Loons, with their striking appearance and haunting calls, are iconic figures on northern lakes. Their distinctive wails and yodels echo across the water, often leading people to wonder about their private lives. A common question arises about these aquatic birds: do loons mate for life?
Understanding Loon Pair Bonds
Loons do not mate for life, a perception often stemming from their consistent return to the same breeding grounds. Instead, their mating behavior is best described as “serial monogamy.” This means that a pair typically remains together for several consecutive breeding seasons, often returning to the same territory each year. Banding studies have revealed that these pair bonds can last, on average, about six to seven years, though some pairs may stay together for a decade or more.
During the breeding season, both male and female loons actively participate in raising their young. They collaboratively build a nest, usually a mound of vegetation near the water, and share incubation duties for their one or two eggs for approximately 26 to 30 days, ensuring successful reproduction.
Factors Influencing Pair Stability
While loon pairs may stay together for multiple seasons, several factors can lead to a change in partners. The death or disappearance of one mate is a direct cause for a pair bond to dissolve, with the surviving loon often finding a new partner. Reproductive success also plays a role, as pairs that consistently fail to fledge chicks may eventually separate.
Territorial disputes are another significant reason for pair changes. A challenging loon can attempt to displace a resident loon from its territory. Such takeovers can be intense, and in roughly 30% of cases involving male intruders, the conflict can be fatal to the resident male. Evictions are common for both sexes, and the evicted loon must then seek a new territory and mate.
The Role of Territory in Mating
The breeding territory holds immense importance for loons, often surpassing their allegiance to a specific mate. Loons demonstrate high fidelity to their chosen breeding lakes, returning to the same location year after year. Males typically arrive first in the spring to establish or reclaim their territory, with females following days to weeks later. If a loon’s mate does not return or is displaced, the resident loon will readily accept a new mate to maintain its hold on the territory.