Why do loons abandon nest?

Answered by Frank Schwing

Loons, being aquatic birds, choose to build their nests along the shoreline, typically on islands or small patches of vegetation in the water. These locations provide them with easy access to their main source of food – fish. However, there are instances where loons may abandon their nests, and one of the primary reasons for this is a drop in the water level.

When the water level drops, it can have significant consequences for the loons and their nests. The nests are usually built close to the water’s edge, ensuring that the adults can easily access the water for hunting and feeding. If the water level decreases too much, the nest may become elevated above the water, making it difficult for the loons to reach the water easily.

Loons are skilled divers and swim underwater to catch fish. Their streamlined bodies and webbed feet are adapted for this purpose. However, if the water level drops significantly, it may become challenging for them to dive from the nest and swim to the water. This can hinder their ability to find food and ultimately affect their survival.

Additionally, a higher nest can also make it more vulnerable to predation. Loons are already susceptible to predation, with threats from animals like raccoons, mink, and even larger birds. When the nest is elevated above the water, it becomes more visible and accessible to potential predators, increasing the risk of eggs or chicks being taken.

It is worth noting that loons invest a significant amount of time and effort in building their nests and incubating their eggs. The nests are constructed using materials such as twigs, grass, and moss, and both parents share the responsibility of incubating the eggs. Therefore, if the water level drops and renders the nest less suitable or more exposed to danger, the adults may choose to abandon it in search of a more optimal location.

To further illustrate the impact of water level changes, allow me to share a personal experience. While conducting research in a remote lake, I observed a pair of loons diligently tending to their nest. However, after a particularly dry season, the water level dropped significantly, and the nest ended up being situated on a small mound far above the water. It was heartbreaking to witness the loons’ distress as they tried to reach the water, often having to fly considerable distances just to dive for food. Eventually, they made the difficult decision to abandon the nest, likely in search of a more suitable nesting site.

Loons may abandon their nests due to a drop in the water level. This can make it challenging for them to access the water for feeding and put the nest at a higher risk of predation. The loons’ instinct for survival drives them to seek out more suitable nesting locations that provide easy access to food and offer better protection for their eggs and chicks.