Feeding the birds at the Beth Chatto Gardens

In the garden we have never fed the birds in any targeted way, other than by providing seeds and insects on the plants we grow. We generally leave seed bearing plants over winter before they are cut down and want our birds to help us in keeping nature ('pests') in balance by using the resources we provide, inadvertently but in abundance given that we use no pesticide sprays.

But customers have sometimes questioned why we don't try and do more, and this spring we have installed a range of garden bird feeders close to the tearoom.

This has to be a good thing, doesn't it? Well, as so often the answer is 'yes and no'. Bird feeding is good, providing visual interest to visitors, and hopefully encouraging them to manage their own gardens in a wildlife-friendly manner. But it is only good if it is done in a way that doesn't harm the birds, and doesn't have unintended consequences which might affect the gardens or the visitor experience.

It all comes down to the detail of how, what, when and where. The where is easy: feeding around the tearooms where most visitors will see them is better than scattered around the garden where we want the birds to be eating the natural fruits and seeds our plants provide, as well as suppressing potentially harmful outbreaks of greenflies, caterpillars, grubs and other plant suckers and munchers. Hopefully also by being where there is more human activity, we are making it less likely that our local Sparrowhawks will find easy pickings.

Add to that some shrubs and climbers nearby where the songbirds can take refuge when there is a hawk around. But bushes and shelter can hide other predators, namely cats. We have recently brought in a couple of cats to help control mice in the nursery area. We hope the cats will find all they need doing their job, but to be on the safe side, we have sited the feeders away from places where cats could lie in wait or from launch pads from which cats might spring. We don't want the birds we are feeding to become cat food!

Predation is one risk we must manage, and so is disease. Birds generally don't observe social distancing around feeders, so that diseases can be passed around. Bird flu is one, but perhaps of greater concern are bacterial diseases, especially avian trichomoniasis. This has been implicated in the very serious declines in recent years of Greenfinches and Chaffinches especially. The answer? Regular cleaning of the feeding containers, disassembled and empty, ensuring a full disinfection on a monthly basis, washing and scrubbing with non-toxic products such as diluted bleach or white vinegar.

Birdfeeder hygiene is also important around the site of the feeders. Seed is often spilt by the birds, and dropped seed can harbour both diseases and rats, neither of which we want to see. So it is important that spillage can be swept away regularly, every day or two.

Then there is the question of what to feed and not to feed with. Not pure carbs like bread... that is just empty calories with little nutritional value. And not whole peanuts especially during the breeding season when a chick could easily choke on a whole peanut. It is much better to offer a mix of seeds (including sunflower hearts for larger finches and nyjer or flax seeds for Goldfinches), alongside fat balls and mealworms for Robins and suchlike. The greater variety of foods the more types of birds will benefit. But whatever is provided remember that especially in damp, warm weather the food can spoil and become a health hazard.

The final consideration is when to feed. Food supplies are most likely to be running low in cold weather, even hidden by snow or heavy frost. Supplementary feeding then can be a lifeline. Current thinking is that it is best to provide food all the year round, but to adjust the amounts down at times of lower demand.

Songbird populations need help, and the right sort of feeding does help. But even the RSPB has started to advocate caution. Feeding tends to work best for the more dominant visitors like Blue Tits.  Great Tits and Starlings. And there is some evidence that by allowing these to build bigger populations supported by feeding, it can alter ecological balance against less dominant species (eg Coal and Willow Tits), in part through taking over breeding sites. Unintended consequences indeed!

For the moment we will continue to provide food, monitor what goes on and adjust as appropriate. And right at this moment, early summer, it is reassuring to note that rather few birds are coming to the feeders. Maybe the birds haven't found them yet as they have been out for only a couple of months...but what I prefer to think is that our diverse, organic garden is providing all of what most of our birds need for most of the time: seeds and fruits, insects and soil and leaf-litter invertebrates. That's 'ecological and sustainable'!

By Dr Chris Gibson