Loon Preservation Committee: Loon Facts of the Month -- June

In New Hampshire, the first week of June marks the peak of nest initiation for loons. What does nesting look like in the loon world?

Loons are a ground-nesting species. Because of the extreme rear-placement of their legs on their bodies, they cannot walk well on land. As such, they build their nests close to the water's edge. In most cases, loons will spend some time building up a nest bowl in the days prior to egg laying. To build up the bowl, they often use their bills to grab muck and aquatic vegetation from the lake bottom and toss this nest material close to shore.They then climb up to their selected nest site, reach down to their accumulated pile of nest material, and build the bowl up around their bodies. Sometimes, loons may build up nests at several different sites on a lake before deciding which one they ultimately want to use.

Typically, loons will lay two eggs (though in some cases they may lay just one, and very rarely may lay as many as three). Based on data gathered from LPC's Live Loon Cams and trail cameras put out at nests across the state in the past, we know that eggs are often laid about 60 hours (2.5 days) apart. Before the second egg is laid, the loons will usually only incubate their first-laid egg intermittently, often spending several hours off the nest at a time. Once the second egg has been laid, they will incubate much more consistently. In order to achieve this near-constant incubation, the male and female of the pair share incubation duties, each taking shifts of 4-6 hours, on average, before swapping. This allows each member of the pair time to eat, preen, and otherwise take care of its own needs.

On average, loons will incubate their eggs for 26-28 days before chicks hatch. During the nesting period, loons are vulnerable to human disturbance. Close approach by humans (in motorboats or self-powered boats like canoes, kayaks, or stand up paddleboards) can be enough to flush loons off of their nests. Repeated human disturbance may lead loons to abandon their nests. As you are out and about on the lakes this summer, please keep an eye out for loon nests—especially when boating in likely areas, such as around island shorelines, in marshy areas, or along the shorelines of protected coves—and give any nests that you see a wide berth. Please check out our Loon Behavior Guide to learn more about how to determine when loons—both on the nest and in the water—need more space. Thank you!