City living shortens great tits’ telomeres

Urban living could pose risks to great tits, at least in terms of their DNA.

City life comes with a host of factors that can, for better or worse, affect a bird over its life span. To see how urbanization might influence early development in great tits (Parus major), biologists at Lund University in Sweden took newly hatched great tits from the city and the country and mixed them up. After just two weeks, great tits raised in urban environments had shorter telomeres regardless of where they were born, the team reports June 14 in Biology Letters.

Telomeres are bits of DNA that protect the ends of chromosomes from unraveling or degrading. If telomeres get too short, cells are more likely to die. Telomere length is associated with longevity in other birds as well as in humans. So if growing up in an urban setting shortens birds’ telomeres, it could lead to a host of other problems down the line, the team argues.