Will food coloring kill hummingbirds?

With food coloring being dangerous to a human’s health, it has raised the question if the dye we are using in hummingbird feeders are dangerous to them as well. It is believed that when the hummingbirds were ingesting the red dyes from their feeders, it was weakening the shells of the eggs that they laid.

With the weakening of the egg shells, it caused the eggs to crack during incubation and the baby bird inside the shell would die. With the shells breaking, there is not enough of a population of new hummingbirds being born to replace the hummingbirds that are dying, making the numbers of hummingbirds decline.