Illustration by Adelaide Tyrol
In a showdown between a bald eagle and a great horned owl, who would win?
A bald eagle has a wingspan that can be nearly seven feet. It can weigh up to 14 pounds. It has piercing yellow eyes and a large, hooked bill. It is a symbol of pride and power. In comparison, a great horned owl is puny. Its wingspan is not quite five feet, and it weighs about seven pounds at most.
Bald eagles and great horned owls have been struggling over the same piece of real estate at North Springfield Lake, in Springfield, Vermont, for some years now. If you think the bald eagles could easily evict their rivals, well, I’m sure they wish they could.
Vermont bird watchers, conservationists, and biologists were excited and hopeful in 2003 when bald eagles were spotted at the North Springfield Lake, a few miles west of the Connecticut River, carrying branches and other nesting materials. Until last year, Vermont was the only state in the continental United States not to have a breeding pair of bald eagles.
Sure enough, the eagle pair built a nest. Bald eagles build the largest nests in North America. The record is nine feet wide, and the nests are typically five feet deep. They can support the weight of a grown man. However, this eagle pair, after building their nest, did not take the next logical step and lay eggs.
“They might have been just playing at building a nest,” says Gary Pelton, a wildlife biologist for the U.S. Army Corps of Engineers at North Springfield Lake. Sometimes bald eagles appear to build a nest for practice, he says.
Forrest Hammond, a wildlife biologist with the Vermont Fish and Wildlife Department, says it can take bald eagles a whole season to build a nest. The pair then uses that nest the next year.
When the lake froze over that winter, the bald eagles moved on. Bald eagles are primarily fish-eating birds; they need open water to feed.
Great horned owls, meanwhile, don’t eat fish. It’s one of the few things they don’t eat. This adaptable bird is best known for being the only animal that regularly eats skunks. Great horned owls also eat geese, crows, other raptors, amphibians, and reptiles, but mostly they eat small mammals, such as rabbits.
Great horned owls nest early in the year. They may lay eggs in late January or early February. They don’t have to wait for a thaw. They don’t have to wait to build a nest. They don’t even build their own nests.
These owls typically use nests abandoned by crows and hawks, which may build new nests each year. The owls are such sloppy housekeepers that they do nothing to fix or refurbish the nests they use. They also don’t reuse the nest the next year. Usually, they’ve trashed it.
The winter after the bald eagles built a nest at North Springfield Lake, great horned owls laid their eggs and raised their young in it. By the time the bald eagles returned to the lake, the owls were already established, defending the nest from the eagles that built it.
It’s logical that the much larger eagle should have no problem getting a great horned owl to do its bidding. But no. While it may not be much of a nest-builder, the great horned owl is fierce, while a bald eagle is laid back, some even say lazy. No match for the owl.
So the great horned owls used the nest in 2004 while the eagle pair remained nest-less and nearby, Pelton reports. The following year, after the great horned owls did not return to the nest, the bald eagles resumed bringing nest materials to the site. Bald eagles have a strong nest-building instinct and will refurbish a nest year after year. One bald eagle nest in New Hampshire was observed being occupied for 45 years.
But again in 2005, although the eagles refurbished the nest, they did not lay eggs. And again the following year, the great horned owls got to the nest first and laid their eggs there.
Pelton, Hammond, and others say that the North Springfield Lake is probably not the best site for a bald eagle nest. The lake stays frozen too long, hemming in the eagles’ potential nesting season.
In 2006, bald eagles did nest in Rockingham, not far from North Springfield Lake. Vermont finally had its breeding bald eagle pair.
The great horned owls are not the bad guys. They’ve been stealing nests from bald eagles for millennia without harming bald eagle populations. The bald eagle’s bigger competition for real estate is with us. We like the same waterfront sites for our homes that bald eagles prefer for their nests. Our laws protect bald eagle nest sites, but only if the eagles get there first.
Madeline Bodin is a freelance writer living in Chester, Vermont.