The Great Horned Owl – Everything You Need to Know About It

13 mins read



Let’s take a look at one of North America’s most iconic birds, The Great Horned Owl, also known as the ‘ Winged Tiger ‘ or tiger owl.

Class: Aves

Family: Strigidae

Bird Species: Bubo virginianus

Order: Strigiformes

Physiology

The Great Horned Owl (bubo virginianus) is a raptor and lives mainly on mice, rats, large insects, rabbits, and voles. It will use its talons to catch prey or to strike a quick blow with its wings on its opponent. This bird has two eyes that are encased in rings of yellow color with a white throat.

They have been known to have wingspans up to 4 feet long as well as two nearly identical tails with a tail length of 7.7 to 9.9 inches that allow for more maneuverability in flight or when hunting prey on land. The great horned owl can be found in all states except for Alaska.

They are also among the earliest nesting birds, usually found near large fields and forests. The great horned owl hunts during the still night and will use its eyesight to either see only two feet in front of it or about 7 or 8 feet out; they have excellent night vision. It can strike prey up to five feet away with its talons.

Let’s talk about The Great Horned Owl identification, it is a very large widespread owl that is a part of the typical owl family – the Tytonidae. The bird has prominent ear tufts and long rounded wings, which are brown to gray with white spots. It has a bold stance, a beard of feathers on its face, yellow eyes, and legs which are covered with downy feathers that help keep them warm in autumn and winter. It has a beak that is hooked, making it useful for catching its prey from inside of grasses and caverns. It has an average length of inches in length with a wingspan that is around 6.5 feet and a weight of nearly. It is one of the largest owls in the world.

The great horned owl’s vision, vocalization system, reproductive rate, longevity, metabolism, growth rate, and diet are all fascinatingly different than humans. Below I will discuss each of these aspects of the bird’s physiology.

Because the Great Horned Owl lives mostly in open areas, they must have long feathers to protect themselves. When they are on the ground, their feet are small compared to the rest of their body which helps them avoid being trapped or tracked down by their predators. Their talons are very powerful and can kill prey with one strike; however, they do not hunt during daylight hours due to their lack of good sight. They can fly up to speeds up to 40 miles per hour and dive at speeds of up to 150 miles per hour while hunting for prey at night.

photo 1517359828850 1a4aae6d70f9?ixid=MnwxMjA3fDB8MHxzZWFyY2h8Mnx8Z3JlYXQlMjBob3JuZWQlMjBvd2x8ZW58MHx8MHx8&ixlib=rb 1.2
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1. Vision

The great horned owl’s eyes have been known to have six million cone cells, which are used for color vision. This means it can see about two feet in front of it on a black and white level. However, the great horned owl has rods on its retina that can see up to about 7 or 8 feet, allowing for better night vision. This bird has yellow rings around its eyes that cause more light to come into its eye. The yellow rings act like glasses, if you will. Their eyes have been known to have a retina that is about 30% larger than a human’s retina. This allows the owl to get more light into its eye, therefore making it better at night vision. When it is hunting, it searches for its prey by sight and sound. It can heard from between four and 20 miles away, making it very successful at hunting even in areas where there are no artificial lights

brown and gray owl
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2. Vocalization System

The vocalization system of the great horned owl is very unique compared to barn owls. The great horned owl has three different types of calls that it can use in several different combinations, along with a raspy screech and a very deep booming call. It can produce about fifteen different sounds and vocalizations throughout its lifetime. The greatest call variation comes from the young owls, who develop their own signature whistle.

3. Longevity

The lifespan of a great horned owl is very long compared with a snowy owl. The average lifespan is about 20 years in the wild, but it has been known to live up to 30 years in captivity. The male great-horned owls will live longer than their female counterparts. Both males and females can live for more than 20 years.

4. Metabolism

The metabolism of the great horned owl is extremely fast compared with humans. The great horned owl can burn through its fat reserves in an amazing amount of time. If you compare the metabolism rates of the great horned owl to that of humans, it burns through its fat reserves in about 6 hours while humans take 7 days. Not only that, but one hour after eating a prey item, the great horned owl can burn through its fat reserves. A human could not do that until about 7 hours after eating. This is possible because of the number of mitochondria found in each cell of the great horned owl. Mitochondria occur in large amounts and aid in this bird’s metabolism.

5. Growth Rate

The growth rate of the great horned owl is also very fast compared to humans. The young birds grow at about 4-8 gms an hour and will grow at a rate of 1 inch per week, starting from the time they hatch as chicks and continuing as juveniles to adults as long as they are healthy and getting enough food. This amount of growth is very fast and allows the young birds to become adults in about 7 months, which is shorter than the great horned owl’s average lifespan.

6. Diet

The Great Horned Owl is not a prey species, which eats mostly small mammals, birds, reptiles, large insects, amphibians, and invertebrates in its native range in middle South America; rodents, rabbits, snakes, and other mammals in winter; occasionally eating large insects in the spring and summer; birds (including gamebirds) in winter. They sometimes attack small peregrine falcons.

The bird preys mainly on mice and skunks (mammalian prey) by grabbing them with their feet and then stabbing them with their long-curved beak. The amount that this type of bird eats depends on its metabolism as well as its size. The great horned owl can eat up to .73 cubic feet of prey every night, which is equivalent to 2 mice every day. This means that this bird can eat up to 10 mice in one night just by itself.

 

7. Habitat

Wo The Great Horned Owl (bubo virginianus) is the largest and the most widely distributed of North America’s owls. The Great Horned Owl is distributed throughout North America, ranging from the arctic tundra to the southern United States. They can be found in various parts of the United States and Canada, but they are more common in the northern parts of the U.S. and Canada. This owl is migratory, with most sightings occurring during migration periods in the spring and fall; however, they may also travel to other areas such as Hawaii or Alaska during warmer months. They migrate for different reasons, such as finding food or searching for a mate; finding both of these birds may indicate that there will be an event nearby that attracts lots of people (such as music festivals), which may attract predators like this owl to nearby locations.

Bubo virginianus dis
Source: Wikipedia CC BY-SA 3.0 @ All Rights Reserved

The Great Horned Owl can be found from the Atlantic seaboard to the Great Plains and from Alaska to the central America. In Alaska, they are common owls in most areas. In Canada, these birds can also be found near wetlands. They are found throughout Canada where they are known as ‘hoot owls’, and in many other countries around the world including Argentina, Brazil, Chile, Denmark, England, Ireland, Israel, Japan, Russia, South Africa, and Sweden, they wander long distances.

Throughout their range, this nocturnal bird can be found in all sorts of habitats, from open deserts to dense forests. They are also seen at altitudes up to 10000 ft above sea level, and they wander long distances. Occasionally, they have been seen sitting quietly in the daytime and late afternoon at the tops of tall trees.

This owl makes a variety of sounds like most owls to communicate with other owls or to scare off intruders. They give a warning call that sounds like a human whistle and another call that makes a low hissing noise like air escaping from an automobile tire.

The Great Horned Owl usually nests on the ground, but it will nest in hollows in trees if there are none on the ground available. The male chooses the nesting site, which is often undisturbed rocky cliffs, or they make a nest on cliff ledges; the nest material, like all other large birds, is nearby branches and twigs, which make it as strong as a heavy brush.

8. Urban and Rural Nesting

While there is no variation in production between urban and rural populations, there are disparities in nest selection. These owls are atypical of the open country. Rural owls are more likely to use ancient raptor nests than urban birds, who prefer crows or squirrel nests. In addition, compared to rural nesting habitats for Great Horned Owls, urban nesting individuals use trees that are taller/wider in diameter and nest significantly higher. The reason for this increasing tree height is that big trees are employed for decoration, shade, and shelter in metropolitan settings. Human avoidance was blamed for the higher nesting in the taller trees because the great horned owls hunt along highways, both rural and urban nesting locations were frequently within range of paved roads from the northern populations.

Adult great horned owls who nest in urban locations are more likely to deposit eggs earlier than those who nest in rural regions, according to studies. In Wisconsin, eggs in rural nests hatched a month earlier than their counterparts in urban locations (in January rather than February), owing to increased shelter from wind and cold. Nesting owls in Winnipeg, Manitoba, began nesting five to six weeks sooner than those in rural Manitoba, owing to a particularly mild winter by Winnipeg’s standards, as well as the benefit of the city’s urban heat island.

They also keep in mind climate change when they think about nesting.

 

9. Mating Call

A male’s mating call is a highly specific series of guttural hoots. These hoots are so low and so soft that they can be hard to pinpoint within the forest. A female owl hears these calls with her ear on top of her head, which is positioned low to the ground.

The first part of the male’s mating call is similar to that of an adult female who has just laid an egg. The female responds with her own set of hoots, which peaks right before she lays another egg; this builds up the anticipation for copulation in both birds before it happens.

The male’s second call is one of the most specialized syllables he will make. A male owl calls out this almost-piercing, low-frequency cry in order to attract a female. It is the only sound that indicates that it is mating season, which makes it perfect for attracting a mate. This mating call is most commonly given around dusk and dawn when he knows that most females are hungry for food.

The last part of the male’s mating call is similar to an adult female’s “keeow” sound. Her “keeow” signals to the males that she is ready to mate with whoever has the highest status in her region.

Female Great Horned Owls don’t respond to the hunting calls of males. Both sexes will leave their nests after hearing the calls of other owls, but once the hatchlings are alone, they immediately head for a nearby stream to fill their bellies with fresh water. The fact that they leave their nest so soon is what makes the mating call so effective.

The male owl makes his mating call every night, hoping to attract a female who has been listening closely to his raspy hoots. He switches between two different mating calls during the nesting season: a short series of hoots and a soft, almost whisper-like cry that sounds like “kw...”. In comparison to the females, his mating call is much deeper and throatier.

A female Great Horned Owl will not come down from her nest until she has been hearing the mating calls of a male for a couple of weeks. She chooses a mate based on his size, his age, and how convincing his courting calls sound. Once she has made her decision, this female will leave her body weight in mouse skeletons outside her nest to show how big of a meal she can provide for him during their courtship period.

10. Reproduction

The Great horned owl is a bird that breeds throughout North Africa, Europe, Central Asia, and the Middle East. When it starts to breed in late spring or early summer, it is considered to be the breeding season. The female begins laying eggs in the nest but does not sit on them. The female and male take turns incubating and sitting on their eggs for three weeks following the last egg’s laid.

While this process takes place, both parents hunt for food while taking care of their young ones at night. Eggs hatch after about 28 days, and the chicks will remain with their parents until they are able to fly at about four months old when they move away from them so they can find a territory of their own. These kinds of owls are considered to be monogamous pairs.

During the one to two years that it lives, there is not much difference between the facial disc or any other physical appearance of a Great Horned Owl and a normal owl. During this time, however, the Great Horned Owl will grow and develop greatly in size and also lose its feathers.

11. Their Predator

The Great Horned Owl has no natural predators. Wounding or killing the owl is usually difficult because it does not perch on branches “like other birds” but instead sits out on open limbs, making it difficult to get a shot at the bird with a firearm.

There are some insect species that can prey upon owls, such as large carpenter ants, and may also attack eggs and nestlings when they come across them in their search for food. Other than such circumstances, there are no known natural enemies of this raptor species.

In recent years, some owls have been killed by domestic cats. In order to produce a more appetizing meal, some feral cats have been intentionally fed by owls, resulting in the bald birds of prey being killed. Owls are known to be more of a threat for damage to humans and their property than domestic cats are.

In certain parts of North America, the Northern Hawk Owl has been expanding its range and eating Great Horned Owls. There is a theory that the Northern Hawk Owl may have been artificially selected for its rapid attack on owl-prey because it is believed that the Northern Hawk Owl might have been able to kill larger owls despite being smaller on average than them. The Northern Hawk Owl can prey upon the Great Horned Owl due to it being able to snatch an owl from its high perch, while no other avian predator is known to have this advantage against the Great Horned Owl.

Close-Up Shot of a Great Horned Owl Looking at Camera
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The only animals that are confirmed to prey upon the Great Horned Owl are humans, which hunt them for their feathers and meat. Some of the human-caused deaths of Great Horned Owls may involve poisoning, usually when farmers use poison gas in order to control vermin populations. Roughly 20% of all known deaths in Idaho are caused by humans. The 80% majority of unnatural deaths are either caused by cars or electrocution.

The birds of prey are not known to be hunted by the larger raptors in their range, despite their size being considerably greater. This is because smaller raptors are vulnerable to injury when attacking the fierce talons of the Great Horned Owl. However, there was an instance where a golden eagle was observed attacking a Great Horned Owl that it had successfully captured.

The human-caused death rate of owls has led their conservation status to change to “vulnerable” species in some places.

12. Conservation

The great horned owl has been classified as an endangered species due to habitat loss and human interference with their natural food sources. Their main fierce predators are humans themselves, thanks to decreased large rodent populations thanks to habitat destruction. Another reason for this decline is the decrease in the number of prey these birds can catch.

Human activities have also made it difficult for the great horned owl to nest in their natural environments. The same habitats that are ideal for nesting are logged for construction materials, which puts the eggs at risk of being crushed or buried.

The great horned owl has also been hunted by humans illegally because they are believed to be responsible for diminishing other animal populations like rabbits and mice. This behavior makes it difficult to rebuild the population of great horned owls because they do not have sufficient members in their family groups. It is estimated that the population of great horned owls has decreased by 30% over the last seven years. There are still great horned owl populations living in urban areas, which are mostly avian- predators.

The US Fish and Wildlife Service is currently working on potential conservation methods for greater horned owls, but none have been found yet until significant changes are made in their habitats. Scientists are currently investigating ways to protect owl eggs and nests by using scare tactics like predator decoys or owl calls.

The status of the great horned owl would be improved by reducing the urban sprawl that is taking over green spaces, which are important for their nesting habits. Camping in protected areas needs to be prohibited since these birds are not used to human proximity. Wildlife rehabilitation centers should promote the adoption of great horned owls so they can live in captivity if they cannot survive in the wild anymore. Steps have been taken to ensure all captive birds, prey to human amusement, are returned to their natural habitat. These steps will help ensure that the great horned owl is able to continue living in its natural environment for years to come.

13. Miscellaneous

The Great Horned Owl is an early nesting bird and is one of the most sought-after birds in North American coinage. These birds have appeared on a total of three different coins from the United States of America, two from Canada and also from Mexico. This owl is shown on a 2015 coin from Canada’s Birds of Prey series, along with the Hoary Bat, Northern Hawk Owl, and the Red-Tailed Hawk. One side of this coin shows an adult owl in flight with a hare in its talons, while a nest with two small owls inside is on the other side. The obverse side shows Queen Elizabeth II’s facial image.

Buy Canadian Silver Owl Coins | Buy Silver Owl Coins | KITCO
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