Ursus arctos
Linnaeus, 1758 · speciesAt a glance
Sources14 archives
Databases and archives Ursus arctos's data was compiled from.
WikipediaWikimedia Foundation21 languages↗
Animal Diversity WebUniv. of Michigan MZspecies account↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility42 002 records↗
OBISOcean Biodiversity Information System132 records↗
ENAEuropean Nucleotide Archive · EMBL-EBI555 eDNA detections↗
BOLD SystemsCentre for Biodiversity Genomics547 specimens↗
NPASSNat. Product Activity & Species Sourcecompounds↗
Open Tree of LifeOpenTreephylogeny backbone↗
GoaTGenomes on a Tree · Sangergenome & karyotype↗
NCBIUS National Library of Medicinegenome & karyotype↗
Paleobiology DatabasePBDB consortiumfossil record↗
WikidataWikimedia Foundationstructured facts↗
GLoBIGlobal Biotic Interactionsbiotic interactions↗Every layer below draws on the sources above — open one to explore it, or use ← → to move between tabs.
The Kodiak bear (Ursus arctos middendorffi), also known as the Kodiak brown bear, sometimes the Alaskan brown bear, inhabits the islands of the Kodiak Archipelago in southwest Alaska. It is the largest recognized subspecies or population of the brown bear, and one of the two largest bears alive today, the other being the polar bear. Physiologically, the Kodiak bear is very similar to the other brown bear subspecies, such as the mainland grizzly bear (Ursus arctos horribilis) and the extinct California grizzly bear (U. a. californicus), with the main difference being size. While there is generally much variation in size between brown bears in different areas, most usually weigh between 115 and 360 kg (254 and 794 lb). The Kodiak bear, on the other hand, commonly reaches sizes of 300 to, and has even been known to exceed a weight of 680 kg. Despite this large variation in size, the diet and lifestyle of the Kodiak bear do not differ greatly from those of other brown bears. Kodiak bears have interacted with humans for centuries, especially hunters and other people in the rural coastal regions of the archipelago. The bears are hunted for sport and are encountered by hunters pursuing other species. Less frequently, Kodiak bears are killed by people whose property (such as livestock) or person are threatened. There is increasing focus on conservation and protection of the Kodiak bear population as human activity in its range increases. The IUCN classifies the brown bear (Ursus arctos), of which the Kodiak is a subspecies, as being of "least concern" in terms of endangerment or extinction, though the IUCN does not differentiate between subspecies and thus does not provide a conservation status for the Kodiak population. The Alaska Department of Fish and Game however, along with the United States Fish and Wildlife Service to a lesser extent, closely monitor the size and health of the population and the number of bears hunted in the state.
No narrative description available for this taxon yet.
Size & morphology4
Life cycle & reproduction9
Diet & foraging6
Habitat & environment4
Physiology & chemistry3
Other traits5
Compounds documented for Ursus arctos across natural-product and food-composition databases — not just the ~150 nutrients on a classic label ("nutritional dark matter").
Compound class profile5 classes
Documented compounds35 total
| Compound | Class | Amount | Source |
|---|---|---|---|
| Acetylcholine | present | NPASS | |
| AWDRATDZQPNJFN-GVEVGHGRSA-N | present | NPASS | |
| AWDRATDZQPNJFN-HGCRTIQHSA-N | present | NPASS | |
| BHQCQFFYRZLCQQ-DUZHRHDZSA-N | present | NPASS | |
| BHQCQFFYRZLCQQ-UDTVJMINSA-N | present | NPASS | |
| BHTRKEVKTKCXOH-DPOCHCJHSA-N | present | NPASS | |
| BHTRKEVKTKCXOH-VSHSPWMTSA-N | present | NPASS | |
| Chenodeoxycholic Acid | present | NPASS | |
| Cherianoine | present | NPASS | |
| cholate | present | NPASS |
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 Ursus arctos has left across the world's sequence archives.
At a glance
★ 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.
Besides the big genome in the nucleus, cells carry a small, circular loop of DNA inside the cell's energy factories — the mitochondria. It is inherited almost only from the mother and is a leftover from ancient bacteria that moved into the cell. The mitochondrial markers above (ND*, COX, CYTB…) are read from exactly this loop. Outer ring = one strand, inner ring = the other.
The complete instruction manual Ursus arctos carries — its genome. We read it from three angles — how big it is, how the DNA is packed into chromosomes, and how completely it has been sequenced — and explain how to read each value as you go.
Genome sizehow big the whole instruction manual is
Measured in base pairs (bp) — the individual letters of DNA (human ≈ 3.2 Gb, a bacterium a few million). The chart places this genome on a logarithmic scale — each step to the right is ten times bigger — among reference organisms. Across species a bigger genome loosely tracks with larger cells, slower growth and lower-energy lifestyles (powered flight favours small genomes) — yet it does not imply more genes or a more advanced organism (the long-standing C-value paradox).
Chromosomes & ploidyhow the DNA is packaged
2n is the full chromosome count in a normal body cell; n is a gamete (egg or sperm), which carries half. Ploidy is how many complete chromosome sets each cell holds — 2× (diploid) is typical for animals, while higher levels (polyploidy) are common in plants. Click any value below to see the underlying records and sources.
Sequencing statusassembly quality — how far to trust these numbers
Assembly level tells you how finished the sequence is — from fragmented contigs, through scaffolds, up to a full chromosome-level assembly. BUSCO % estimates completeness: the share of genes expected to be present that were actually found. These describe the data quality, not the organism.
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
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 Ursus arctos. Above itBeside it, the bars count how many dated finds fall in each slice of time; the tallest bar is labelled, and heights use a square-root scale so that thin slices stay visible next to rich ones. Read this as how well each stretch of time is preserved and studied — thick bars mean plenty of the right kind of rock and plenty of collectors, which is related to, but not the same as, how common it actually was. The orange marker is the DNA clock: DNA accumulates mutations at a roughly steady rate, so comparing this species' DNA with its relatives estimates when the lineage split off — independently of any fossil.
The two clocks disagree here. The fossil record reaches back to 2.58 Ma, but the molecular clock dates the lineage to only 0.82 Ma — about 1.76 Myr younger. A fossil cannot be older than the lineage it belongs to, so one of the two is off: either the fossil is assigned to the wrong species, or the clock is running fast.
How it livedPBDB
Record type42 191 records
Origin
Range
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
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.
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Holding institutions39 of 65 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
| Institution | Specimens |
|---|---|
| miljodirlocation not on record | 1 946 |
| Edmonton, CA | 1 158 |
| Stockholm, SE | 632 |
| Berkeley, US | 174 |
| Tacoma, US | 67 |
| München, DE | 65 |
| Helsinki, FI | 63 |
| Museo civico La Terra e l'Uomo di Crocetta del Montellolocation not on record | 61 |
| Salzburg, AT | 43 |
| NTNU-VMlocation not on record | 39 |
| Norwegian University of Life Sciences (NMBU)location not on record | 37 |
| Instytut Ochrony Przyrody Polskiej Akademii Nauklocation not on record | 37 |
| Seattle, US | 34 |
| Oulu, FI | 30 |
| Philip L. Wright Zoological Museumlocation not on record | 26 |
| East Lansing, US | 23 |
| Wuzhou, CN | 21 |
| Dhaka, BD | 17 |
| Geneva, CH | 15 |
| Denver, US | 13 |
| Kuopio, FI | 11 |
| Porvoo, FI | 11 |
| Washington State University, Charles R. Conner Museumlocation not on record | 11 |
| Tromsø, NO | 10 |
| University of Wyoming Museum of Vertebrateslocation not on record | 9 |
| Toronto, CA | 8 |
| New Haven, US | 8 |
| Chicago, US | 7 |
| Bonn, DE | 7 |
| Los Angeles, US | 7 |
| Kristiansand, NO | 7 |
| Washington, US | 6 |
| Saint John, CA | 6 |
| Provo, US | 4 |
| Sam Noble Oklahoma Museum of Natural Historylocation not on record | 4 |
| Barcelona, ES | 4 |
| Cambridge, US | 3 |
| Albany, US | 3 |
| CASlocation not on record | 3 |
| Natural History Museum of Utahlocation not on record | 3 |
| Universität Zürich, Naturhistorisches Museumlocation not on record | 3 |
| Zacatecas, MX | 2 |
| STOCKHOLM, SE | 2 |
| Fort Hays State University, Sternberg Museumlocation not on record | 2 |
| Ohio State University - Mammal Division, Columbus, OH (OSUM)location not on record | 2 |
| Muzeum Górnośląskie w Bytomiulocation not on record | 2 |
| Zoological Survey of Indialocation not on record | 1 |
| MRI-PASlocation not on record | 1 |
| Iowa City, US | 1 |
| Universidad Católica de Manizaleslocation not on record | 1 |
| San Diego, US | 1 |
| Forssa, FI | 1 |
| MZLUlocation not on record | 1 |
| SMNHTAUlocation not on record | 1 |
| National Institutes of Health, Laboratory of Genomic Diversity, United Stateslocation not on record | 1 |
| Royal Saskatchewan Museumlocation not on record | 1 |
| Tomioka, JP | 1 |
| Tallinn, EE | 1 |
| Metsähallituslocation not on record | 1 |
| Philadelphia, US | 1 |
| University of Nevada, Museum of Biologylocation not on record | 1 |
| Auckland, NZ | 1 |
| MF, TWlocation not on record | 1 |
| Science Museum of Minnesotalocation not on record | 1 |
| Ann Arbor, US | 1 |
Where the DNA of Ursus arctos 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
Where its DNA was found
How strong is each trace?
Modelled climatemodelled
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.