TO FEED OR NOT TO FEED

I’m increasingly conflicted on the subject of feeding garden birds. On the one hand, these are wild creatures and I’m reluctant to interfere with their natural behaviour. On the other, feeding helps keep them alive through the challenging winter months.

Our feeders hang from the old hedge that runs along the track to our house and ends just across the drive from the kitchen window. They help make the chore of washing-up a little less tedious. I’d find it difficult to stop, but often, when I’m cleaning the dishes, I fret about the consequences beyond keeping a few more birds alive over winter. What are the effects of this meddling on the local bird populations? And what might those effects look like at a bigger scale given that so many of us now provide food for birds?

I’m probably a little old-fashioned in the foods I put out. Mixed seed, peanuts, sunflower seeds and fat balls are about as adventurous as it gets. I did once try the tiny, jet-black nyjer seeds, having read that they are favoured by Goldfinches. The experiment failed, though Goldfinches are now regular visitors and seem perfectly happy with sunflower hearts; score one for the traditional approach. I’ve yet to be tempted by mealworms or waxworms, though they apparently attract a wider range of birds, including insect eaters such as Wrens, Pied Wagtails and even Treecreepers.

When the bird-feeders go back up it feels like an admission that summer is drawing to a close once again. The birds are slow to cotton on at first, and natural food is usually plentiful at this time. But as the temperature starts to fall, word gets around and numbers begin to build up. I guess that survivors from the previous winter check the site regularly, knowing that it has been productive in the past.

In cold weather, especially later in the winter when natural food is scarce, the number of birds using the feeders is impressive. Most abundant is the Blue Tit. My best count so far is seventeen, all either on the feeders or waiting their turn in the hedge close by. With help from the less common species they work their way through perhaps five fat balls and a long feeder of peanuts every day. How many individual Blue Tits visit during a typical winter is anyone’s guess, but given the constant toing and froing along the hedge-line I suspect it might creep into three figures. I’d love to know.

While the Blue Tits are a near-constant presence, it’s all or nothing with the Long-tailed Tits. In winter these birds travel in small flocks, up to about fifteen strong. Each group has its own patch and moves around it in wide circuits to help improve foraging efficiency. They feed for the most part on invertebrates, which react to disturbance from foraging birds by flying away, by staying still and relying on camouflage, or by retreating into cracks and crevices. This reduces the hit rate for birds, and means that it’s best for them to keep moving into areas that have been free of disturbance for longer, where prey is more likely to be caught off guard.

I happened to be watching my parents’ bird table one day as the regular Long-tailed Tit flock arrived. As was their habit, they headed across to this reliable food source from the nearby cherry tree. Only, today, it wasn’t reliable. In fact, it was missing entirely. My dad had taken the table into the garage to add another feeder. The birds, in twos and threes, took it in turns to fly out to the exact spot where it had stood, hovering there for a few seconds as if disbelieving their own eyes, before returning to the cherry tree.

Artificial feeding has some obvious impacts on birdlife as well as a few that are trickier to pin down.

It’s clear, then, that feeding changes patterns of behaviour. But what about changes to the balance and make-up of wild bird communities? Here is a plausible scenario, albeit one that is difficult to prove: Great Spotted Woodpeckers come regularly to most feeding stations. They are bigger than the finches and tits and have a powerful bill that smaller birds do well to keep away from. They can push their way to the front of the feeding queue whenever they fancy, and feed for as long as they want.

Great-spots have increased in recent years. The population has more than quadrupled since the late 1960s. They have colonised new areas, especially in northern England and Scotland, and have also made the leap across the sea to Ireland. It is almost certainly true that garden feeding has aided this process. Surely this is a good thing, worth celebrating? Well, it’s certainly good for the Great Spotted Woodpecker.

Here is another possibility. Burgeoning populations of resident Blue Tits and Great Tits, propped up by bird food, have probably increased the competition for nest sites with other hole nesters. As well as Marsh Tits and Willow Tits, hole-nesting Pied Flycatchers have also declined over recent decades. Willow Tits have gone completely in our area, and Pied Flycatchers are now very scarce. Marsh Tits are far less abundant than they once were, and I only ever see a single pair at the feeders. A direct effect is hard to prove, but it is believed that increased competition for nest sites from Blue Tits and Great Tits has made life far more challenging for other hole-nesting birds.

The consequences of feeding at a national scale are difficult to study, but research is finally starting to reveal some of them. Around half of all households in Britain put out an estimated 60,000 tonnes of food each year (at a cost of £300 million), enough to sustain a remarkable 196 million birds.¹ Wild bird communities are, indeed, being reshaped as a result. Birds that readily take advantage of this food, including Blue Tits, Great Tits, Goldfinches, Siskins and even Woodpigeons, have done well, with numbers rising sharply in recent years - including in built-up areas where feeding in gardens is common. Certain red-list species, including Starlings and House Sparrows, have declined but numbers would no doubt have fallen more steeply in the absence of feeding.

It’s worth keeping in mind that species interact with each other in ways that are sometimes obvious but more often are complex and challenging to disentangle. One possibility is that resident woodland birds gain an advantage over migrants. In the past, severe winters would have knocked numbers back every so often, reducing competition with returning migrants in the spring. Now, our residents are sustained at artificially high levels with limitless food. When the migrants return, they may struggle to find vacant nesting territories. Pity the poor Pied Flycatcher returning from Africa to a wood chock-full of Blue Tits and Great Tits, desperately seeking a free hole in which to nest. Whenever there are winners, it is a near certainty that there will also be losers.

Another issue of concern is disease. Many of them spread more easily if birds are concentrated in small areas, and busy feeding stations provide an obvious focal point. One disease, trichomonosis, is thought to be responsible for the loss of over two-thirds of Britain’s Greenfinches in just ten years - a stark illustration of the damage that can be done. In recent years, Chaffinches have shown a sharp drop in numbers, and disease is high on the list of likely causes. Other species too can be affected, with sick Great Tits, House Sparrows, Woodpigeons and Collared Doves often reported from gardens. We hear much

about the need for regular cleaning of feeders, and we are advised that sites should be changed regularly to try to reduce the risk. Yet the dangers in encouraging such close proximity are impossible to eliminate entirely.

Even bird food itself can cause problems. Various toxins are produced by the moulds that are regularly found on peanuts and in seed mixes when they are tested. This is another area where more research would be helpful to determine the extent and scale of the problem.

So, feeding birds alters their natural behaviour. It concentrates them in small areas and it restructures the balance of local bird communities. Further, through competition or disease, it can cause individual species to decline, sometimes dramatically. It also relies on setting aside land in the tropics and subtropics to grow peanuts and other foods, and so contributes to climate change. Then there is the environmental cost associated with transport. It is big business but is it really sustainable in a climate and biodiversity emergency?

Set against that, feeding can improve survival rates for certain species and brings pleasure to millions of people. It also contributes to the coffers of wildlife charities, as well as to the wider economy.

There is plenty to think about every time I stand at the sink, looking out to the hedge and the feeders that hang from it. Will I beat my count of seventeen Blue Tits? Will I ever see more than two Marsh Tits together? And will the local woodland ever regain its Pied Flycatchers? If I’m honest, I struggle to justify feeding based on logical arguments about the way birds respond to it and the wider ecological and environmental impacts. This is yet another human intervention that tilts the balance in favour of those species adaptable enough to take advantage, and against those that are unable to do so. It is selfishness that ensures my feeders are regularly restocked so that the birds keep coming. That, and insistent prompting from the Blue Tits, clambering forlornly about in the hedge every time the food runs out.