Garden bird seed linked with deaths of critically endangered British doves

Bird seed may be having the unintended consequence of malnourishing the chicks of one of Britain’s most endangered birds.

Turtle dove numbers have declined by 98 per cent since 1970, and in order to protect the remaining population fragments breeding in the UK, researchers have tried to identify the best sources of food for them.

In doing so they found young doves raised on a diet of garden seeds, such as sunflower and niger seeds in gardens or public spaces, were less likely to survive than those fed on wild seeds.

“It could be there is nutritional deficit in bird feed compared to what they are used to,” Dr Jenny Dunn, an animal health specialist at the University of Lincoln told The Independent.

In the study, which was conducted in collaboration with the Royal Society for the Protection of Birds (RSPB), the scientists observed a distinct switch in food preferences which showed them relying more on seed from gardens.

“We weren’t aware that turtle doves were feeding in gardens as much as they seem to be,” said Dr Dunn.

“They could be driven to feed in gardens because it’s an easy food source – more reliable than searching the countryside.”

According to the researchers, this was cause for concern because these easy meals may be acting as a kind of “ecological trap,” tricking the birds into choosing a food source which is not good for them.

While adults themselves are able to happily eat bird seed provided by humans without any negative effects, the seeds they take to feed their nestlings leave the young birds in far worse condition than those on a wilder diet.

These results, which were obtained from DNA analysis of dove droppings, were published in the journal Molecular Ecology.

The lack of fledging success in chicks fed on human-provided seeds builds on previous evidence these birds produced more broods of chicks each year when their diet consisted mainly of wild plants.

However, Dr Dunn said they were not sure exactly why these seeds are not giving the young birds what they need to survive.

An alternative explanation could be that turtle doves are picking up parasites at bird feeders and baths when they mingle with other birds, and this hinders the development of their offspring.

This has happened before, when an epidemic of trichomonosis parasites spread through contaminated bird feeders caused a rapid decline in British greenfinch populations throughout 2006 and 2007.

Turtle doves only spend around a third of the year in Europe, travelling there to breed after wintering in West Africa.

Due to a combination of habitat loss, hunting and disease, numbers in the UK have plummeted and the birds can now only be seen in certain parts of southern and eastern England.

Despite the potential risk posed by common bird seed to young doves, the scientists said there was no need to stop feeding birds altogether.

Most birds feed their young with insects and other small creatures, so there is no risk of other species being affected.

Instead, those who want to help any local turtle doves should provide access to wild seeds.

“The answer is to leave a weedy patch in your garden – what turtle doves need is natural weed seeds and areas of bare ground,” said Dr Dunn.

Bird numbers throughout the UK and the rest of Europe have seen drastic declines in recent decades, largely due to pesticides on farms wiping out their insect prey.