Squirrels better beware – a rallying cry has been issued in Highgate to save the humble garden sparrow.

The small tawny bird has become a less frequent sighting in gardens as, faced with increased competition from squirrels and pigeons, a shortage of bugs and changes to their habitat, they struggle to find enough food.

Elderly residents at Highgate Nursing Home are joining bird lovers across the country to create a sparrow friendly garden to help restore their numbers.

Lisa Gammalliere, activities organiser at the home in Hornsey Lane, where every resident has a bird feeder hanging from their window, said: “We have noticed the sparrows are dwindling in our garden.

“Our residents really love the birds, and the companionship they offer so we wanted to get involved in the campaign.

“It would be a real shame if the much loved garden sparrow became a thing of the past.”

House sparrows are in a sad state, their numbers have plummeted in London by nearly 70 per cent between 1994 and 2009, according to the British Trust of Ornithology.

A spokesman for the Royal Society for the Protection for Birds said: “This is a hell of a decline and we are not entirely sure why this is happening.

“We found that a lot of sparrows were starving to death in the nest in the first year of life because they weren’t getting enough protein because they weren’t getting enough insects.

“A lot of people are aware that there are fewer bees and butterflies around, there are also fewer insects generally and this is part of the problem.”

Several theories abound as to why sparrows have declined so drastically. Some have speculated that electro magnetic radiation from mobile phone masts are harmful, or that they are facing increased threat of predators.

But while scientists are still researching the causes of the decline, the destruction of garden shrubs which made up so much of their urban habitat, are believed to have played a crucial part.

The Wildlife Week, sponsored by Bupa, runs this week. For more information contact 0845 600 4622.