Staff at the Australian National University of Canberra measured the wingspan of some of the song birds that are in museum collections in south-eastern Australia.
[ad#125x125square]Eight species of birds which had been collected between 1860 and 2001 were measured. The University found that four species of bird showed a significant decrease in body size of up to 4 per cent . This is over the last 100 years (approximately) . The researchers ruled out that this decrease in size was due to lack of nutrition.
Other information – In 2006 Professor Yoram Tom-Tov led a study that found that bullfinches, blue tits, dunnocks and great tits weigh less than they used to.