Birds are getting smaller due to climate change, scientists have claimed after examining dead bodies which collided with skyscrapers over four decades.
The study which looked at 70,000 birds which had died after collisions with high-rise buildings in Chicago found that birds have been decreasing in size while their wings had become longer.
The scientists from the University of Michigan said that this was due to global warming, adding to evidence to the long-held theory that climate change is impacting the size of creatures on earth.
The study, published today in the journal, Ecology Letters, found that between 1978 and 2016 the body size of 49 of the 52 species studied significantly decreased.
During the same period, the wing length had increased significantly in 40 species. The scientists claimed this was in order to adjust for the changing weight of the birds.