Body Systems Of the Spectacled owl
Digestive System
Reproduction and Life Cycle
Respiratory System
Nervous System
Skeletal and Muscular System
Circulatory System
Reproduction and Life Cycle
Respiratory System
Nervous System
Skeletal and Muscular System
Circulatory System
Digestive system
Spectacled Owls hunt small animals including mice and the occasional possum or skunk, insects, spiders, many caterpillars, bats, birds up to the size of Jays crabs and frogs. When hunting, they perch on a branch to scan the surrounding area. When they locate their prey they drop down on it.
Because owls cannot chew their food, they swallow small prey animals whole and or tear larger prey into smaller pieces before consumption.
Owls, unlike other birds, do not have a crop in their digestive system. A crop is a loose sac in the throat of many birds that stores prey for later digestion. Because owls lack this feature, prey is passed directly to the digestive system.
An owl's stomach has two parts;
The proventriculus is the glandular stomach. It produces enzymes, acids and mucus that begin the digestion.
The ventriculus, or gizzard, is the muscular stomach. It serves as a filter, holding back indigestible pieces such as bones, fur, teeth and feathers.
The liver and pancreas secrete digestive enzymes into the small intestine where the nutrients are absorbed into the body. After the food passes through the large intestine, it reaches the cloaca which is the joiuning of the reproductive system and the digestive system and finally, the vent which serves as the exit for both the digestive and reproductive system.
Several hours after eating, the indigestible pieces, such as the fur and teeth etc, are consolidated into a pellet and travel back to the proventriculus, where they remain for up to 10 hours before they are regurgitated. Usually the regurgitation of this pellet means that the owl is ready to eat again.
Because owls cannot chew their food, they swallow small prey animals whole and or tear larger prey into smaller pieces before consumption.
Owls, unlike other birds, do not have a crop in their digestive system. A crop is a loose sac in the throat of many birds that stores prey for later digestion. Because owls lack this feature, prey is passed directly to the digestive system.
An owl's stomach has two parts;
The proventriculus is the glandular stomach. It produces enzymes, acids and mucus that begin the digestion.
The ventriculus, or gizzard, is the muscular stomach. It serves as a filter, holding back indigestible pieces such as bones, fur, teeth and feathers.
The liver and pancreas secrete digestive enzymes into the small intestine where the nutrients are absorbed into the body. After the food passes through the large intestine, it reaches the cloaca which is the joiuning of the reproductive system and the digestive system and finally, the vent which serves as the exit for both the digestive and reproductive system.
Several hours after eating, the indigestible pieces, such as the fur and teeth etc, are consolidated into a pellet and travel back to the proventriculus, where they remain for up to 10 hours before they are regurgitated. Usually the regurgitation of this pellet means that the owl is ready to eat again.
reproduction and the Life cycle
The Spectacled Owl can live up to 25 years in captivity. They are monogamous meaning that they only have one mate at a time. Once the young owls leave the nest, both parents continue to take care of them. In captivity juvenile owls have been observed to take up to five years to acquire their adult plumage, however it is quite likely that this occurs quicker in the wild.
Spectacled Owls are cavity nesters, meaning they seek out holes in trees to nest. Nesting occurs anywhere between January and August. Clutch size for these owls is usually two white eggs, though often only one chick will survive, and incubation lasts for 36 days. Six to eight weeks after hatching, they are ready for their first flight. They won't be able to fly efficiently, however, until they have attained their adult plumage. They will mature at three to five years of age.
Spectacled Owls are cavity nesters, meaning they seek out holes in trees to nest. Nesting occurs anywhere between January and August. Clutch size for these owls is usually two white eggs, though often only one chick will survive, and incubation lasts for 36 days. Six to eight weeks after hatching, they are ready for their first flight. They won't be able to fly efficiently, however, until they have attained their adult plumage. They will mature at three to five years of age.
respiratory system
The avian respiratory system is different from other vertebrates because it contains smaller lungs and in addition to lungs it contains nine air sacs. In mammals air movement is bidirectional, meaning that the air moves back and forth into and out of the lungs and as a result the new air is mixed with the old air and this mixed air has less oxygen.
However in avian, the air flow is unidirectional. This means that the air moving through the bird’s lungs is largely fresh air and therefore has a higher oxygen content and more oxygen is able to diffuse into the lungs.
Most avian, including Spectacled Owls, have nine air sacs;
· One interclavicular sac
· Two cervical sacs
· Two anterior thoracic sacs
· Two posterior thoracic sacs
· Two abdominal sacs
Air sacs have thin walls with few blood vessels so they don’t play a direct role in gas exchange but instead they ventilate the lungs.
Communication is different between the male and the female. A males call sounds like a hammer hitting a hollowed tree repeatedly and it gets more rapid as it becomes more quiet. A females call is more of a screech and it is mainly used to attract males during mating season.
However in avian, the air flow is unidirectional. This means that the air moving through the bird’s lungs is largely fresh air and therefore has a higher oxygen content and more oxygen is able to diffuse into the lungs.
Most avian, including Spectacled Owls, have nine air sacs;
· One interclavicular sac
· Two cervical sacs
· Two anterior thoracic sacs
· Two posterior thoracic sacs
· Two abdominal sacs
Air sacs have thin walls with few blood vessels so they don’t play a direct role in gas exchange but instead they ventilate the lungs.
Communication is different between the male and the female. A males call sounds like a hammer hitting a hollowed tree repeatedly and it gets more rapid as it becomes more quiet. A females call is more of a screech and it is mainly used to attract males during mating season.
Nervous system
Birds have a three part brain with a section for olfaction, optics and hearing. The cerebrum of the brain is the front part of the brain and contains the cerebral cortex. There seems to be a lot more cerebral tissue in birds than in most mammals.
The hyperstriatum of the brain is the section associated with intelligence. Owls have great memories and the part of the brain that deals with memory is called the hippocampus. The medulla is the section of the brain used for hearing. Because Spectacled Owls hunt in the dark, they rely on their hearing and can have up to 47,000 neurons in their medulla.
The hyperstriatum of the brain is the section associated with intelligence. Owls have great memories and the part of the brain that deals with memory is called the hippocampus. The medulla is the section of the brain used for hearing. Because Spectacled Owls hunt in the dark, they rely on their hearing and can have up to 47,000 neurons in their medulla.
skeletal and muscular system
The Spectacled Owl's skeletal system is similar to most birds, designed for walking and flying, it is light and strong. Their skeleton makes up 7-9% of their total body weight. Many of the bones that would be seperated in humans are fused in owls in order to support the owl's body weight on the ground. Some bones are also hollow in order to reduce their overall weight.
Contrary to popular belief, owls cannot turn their heads in a full circle, however they can turn their heads up to 270 degrees left or right from the forward facing position. In order for this to be possible; an owl's neck has 14 vertebrate (twice as many as humans); Owls only have on occipital articulation (the bone on top of the backbone), while humans have two, allowing the owl to pivot on the vertebrate column the same as humans pivot on their foot (their muscular system also assists this movement); their jugular veins are arranged in a manner that enables this movement without cutting off blood supply.
Other bones that are pertinent to the Spectacled Owl's function include the sternum, the carina, the wing bones, and the tarso-metatarsi. The sternum is the large, flat breatbone that supports the flight muscles. In addition, it protects the heart, lungs and other internal organs.
The carina, or the sternum keel, is an extension of the breast bone. It runs along the midline of the sternum, perpendicular to the plane of the ribs. The carina functions as an anchor for the attachment of the birds wing muscles, providing leverage for flight. In Spectacled Owls, the carina is narrow at its upper part and becomes broader towards the belly while the lower edge of the sterbum has two deep notches on either side.
The wing bones are relatively long and the wing surface is broad which allows for easy take-offs and effortless flights. The tarso-metatarsi are the foot bones. They are relatively short and stout in owls, which aids the efficient killing and carrying of prey.
Contrary to popular belief, owls cannot turn their heads in a full circle, however they can turn their heads up to 270 degrees left or right from the forward facing position. In order for this to be possible; an owl's neck has 14 vertebrate (twice as many as humans); Owls only have on occipital articulation (the bone on top of the backbone), while humans have two, allowing the owl to pivot on the vertebrate column the same as humans pivot on their foot (their muscular system also assists this movement); their jugular veins are arranged in a manner that enables this movement without cutting off blood supply.
Other bones that are pertinent to the Spectacled Owl's function include the sternum, the carina, the wing bones, and the tarso-metatarsi. The sternum is the large, flat breatbone that supports the flight muscles. In addition, it protects the heart, lungs and other internal organs.
The carina, or the sternum keel, is an extension of the breast bone. It runs along the midline of the sternum, perpendicular to the plane of the ribs. The carina functions as an anchor for the attachment of the birds wing muscles, providing leverage for flight. In Spectacled Owls, the carina is narrow at its upper part and becomes broader towards the belly while the lower edge of the sterbum has two deep notches on either side.
The wing bones are relatively long and the wing surface is broad which allows for easy take-offs and effortless flights. The tarso-metatarsi are the foot bones. They are relatively short and stout in owls, which aids the efficient killing and carrying of prey.
Circulatory system
The Spectacled Owl has a closed circulatory system which increases the efficiency of blood flow. It has two circuits and a four chambered heart. The four chambered heart allows for the efficiency in nutrient and oxygen transport to provide the owl with enough enrgy to fly and maintain high levels of activity. One special characteristic of the owl's circulatory system is the arrangement of arteries that allow them to rotate their head 270 degrees.