On February 3rd, Daniel and Virginia Poleschook presented stories about many of the banded loons that they have monitored during their 27 years studying loons in Washington. Their presentation covered family histories, stories of migration, and other fascinating facts and details about these loons. For those who were unable to attend live, the presentation was recorded and can be accessed here.

Next, we brought the loons to VCA Capital Area Veterinary Emergency and Specialty, where radiographs were taken to assess whether they had any internal injuries. Thankfully, the radiographs came back clean for all 10 loons. Though they were a bit thin after their ordeal, none had any internal injuries that would prevent them from being released. The bloodwork came back clean for 9 of the 10—the tenth loon had slightly elevated lead levels. This loon’s radiograph did not show a metal object, indicating that it had managed to pass whatever had caused its mild case of lead poisoning. All ten loons were transferred to Wings of the Dawn Wildlife Rehabilitation, where rehabilitator Maria Colby kept them for feeding and observation. Maria also treated the lead poisoned loon with chelation medicine to remove the toxic metal from its body. The loons were hungry—in the day they were with Maria, they ate a combined total of nearly 30 pounds of fish!

Our winter band resight data indicates that New Hampshire breeding loons tend to spend their winters off of the New England coast. The loons that we released at Odiorne Point will be in good company this winter!

What caused 10 adult loons, 9 of which had no discernable health problems, to become iced in? As we evaluated the loons, we discovered that most were in the midst of molting their primary feathers (the large feathers on the outer tips of the wings). These feathers are required for flight, and without them the loons were trapped, unable to take off as the ice came in. The molt of primary feathers is normal—loons' feathers get worn out and need to be replaced each year. However, it typically occurs when loons are on their wintering grounds and have no need to fly. We can only speculate as to why these 10 loons did not leave their lakes for the ocean in the fall and early winter, when migration normally occurs. It is possible that warm autumn and December temperatures may have overridden the other cues that would typically trigger their migration. What we do know for certain is that by the time the ice started coming in in late January, it was too late for the loons to make it off of the lake on their own—they were caught in the middle of their feather molt and unable to leave.

For loons, the wing molt is simultaneous—they lose all of their primary feathers at once, rather than replacing the feathers sequentially over time. Loons have heavy bodies and relatively short and narrow wings, resulting in high rates of wing loading (the amount of weight supported by each square inch of wing). That means that loons have to work hard to take flight, and once in the air it takes sustained effort (constant wing flapping) for them to remain in flight. The loss of small numbers of feathers over time may, then, make this process even more difficult—as Glen Woolfenden noted in his paper on the subject, the loss of even one primary feather from each wing would be a considerable handicap for a loon when it comes to taking off and sustaining flight. Thus, while it leaves them flightless for 4-6 weeks, a simultaneous wing molt may be a better strategy for loons than a stepwise molt (in which the feathers on each wing molt sequentially) because the latter would make flight more difficult (or impossible) for them over an even longer period of time.

In many bird species, flight feathers are lost and replaced during the post-breeding molt, which typically occurs in the late summer or early fall. While loons go through a partial molt at this time (replacing the black and white feathers on their heads and bodies with their more drab grey and white winter plumage), they do not molt their flight feathers until much later. That’s because it takes 4–6 weeks for loons to replace their flight feathers and in that time, they are flightless. If loons were to molt these feathers in the fall, they would risk becoming iced-in if their lake froze over in early winter. Instead, loons delay their flight feather molt until winter, when they are (or should be) on their wintering grounds and have no need to fly.

In the fall, loons undergo an incomplete molt, replacing the worn black and white feathers of their breeding plumage with the grey feathers of their winter plumage. This molt starts at the base of the bill (as shown in this photo) and works backwards across the body. The flight feathers on their wings are not replaced at this time—those feathers are replaced in the winter, when loons are on the ocean. Photo courtesy of Brian Reilly.

This month, add some loon themed decor to your kitchen with the Loon Pattern Oven Mitt set! This three piece set features one loon print oven mitt, one light blue waffle towel, and one dark blue waffle towel. Get yours in our online store!