Cobweb weaver vs Oso Polar

Steatoda nobilis compared with Ursus maritimus

Key Differences

• Cobweb weaver is Not Evaluated while Oso Polar is Vulnerable.

Taxonomic Classification

Rank	Cobweb weaver	Oso Polar
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum	Arthropoda (artrópodos)	Chordata (cordados)
Class	Arachnida (arácnidos)	Mammalia (mamíferos)
Order	Araneae (araña)	Carnivora (carnívoros)
Family	Theridiidae	Ursidae (Bears)
Genus	Steatoda	Ursus (Bears)
Species	Steatoda nobilis	Ursus maritimus

Evolutionary Relationship

Cobweb weaver and Oso Polar share a common ancestor at the Kingdom level: Animalia. (Animals)

Conservation Status

Cobweb weaver

NE — Not Evaluated

Oso Polar

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Cobweb weaver	Oso Polar
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Cobweb weaver

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Europe (7 countries), North America (United States), and South America (Ecuador).

Oso Polar

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate coniferous forests, and boreal forests and taiga, among 4 distinct biome types within the Palearctic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Found in Norway. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Cobweb weaver

The noble false widow (Steatoda nobilis) is a theridiid spider that has attracted considerable media attention in the British Isles and along the Atlantic coast of Europe due to its painful but rarely dangerous bite and its rapid range expansion facilitated by human activity. Originally native to the Canary Islands and Madeira, the species arrived in southern England during the 19th century, likely via banana shipments, and has since spread northward through Britain and westward into Ireland, while also establishing populations along the Iberian Peninsula and Atlantic France. Females are robust, with a dark brown carapace and a distinctive cream-colored pattern on the bulbous abdomen that varies between individuals; females reach 8.5–14 millimeters in body length, making this one of the larger European theridiids. The species constructs persistent, tangled cobwebs in sheltered locations outside buildings—under window ledges, in door frames, and in garden walls—as well as within homes in cooler seasons. It is a generalist predator, capturing insects and other invertebrates, and has been reported to occasionally subdue prey considerably larger than itself, including small lizards. Steatoda nobilis venom produces steatodism, which can cause localized pain, swelling, and in rare cases systemic symptoms. Its conservation status has not been formally assessed, but its expanding range demonstrates considerable resilience.

Oso Polar

El mayor carnivoro terrestre de la Tierra, el oso polar puede superar los 700 kg y se encuentra en el hielo marino del Artico, desde Canada hasta Rusia. Es un mamifero marino altamente especializado que depende del hielo marino para cazar focas anilladas y barbadas. Excelente nadador capaz de cubrir grandes distancias en agua abierta. Clasificado como Vulnerable, sus poblaciones soportan una presion severa por la rapida perdida de hielo marino artico debida al cambio climatico.