Researchers have discovered that penguins have genes that allow for salty and sour flavors but lack receptors to taste sweet, umami, and bitter--possibly because they don’t function well in cold environments.

Penguins may only be able to “taste” salty and sour flavors.

Researchers at the University of Michigan have determined that the animals lack the receptors for the other flavor senses--sweet, umami, and bitter.

These findings were discovered after the team sequenced the genomes for Adélie and emperor penguins.

The genes responsible for umami and bitter appear to be broken or absent in penguins but have been found in other birds.

Birds in general are thought to have lost the ability to taste sweets long ago.

It has been hypothesized that these three missing flavor dimensions do not perform well in cold temperatures so they may have become non-functional over time.

Other scientists caution that while the absence of receptors probably means that they lack the ability to taste