What happened: Researchers from Chicago's Field Museum measured skulls and teeth of 121 Madagascar flying fox specimens collected over 150 years in nine museums and found a clear drop in size beginning around 1980, when hunting likely became commercial, Popular Science reports on the study in the Journal of Mammalogy. The bats, with wingspans up to five feet, eat fruit and are legally considered vermin, and are also hunted for food.

Why it matters: If hunters remove the largest, older, breeding-age bats, that can hurt the whole population, the researchers say.

How much agreement is there? Some disagreement. The study shows a correlation, not proof: the authors say deforestation, climate change and shifting fruit seasons may also play a part.

Could someone help? Old museum specimens made the discovery possible, a reason to support natural history collections and the field biologists who use them.