The northern saw-whet owl (Aegolius acadicus) is a small owl native to North America. Saw-whet owls are one 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 feet up. Saw-whets are often in danger of being preyed upon by larger owls and raptors. Northern saw-whet owls are also migratory birds without any strict pattern.
No narrative description available for this taxon yet.
⚠ sources differ — AnAge: 118 g · AmnioteDB: 95.62 g · AVONET: 101 g · EltonTraits: 101 g
Body mass (female)131 g
Body mass (male)77.4 g
Hand-wing index29.8
Kipp's distance40.2 mm
SVL18 cm
Secondary length95 mm
Tail length78 mm
Tarsus length23.6 mm
Wing length135 mm
Life cycle & reproduction11
Age at maturity (male)365 days
Age at sexual maturity365 days
Egg mass10.2 g
Fledging age30.25 days
Fledging mass96 g
Gestation27 days
Incubation27 days
Litter size5.5
Litters per year1 /year
Max. longevity210 months
Neonate mass7.5 g
Diet & foraging6
Ground90 %
Invertebrate20 %
Trophic levelcarnivore
Trophic nicheVertivore
Understory10 %
Vertebrate endotherm80 %
Habitat & environment4
HabitatForest
Migration3.0
Primary lifestyleInsessorial
Range size5 712 892 km²
Physiology & chemistry1
Metabolic rate0.654 W
05DNA & barcoding15 specimens
A DNA barcode is a short, standardised stretch of genes that works like a fingerprint — enough to tell one species from another. Below is the molecular trace Aegolius acadicus has left across the world's sequence archives.
At a glance
DNA specimens15
BINs1
Marker genes1
eDNA detections15
Countries1
The DNA barcodethe species' typical barcode, built from every sequenced specimen
COI-5P694 bp consensus14 specimens
ACGT
▸ drag or hover over the strip to read any position — letter and how much it varies
Violet ticks below the strip = positions where individuals differ; flat = the species' unchanging signature. 98% of positions are identical in every specimen.
Where individuals differ — all 11 variable positions, in barcode order
Each circle is a barcode variant; bigger = more specimens, colour = region. Lines join the most similar variants and the tick marks count the mutations between them — a tight cluster is one “dialect”, a long line a more divergent lineage. Click a circle to list its actual specimens.
Diversity (π)0.40%
Haplotypes3
BIN1
Most divergent pair0.43%
N.America
Closest relatives by DNA barcode
The species whose COI barcode is most similar to this one — a quick “who is this most like”. The percentage is how much the barcode differs; it approximates, but is not, the full evolutionary tree.
★ the standard DNA barcode for this group — the short region actually read to tell this species apart. The rest are extra genes sequenced along the way.
★COI-5P
animal barcode
07Deep time0.21–0 Ma
How far back this lineage goes — and how we know. Everything here is measured in Ma, short for “mega-annum”: millions of years ago. The chart reads left to right like a calendar of the Earth, from the deep past on the left to today at the right edgetop to bottom like a core drilled through the Earth, from the deep past at the top down to today at the bottom.
At a glance
Fossil range0.21–0 Ma Pleistocene, Holocene
Dated fossil finds7
StatusStill living record runs to the present
When this lineage existed
How to read this: the coloured strip along the bottomdown the left is the geological calendar — the standard epochs (Pliocene, Pleistocene…) every museum uses, shown so you can see which chapter of Earth's history this lineage lived in. This lineage is a young one, so the strip is zoomed in to epochs — the finer subdivisions inside a period. The solid bar is the fossil range: the span between the oldest and the youngest fossil that palaeontologists have assigned to Aegolius acadicus. Above itBeside it, each dot is one dated fossil find — few enough to count, so they are drawn individually rather than as a graph.
fossil range (PBDB)each dot = one dated find
How it livedPBDB
Environmentterrestrial
Life habitvolant
Dietcarnivore, insectivore
Motilityactively mobile
Visionwell-developed
Compositionhydroxyapatite
Reproductionoviparous, brooding
Ontogenyaccretion,modification of parts
08Occurrence & distribution
Record type137 583 records
Wild obs. + sensor136 250
Museum / vouchered1 278
Fossil8
Other47
Origin
Native115
Range
Area of Occupancy AOO120 848 km²
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Coordinate accuracy63% within 1 km
≤100 m 1 613≤1 km 843≤10 km 355>10 km 1 107
3 918 georeferenced · 132 332 without coordinates
Open the mapobservation + sensor136 250
Museum / Voucheredphysical evidence
Backed by a physical specimen — a herbarium sheet, sample or voucher held in a collection. “Vouchered” means supported by material evidence, not just an observation.
Coordinate accuracy28% within 1 km
≤100 m 62≤1 km 142≤10 km 393>10 km 120
717 georeferenced · 561 without coordinates
Open the institutions mapphysical evidence1 278
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
10Collections & institutions
Holding institutions37 of 57 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
Institution
Specimens
Seattle, US
197
Museo civico La Terra e l'Uomo di Crocetta del Montellolocation not on record
130
Saint John, CA
97
Ann Arbor, US
79
Washington State University, Charles R. Conner Museumlocation not on record
74
Mongolian Museum of Natural Historylocation not on record
69
München, DE
66
Philadelphia, US
66
Denver, US
66
Tacoma, US
56
Royal Saskatchewan Museumlocation not on record
47
Albany, US
29
Delaware Museum of Nature and Sciencelocation not on record
23
Zacatecas, MX
22
Edmonton, CA
22
Ohio State University - Bird Division, Columbus, OH (OSUM)location not on record
21
Central Michigan University Museum of Cultural and Natural Historylocation not on record
19
US
14
CASlocation not on record
14
Iowa City, US
12
Ithaca, US
11
Chicago, US
10
Philip L. Wright Zoological Museumlocation not on record
9
Cambridge, US
8
Santa Cruz, US
7
Washington, US
7
Sam Noble Oklahoma Museum of Natural Historylocation not on record
7
University of Nebraska State Museumlocation not on record
7
Science Museum of Minnesotalocation not on record
6
Ciudad de México, MX
5
Wuzhou, CN
5
Texas Cooperative Wildlife Collectionlocation not on record
4
San Diego, US
4
University of Victorialocation not on record
4
Moore Laboratory of Zoology, Occidental Collegelocation not on record
4
Vancouver, CA
4
Universidad Católica de Manizaleslocation not on record
3
ASNHClocation not on record
3
Helsinki, FI
2
Université de Montréallocation not on record
2
Indiana State Universitylocation not on record
2
EL PASO, US
2
2
Cincinnati, US
2
Mexico City, MX
2
Gothenburg, SE
1
Geneva, CH
1
Chicago, US
1
Stockholm, SE
1
Bourges, FR
1
Toronto, CA
1
Morelia, MX
1
Ensenada, MX
1
Louisiana State University, Museum of Zoologylocation not on record
1
St. Paul, US
1
South Kensington, GB
1
Los Angeles, US
1
57 institutions · 1 257 of 1 278 vouchered records shown · 16 without an institution code
09Environmental DNA15 detections
Where the DNA of Aegolius acadicus was picked up in samples of water, soil or air — nobody saw the organism, only its DNA left behind. A trace is a clue that the species was near, not a confirmed sighting.
Signal
Detections DNA found15
Studies independent surveys1
Countries1
Signal confidence: weakweighed across independent studies, places & mapped detections
Where its DNA was found
0 of 15 detections have coordinates
Open the map1 country0
How strong is each trace?
DNA read depthRead counts were not reported for this species — the map shows presence only, not how strong each trace was.
Modelled climatemodelled
−15°Ctemperature across detection sites+40°C
Temperature median10.7 °C 7.70–13.8
Seasonal swing summer↔winter20.9 °C
Max temp (day)13.7 °C 11.8–15.9
Min temp (night)8.90 °C 5.30–12.6
Precipitation93.0 mm/mo 30.1–102
Air humidity60.4 % 58.3–62.6
Moisture balance61.0 mm/mo
Vapour deficit556 Pa 470–622
Wind speed7.40 m/s
Cloud cover46.1 % 38.6–57.0
CHELSA 1981–2010, ~9 km grid, at location & month of 14 detection points · median with p10–p90 · reflects where sampling happened, not only the true niche
How to read this: each dot is one detection of this species' DNA in an environmental sample. The confidence meter weighs how many independent studies and places back up the signal — one detection in one study is a hint; many across several studies is solid. Records dated before 2008 (when eDNA methods began) are treated as likely mislabeled and left off the map.
WikipediaWikimedia Foundation11 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility137 576 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI15 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics15 specimens↗
Open Tree of LifeOpenTreephylogeny backbone↗
Paleobiology DatabasePBDB consortiumfossil record↗
WikidataWikimedia Foundationstructured facts↗
IOC World Bird ListIOCbird checklist↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗