Do emperor penguins mate for life?

Emperor penguins do not mate for life. However, a male and a female often pair up for one breeding season.

Emperor penguins are considered serially monogamous, meaning that while individual males and females usually form an exclusive pair bond for a breeding season, the partnership rarely continues beyond that year. One study from 1999 found that only about 15 percent of pairs manage to reunite in successive breeding seasons—a rate lower than the average for most other penguin species.

(How do emperor penguins recognize each other?)

In most cases, if the previous mate of a female emperor penguin does not return to a colony’s breeding grounds in time for breeding season, she will pair up with another mate. Research suggests that switching partners does not affect the rate of reproduction in emperor penguins; this behavior may be an adaptation to life in the harsh Antarctic environment, where the breeding season is short and penguins must balance time, food, and energy to raise a chick.

While emperor penguins may not be lifelong partners, the bonds they form each breeding season are essential to the survival of their offspring. They begin breeding in autumn (around April), and each female lays a single egg in late May or early June. She transfers the egg to the male, who incubates it through the Antarctic winter—fasting for months and enduring extreme cold. In August, as the egg hatches, the female returns from her long journey to the sea and takes over responsibility of the hatchling, allowing the male to recover his strength. From that point on, both parents alternate between long feeding trips and chick care. This teamwork ensures that chicks—born fragile and unable to keep warm on their own—have the best chance of survival.