They waddle down to the water to wash off the rust-colored guano that stains their pelts and produces a pungent odor that within days becomes expected with each landing.
In the ancient oceans, green rust's ability to pull nickel out of the water would have been critical for some life forms, since nickel is an important nutrient for microbes that produce methane.
Since NASA's Curiosity rover made its way to Mars, it's been sending back a wealth of data from our rust-colored planetary neighbor: landscape photos, radiation readings and even evidence of liquid water.