Comprises a distinctive lineage of slender, medium to large-sized diurnal raptors measuring typically between 40 and 60 centimeters in total body length, supported by a broad wingspan reaching 100 to 150 centimeters. Anatomically, they are characterized by notably long, narrow wings, an elongated tail, and slender legs equipped with elongated tarsi that facilitate prey extraction from within dense grass cover. The taxon exhibits conspicuous sexual dimorphism, in which females are consistently heavier and larger, dominated by cryptic brownish and streaked plumage, whereas adult males showcase contrasting patterns dominated by ash-grey, white, and sharp black wingtips. A diagnostic and evolutionarily significant trait is the presence of a pronounced facial disc formed by stiff, acoustically reflective feathers, which channel high-frequency sounds directly into oversized auditory cavities.

Geographical distribution: Holds an expansive, nearly cosmopolitan geographical presence, occupying ecological niches across Eurasia, Africa, Australasia, and the entirety of the Americas, spanning from subarctic tundras in North America down to the southernmost grasslands of the Southern Cone. Many northern taxa undertake extensive intercontinental migratory journeys to reach tropical and subtropical wintering zones, whereas equatorial and island populations generally remain non-migratory and sedentary throughout the year.

Habitat: Demonstrates strict ecological specialization for wide-open landscapes, consistently avoiding dense temperate woodlands, closed-canopy rainforests, and rugged alpine terrains. Prime environments include freshwater and saltwater wetlands, extensive marshlands, temperate grasslands, low-elevation steppes, savanna biomes, and tundra expanses. It readily adapts to anthropogenically modified open lands, exploiting cereal croplands, wet meadows, pastures, and fallow fields where dense herbaceous layers sustain healthy prey populations.

Feeding: Functions as an opportunistic and specialized predator whose diet relies heavily on small herbivorous mammals, particularly rodents, voles, and shrews. This core sustenance is routinely diversified with passerine birds, ground-dwelling bird nestlings, small reptiles, amphibians, and macroscopic orthopterans depending on seasonal abundance. Hunting success relies not merely on sharp vision but on exquisite auditory acuity, allowing the raptor to detect acoustic rustles emitted by hidden prey beneath thick vegetative screens before dropping abruptly with extended talons.

Behavior: Renowned for a peculiar, highly buoyant hunting strategy characterized by low-level quartering flights conducted just 1 to 3 meters above herbaceous layers. During this flight, the wings are held in a slight yet distinct dihedral V-shape, allowing for sudden, low-speed stalls, sharp turns, and rapid drops caused by an exceptionally low wing-loading ratio. While generally solitary hunters, individuals frequently assemble into large communal roosts situated directly on marshy ground or dense reedbeds during non-breeding intervals and migratory stopovers to optimize thermal conservation and deter nocturnal terrestrial predators.

Nesting: Unlike most other raptors that select trees, cliffs, or man-made structures, this group nests strictly upon the ground hidden deep within reedbeds, tall rushes, or extensive crop patches. The female meticulously accumulates dried vegetation, stalks, and reeds to construct a flat or elevated platform capable of keeping the brood dry. Clutch size typically ranges from 3 to 6 eggs, pale bluish-white in hue, which are incubated exclusively by the female for roughly 30 to 35 days. An iconic breeding display involves aerial food passes, where the foraging male drops freshly caught prey mid-air to the female, who catches it adeptly upside down.

Conservation status: Classified as a collective group primarily under the status of Least Concern (LC) by the International Union for Conservation of Nature (IUCN), though several localized taxa and regional subspecies face severe threats that place them under Vulnerable (VU) or Endangered (EN) listings. The primary anthropogenic threats include the widespread drainage of wetland ecosystems, habitat fragmentation caused by intensive monocultures, incidental nest mortality driven by early mechanized agricultural harvesting, and severe secondary poisoning linked to the uncontrolled use of rodenticides.