Common Quaking Grass vs Oso Polar

Briza media compared with Ursus maritimus

Taxonomic Classification

Rank	Common Quaking Grass	Oso Polar
Kingdom	Plantae (planta)	Animalia (Animals)
Phylum	Magnoliophyta (Flowering Plants)	Chordata (cordados)
Class	Liliopsida (Monocots)	Mammalia (mamíferos)
Order	Poales (Grasses)	Carnivora (carnívoros)
Family	Poaceae (Grass Family)	Ursidae (Bears)
Genus	Briza	Ursus (Bears)
Species	Briza media	Ursus maritimus

Conservation Status

Common Quaking Grass

VU — Vulnerable

Oso Polar

VU — Vulnerable

Population: ~26.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	Common Quaking Grass	Oso Polar
Diet	—	Carnivore
Average Lifespan	—	25 years
Average Length	—	2.4 m
Average Weight	—	450.0 kg

Habitat & Geographic Range

Common Quaking Grass

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, temperate grasslands and steppes, and flooded grasslands and savannas, among 6 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Japan), Europe (7 countries), North America (Canada, United States), and South America (Argentina). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

Common Quaking Grass

The Common Quaking Grass, <em>Briza media</em>, is a perennial grass in the family Poaceae, native to Europe and parts of Asia and introduced to North America and South America. It is a characteristic species of ancient, species-rich calcareous grasslands, meadows, and chalk downlands, where it typically grows in well-drained, nutrient-poor soils in full sun. The species is easily recognized by its heart-shaped, flattened spikelets that hang on delicate, hair-like stalks and tremble in the slightest breeze, producing the distinctive quaking motion that gives the genus its common name. The spikelets are typically pale green when immature, turning golden-brown as they ripen, and the whole inflorescence is highly ornamental. <em>Briza media</em> is an important component of calcareous grassland communities, providing structure and seed resources for invertebrates and birds. It is sensitive to agricultural improvement and is often used as an indicator of long-undisturbed grasslands. The species is assessed as Vulnerable on the IUCN Red List, reflecting declines linked to habitat loss, agricultural intensification, and conversion of traditional grasslands. Biological traits such as average lifespan, body size, and specific dietary preferences remain poorly documented for this species.

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.