Hummingbirds adapted to use fructose for energy production just like glucose:
> Now new research from the University of Toronto Scarborough shows they are equally adept at burning both glucose and fructose, which are the individual components of sugar; a unique trait other vertebrates cannot achieve.\
> From an evolutionary perspective the findings make perfect sense, says Welch. Whereas humans evolved over time on a complex diet, hummingbirds evolved on a diet rich in sugar. "Hummingbirds are able to move sugar from their blood to their muscles at very fast rates, but we don't yet fully understand how they are able to do this," he says.
> Now new research from the University of Toronto Scarborough shows they are equally adept at burning both glucose and fructose, which are the individual components of sugar; a unique trait other vertebrates cannot achieve.\
> From an evolutionary perspective the findings make perfect sense, says Welch. Whereas humans evolved over time on a complex diet, hummingbirds evolved on a diet rich in sugar. "Hummingbirds are able to move sugar from their blood to their muscles at very fast rates, but we don't yet fully understand how they are able to do this," he says.
https://www.sciencedaily.com/releases/2013/12/131205165823.h...