The Ruffed Grouse’s Mysterious “Crazy Flight”

Exploring the Ruffed Grouse behavior enigma of crazy flight through history and science

It was late September, the Minnesotan air was cool, and Ruffed Grouse were on my mind. We had just thrown our hunting gear in the back of the pickup, ready to head out for a day of chasing dogs through grouse cover, when my cell phone began to vibrate. Normally, I would let it go to voicemail. However, having only just walked out of the camp, my fiancée calling would have meaning.

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“A grouse just flew through the window and landed on the bed,” Sabrina said with a mix of shock and nervous laughter.

“What?” I responded.

Slower and more pronounced, she said, “A grouse flew through the window and landed on the bed.”

I hung up the phone with slight confusion on my face and turned to my companions. “I need to walk back up to camp,” I told them.

When I arrived at the scene of the incident, it was very much as described. A young grouse had flown through a second story window and landed on the bed in front of our dog, Marty. Despite being a 15-pound, non-hunting dog, it was known that day forward that Marty’s Ruffed Grouse hunting skills were unrivaled.

This is not the first time I saw this happen. And believe it or not, the behavior has an actual name: crazy flight. Written references can be found going back to the turn of the century in anything from hunting classics to ornithology books.

What is Crazy Flight?

Crazy flight is when a Ruffed Grouse flies at top speeds for great distances. It occurs specifically around summer’s transition into autumn, right as leaves begin to fall. First-year grouse in particular exhibit this behavior. Grouse can be seen making huge flights across highways, big open fields, and even into metropolitan areas like New York City. During many of these events, these birds end up going headfirst into windows, a threat to birds in general. However, this specific behavior and the speed associated with it make it both deadly and destructive.

Victor C. Friesen wrote of The Crazy Flight Phenomenon of the Ruffed Grouse in Volume 29, Number 03 of the print Canadian journal “The Blue Jay.” He pointed to a reference by John Audubon himself in 1820 that described the behavior as “partial sorties.”

William Harden Foster, famous painter and Ruffed Grouse hunter, referred to it as the “crazy” season. He wrote, “Few writers on the ruffed grouse fail to recognize and make note of the bird’s so-called crazy season. This is supposed to be a time in the autumn when grouse begin dashing hither and yon, and often end up by driving blindly into buildings, wire lines, or other obstructions. Some old gunners who were never especially impressed by this ‘crazy’ season theory believed that the grouse becomes unnaturally nervous while the autumn leaves are showering down and will do extraordinary things while thus temporarily agitated.”

Foster described each side of the debate as to why the crazy flight occurs nearly 100 years ago. Believe it or not, that debate has raged on. While it has not technically been solved, the scientific community has some much more grounded and widely accepted concepts.

Why do Ruffed Grouse commit to crazy flight?

Fear may be a driving factor for crazy flight. Ruffed Grouse, when pursued by predators, will fly hard and fast, sometimes for great distances. Birds of prey can drive them an even greater distance with a more erratic flight. However, this is a year-long behavioral response.

Foster did not believe that something as simple as leaves falling to the ground caused birds to commit such a rash act. “It can hardly be accepted as reasonable that a race of birds that has lived in a land of falling leaves from time immemorial should develop an annual panic when other natural phenomena such as thunderstorms, hail, or heavy snows fail to produce any sort of nervous upset,” he wrote.

One of the more interesting concepts was noted by Friesen in 1925 in a study that found seven out of 10 Ruffed Grouse died as a result of crazy flight also had stomach worms. In 1947, “A ruffed grouse marked by attaching a bell to its wing was found later with a broken neck, having flown against a tree,” wrote Friesan. “The suggestion was that the bird, irritated by the bell, responded similar to a bird irritated by a parasite.”

Later studies found a lack of stomach worms. In 1927, another theory was that Ruffed Grouse “inherited the instinct of migration.” (Friesen 1971) By 1948, that was debunked by studies noting no pattern in the direction in which these crazy flight birds were headed.

Food as a topic has also been cited as a potential cause of crazy flight. A very specific claim was made around “moldy and fermented rose hips.” As Friesen points out, a decade long study by the state of New York eliminated rose hips as a significant Ruffed Grouse food.

Maybe slightly more unusual, but more widely accepted, is an idea around a Ruffed Grouse’s urge for certain foods. Foster wrote on this idea,

“The logical answer to why grouse move considerable distances is because of their quest of food. A grouse eats about everything from grasshoppers to acorns and one ornithology lists one hundred and sixteen known items of grouse diet to which several more might be added. The strange part of it is that the grouse is a decided gourmet. It will apparently pass by quantities of food that is known to be a part of its diet and go long distances for some other item.”

Foster’s interest in the subject was about how grouse can seemingly vanish from areas that normally hold grouse, even with food present, causing frustration for the “novice gunner.”

In John Audubon’s research, 50,000 Ruffed Grouse flushes were observed and resulted in only six accidental deaths. This is testament to any grouse hunter’s knowledge of how Ruffed Grouse can fly through thick cover, dodging the best grouse shooting techniques.

The theories on crazy flight have certainly added to its mystery.

Why Did a Grouse Fly Through My Window? – Current Science

The most important clues to the theory of crazy flight have to do with both the age of the birds and the time of year. This time of year is when broods break up, resulting in younger birds finding a new home turf.

Friesen wrote,

“Edminster (1947) provides us with one of the most detailed explanations of the crazy flight phenomenon. Young Ruffed Grouse become quarrelsome as they attain sexual maturity in fall. A bird may be driven away by a member of its own brood, and its flight may be reckless as it seeks to flee its tormentor. This bird must find a territory elsewhere, but it may encounter further hostility from other grouse already established there. With continued harassment, the grouse will become ‘more nervous’ and ‘more desperate’ because of its ‘growing inferiority complex.’ It will thus fly out of its normal habitat, and on occasions, fly against objects in those un- familiar surroundings.”

The Connecticut Department of Energy and Environmental Protection concurs with the idea saying, “In early fall, many grouse exhibit a dispersal behavior commonly referred to as ‘crazy flight.’ At this time of year, grouse are often seen in unusual habitats or are victims of collisions with trees, cars, or houses, etc. This strong urge to disperse is largely exhibited by young birds, whereas adults tend to remain within the previous year’s home range.”

Does Crazy Flight Have a Significance to Grouse Hunting?

While the mystery of the Ruffed Grouse’s crazy flight has untangled over the centuries, the truth is that its significance to hunting Ruffed Grouse is only minor. This is because the days of early September grouse seasons ended with the market hunting era. Much as we mark the coming of Blue Jays to signal the arrival of migrating woodcock, one could derive the evidence that broods are breaking up when crazy flights begin. Although, unlike the American woodcock, it’s probably before the season opens. Most states have designed their hunting season to not overlap with brooding behavior as to limit the vulnerability of a bird exhibiting such behavior when encountered by a grouse hunter.

Foster talked about this in his classic New England Grouse Shooting,

“The gunner of the earlier period started in on the first of September when the young birds were still in flocks. The country gunner knew where many of these used to start sixty or seventy pa’tridges in a day; he may be remembering those early-season trips when he went from one to another of these spotted broods. To start six or eight of them on a certain well-remembered day would not be at all improbable. This might well mean sixty or seventy different birds if the flocks ran large. But the same gunner, on the same year, didn’t move those sixty birds after the middle of October… Today our open seasons do not begin until after the birds are scattered and the seasons are much shorter.”

I will never forget the day of Marty’s great hunt from his bed, shattered glass spread across our bags and clothes. His hunt piqued my interest in asking, why would a grouse do this? It brought me on an incredible 200-year journey featuring iconic people, unique ideas, and an amazing history of observing the Ruffed Grouse behavior called “crazy flight.”