Feeding birds may kill them

We love to attract birds to our gardens, but feeders can pose a deadly risk

- James Fair

EIGHT OR SO YEARS AGO, DICK WOODS was attracting an estimated 50 greenfinches to the birdfeeders outside his converted barn near Canterbury, Kent. They vastly outnumbered the other species, and then – over a just a couple of weeks – they completely disappeared.

Woods's visitors had succumbed to a deadly disease that has killed around 70 per cent of British greenfinches: trichomonosis, a parasite that first jumped to songbirds from pigeons around 2005. It's thought to be spread mainly on and around birdfeeders, and this got Woods, who is a design engineer by trade, thinking.

The result was Finches' Friend, a redesigned birdfeeder that Woods manufactures at home and says reduces disease transmission. Trichomonosis is spread in saliva, and infected birds regurgitate their food. “You don’t want birds walking, vomiting and defecating in the food provided, so the first thing to do is stop that,” he says. That means the feeder can’t be open for birds to walk in, as in some models.

You also don’t want one bird to drop food from one feeding position onto another below, or the feeder to have open ports into which rain can pour, as the parasite survives better in wet food. Smaller feeders are better, too, because food isn’t sitting around in them for long periods. Woods has also introduced nifty features that make his design easier to clean. (In my experience, this is objectively true.)

But he can’t say for sure that his products are effective. He’s tried to persuade conservation groups such as the RSPB to carry out studies to see if they can protect finches (the group most prone to trichomonosis), but so far has been met with a metaphorical shrug of the shoulders.

As well as greenfinches, chaffinches have been hit, declining by nearly 20 per cent in the past decade, while goldfinches, in contrast, have largely gone. The other way, benefiting from supplementary food – the reasons that are still not fully understood.