a welcome dose of nature on our doorsteps, window ledges and in our gardens. in the uk we spent more than £250 million every year on food for our feathered friends. but there's a limited number of familiar resident species that eat the thousands of tonnes of peanuts, seeds and suet that we put out for the birds, and scientists now say this constant supply of supplementary food could have boosted the population of those species at the expense of others. an ongoing rise in the population of great tits and blue tits, for example, could be costly for some of the birds that we don't often see in our gardens. i would worry a psychologist is that by providing commerce auto, unlimited feed for species like blue and grey tips we impact on the species that complete with blue and great tips. the two other species of tips. people may not have heard of them. one is called a mashed hit and one is called a willow tip. they are among the fastest declining birds in the uk. blue and grey tips may be called a dominant species where this mask and willow tips are subordinate species so basically in battles for food and west site it is the blue