In the largest colony on Earth, penguins frequently engage in mating rituals: what drives them to "break hearts"?

Phillip Island is home to 37,000 little penguins, making it the largest colony of this species in the world. The world-famous Penguin Parade attracts thousands of visitors each year as people flock to witness the remarkable seabirds returning from the ocean to their nests, according to PHYS.org.

It is commonly believed that penguins are among the most loyal birds and choose a mate for life. However, new research led by Professor Richard Reina from Monash University reveals that not all penguins actually select lifelong partners.

Over the course of two decades, the researchers observed the colony and concluded that during favorable conditions, seabirds tend to stay with their partners, although they often stray. However, after an unsuccessful breeding season, seabirds may seek a new partner for the next season to increase their reproductive success.

The scientists found that the divorce rate among penguins is a more reliable predictor of the colony's reproductive success than environmental factors, such as habitat change or behavioral traits. For instance, the time spent foraging correlates with higher divorce and re-pairing rates during the breeding season, leading to reduced reproductive success across the colony.

Observations indicate that a primary reason for divorces is the low number of chicks. However, the team also discovered that this risky decision by seabirds could further diminish the success of their subsequent breeding attempts.

According to Professor Reina, they monitored 13 breeding seasons of little penguins, tracking which individuals changed partners and divorced. The team recorded about 250 divorces among approximately 1,000 penguin pairs throughout the study. The results also suggest that years with lower divorce rates among penguins were also years of higher breeding success.

Professor Andre Chiardi, a marine scientist from Phillip Island Nature Parks, stated that the divorce rate is an accurate predictor of success, as it correlates more closely with breeding metrics than other factors affecting penguins. Researchers now believe it is crucial to consider social dynamics alongside other factors, such as environmental influences, in future studies. This is expected to help develop more effective strategies for protecting vulnerable species.