On a recent ferry ride out to the Casco Bay Islands, I spotted hundreds of Common Loons on the ocean, many of them busy diving and foraging for their seasonal diet of saltwater prey. The majority had already traded in their striking black-and-white tuxedo worn during the breeding season in exchange for the duller, grayish-brown plumage that they wear in winter when they don’t need to attract a mate or display their reproductive fitness. But there were others swimming about that appeared neither here nor there, looking bedraggled and unkempt with messy spots on their backs and a mottled mix of feathers on their heads.
This scraggly look wasn’t a sign that these loons were unhealthy or aging: instead they were in the midst of their winter molt. Adults exchange their feathers for a shiny new set each winter by undergoing a complete molt usually starting in late September or October, but sometimes later. The whole process takes about five to six weeks.
In addition to looking awkward at this stage, they are also unable to fly for several weeks. As part of the winter molt, loons lose all of their feathers, including flight feathers, and can’t fly until they have grown back.
It’s usually not an issue for those on their ocean wintering grounds, because loons tend to dive to escape most immediate threats rather than taking flight and don’t need to take to the air to catch prey. But what happens if an adult starts the winter molt while still on his or her breeding lake or pond, before migration?
Normally, Maine loons take flight from their breeding lakes long before the ice closes in to spend winter where salty, tidal waters remain unfrozen. And usually it’s there that they undergo molting. And this trend has held true in 2024 for the most part. My day on Casco Bay helped assure me that, even with the unbelievably warm fall we’ve had, many loons have taken their cue and headed to ocean waters. But every year, some adults will remain on lakes long into the fall and winter and start molting while still on fresh water. If the ice closes in during the period when they are flightless, they can find themselves without enough open water for takeoff once they regain flight capabilities and can get trapped in the ice.
Young of the year can also find themselves in a similar predicament if they remain for too long on their natal lake before attempting their first migration to the ocean. Normally one parent (and sometimes both) will continue to care for the chick until it is ready to fly and forage on its own. Then, sometime after it reaches 12 weeks of age, the chick will be left on its own to find its way to coastal waters. I receive a lot of distress calls in the fall about lone chicks, but these chicks generally aren’t in any trouble. This is just how it is with loons and many chicks do fine finding their way to ocean wintering areas. But it’s not true for all chicks, and a number of chicks each year don’t manage to fledge off their pond before ice-in.
Why do some young and adults stay too long and what can you do? Quite often if an iced-in loon is rescued or a carcass is recovered, some type of underlying issue is found that likely prevented it from flying off the lake, such as an injury, infection, illness, or a developmental issue. Human-related causes can also be the culprit, including lead poisoning, entanglement in fishing line, or trauma from boat strikes. I relayed a story last year about a loon that was iced in and later died, which was found to have a bullet embedded in muscle and a fishing hook in the gut, in addition to injuries from an eagle attack. It’s no wonder this loon couldn’t take flight.
However, there isn’t always an obvious cause. When there’s a warmer fall, some loons just seem to get complacent about staying on freshwater, maybe lulled by the warmer water temperatures or fishing without competitors.
So, should you be worried if you’re still seeing a loon on a lake or pond near you? Not yet. With the persistent warm temperatures this fall, we’re not even close to the point where water bodies are at risk of freezing over. Late migrators become vulnerable when ice starts forming around the edges, reducing the area of open water.
While many people want to help when they see an iced-in loon, there’s often not a lot that can be done. Ice rescues can be very dangerous for both the rescuers and the loon (which can dive under the ice to escape and drown), so only a few organizations will attempt them. Some local fire departments and local entities are also gaining experience and training in ice rescues and may be able to help. State agency staff don’t participate in ice rescues, although game wardens can sometimes help determine if a loon is in need of rescue and potentially connect you with rescuers. Maine Audubon doesn’t engage in ice rescues either.
For those who perform winter loon rescues, attempts are only possible once the loon is enclosed in a very small area of open water relatively close to shore, the ice is thick enough to support the weight of rescuers and equipment, and there is rescuer availability. Rescuers might also consider if there may be a thaw on the way, providing the loon with a brief window for escape—a better situation for all involved. All individuals who engage in ice rescues undergo training and drills, acquire specialized equipment, and practice in safe conditions to perfect their skills and safety measures. Those who are untrained should never attempt to rescue an iced-in loon.
It’s a tough thing to witness and many struggle to accept it when a loon dies. At least in Maine we can take some solace in the fact that the loon population as a whole is thriving, despite the threats that individual loons face. And loons have shown us that they are resilient.
Where to report iced-in loons:
Maine State Warden Dispatch at 1-800-452-4664 or the Warden Service at (207) 287-8000
The Wildlife Assistance Hotline, (207) 361-1400, coordinated by the Center for Wildlife
Biodiversity Research Institute, (207) 839-7600, bri@briwildlife.org
