Strix virgata

Geographic Range

Ciccaba virgata is widely distributed throughout the Nearctic and Neotropics, from northern Mexico to Brazil and Argentina.

• Biogeographic Regions
• nearctic nearctic
• neotropical neotropical

Habitat

Inhabiting elevations between sea level and 2500 meters, mottled owls are often quite abundant within their range. Their habitats are extensive and diverse; they can live in a wide variety of forest and thicket edge, tropical rainforest, dry thorn forest, tropical lowland forest, pine-oak woodland, and humid evergreen jungle. They can also live in areas with scattered trees, often close to towns and villages.

• Habitat Regions
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest
• rainforest rainforest

Physical Description

Ciccaba virgata individuals are medium-sized owls with brown eyes. They are mostly dark except for light brown facial markings. Mottled owls have yellow-grey to blue-grey bills and their toes are greyish-yellow. Their dorsal markings are much less noticeable than the vertical streaks on their chest and throat. They look larger than they are because of their thick feathers.

In owls, females are generally larger than the males. This evolution of a reversed size dimorphism has been explained in many different ways. Researchers measure body mass during the breeding season, wing length, tail length, bill length, tarsal length, and foot span. Female mottled owls weighed significantly more than males and have significantly longer wing chords. Ciccaba virgata has the most noticable dimorphism yet documented among owls.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger

Reproduction

Mottled owls are monogamous, neither female nor male have any involvement with other nesting birds besides their mate.

• Mating System
• monogamous monogamous

Ciccaba virgata have smaller clutches than ecologically similar or closely related species. This species usually lays 1 to 2 eggs between February and May. Mottled owls usually nest in holes of trees, tops of broken off palm and occasionally in empty nests of other birds.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• oviparous oviparous

Females incubate eggs while males find food and bring it back to the nest. Both males and females care for the young.

• Parental Investment
• pre-hatching/birth
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • male
  • protecting
    • female
• pre-independence
  • provisioning
    • male
  • protecting
    • female

Lifespan/Longevity

There is no information available regarding the lifespan of this species.

Behavior

Mottled owls are solitary and strictly nocturnal. They roost in dense foliage by day and may be mobbed by small birds if detected. These owls spend their waking hours hunting, preening, yawning, stretching, and combing their heads with their claws.

• Key Behaviors
• arboreal arboreal
• flies
• glides
• nocturnal nocturnal
• motile motile
• solitary solitary
• territorial territorial

Home Range

The home range of male C. virgata is 2.8 hectares.

Communication and Perception

This species uses an array of vocalizations, such as hoots, whistles, screeches, screams, purrs, snorts, chitters, and hisses. When a mottled owl hoots, it is often territorial and associated with courting. The males have a lower pitched hoot than females. When faced with a threat, owls produce clicking noises with their tongues. As part of a mating display, owls have the ability to clap their wings in flight.

Mottled owls produce an array of calls. Their territorial call consists of a series of deep hoots, sounding like "bru bru" and "bu bu bu" or cowooawoo or keeooweeyo. They also have a whistled screech. Mottled owls have been observed to have an enlarged voice box which allows them to produce low-pitched notes for their size.

Owls have keen hearing and vision in low-light situations. They lack color vision.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Ciccaba virgata individuals feed on a diverse diet including large insects such as beetles , grasshoppers , and cockroaches . They also feed on small mammals , birds , snakes , lizards , salamanders , and frogs . They are considered opportunistic feeders as they may be attracted to artificial lights. Mottled owls primarily hunt from perches which can be found along a forest edge.

Mottled owls have keen vision, hearing, and maneuverable flight, contributing to their success as predators. Although they lack color vision, these owls can rotate their heads to see in different directions. These owls also have sensitive ears that allow them to pinpoint sound sources in total darkness. Still, their ranges of hearing are not wide and contain deaf spots. Their wing feathers have adapted to dampen sound during flight, so they can approach their prey without being heard.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates
  • insectivore insectivore

• Animal Foods
• birds
• mammals
• amphibians
• reptiles
• insects

Predation

Owls are at the top of the food web. They have no major predators.

Ecosystem Roles

This species is a generalist predator, and potentially impacts many prey populations.

Economic Importance for Humans: Positive

Mottled owls have been studied by scientists and research has been published on their breeding behavior. They also help control some rodent and insect pest populations.

• Positive Impacts
• research and education
• controls pest population

Economic Importance for Humans: Negative

There are no known adverse affects of Ciccaba virgata on humans.

Conservation Status

This widespread species is not globally threatened. Ciccaba virgata are considered common in many habitats and can be seen largely in protected areas.

Additional Links

Encyclopedia of Life

Contributors

Matthew Wund (editor), University of Michigan-Ann Arbor.

Jess Fetter (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

References

Buchanan, M. 1971. The Mottled Owl Ciccaba Virgata in Trinidad.. Ibis , 113: 105-106.

Gerhardt, , D. Gerhardt. 1987. Size, Dimorspism, and Related Characteristics of Ciccaba Owls From Guatemala. 2nd Owl Symposium: 190-196. Accessed September 22, 2004 at http://www.ncrs.fs.fed.us/pubs/gtr/other/gtr-nc190/GERHARD.PDF#xml .

Gerhardt, R., D. Gerhardt, C. Flatten. 1994. Breeding Biology and Home Range of Two Ciccaba Owls. Wilson Bulletin , 106: 629-639.

Gerhardt, R. 1991. Response of Mottled Owls to Broadcast of Conspecific Call.. Journal of Field Ornithology , 62: 239-244.

Wylie , S. 1976. Breeding the Mottled Owl at the St. Louis Zoo. The Avicultural Magazine , 82: 64-65.

The British Ornithologists' Union. 1985. A Dictionary of Birds . South Dakota: Buteo Books.

1999. Handbook of the Birds of the World. Vol. 5. Barn-owls to Hummingbirds . Barcelona: Lynx Edicions.

Birds of Prey Foundation. 2004. "Owl Facts" (On-line). Accessed March 28, 2003 at http://www.birds-of-prey.org/educate/owls.htm .

1994. The Food Habits of Sympatric Ciccaba Owls in Northern Guatemala.. Journal of Field Ornithology , 65: 258-264.

Owl Pages. 2005. "The Owl Pages: Information about Owls" (On-line). Accessed September 22, 2004 at http://www.owlpages.com/species/strix/virgata/Default.htm .