Standing in the freezing blizzards and pitch dark of the Antarctic winter, male emperor penguins are often viewed as the most dedicated of fathers in the animal kingdom. Well, I’m sorry to have to break it to you, but some of these devoted dads are not all they seem.

The life cycle of the emperor penguin has been well documented, not least for the ever popular March of the Penguins documentary. But it might be that researchers have been making sweeping generalizations about the birds and that there is far greater variability within their mating habits. In fact, some males seem to take sneaky snack breaks when we all thought they were fasting. This new behavior has been reported in the Journal of Experimental Biology. 

In general, both penguin sexes start to make their arduous trek of around 100 kilometers (62 miles) from the ocean to their breeding ground inland at around April time. When they reach the spot, the males and females partake in their annual hanky-panky. The female lays a single egg that is swiftly delegated to the male, while the female undergoes her long waddle back to the water to stock up.

This means that the males can be fasting for up to an impressive 115 days, until the female returns and he can finally go feed himself. Undergoing one of the longest fasts in nature makes the males, in many people’s eyes, the most committed of fathers.

But not all emperor penguin colonies are so far from the edge of the ice, and in 1998 a small team of biologists got the chance to visit one of these more accessible colonies at Cape Washington at the end of May. This was the first time that anyone had ever been to a colony on the edge of the ice in the darkness of winter, and the researchers were intrigued to find “many fresh tracks leading to and from the colony.”

When they reached the colony of penguins, which at this point in the year would have been made up of courting males and females, they could see two groups of up to 30 birds returning from the edge of the ice. From the research boat, scientists also saw groups of penguins feeding and heard even more out at sea. After tagging a few of them, they confirmed that the birds were indeed still eating.

They suspect that the males were going out in the darkness, despite the increased risk of predators and being trapped beneath the freezing ice, right up until the female laid her egg. This would mean that rather than fasting for 115 days, these males were only doing so for a much more manageable 65.

Since most studies have been done on colonies far from the coast where it is impractical for males to have a cheeky dip before the egg is laid, scientists have assumed that all penguins behave similarly. It now seems that some males don't deserve quite the heroic reputation we have given them, although lets be honest, it's still pretty damn impressive.