Facilitating the protection and restoration of species and ecosystems at risk on BC’s South Coast
Northern Pygmy-owl, swarthi subspecies
Glaucidium gnoma swarthi
Glaucidium
gnoma
swarthi
A member of the family Strigidae (“typical owls”), this is one of three subspecies of Northern Pygmy Owl that breed in BC. The swarthi subspecies is also referred to as “Vancouver Island Pygmy Owl”.
Length: 15.5-18 cm. As the name implies Northern Pygmy Owl are small owls. As with several other owl species, they are “earless” (lacking ear tufts on the head). Adult plumage for this subspecies is the same on both sexes and “reverse sexual dimorphism” (females being larger than males) is evident. The body is plump with a long narrow tail that the bird flicks up and down when perching. Dorsal and wing plumage is brown to reddish brown with large white spots. The head is brown, speckled with white and the yellow eyes have white eyebrows. Chest and belly plumage is creamy white with dark bars and streaks. The long dark brown tail has white horizontal barring. Juvenile birds are similar to adults but do not develop spots on the body or head until they mature. This owl is diurnal (active during the day) and more specifically crepuscular (hunt at dawn and dusk), and is often a target of defensive aerial “mobbing” from other birds (e.g. crows). Two distinct black “eyespots” outlined in white on the back of the head are thought to confuse and distract birds when they attack, possibly protecting the front of the head and eyes. Recent DNA evidence suggests the present designation of G. gnoma may warrant reclassification to G. californicum, composed of four distinct western races in North America. There has been little studied on the swarthi subspecies and much about its biology is inferred from the mainland form.
Download Species Fact Sheet in PDF
Status
Global Status:
G4G5T3Q
Provincial Status:
S3
BC List Status:
Blue (Considered to be of Special Concern)
Similar Species
Northern Saw-whet owl are the only other small owl species that could be mistaken for Northern Pygmy-owl. However the larger Sawwhet has a stubby tail and lacks eyespots on the back of the head.
Ecology
Range
Elevations: 50 to <1700 m. This subspecies is resident and endemic across Vancouver Island and the Gulf Islands.
Habitat
This non-migratory owl is adaptable to a range of forest types and associated habitat features as long as sufficient nest cavities are available and disturbance is low. Northern Pygmy-owl is more of a generalist than other owl species and will utilize interior forest areas, riparian zones and open stands as well as clearings and immature stands with lower structural diversity. Abandoned woodpecker (Northern Flicker and Hairy Woodpecker) cavities 3-18 m from the ground, in a variety of mainly coniferous species located near the forest edge are used for nesting. Large mature trees (>60 cm dbh) with cavities appear to be a major factor for habitat use. Nest sites are strongly associated
with stands on steep hillsides, precipitous talus slopes, or steep ravines not far from water. During breeding season nesting sites and associated habitat are strongly defended. Home range size has been observed at up to 75 ha in size anywhere from 600 m to 1.6 km apart from adjacent breeding pairs.
Diet
All Pygmy-owls employ a “perch and pounce” hunting tactic. Northern Pygmy-owl have a variable diet influenced by seasonal
availability and parenting demands. Approximately 90% of the bird’s diet is composed of small mammals (i.e. rodents) and
songbirds. However reptiles, amphibians and insects are all exploited. An aggressive predator for its size, Pygmy-owls have been
known to take prey up to twice their weight.
Life Cycle
Breeding birds begin to defend nest cavities and territories as early as late February. Breeding begins at one year of age, birds breed every year.
Threats
Dependence on population of primary cavity excavator species such as woodpecker (Northern Flicker, Hairy Woodpecker) for availability of nesting cavities. Population density and abundance is likely low and is tied to nest cavity availability.
Excessive fragmentation, loss of preferred nesting features and prey availability (tied to forest structure) are moderate threats. While Northern Pygmy-owl utilizes a mix of mature and less structurally diverse open forest habitats rural/urbanized landsca
Predation from Barred Owl who prey on smaller owl species and are expanding their range in BC. Raccoon and Douglas and Grey Squirrel may predate on eggs and chicks
Competition from European Starling and Douglas and Grey Squirrel that may compete with or harass adults for nesting cavities.
Conservation and Management
Apply conservation and management objectives as set-out in the “Managing Identified Wildlife – Accounts V. Northern Pygmy-Owl Glaucidium gnoma swarthi”. Integrate complementary objectives,recommendations and assessment methods found in “Status of Vancouver Island Northern Pygmy-owl (Glaucidium gnoma swarthi) in British Columbia” and Best Management Practices for Raptor
Conservation during Urban and Rural Land Development in British Columbia. Inventory and monitoring resources include
standardized methods (RISC standards # 11 Inventory Methods for Raptors (Version 2.0). For further details on conservation and
management objectives for this species, please consult the resources and references provided or contact provincial and
federal agencies.
This subspecies is subject to protections and prohibitions under the BC Wildlife Act and is Identified Wildlife under the Forest and Range Practices Act. Habitat for this species may also be governed under provincial and federal regulations including the Fish Protection Act, Migratory Birds Convention Act and Federal Fisheries Act as well as Regional and local municipal bylaws.
RESOURCES
For further information see:
VI Wilds is a non-profit information and conservation site hosted by the University of Victoria.
A source for authoritative conservation information on thousands of plants and animals and hundreds of ecological communities in BC. From here connect to all provincial and federal recovery plans (including the SARA Registry), COSEWIC (Committee on the Status of Endangered Wildlife in Canada), Identified Wildlife guidance and conservation requirements for specific species and ecological communities of conservation concern impacted by forestry activities) and links to E-Flora and E-Fauna (the Electronic Atlas of the Plants and Wildlife of British Columbia).
Environmental guidelines for urban and rural land development in BC.
Learn what species are at risk in your area, search by name, habitat type, regional district and forest district.
Sources
B.C. Conservation Data Centre. 2016. [Internet] [Updated March 05, 2015]. Conservation Status Report: Glaucidium gnoma swarthi. B.C. Minist. of Environment. B.C. Conservation Data Centre. 2010. [Internet] [Updated August 3 1997]. Species Summary: Glaucidium gnoma swarthi. B.C. Minist. of Environment.
Cooper, J. and S. M. Beauchesne. 2004. [Internet] Accounts and Measures for Managing Identified Wildlife – Accounts V. 2004. Northern Pygmy-Owl Glaucidium gnoma swarthi
Darling, L. M. 2003. [Internet]. Status of Vancouver Island Northern pygmy-owl (Glaucidium gnoma swarthi) in British Columbia. (Wildlife bulletin; no. B-113)
Demarchi, M.W. and M.D. Bently. 2005/2013. [Internet].Best Management Practices for Raptor Conservation during Urban and Rural Land Development in British Columbia. B.C. Minist. of Environ., Victoria, B.C. Minist. of Environment BMP Series.
Heritage Community Foundation. [Internet] [2010]. Reprinted from Alberta Wildlife Status Report No. 8 (1998), with permission from Alberta Sustainable Resource Development. Northern Pygmy Owl.
Ministry of Environment, Lands and Parks Resources Inventory Branch. [Internet].2001. RISC standards # 11 Inventory Methods for Raptors (Version 2.0).
Owling.com. 2001. [Internet] [2010]. Northern Pygmy-Owl Biology. A Reference for North and Central American Owls.
Proulx, G. et al. 2003. A Field Guide to Species at Risk in the Coast Forest Region of British Columbia. Published by International Forest Products and BC Minist. of Environment. Victoria (BC).
Credits
Species Profile prepared by: Pamela Zevit of Adamah Consultants for the South Coast Conservation Program (SCCP) in partnership with:
International Forest Products (Interfor), Capacity Forestry (CapFor) and the BC Ministry of Environment (BC MoE). Funding for this factsheet
was made possible through the Sustainable Forestry Initiative (SFI): http://www.sfiprogram.org/
Updated and revised by: Isabelle Houde, RPBio in consultation with the SCCP. Part of the National Conservation Plan, this project was
undertaken with the financial support of the Government of Canada. Dans le cadre du Plan de Conservation National, ce projet a été réalisé
avec l’appui financier du Gouvernement du Canada.
Every effort has been made to ensure content accuracy. Comments or corrections should be directed to the South Coast Conservation
Program: info@sccp.ca. Content updated January 2016.
Image Credits: Northern Pygmy-owl (front and back): Gord Gadsden, Northern Pygmy “Owlet” (juvenile): Sonoma Wildlife Rescue
Association CA, Northern Saw-whet Owl mainland form: Brendan Ially (Flickr), Habitat: Pamela Zevit. Only images sourced from “creative
commons” sources (e.g. Wikipedia, Flickr, U.S. Government) can be used without permission and for non-commercial purposes only. All other
images have been contributed for use by the SCCP and its partners/funders only.
SHARE
