A lake on the outskirts of Portland, Maine, became a highly unusually scene last summer when a kayaker happened upon a dead bald eagle floating face down, pierced through the heart.
Turns out it wasn’t some Great Gatsby-type story of revenge, but rather an angry loon trying to protect its chick. It’s the first documented case of loon-on-eagle haliacide (Haliaeetus leucocephalus being the Latin name for bald eagles) and shows that for all the glory of seeing loons take flight over misty lakes and hearing their calls at dusk, they can be cold-blooded killers. Those beady red eyes always held a hint of malevolence.
The crime scene got phoned into Maine’s Department of Inland Fisheries and Wildlife over the summer, and the agency publicized it earlier this week in a blog post complete with Weegee-like photos of the dead eagle and a game warden retrieving it from the waters of Highland Lake. A local resident reported a “‘hullabaloo’ the previous night, consistent with agitated loons,” which is the most Maine phrase I could imagine. The scene also included a dead loon chick, giving the department’s wildlife experts a lead in the case that had no direct witnesses to the crime.
An autopsy report revealed that the puncture wound in the eagle’s chest was consistent with the size and shape of a loon’s bill. Danielle D’Auria, a biologist with Inland Fisheries and Wildlife’s bird group who studies loons and other species, told Earther that loons’ bills are a “tool for defense and attacking primarily other loons.”
During spring, loons return from the coast where they spend winter to their summer lake homes. During that season of re-acclimation, male loons in particular will defend their territory from interlopers by diving below the water and then propelling themselves up to jab at their foes. Loons are often marked with scars from these kinds of attacks, according to the department’s blog post. But killing an eagle death is apparently a new level of documented loon aggression.
D’Auria, who authored the Inland Fisheries and Wildlife blog post, said she first became aware of the case in September through the “loon grapevine.” Turns out there’s a Northeast Loon Study Working Group that meets once a year and stays informally connected on all things loon-related in the region. The group is primarily focused on investigating loon conservation—as opposed to loon violence—but the two tie together.
“They’re pretty much a top predator in a lake ecosystem,” D’Auria said. “They really can be considered sentinels or biological indicators of the health of an ecosystem.”
The same is true for eagles, which were listed as an endangered species in Maine and and 42 other states (they were listed as threatened, a slightly less dire classification, in the five remaining Lower 48 states) in 1978. That was due to the widespread use of DDT as a pesticide, which had the nasty side effect of messing with their reproduction and weakening the shells of eggs so that many broke or failed to hatch.
Eagles have since been delisted, and the rebound in population is hailed as one of the most powerful endangered species success stories. But now, their numbers are great enough that they’re coming into conflict with other birds, raising the risk of more eagle violence.
“There’s been now more conflicts between this top predator and other birds that we care about,” D’Auria said. “We have seen lots of instances where eagles and loons are interacting in this way, [where] an eagle is going after either adults or their chicks, and loons trying to defend themselves or defend their chicks. This is the first instance that we know of where an eagle was actually killed by a loon.”
Loons also aren’t afraid to stand up to people. My brother-in-law once had a loon come at him while he was kayaking (though he is an asshole and probably had it coming, tbh). When asked about the incident in a group text, he offered this advice: “Don’t fuck with loons Bribri.”
D’Auria said much the same, albeit in a much more professional manner, noting that loons are “all muscle” and that even though humans are bigger, we should definitely give them their space. If a loon rises up to do what she called “the penguin dance,” where it lifts out of the water and puffs its chest at you, you’re probably too close. Ditto for if it lies flat over its nest, another sign of agitation. Giving loons and other wildlife space is the right thing to do, but also do you really want to end up on the 10 o’clock news?
As for the case of the dead eagle, the perpetrator remains on the loose. It should be considered armed and dangerous.
Update May 21, 2020, 5:35 p.m.: This post has been updated to reflect the fact that a loon did not commit homicide, the act of killing a human. It committed haliacide. Thanks to eagle-eyed (sorry) reader Stephen for spotting the issue.