Local Owl Species in Marin
By Audrey Whitten and Oliver Casey
There are roughly 200 different owl species. (Fun Owl Facts for Kids) In Marin County there are four main owl species: the Barn Owl, the Great Horned Owl, the Western Screech Owl, and the endangered Spotted Owl. Two specific species with several differences are the Barn Owl and the Great Horned Owl. To mention a few; the Great Horned Owl is a bit larger than the Barn Owl, and it is also much darker and bulkier. This species also lives in forests, whereas the Barn Owl is better adapted to large open fields and meadows. A great way to tell the difference between these two owls is by their call. The Barn Owl has a raspy screeching noise, and the Great Horned Owl makes a much deeper, shuttering series of hoots. Both species are considered to be at low concern of endangerment in North America due to their large popularity and are commonly found in Marin. Scientists have provided us with a diverse collection of information on owls, specifically the Great Horned Owl and the Barn Owl.
The Great Horned Owl
Great Horned Owls are most likely on low concern due to their ability to adapt easily as long as their is a space to nest. This allows them to live in multiple habitats, from open woodlands, deserts, and even cities. (Great Horned Owl) However, they typically live in open woodlands and nest in trees. They will also nest in man-made platforms in suburban areas. (Great Horned Owl) In building nests, they typically use twigs, feathers, pellets, and fur from their prey. (Great Horned Owl) Before laying their eggs, a monogamous pair of owls will roost together for several months and defend their territory fiercely, often killing intruders. (Great Horned Owl) Finally, when one to four eggs are laid, the incubation period lasts about 30-37 days. (Great Horned Owl) When born, the nestlings’ eyes are closed, pink, with little down feathers and are considered helpless. (Great Horned Owl) Eventually they will grow into a 18.1-24.8 in long, 32.1-88.2 oz adult owl with grey-brown feathers on its body, reddish face, and a white patch on the throat. (Great Horned Owl) They will go from being helpless to fierce predators on the top of the food chain.
In terms of hunting and fitting into Marin’s ecosystem, the Great Horned Owl keeps many populations in check and “Great Horned Owls have the most diverse diet of all North American raptors.” (Great Horned Owl) They are known to be fierce predators; hunting primarily mammals from small rodents to other birds and small to medium sized animals. Examples usually include; hares, rats, crows, and raptors. (Great Horned Owl) Like other owls, the Great Horned Owl is nocturnal and hunts at night, however, they are also known to hunt during the day. (Great Horned Owl) When hunting, they use their large eyes for night vision to spot their prey. After spotting their prey, they pursue the animal in the air and, depending on the size of the animal, will use their strong talons to sever their prey’s spine. (Great Horned Owl) Great Horned Owls are rarely hunted themselves, only will their undefended owlets and eggs become food for larger birds and, coyotes, racoons etc. (Great Horned Owl) Due to their diverse diet and fierce behavior allows the Great Horned Owl to adapt easily and is what makes them common throughout North America, specifically Marin.
The Barn Owl
“Ghostly pale and strictly nocturnal, Barn Owls are silent predators of the night world” ("Barn Owl"). When hunting, they fly back and forth over a field or meadow, and swoop in when their incredible hearing senses prey ("Barn Owl"). Their diet includes mainly rats, mice, and voles; however, they can also eat lemmings, shrews, bats, and rabbits ("Barn Owl"). They often kill and store dozens of rodents at their nest to save for later. This habit is especially common during incubation periods, which are about a month long ("Barn Owl"). Eggs are laid in a nest crafted by the mother, who has done so by regurgitating her own pellets and crushing them up with her feet ("Barn Owl"). These nests are traditionally located in small crevices, burrows, ledges, and caves; however, they also often reside in human-made structures such as barns and silos ("Barn Owl"). When eggs hatch, the offspring are helpless and white all over ("Barn Owl"). These offspring will grow up to be around 40 cm long with a 50 cm wingspan. They will also go from being completely white to having a white underside, and buff and gray backs ("Barn Owl").
Barn Owls are crucially important in our environment, as they eat huge amounts of rodents, thus keeping the population in check. Without their presence, rat and mice populations could skyrocket and these pests could devastate the populations of what they eat: “grains, fruits and seeds” ("What do Mice Eat"). In addition, mice and rats could devastate crops and be a general nuisance to residents of our local area. Barn owls don’t really have any predators, although their babies are sometimes eaten by snakes, and they can also become prey to Great Horned Owls ("Barn Owl"). Like Great Horned Owls, they are of low concern ("Barn Owl"). However, they are more easily affected by humans than the Great Horned Owl. It is believed that their populations have dropped due to loss of available nesting area; that’s why nesting boxes have helped them specifically ("Barn Owl"). They are also greatly affected by rat poisons, due to the rodents making up a large part of their diet ("Barn Owl"). In Marin, it’s our goal to help the Barn Owl maintain a steady population.
Scientists have been able to provide us with such a vast knowledge of owl species, including their behavior, diet, and habitat. In Marin, it is our duty to use this information to help our local owl species thrive in a healthy resourceful environment.
Works Cited
"Barn Owl." All About Birds. The Cornell Lab of Ornithology, n.d. Web. 29 May 2015.
"December BOTM: Our Local Owls." Wild Birds Unlimited. Wild Birds Unlimited, Inc., n.d. Web. 29 May 2015.
"Fun Owl Facts for Kids." Animal Facts. Science Kids, 9 Feb. 2015. Web. 01 June 2015.
"Great Horned Owl." All About Birds. The Cornell Lab of Ornithology, n.d. Web. 29 May 2015.
"What Do Mice Eat - Mouse Bait." Orkin. Orkin, LLC, n.d. Web. 31 May 2015.
There are roughly 200 different owl species. (Fun Owl Facts for Kids) In Marin County there are four main owl species: the Barn Owl, the Great Horned Owl, the Western Screech Owl, and the endangered Spotted Owl. Two specific species with several differences are the Barn Owl and the Great Horned Owl. To mention a few; the Great Horned Owl is a bit larger than the Barn Owl, and it is also much darker and bulkier. This species also lives in forests, whereas the Barn Owl is better adapted to large open fields and meadows. A great way to tell the difference between these two owls is by their call. The Barn Owl has a raspy screeching noise, and the Great Horned Owl makes a much deeper, shuttering series of hoots. Both species are considered to be at low concern of endangerment in North America due to their large popularity and are commonly found in Marin. Scientists have provided us with a diverse collection of information on owls, specifically the Great Horned Owl and the Barn Owl.
The Great Horned Owl
Great Horned Owls are most likely on low concern due to their ability to adapt easily as long as their is a space to nest. This allows them to live in multiple habitats, from open woodlands, deserts, and even cities. (Great Horned Owl) However, they typically live in open woodlands and nest in trees. They will also nest in man-made platforms in suburban areas. (Great Horned Owl) In building nests, they typically use twigs, feathers, pellets, and fur from their prey. (Great Horned Owl) Before laying their eggs, a monogamous pair of owls will roost together for several months and defend their territory fiercely, often killing intruders. (Great Horned Owl) Finally, when one to four eggs are laid, the incubation period lasts about 30-37 days. (Great Horned Owl) When born, the nestlings’ eyes are closed, pink, with little down feathers and are considered helpless. (Great Horned Owl) Eventually they will grow into a 18.1-24.8 in long, 32.1-88.2 oz adult owl with grey-brown feathers on its body, reddish face, and a white patch on the throat. (Great Horned Owl) They will go from being helpless to fierce predators on the top of the food chain.
In terms of hunting and fitting into Marin’s ecosystem, the Great Horned Owl keeps many populations in check and “Great Horned Owls have the most diverse diet of all North American raptors.” (Great Horned Owl) They are known to be fierce predators; hunting primarily mammals from small rodents to other birds and small to medium sized animals. Examples usually include; hares, rats, crows, and raptors. (Great Horned Owl) Like other owls, the Great Horned Owl is nocturnal and hunts at night, however, they are also known to hunt during the day. (Great Horned Owl) When hunting, they use their large eyes for night vision to spot their prey. After spotting their prey, they pursue the animal in the air and, depending on the size of the animal, will use their strong talons to sever their prey’s spine. (Great Horned Owl) Great Horned Owls are rarely hunted themselves, only will their undefended owlets and eggs become food for larger birds and, coyotes, racoons etc. (Great Horned Owl) Due to their diverse diet and fierce behavior allows the Great Horned Owl to adapt easily and is what makes them common throughout North America, specifically Marin.
The Barn Owl
“Ghostly pale and strictly nocturnal, Barn Owls are silent predators of the night world” ("Barn Owl"). When hunting, they fly back and forth over a field or meadow, and swoop in when their incredible hearing senses prey ("Barn Owl"). Their diet includes mainly rats, mice, and voles; however, they can also eat lemmings, shrews, bats, and rabbits ("Barn Owl"). They often kill and store dozens of rodents at their nest to save for later. This habit is especially common during incubation periods, which are about a month long ("Barn Owl"). Eggs are laid in a nest crafted by the mother, who has done so by regurgitating her own pellets and crushing them up with her feet ("Barn Owl"). These nests are traditionally located in small crevices, burrows, ledges, and caves; however, they also often reside in human-made structures such as barns and silos ("Barn Owl"). When eggs hatch, the offspring are helpless and white all over ("Barn Owl"). These offspring will grow up to be around 40 cm long with a 50 cm wingspan. They will also go from being completely white to having a white underside, and buff and gray backs ("Barn Owl").
Barn Owls are crucially important in our environment, as they eat huge amounts of rodents, thus keeping the population in check. Without their presence, rat and mice populations could skyrocket and these pests could devastate the populations of what they eat: “grains, fruits and seeds” ("What do Mice Eat"). In addition, mice and rats could devastate crops and be a general nuisance to residents of our local area. Barn owls don’t really have any predators, although their babies are sometimes eaten by snakes, and they can also become prey to Great Horned Owls ("Barn Owl"). Like Great Horned Owls, they are of low concern ("Barn Owl"). However, they are more easily affected by humans than the Great Horned Owl. It is believed that their populations have dropped due to loss of available nesting area; that’s why nesting boxes have helped them specifically ("Barn Owl"). They are also greatly affected by rat poisons, due to the rodents making up a large part of their diet ("Barn Owl"). In Marin, it’s our goal to help the Barn Owl maintain a steady population.
Scientists have been able to provide us with such a vast knowledge of owl species, including their behavior, diet, and habitat. In Marin, it is our duty to use this information to help our local owl species thrive in a healthy resourceful environment.
Works Cited
"Barn Owl." All About Birds. The Cornell Lab of Ornithology, n.d. Web. 29 May 2015.
"December BOTM: Our Local Owls." Wild Birds Unlimited. Wild Birds Unlimited, Inc., n.d. Web. 29 May 2015.
"Fun Owl Facts for Kids." Animal Facts. Science Kids, 9 Feb. 2015. Web. 01 June 2015.
"Great Horned Owl." All About Birds. The Cornell Lab of Ornithology, n.d. Web. 29 May 2015.
"What Do Mice Eat - Mouse Bait." Orkin. Orkin, LLC, n.d. Web. 31 May 2015.