning little bird; but in just 15 years their population has dropped by 50%.

Worryingly recent scientific reports have suggested that the primary reason for the decline in greenfinch and many other familiar species is the food we put out for them. Most of us (me included) fill our bird feeders with seed or nuts and then leave them until the birds have eaten them. We refill the feeders again and so the cycle goes on. But there are two big problems. The first is that birds are not exactly clean. They poo where they feed and that can lead to a build up of some really nasty viruses on the feeders and in the food. Most of these viruses are harmless to us, but fatal to our feeding birds.

The second problem is rotting food. We have all had patches where very few birds are using our gardens to feed and on those occasions the food will often rot. In the case of peanuts; the rotting food can release a toxin which is equally fatal to feeding song birds.

The next problem is inconsistency when we feed our birds. Holidays, weekends away, work pressures can lead to feeders running empty. Many small birds such as blue tits will fly up to a mile or more to get to a specific feeder. In winter the bird can use up all their remaining fat reserves to reach the food source.

If the feeder is empty the bird won’t have enough fat stored to return to its roost and will die on route. In spring and early summer, we also wrongly assume we can stop feeding birds. During wet or cold breeding seasons birds are increasingly relying on us to provide food for their young. So long as we provide the right type of food-supplementing their diet during periods of low natural food availability is important.

Let’s make the right decisions this spring for the birds in our garden:

1) Make sure you clean bird feeder with a mild disinfectant once every two weeks. Don’t forget to rinse them with water afterwards!

2) Remove wet or rotting food from feeders and replace them frequently with dry and fresh food.

3) If you go away on holiday, treat the birds like any other animals and ensure you have someone free to feed them in your absence.

4) Feed them with a variety of foods (nuts, seeds, meal worms and fat balls) to maximise nutritional benefits and support the widest range of species possible.

5) Ensure there is a source of fresh water that the birds can drink from nearby and keep the water clean and regularly changed.

6) Feed them all year round; there is an argument that says we should make them so dependent on us. But I personally believe that the lack of food and the unreliable weather conditions means we should feed them throughout the year.

7) Finally, always buy you food from a reputable retailer; pet shop bought loose food is often cheaper; but not the best for our wild birds.

ANDY LESTER