Like humans, aging birds have fewer and fewer friends, but the reasons for this phenomenon are unclear. In new research, it is believed that birds simply lose the desire to socialize as they age, reports "Msn".

When it comes to old people, it is assumed that they have fewer friends because they are more selective about the company they spend time with. However, one of the reasons could be the fact that there are fewer and fewer people their age to hang out with.

Why do old birds have fewer and fewer "feathered friends"? The team of researchers, led by Imperial College London, behind the new study studied an isolated sparrow population on Lundy Island, in the Bristol Channel that separates southwest England from south Wales.

By mapping the age and social networks of all the birds, it was found that older sparrows have fewer friends, as do humans. The reason may be that there is no "evolutionary pressure" to make new friends. Cooperation and friendship have been shown to help younger birds survive and breed more successfully, which is not the case with older birds.

Lead researcher Dr Julia Schroeder, from Imperial College's Department of Natural Sciences, said the same evolutionary mechanism may be present in humans, as old people are less inclined to make new friends. Combined with fewer potential friends of the same age, this can be a cause of loneliness in the elderly.

Study co-author Dr Jamie Dunning, from the University of Leeds, explained that the new research is one of the first to suggest that birds, like mammals, also reduce the number of 'friends' they have as they age.

Lundy Island, where the sparrow research was conducted, hosts a closed population of sparrows, meaning no birds leave or come from the island. This allowed the team to collect very accurate data about the sparrows, including their age, breeding success and social life.

Previous research has shown that friendship (especially with the opposite sex) helps island sparrows breed successfully. In the new study, researchers looked at the second half of the birds' lives and found that sparrows' socializing in later years simply changes.

Dr. Schroeder argues that lack of companionship is not a problem for older birds. She says that "young birds have great evolutionary benefits from socializing, but when they become parents, the lack of social life leaves no negative consequences for them."

Studying these changes in sparrows and humans may show how we can help the elderly begin to make new friends, thereby alleviating the major problem of loneliness in the elderly.