Sunday, April 14, 2013

The Winged Tiger in Our Woods

I overheard a conversation some time ago. A woman was lamenting the disappearance of her cat. It was outside at night, and never returned. In the woods near her home, she had seen the tracks of a fisher. With a wavering voice, she concluded that her beloved tom had been taken by the fisher.

Outdoor cats are predators which kill billions of birds and mammals.
The out-of-doors can be a dangerous place for all manner of animals. A house cat out-of-doors is a predator. A recent study has significantly raised the estimate of carnage from outdoor cats; they are the leading cause of death among both birds and mammals in the United States, killing 1.4 billion to 3.7 billion birds each year. A beloved house cat sometimes brags of its prowess by depositing a carcass at the feet of its owner (or cat servant). Sometimes the cat lover will complain about the carcass, but rarely about the unseen toll that the out-of-doors cat may take on other wildlife.

However, fair is fair. Out-of-doors, the distinction between predator and prey is rarely a firm distinction. Beloved domesticated kitty and untamed wild animal means nothing when they all roam, unleashed through the woods, shrubs and fields. Predator may become prey. The predatory house cat may be preyed upon, and not return home come morning.

I was tempted to interrupt the woman whose quavering voice lamented the loss of her beloved tom and tell her that beloved kitties are not killed by fishers if they are kept indoors. I did not say that to her. I say it now to all cat owners. Your outdoor cat is a predator. It is also fair prey. Keep it inside. End of sermon.

Pound for pound and ounce for ounce, the fisher may be the most formidable four legged predator in our woods, quite capable of killing an animal larger than itself, including tame pussy cats and of holding off, or even taking down, most slobbering house dogs. However, I suspect the fisher takes the blame for more house cat disappearances than it deserves. The true tiger in our woods is not fur bearing, but feathered - a stealth hunter.

Great Horned Owl guards its nest at Heinz NWR
Bubo virginianus - The Great Horned Owl. One of the folk names for the Great Horned Owl is Cat Owl. When food is short, wrote Edward Forbush, the Massachusetts ornithologist, “the owl will attack even the domestic cat, and usually with success.”

The Great Horned Owl is our most widespread owl, found throughout North and South America, and adapted to a wide variety of habitats.  “Powerful” and “dangerous” are the adjectives most frequently used by writers from the early nineteenth to the early twenty-first centuries to describe this bird. John James Audubon knew it as one of the most common species along the shores of the Ohio and Mississippi  Rivers. “The Great Horned Owl,” Audubon wrote, “lives retired, and it is seldom that more than one is found in the neighbourhood of a farm, after the breeding season; but as almost every detached farm is visited by one of these dangerous and powerful marauders, it may be said to be abundant. The havoc which it commits is very great. I have known a plantation almost stripped of the whole of the poultry raised upon it during spring, by one of these daring foes of the feathered race, in the course of the ensuing winter.”

Great Horned Owl - Bombay Hook NWR
The Great Horned Owl may have an equal in the Western Hemisphere as a predator, but it has no superior. And in our neighborhoods, it has no superior. The imperial looking Bald Eagle doesn’t begin to compare as a predator. Our national symbol is quite content to feed on a deer carcass (something a Great Horned would never do), or steal fish from an osprey. The Bald Eagle is an adept fish hawk. When necessary, it is capable of taking the similarly sized Canada Goose. But the Great Horned Owl can also take the Canada Goose is spite of the goose weighing three times as much as the owl. It may take a Wild Turkey which can weigh even more than the goose. And, the Great Horned has been observed driving the Bald Eagle away from its aerie and appropriating the nest for its own use.  Again, quoting Forbush: “The Great Horned Owl is no respecter of persons. It kills weaker owls from the Barred Owl down, most of the hawks and such nocturnal animals as weasels and minks.”  In Texas during a three night period, a Great Horned took a Cattle Egret, a Great Blue Heron, and a gray fox.

Great Horned Owl near Bisbee, AZ
The Great Horned Owl has many enemies that hate him, but none that are dangerous, except for humans. It has earned the particular enmity of the crow. And for good reason - its depredations among the crow population can be prodigious. It will take old and young crows from the nest at night and during the winter will pick crows off of their night roosts. It is crows that will most often give away the Great Horn’s presence during the day. When you see crows noisily flying around the top of a tree, it is quite likely that they are mobbing their most dangerous enemy. Eventually the crows’  harassment may stir the desultory owl into flight; as it leisurely flies off, the crows continue their uproarious pursuit.  Pete Dunne writes: “Absolutely hated by crows, who amuse themselves by gathering around roosting owls and haranguing them with a gritty vehemence they inflict on no other enemy.” Except - there is nothing amusing about the crows’ actions. The presence of the Great Horned Owl is a mortal danger to the crows. The crows may be courageous and bold during the day, but when night descends they cede any advantage they might have to the powerful stealth hunter of the night.

The Great Horned Owl shares habitat with the Red-tailed Hawk. If you have the hawk, you  almost certainly have the owl. One is diurnal, the other nocturnal. The Great Horned Owl nests early, often as early as February when winter still holds its grip. It will sometimes appropriate an old Red-tailed Hawk nest.

In our regenerated Vermont woodlands, it is very difficult to sight a Great Horned Owl. One time on a wooded Newfane hill, I was sure there was a Great Horned in a tree overhead - the mobbing crows gave away its presence with their loud and wild cawing. But the owl was impervious to the crows and I never saw a shadow of its flight.

At night it is easier to know its presence. I have often heard this owl at night as it queries the dark landscape and answers itself: “Whooo’s awake? ... Meee, too .... Whooo’s awake? .... Meee too.” The owl is probably calling for its mate, but he is also telling me that the night belongs to him.

Great Horned Owl near Wilcox, AZ
One January day in Arizona, I saw three Great Horned Owls. I was with people who knew where they roosted.  They led the way through the desert to a copse near a watering hole where we searched the bare trees for the owl. Its appearance as it perched on the limb conveyed a somnolent disregard for us, or perhaps a haughty arrogance. But as it turned its head and blinked in my direction I felt a sleepy malice in his stare. I was glad that I was too big to be in danger from this winged tiger. At least, I think I was too big.

Chris Petrak
Tails of Birding


  1. They are truly a magnificent bird. I see them occasionally in our area. And have gotten some nice photos of them.

  2. I can believe the house cat carnage. Dogs are ironically less dangerous. My dog tried to catch squirrels and birds for years and never came close to her dismay.

  3. Fabulous post. I've noticed that frequently the uninitiated (non wildlife folks) will attribute a pet death to something dramatic and, usually, some native wildlife species. More often I expect the cause is cars, dogs, and other cats.

    There are, of course, also many wildlife species where I live that might kill a cat, including foxes, coyotes, bobcats, bears and mountain lions. I don't know if they'd all bother, but I've been told that bobcats do NOT tolerate competition from other kitties, so will dispatch them, and walk away. We ALSO have great horned owls, and I didn't know about their cat killing propensities, nor their crow killing bent. Super interesting.

    Our kitties are indoor cats (I am a conservation biologist, after all), so I have little to fear for them, save too much kibble and too little exercise. One final note: even if your pet does not kill animals, they can cause great stress which can tip the scales if they are just barely able to get by. For the wildlife, they believe their life is in danger, so I it's probably very physiologically stressful and energetically expensive to be pursued by a predator, regardless of how inept the dog (or cat) is.

  4. Very well written post and an enjoyable essay to read. Perhaps due to the lesser density of trees in the intermountain west, Great Horned Owls are fairly easy to find year round. In my birding patch I know of five active nests. I've observed only one hatched owlet so far. I can almost always find the smaller male mate nearby. A magnificent beast that will forever thrill me.

  5. Excellent post! Friends who ranched in a rural canyon told me that owls and coyotes took many of their barn cats -- the lighter-colored ones never lasted long. I love cats, and would never dream of letting a cat of mine roam the neighborhood. Catios, people!

    The MidwestWeekends blog noted a recent NY Times article. Excerpt:

    We watched a New York Times video that called owls 'an avian tribe apart.'

    In the video, Norman Smith, director of the Audubon Blue Hills Trailside Museum in Milton, Mass., talks about a nesting pair of great horned owls he had watched.

    “They brought in a pheasant, a number of ducks, a small raccoon, a woodchuck, two cats and a toy poodle,'' he said. “A lot of (chicks) don't survive, but if every great horned owl chick that hatched survived, there would be virtually nothing left in these woods.''

    Thanks for the fine post!

  6. Well said, Chris. I am glad for the admonition to keep one's cats indoors. And I discovered the deadly nature of this owl when I lived in Idaho for a couple of years back in the 80's. It was really my first encounter with living with this species nearby and back then we lived far out in the country in a small ranching area. Everyone had cats that lived outdoors. We had a new kitten that was playing on the front porch. I left early in the morning to do errands and when I came back the kitten was gone. I suspect the nearby nesting Great Horned owls ate it for breakfast before tucking in for the day. This incident, plus a couple of others, plus becoming more educated on the subject has led me to keep my cats indoors for the past 13 years. I only wish more cat owners would learnt his lesson! A very timely and appropriate post!