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Northern saw-whet owl

March 04, 2023

The northern saw-whet owl (Aegolius acadicus) is a species of small owl in the family Strigidae. The species is native to North America. Saw-whet owls of the genus Aegolius are some of the smallest owl species in North America. They can be found in dense thickets, often at eye level, although they can also be found some 20 ft (6.1 m) up. Saw-whets are often in danger of being preyed upon by larger birds of prey. The northern saw-whet owl is a migratory bird without any strict pattern.

Northern saw-whet owl
CITES Appendix II (CITES)[2]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Aegolius
Species:
A. acadicus
Binomial name
Aegolius acadicus
(Gmelin, JF, 1788)
Subspecies

Aegolius acadicus acadicus
Aegolius acadicus brooksi

Geographical distribution of the Northern saw-whet owl.
  Year-round
  Nonbreeding
  Nonbreeding (scarce)
Synonyms

Nyctala acadica

Taxonomy

The northern saw-whet owl was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the other owls in the genus Strix and coined the binomial name Strix acadicus.[3] Gmelin based his description on the "Acadian owl" from Nova Scotia that had been described and illustrated in 1781 by the English ornithologist John Latham in his multi-volume work A General Synopsis of Birds.[4][5] The northern saw-whet owl is now one of five species placed in the genus Aegolius that was introduced in 1829 by the German naturalist Johann Jakob Kaup.[6][7] The genus name is Latin for a screech owl, the word came from the Ancient Greek aigōlios meaning "a bird of ill omen". The specific epithet acadicus is from "Acadia", the name of a former French colony in Nova Scotia.[8]

Two subspecies are recognised:[7]

  • A. a. acadicus (Gmelin, JF, 1788) – south Alaska, Canada, north, southwest USA and north Mexico
  • A. a. brooksi (Fleming, JH, 1916) – Haida Gwaii (formerly the Queen Charlotte Islands) (off British Columbia, Canada)

Description

The scientific description of one of the subspecies of this owl is attributed to the Rev. John Henry Keen who was a missionary in Canada in 1896.[9] Adults are 17–22 cm (6.7–8.7 in) long with a 42–56.3 cm (16.5–22.2 in) wingspan.[10][11] They can weigh from 54 to 151 g (1.9 to 5.3 oz) with an average of around 80 g (2.8 oz),[12][13] making them one of the smallest owls in North America.[14] They are similar in size to the American robin. Northern saw-whet owls do not exhibit sexual dimorphism through their plumage and were often sexed by size dimorphism, where females are larger than males. Females on average weigh 100 g and males on average weigh 75 g.[15] Northern saw-whet owls have porphyrin pigments in their flight feathers. When exposed to a UV light the ventral side of the wing, the feathers will fluoresce a neon pink. This is used in order to estimate molt and age in adult northern saw-whet owls.[16]

The northern saw-whet owl has a round, light, white face with brown and cream streaks; they also have a dark beak and yellow eyes. Juveniles have a dark brown head and wings, and a tawny rust-colored breast and belly. There is also a distinct white, Y-shaped coloration between their eyes.[17] The juveniles can often be confused with the juvenile Boreal owls. Northern saw-whet owls resemble the short-eared owl, because they also lack ear tufts, but are much smaller. The underparts are pale with dark shaded areas; the upper parts are brown or reddish with white spots. They are quite common, but hard to spot.

There are two subspecies of the northern saw-whet owl: the Aegolius acadicus acadicus found all around North America and the non-migratory Aegolius acadicus brooksi endemic to the Haida Gwaii archipelago in British Columbia.[18]  A. a. brooksi is identified by a darker, buffier plumage[17] and has been proposed as a separate species, the Haida Gwaii saw-whet owl. Isolated populations of northern saw-whet owls in the Allegheny Plateau and Southern Appalachian Mountains have been found to be morphologically different to mid-range owls and as genetically distinct as the subspecies A.a.brooksi in British Columbia.[19]

Vocalisation

The northern saw-whet owl makes a repeated tooting whistle sound. Some say they sound like a saw being sharpened on a whetstone.[20] They usually make these sounds to find a mate, so they can be heard more often April through June when they are looking for mates. Despite being more common in spring, they do vocalize year round. The advertising too-too-too call has been heard up to 300 meters away through forest.[19] At least 11 different vocalizations have been reported for the northern saw-whet owl. These include the Advertising call,[21] the Rapid call,[22] Whine,[23] Ksew call, Tssst call, Squeaks,[24] Twittering call (similar to an American Woodcock), Guttural chuck, and begging calls of nestlings. Two additional calls only recorded in brooksi include the Transition Call and Alternate Whine. Non-vocal sounds such as bill snapping are used as a warning call by adults, juveniles and nestlings usually when approached up close or when in the hand.[19]

Distribution and habitat

Their habitat is coniferous forests, sometimes mixed or deciduous woods, across North America. Most birds nest in coniferous type forests of the North but winter in mixed or deciduous woods. They also love riparian areas because of the abundance of prey there.[25] They live in tree cavities and old nests made by other small raptors. Some are permanent residents, while others may migrate south in winter or move down from higher elevations. Their range covers most of North America south of the boreal forest, including southeastern and southcentral Alaska, southern Canada, most of the United States and the central mountains in Mexico.

Some have begun to move more southeast in Indiana and neighboring states. Buidin et al. did a study of how far north the northern saw-whet owls breed and they found that they can breed northward of 50° N, farther than ever recorded before.[26] Their range is quite extensive and they can even breed in the far north where most birds migrate from to breed. They are an adaptive species that can do well in the cold.

There are two semi-isolated permanent populations in the eastern part of the United States. This first is a population along the West Virginia border in the Allegheny Plateau. The second population is in the higher elevations (>4000 ft) of the southern Appalachian Mountains of western North Carolina, eastern Tennessee, and southwestern Virginia. Although there are abundant populations in the Northern and Western Regions of North America, in some counties of North Carolina, it is currently listed as a threatened species due to a decline in suitable habitat.[27] This is due to loss of boreal forests from hemlock woolly adelgid, logging, and pollution.[27]

Behavior and ecology

Breeding

 
Three juveniles in Oregon, United States

Northern saw-whet owls lay about four or six white-colored eggs in natural tree cavities or woodpecker holes. Males will often sing from a nest site[19] and cache food in nest sites in order to attract a female.[15] The father does the hunting while the mother watches and sits on her eggs. Females can have more than one clutch of eggs each breeding season with different males. Once the offspring in the first nest have developed their feathers the mother will leave the father to care for them and go find another male to reproduce with.[25] This type of mating is sequential polyandry. They compete with boreal owls, starlings and squirrels for nest cavities and their nests may be destroyed or the nestlings eaten by those creatures as well as nest predators such as martens and corvids. Saw-whet owls of all ages may be predated by any larger species of hawks or owls, of which there are at least a dozen that overlap in range including Accipiter hawks, which share with the saw-whet owls a preference for wooded habitats with dense thickets or brush.[11]

In 2014 nesting northern saw-whet owls were found in breeding nest boxes in the Southern Appalachian mountains. This is the most southeastern known breeding area in the United States.[15]

Food and feeding

 
On a daytime hunt in a brushy area, Homer, Alaska

The northern saw-whet owl has vertically asymmetrical ears and different shapes of the ear openings. Because the sound reaches the ears at a different time and is of different intensity, the northern saw-whet owl can very precisely localize its prey. Such accurate sound localization allows it to hunt in complete darkness by hearing alone.[28][29] A study by Beatini et al showed that the northern saw-whet owl had a possible frequency sensitivity of 0.7 to 8.6 kHz with the best sensitivity ranging from 1.6 to 7.1 kHz.[30] This allows it to hunt in the dark purely by sound. The birds wait on a high perch at night and swoop down on prey. They mainly eat small organisms with a strong focus on small mammals in their diet. Swengel and Swengel (1992) reviewed ten studies that found northern saw-whet owls eating almost exclusively mammals (88% to 100%), with most of the mammals being rodents (85% to 99+%). Specifically in their Wisconsin study, the Swengels counted saw-whet owls as most often eating deer mice (Peromyscus; ~68% of captured prey), voles (Microtis pennsylvunicus and M. ochrogaster; ~16%), and shrews (~9%; Blarina brevicauda and Sorex cinereus).[31] A similar study by Holt and Leroux (1996) in Montana found saw-whet owls eating more voles (60%) than other mammal species.[32] Engel et al. (2015) also found in the saw-whet owl a strong preference for small mammals (89%), with 55% of prey being two species of voles.

Holt and Leroux compared the eating habits of northern saw-whet owls to northern pygmy owls and found that they prey on different animals for their main food source, with the saw-whet owl's diet 98% small mammals, while for pygmy owls over one-third of their prey was birds. Their study concluded that these owls could adapt depending on the prey and also with the other predators in the areas where they live. Engel et al. (2015) in Chain O'Lakes State Park, Illinois, during the winter of 1987–88, compared northern saw-whet owls to long-eared owls. Engel confirmed the saw-whet owl's strong preference for small mammals. Their diet appeared varied in the winter, and was less tied to one mammal than was the long-eared owl; at times, northern saw-whet owls hunted larger prey, such as the meadow vole (M. pennsylvanicus).[33]

Other mammals preyed on occasionally include shrews, squirrels (largely chipmunks and red squirrels), various other mice species, flying squirrels, moles and bats. Also supplementing the diet are small birds, with passerines such as swallows, sparrows, kinglets and chickadees favored. However, larger birds, up to the size of rock pigeon (which are typically about 4 times as heavy as a saw-whet owl) can even be taken.[11] On the Pacific coast they may also eat crustaceans, frogs and aquatic insects. Like many owls, these birds have excellent hearing and exceptional vision in low light.

Popular culture

An adult female northern saw-whet owl was found dehydrated and hungry within the wrapped branches of the Rockefeller Center Christmas Tree during its installation on November 16, 2020. The bird was discovered by workers who transported the spruce 170 miles (274 km) from Oneonta, New York to New York City. The feathered stowaway, named Rockefeller (Rocky), endured the three-day road trip and generated much public interest and media coverage. She was taken to a wildlife center for a check-up and nursed to full strength before being released on the grounds of the wildlife center in Saugerties, New York.[34] Rocky gained more fame when Frontier Airlines announced that her image will be featured on the aircraft tails in their fleet.[35]

References

  1. ^ BirdLife International (2016). "Aegolius acadicus". IUCN Red List of Threatened Species. 2016: e.T22689366A93228694. doi:10.2305/IUCN.UK.2016-3.RLTS.T22689366A93228694.en. Retrieved 11 November 2021.
  2. ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. ^ Gmelin, Johann Friedrich (1788). Systema naturae per regna tria naturae : secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (in Latin). Vol. 1, Part 1 (13th ed.). Lipsiae [Leipzig]: Georg. Emanuel. Beer. p. 296.
  4. ^ Latham, John (1781). A General Synopsis of Birds. Vol. 1, Part 1. London: Printed for Leigh and Sotheby. p. 149, No. 38; Plate 5 fig. 2.
  5. ^ Peters, James Lee, ed. (1940). Check-List of Birds of the World. Vol. 4. Cambridge, Massachusetts: Harvard University Press. p. 173.
  6. ^ Kaup, Johann Jakob (1829). Skizzirte Entwickelungs-Geschichte und natürliches System der europäischen Thierwelt (in German). Darmstadt: Carl Wilhelm Leske. p. 34.
  7. ^ a b Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (August 2022). "Owls". IOC World Bird List Version 12.2. International Ornithologists' Union. Retrieved 10 December 2022.
  8. ^ Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 33, 29. ISBN 978-1-4081-2501-4.
  9. ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2009). The Eponym Dictionary of Mammals. Baltimore: Johns Hopkins University Press. p. 220. ISBN 9780801895333.
  10. ^ "Northern Saw-whet Owl". All About Birds. Cornell University. 2011.
  11. ^ a b c "Northern Saw-whet Owl - Aegolius acadicus". The Owl Pages. 2011.
  12. ^ Sibley, David Allen (2003). The Sibley Field Guide To Birds of Eastern North America (1st ed.). New York: Alfred A. Knopf. p. 229. ISBN 978-0-67-945120-4.
  13. ^ Dunning Jr., John B. (2007). CRC Handbook of Avian Body Masses (2nd ed.). CRC Press. ISBN 978-1-42-006444-5.
  14. ^ Vanner, Michael (2003). The Encyclopedia of North American Birds. New York: Barnes & Noble. p. 192. ISBN 0-7607-3460-7.
  15. ^ a b c McCormick, John (2014-08-01). "Northern Saw-whet Owl (Aegolius acadicus) Abundance and Distribution in the Southern Appalachian Mountains of Northeast Tennessee". Electronic Theses and Dissertations.
  16. ^ Weidensaul, C. Scott; Colvin, Bruce A.; Brinker, David F.; Huy, J. Steven (June 2011). "Use of Ultraviolet Light as an Aid in Age Classification of Owls". The Wilson Journal of Ornithology. 123 (2): 373–377. doi:10.1676/09-125.1. ISSN 1559-4491. S2CID 28913007.
  17. ^ a b Dunn, Jon L.; Alderfer, Jonathan K. (2017). National Geographic field guide to the birds of North America (7th ed.). Washington, D.C.: National Geographic Society (U.S.). ISBN 978-1-42-621835-4. OCLC 1002108930.
  18. ^ Waterhouse, F. Louise; Doyle, Frank I.; Turney, Laurence; Wijdeven, Berry; Todd, Melissa; Bergman, Carita; Vennesland, Ross G. (June 2017). "Spring and Winter Home Ranges of the Haida Gwaii Northern Saw-Whet Owl (Aegolius acadicus brooksi)". Journal of Raptor Research. 51 (2): 153–164. doi:10.3356/jrr-16-48.1. ISSN 0892-1016. S2CID 89814991.
  19. ^ a b c d Rasmussen, Justin Lee; Sealy, Spencer G.; Cannings, Richard J. (April 7, 2008). A. F. Poole (ed.). "Northern Saw-whet Owl (Aegolius acadicus)". The Birds of North America. Ithaca, NY, USA: Cornell Lab of Ornithology. doi:10.2173/bna.42. ISSN 1061-5466.
  20. ^ Bull, John; Farrand, John Jr. (1994). National Audubon Society Field Guide to North American Birds. New York: Alfred A. Knopf. p. 555. ISBN 0-679-42852-6.
  21. ^ "Advertising call". Xeno-canto Foundation.
  22. ^ "Rapid call". Xeno-canto Foundation.
  23. ^ "Whine". Xeno-canto Foundation.
  24. ^ "Squeaks". Xeno-canto Foundation.
  25. ^ a b DeLella Benedict, Audrey (2008). The Naturalist's Guide to the Southern Rockies: Colorado, Southern Wyoming, and Northern New Mexico. Golden, Colorado: Fulcrum Publishing. p. 568. ISBN 978-1-55591-535-3.
  26. ^ Buidin, Christophe; Rochepault, Yann; Savard, Jean-Pierre L.; Savard, Michel (September 2006). "Breeding range extension of the Northern Saw-Whet Owl in Quebec". The Wilson Journal of Ornithology. 118 (3): 411. doi:10.1676/05-092.1. S2CID 85625756.
  27. ^ a b Milling, Timothy & Rowe, Matthew & Cockerel, Bennie & Dellinger, Tim & Gailes, Johnny & Hill, Christopher. "Population Densities of Northern Saw-whet Owls (Aegolius acadicus) in Degraded Boreal Forests of the Southern Appalachians". Biology and conservation of owls of the Northern Hemisphere: 2nd International symposium. Gen. Tech. Rep. NC-190. St. Paul, MN: U.S. Dept. of Agriculture, Forest Service, North Central Forest Experiment Station. 272-285. Publication Series: General Technical Report (GTR)
  28. ^ Frost, B.J.; P. J. Baldwin; M. Csizy (1989). "Auditory localization in the northern saw-whet owl, Aegolius acadicus". Canadian Journal of Zoology. 67 (8): 1955–1959. doi:10.1139/z89-279.
  29. ^ Gutiérrez-Ibáñez, Cristián; Andrew N. Iwaniuk; Douglas R. Wylie (2011). "Relative Size of Auditory Pathways in Symmetrically and Asymmetrically Eared Owls". Brain Behav Evol. 78 (4): 281–301. doi:10.1159/000330359. PMID 21921575. S2CID 6013325.
  30. ^ Beatini, Julia R.; Proudfoot, Glenn A.; Gall, Megan D. (February 2018). "Frequency sensitivity in Northern saw-whet owls (Aegolius acadicus)". Journal of Comparative Physiology A. 204 (2): 145–154. doi:10.1007/s00359-017-1216-2. ISSN 0340-7594. PMID 28993864. S2CID 19735506.
  31. ^ Swengel, Ann B.; Swengel, Scott R. (August 1992). "Diet of Northern Saw-whet Owls in southern Wisconsin" (PDF). The Condor. 94 (3): 707. doi:10.2307/1369255. JSTOR 1369255. Retrieved 29 November 2011.
  32. ^ Holt, Denver W.; Leroux, Leslie A. (March 1996). "Diets of Northern Pygmy Owls and Northern Saw-whet owls in West-Central Montana" (PDF). Wilson Bulletin. 108 (1): 123. Retrieved 29 November 2011.
  33. ^ Engel, Joshua I.; Dubey, Nandu; Gnoske, Thomas P. (March 2015). "Diet Comparison of Two Wintering Species of Owl in the Same Stand of Trees in Northern Illinois". Transactions of the Illinois State Academy of Science. 108 (1): 17–19.
  34. ^
    • Sparks, Hannah (November 18, 2020). "Adorable owl found tucked inside Rockefeller Christmas tree". New York Post. from the original on November 22, 2020.
    • . USA Today. Associated Press. November 19, 2020. Archived from the original on November 25, 2020. Retrieved November 26, 2020.
    • Daly, Natasha (November 24, 2020). "Rockefeller, the viral stowaway Christmas tree owl, flies free". National Geographic Society.
    • Wong, Wilson (November 25, 2020). "Rocky, the tiny owl that was rescued from the Rockefeller Center Christmas tree, takes flight". NBC News.
    • "Rocky the Christmas tree stowaway owl returns to the wild". Associated Press. November 25, 2020. Retrieved November 25, 2020.
  35. ^
    • "Rocky the Owl to be Featured on a Frontier Airlines Plane Tail". Frontier Airlines. December 1, 2020. Retrieved December 4, 2020.
    • "Rocky the Christmas tree owl to be featured on Frontier Airlines plane tail". WFLA News Channel 8 Tampa. December 2, 2020. Retrieved December 4, 2020.
    • "Rocky the Owl to Take Flight with Frontier Airlines". Hudson Valley Post. December 3, 2020. Retrieved December 4, 2020.

External links

  • Northern Saw-whet Owl Species Account - Cornell Lab of Ornithology
  • Northern Saw-whet Owl - Aegolius acadicus - USGS Patuxent Bird Identification InfoCenter
  • "Aegolius acadicus". Integrated Taxonomic Information System. Retrieved 24 February 2009.
  • "Northern Saw-whet Owl media". Internet Bird Collection.
  • Northern Saw-whet Owl photo gallery at VIREO (Drexel University)
  • Interactive range map of Aegolius acadicus at IUCN Red List maps

March 04, 2023
northern, whet, northern, whet, aegolius, acadicus, species, small, family, strigidae, species, native, north, america, whet, owls, genus, aegolius, some, smallest, species, north, america, they, found, dense, thickets, often, level, although, they, also, foun. The northern saw whet owl Aegolius acadicus is a species of small owl in the family Strigidae The species is native to North America Saw whet owls of the genus Aegolius are some of the smallest owl species in North America They can be found in dense thickets often at eye level although they can also be found some 20 ft 6 1 m up Saw whets are often in danger of being preyed upon by larger birds of prey The northern saw whet owl is a migratory bird without any strict pattern Northern saw whet owlConservation statusLeast Concern IUCN 3 1 1 CITES Appendix II CITES 2 Scientific classificationKingdom AnimaliaPhylum ChordataClass AvesOrder StrigiformesFamily StrigidaeGenus AegoliusSpecies A acadicusBinomial nameAegolius acadicus Gmelin JF 1788 SubspeciesAegolius acadicus acadicus Aegolius acadicus brooksiGeographical distribution of the Northern saw whet owl Year round Nonbreeding Nonbreeding scarce SynonymsNyctala acadica Contents 1 Taxonomy 2 Description 2 1 Vocalisation 3 Distribution and habitat 4 Behavior and ecology 4 1 Breeding 4 2 Food and feeding 5 Popular culture 6 References 7 External linksTaxonomy EditThe northern saw whet owl was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus s Systema Naturae He placed it with the other owls in the genus Strix and coined the binomial name Strix acadicus 3 Gmelin based his description on the Acadian owl from Nova Scotia that had been described and illustrated in 1781 by the English ornithologist John Latham in his multi volume work A General Synopsis of Birds 4 5 The northern saw whet owl is now one of five species placed in the genus Aegolius that was introduced in 1829 by the German naturalist Johann Jakob Kaup 6 7 The genus name is Latin for a screech owl the word came from the Ancient Greek aigōlios meaning a bird of ill omen The specific epithet acadicus is from Acadia the name of a former French colony in Nova Scotia 8 Two subspecies are recognised 7 A a acadicus Gmelin JF 1788 south Alaska Canada north southwest USA and north Mexico A a brooksi Fleming JH 1916 Haida Gwaii formerly the Queen Charlotte Islands off British Columbia Canada Description EditThe scientific description of one of the subspecies of this owl is attributed to the Rev John Henry Keen who was a missionary in Canada in 1896 9 Adults are 17 22 cm 6 7 8 7 in long with a 42 56 3 cm 16 5 22 2 in wingspan 10 11 They can weigh from 54 to 151 g 1 9 to 5 3 oz with an average of around 80 g 2 8 oz 12 13 making them one of the smallest owls in North America 14 They are similar in size to the American robin Northern saw whet owls do not exhibit sexual dimorphism through their plumage and were often sexed by size dimorphism where females are larger than males Females on average weigh 100 g and males on average weigh 75 g 15 Northern saw whet owls have porphyrin pigments in their flight feathers When exposed to a UV light the ventral side of the wing the feathers will fluoresce a neon pink This is used in order to estimate molt and age in adult northern saw whet owls 16 The northern saw whet owl has a round light white face with brown and cream streaks they also have a dark beak and yellow eyes Juveniles have a dark brown head and wings and a tawny rust colored breast and belly There is also a distinct white Y shaped coloration between their eyes 17 The juveniles can often be confused with the juvenile Boreal owls Northern saw whet owls resemble the short eared owl because they also lack ear tufts but are much smaller The underparts are pale with dark shaded areas the upper parts are brown or reddish with white spots They are quite common but hard to spot There are two subspecies of the northern saw whet owl the Aegolius acadicus acadicus found all around North America and the non migratory Aegolius acadicus brooksi endemic to the Haida Gwaii archipelago in British Columbia 18 A a brooksi is identified by a darker buffier plumage 17 and has been proposed as a separate species the Haida Gwaii saw whet owl Isolated populations of northern saw whet owls in the Allegheny Plateau and Southern Appalachian Mountains have been found to be morphologically different to mid range owls and as genetically distinct as the subspecies A a brooksi in British Columbia 19 Vocalisation Edit The northern saw whet owl makes a repeated tooting whistle sound Some say they sound like a saw being sharpened on a whetstone 20 They usually make these sounds to find a mate so they can be heard more often April through June when they are looking for mates Despite being more common in spring they do vocalize year round The advertising too too too call has been heard up to 300 meters away through forest 19 At least 11 different vocalizations have been reported for the northern saw whet owl These include the Advertising call 21 the Rapid call 22 Whine 23 Ksew call Tssst call Squeaks 24 Twittering call similar to an American Woodcock Guttural chuck and begging calls of nestlings Two additional calls only recorded in brooksi include the Transition Call and Alternate Whine Non vocal sounds such as bill snapping are used as a warning call by adults juveniles and nestlings usually when approached up close or when in the hand 19 Distribution and habitat EditTheir habitat is coniferous forests sometimes mixed or deciduous woods across North America Most birds nest in coniferous type forests of the North but winter in mixed or deciduous woods They also love riparian areas because of the abundance of prey there 25 They live in tree cavities and old nests made by other small raptors Some are permanent residents while others may migrate south in winter or move down from higher elevations Their range covers most of North America south of the boreal forest including southeastern and southcentral Alaska southern Canada most of the United States and the central mountains in Mexico Some have begun to move more southeast in Indiana and neighboring states Buidin et al did a study of how far north the northern saw whet owls breed and they found that they can breed northward of 50 N farther than ever recorded before 26 Their range is quite extensive and they can even breed in the far north where most birds migrate from to breed They are an adaptive species that can do well in the cold There are two semi isolated permanent populations in the eastern part of the United States This first is a population along the West Virginia border in the Allegheny Plateau The second population is in the higher elevations gt 4000 ft of the southern Appalachian Mountains of western North Carolina eastern Tennessee and southwestern Virginia Although there are abundant populations in the Northern and Western Regions of North America in some counties of North Carolina it is currently listed as a threatened species due to a decline in suitable habitat 27 This is due to loss of boreal forests from hemlock woolly adelgid logging and pollution 27 Behavior and ecology EditBreeding Edit Three juveniles in Oregon United States Northern saw whet owls lay about four or six white colored eggs in natural tree cavities or woodpecker holes Males will often sing from a nest site 19 and cache food in nest sites in order to attract a female 15 The father does the hunting while the mother watches and sits on her eggs Females can have more than one clutch of eggs each breeding season with different males Once the offspring in the first nest have developed their feathers the mother will leave the father to care for them and go find another male to reproduce with 25 This type of mating is sequential polyandry They compete with boreal owls starlings and squirrels for nest cavities and their nests may be destroyed or the nestlings eaten by those creatures as well as nest predators such as martens and corvids Saw whet owls of all ages may be predated by any larger species of hawks or owls of which there are at least a dozen that overlap in range including Accipiter hawks which share with the saw whet owls a preference for wooded habitats with dense thickets or brush 11 In 2014 nesting northern saw whet owls were found in breeding nest boxes in the Southern Appalachian mountains This is the most southeastern known breeding area in the United States 15 Food and feeding Edit On a daytime hunt in a brushy area Homer Alaska The northern saw whet owl has vertically asymmetrical ears and different shapes of the ear openings Because the sound reaches the ears at a different time and is of different intensity the northern saw whet owl can very precisely localize its prey Such accurate sound localization allows it to hunt in complete darkness by hearing alone 28 29 A study by Beatini et al showed that the northern saw whet owl had a possible frequency sensitivity of 0 7 to 8 6 kHz with the best sensitivity ranging from 1 6 to 7 1 kHz 30 This allows it to hunt in the dark purely by sound The birds wait on a high perch at night and swoop down on prey They mainly eat small organisms with a strong focus on small mammals in their diet Swengel and Swengel 1992 reviewed ten studies that found northern saw whet owls eating almost exclusively mammals 88 to 100 with most of the mammals being rodents 85 to 99 Specifically in their Wisconsin study the Swengels counted saw whet owls as most often eating deer mice Peromyscus 68 of captured prey voles Microtis pennsylvunicus and M ochrogaster 16 and shrews 9 Blarina brevicauda and Sorex cinereus 31 A similar study by Holt and Leroux 1996 in Montana found saw whet owls eating more voles 60 than other mammal species 32 Engel et al 2015 also found in the saw whet owl a strong preference for small mammals 89 with 55 of prey being two species of voles Holt and Leroux compared the eating habits of northern saw whet owls to northern pygmy owls and found that they prey on different animals for their main food source with the saw whet owl s diet 98 small mammals while for pygmy owls over one third of their prey was birds Their study concluded that these owls could adapt depending on the prey and also with the other predators in the areas where they live Engel et al 2015 in Chain O Lakes State Park Illinois during the winter of 1987 88 compared northern saw whet owls to long eared owls Engel confirmed the saw whet owl s strong preference for small mammals Their diet appeared varied in the winter and was less tied to one mammal than was the long eared owl at times northern saw whet owls hunted larger prey such as the meadow vole M pennsylvanicus 33 Other mammals preyed on occasionally include shrews squirrels largely chipmunks and red squirrels various other mice species flying squirrels moles and bats Also supplementing the diet are small birds with passerines such as swallows sparrows kinglets and chickadees favored However larger birds up to the size of rock pigeon which are typically about 4 times as heavy as a saw whet owl can even be taken 11 On the Pacific coast they may also eat crustaceans frogs and aquatic insects Like many owls these birds have excellent hearing and exceptional vision in low light Popular culture EditThis section contains information of unclear or questionable importance or relevance to the article s subject matter Please help improve this section by clarifying or removing indiscriminate details If importance cannot be established the section is likely to be moved to another article pseudo redirected or removed Find sources Northern saw whet owl news newspapers books scholar JSTOR December 2020 Learn how and when to remove this template message An adult female northern saw whet owl was found dehydrated and hungry within the wrapped branches of the Rockefeller Center Christmas Tree during its installation on November 16 2020 The bird was discovered by workers who transported the spruce 170 miles 274 km from Oneonta New York to New York City The feathered stowaway named Rockefeller Rocky endured the three day road trip and generated much public interest and media coverage She was taken to a wildlife center for a check up and nursed to full strength before being released on the grounds of the wildlife center in Saugerties New York 34 Rocky gained more fame when Frontier Airlines announced that her image will be featured on the aircraft tails in their fleet 35 References Edit BirdLife International 2016 Aegolius acadicus IUCN Red List of Threatened Species 2016 e T22689366A93228694 doi 10 2305 IUCN UK 2016 3 RLTS T22689366A93228694 en Retrieved 11 November 2021 Appendices CITES cites org Retrieved 2022 01 14 Gmelin Johann Friedrich 1788 Systema naturae per regna tria naturae secundum classes ordines genera species cum characteribus differentiis synonymis locis in Latin Vol 1 Part 1 13th ed Lipsiae Leipzig Georg Emanuel Beer p 296 Latham John 1781 A General Synopsis of Birds Vol 1 Part 1 London Printed for Leigh and Sotheby p 149 No 38 Plate 5 fig 2 Peters James Lee ed 1940 Check List of Birds of the World Vol 4 Cambridge Massachusetts Harvard University Press p 173 Kaup Johann Jakob 1829 Skizzirte Entwickelungs Geschichte und naturliches System der europaischen Thierwelt in German Darmstadt Carl Wilhelm Leske p 34 a b Gill Frank Donsker David Rasmussen Pamela eds August 2022 Owls IOC World Bird List Version 12 2 International Ornithologists Union Retrieved 10 December 2022 Jobling James A 2010 The Helm Dictionary of Scientific Bird Names London Christopher Helm pp 33 29 ISBN 978 1 4081 2501 4 Beolens Bo Watkins Michael Grayson Michael 2009 The Eponym Dictionary of Mammals Baltimore Johns Hopkins University Press p 220 ISBN 9780801895333 Northern Saw whet Owl All About Birds Cornell University 2011 a b c Northern Saw whet Owl Aegolius acadicus The Owl Pages 2011 Sibley David Allen 2003 The Sibley Field Guide To Birds of Eastern North America 1st ed New York Alfred A Knopf p 229 ISBN 978 0 67 945120 4 Dunning Jr John B 2007 CRC Handbook of Avian Body Masses 2nd ed CRC Press ISBN 978 1 42 006444 5 Vanner Michael 2003 The Encyclopedia of North American Birds New York Barnes amp Noble p 192 ISBN 0 7607 3460 7 a b c McCormick John 2014 08 01 Northern Saw whet Owl Aegolius acadicus Abundance and Distribution in the Southern Appalachian Mountains of Northeast Tennessee Electronic Theses and Dissertations Weidensaul C Scott Colvin Bruce A Brinker David F Huy J Steven June 2011 Use of Ultraviolet Light as an Aid in Age Classification of Owls The Wilson Journal of Ornithology 123 2 373 377 doi 10 1676 09 125 1 ISSN 1559 4491 S2CID 28913007 a b Dunn Jon L Alderfer Jonathan K 2017 National Geographic field guide to the birds of North America 7th ed Washington D C National Geographic Society U S ISBN 978 1 42 621835 4 OCLC 1002108930 Waterhouse F Louise Doyle Frank I Turney Laurence Wijdeven Berry Todd Melissa Bergman Carita Vennesland Ross G June 2017 Spring and Winter Home Ranges of the Haida Gwaii Northern Saw Whet Owl Aegolius acadicus brooksi Journal of Raptor Research 51 2 153 164 doi 10 3356 jrr 16 48 1 ISSN 0892 1016 S2CID 89814991 a b c d Rasmussen Justin Lee Sealy Spencer G Cannings Richard J April 7 2008 A F Poole ed Northern Saw whet Owl Aegolius acadicus The Birds of North America Ithaca NY USA Cornell Lab of Ornithology doi 10 2173 bna 42 ISSN 1061 5466 Bull John Farrand John Jr 1994 National Audubon Society Field Guide to North American Birds New York Alfred A Knopf p 555 ISBN 0 679 42852 6 Advertising call Xeno canto Foundation Rapid call Xeno canto Foundation Whine Xeno canto Foundation Squeaks Xeno canto Foundation a b DeLella Benedict Audrey 2008 The Naturalist s Guide to the Southern Rockies Colorado Southern Wyoming and Northern New Mexico Golden Colorado Fulcrum Publishing p 568 ISBN 978 1 55591 535 3 Buidin Christophe Rochepault Yann Savard Jean Pierre L Savard Michel September 2006 Breeding range extension of the Northern Saw Whet Owl in Quebec The Wilson Journal of Ornithology 118 3 411 doi 10 1676 05 092 1 S2CID 85625756 a b Milling Timothy amp Rowe Matthew amp Cockerel Bennie amp Dellinger Tim amp Gailes Johnny amp Hill Christopher Population Densities of Northern Saw whet Owls Aegolius acadicus in Degraded Boreal Forests of the Southern Appalachians Biology and conservation of owls of the Northern Hemisphere 2nd International symposium Gen Tech Rep NC 190 St Paul MN U S Dept of Agriculture Forest Service North Central Forest Experiment Station 272 285 Publication Series General Technical Report GTR Frost B J P J Baldwin M Csizy 1989 Auditory localization in the northern saw whet owl Aegolius acadicus Canadian Journal of Zoology 67 8 1955 1959 doi 10 1139 z89 279 Gutierrez Ibanez Cristian Andrew N Iwaniuk Douglas R Wylie 2011 Relative Size of Auditory Pathways in Symmetrically and Asymmetrically Eared Owls Brain Behav Evol 78 4 281 301 doi 10 1159 000330359 PMID 21921575 S2CID 6013325 Beatini Julia R Proudfoot Glenn A Gall Megan D February 2018 Frequency sensitivity in Northern saw whet owls Aegolius acadicus Journal of Comparative Physiology A 204 2 145 154 doi 10 1007 s00359 017 1216 2 ISSN 0340 7594 PMID 28993864 S2CID 19735506 Swengel Ann B Swengel Scott R August 1992 Diet of Northern Saw whet Owls in southern Wisconsin PDF The Condor 94 3 707 doi 10 2307 1369255 JSTOR 1369255 Retrieved 29 November 2011 Holt Denver W Leroux Leslie A March 1996 Diets of Northern Pygmy Owls and Northern Saw whet owls in West Central Montana PDF Wilson Bulletin 108 1 123 Retrieved 29 November 2011 Engel Joshua I Dubey Nandu Gnoske Thomas P March 2015 Diet Comparison of Two Wintering Species of Owl in the Same Stand of Trees in Northern Illinois Transactions of the Illinois State Academy of Science 108 1 17 19 Sparks Hannah November 18 2020 Adorable owl found tucked inside Rockefeller Christmas tree New York Post Archived from the original on November 22 2020 Hoot hoot hoot Tiny owl found in Rockefeller Center Christmas tree USA Today Associated Press November 19 2020 Archived from the original on November 25 2020 Retrieved November 26 2020 Daly Natasha November 24 2020 Rockefeller the viral stowaway Christmas tree owl flies free National Geographic Society Wong Wilson November 25 2020 Rocky the tiny owl that was rescued from the Rockefeller Center Christmas tree takes flight NBC News Rocky the Christmas tree stowaway owl returns to the wild Associated Press November 25 2020 Retrieved November 25 2020 Rocky the Owl to be Featured on a Frontier Airlines Plane Tail Frontier Airlines December 1 2020 Retrieved December 4 2020 Rocky the Christmas tree owl to be featured on Frontier Airlines plane tail WFLA News Channel 8 Tampa December 2 2020 Retrieved December 4 2020 Rocky the Owl to Take Flight with Frontier Airlines Hudson Valley Post December 3 2020 Retrieved December 4 2020 External links EditNorthern Saw whet Owl Species Account Cornell Lab of Ornithology Northern Saw whet Owl Aegolius acadicus USGS Patuxent Bird Identification InfoCenter Aegolius acadicus Integrated Taxonomic Information System Retrieved 24 February 2009 Northern Saw whet Owl media Internet Bird Collection Northern Saw whet Owl photo gallery at VIREO Drexel University Interactive range map of Aegolius acadicus at IUCN Red List maps Retrieved from https en wikipedia org w index php title Northern saw whet owl amp oldid 1127023005, wikipedia, wiki, book, books, library,

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