The black-thighed falconet is the world’s smallest falcon, with adult males measuring just 14 centimeters (5.5 inches) in length and weighing as little as 28 grams (1 ounce), while spanning only 27 centimeters (10.6 inches) across the wings. Among true Falco species, the Seychelles kestrel is the smallest, reaching just 15 centimeters (5.9 inches) in length with a wingspan of 44 centimeters (17.3 inches).
In this article, we focus on the lowest verified measurements recorded from wild individuals, looking at the tiniest falcons by length, weight, and wingspan across different groups and continents. Each species is presented with its minimum known dimensions, along with the unique adaptations that allow it to thrive at such a reduced scale. We also explore their habitats, behavior, and the main threats they face in the wild.
Black-thighed falconet (Microhierax fringillarius)
- Body length: As small as 14 cm (5.5 in).
- Weight: As little as 28 g (1 oz).
- Wingspan: As short as 27 cm (10.6 in).
- Where found: Mainland Southeast Asia and Greater Sundas – in forest edges, clearings, and riverine woodland.
- Conservation status: Least Concern.

The black-thighed falconet is the smallest falcon in the world, reaching just 14 centimeters (5.5 inches) in length with a wingspan of only 27 centimeters (10.6 inches). Small males can weigh as little as 28 grams (1 ounce), making them the lightest birds of prey.
Adapted for life at a miniature scale, it remains agile and fast, using short but powerful bursts of flight from exposed perches. Its relatively long, narrow wings for its body size provide excellent maneuverability and speed, matching the sharp, rapid flight typical of much larger falcons.
This species ranges from southern Myanmar and Thailand through Peninsular Malaysia to Sumatra, Borneo, Java, and Bali. It favors open primary and secondary forests, edges, and clearings, often along rivers or streams, occurring from lowlands up to about 1,200 meters (4,000 feet), and occasionally reaching 1,500 meters (5,000 feet) on Sumatra. It is largely sedentary, forming small, social groups that often hunt and feed communally – an unusual trait among raptors. Its diet consists mainly of large insects such as moths, cicadas, and termites, but it can also take small birds like mannikins and sunbirds.
Tolerant of disturbed habitats, it is even attracted to areas of recent forest clearing where prey is abundant. Although more common in mainland Southeast Asia and Borneo and scarcer on Java and Bali, its wide range and adaptability keep it secure, with no major conservation concerns.
Collared falconet (Microhierax caerulescens)
- Body length: As small as 14 cm (5.5 in).
- Weight: As little as 30 g (1.1 oz).
- Wingspan: As short as 28 cm (11 in).
- Where found: Himalayan foothills and mainland Southeast Asia – open forest edges, plantations, and riverine woodland.
- Conservation status: Least Concern.

The collared falconet is a tiny falcon species, barely reaching 14 centimeters (5.5 inches) in length and spanning just 28 centimeters (11 inches) across the wings. Males are slightly smaller and can weigh as little as 30 grams (1.1 ounces), making this species comparable in size and habits to a shrike rather than a typical falcon.
Its compact body is balanced by long, slender wings that give it remarkable agility and control in short, rapid flights. Perched high above the forest edge, it moves with swift, deliberate precision, perfectly adapted to life at such a tiny scale.
This species ranges from the Himalayan foothills of northern India, Nepal, and Bhutan through Myanmar to mainland Southeast Asia, including Thailand, Laos, Cambodia, and Vietnam. It prefers open deciduous forest, forest edge, plantations, and abandoned cultivation with trees, often near rivers and streams. It occurs mainly below 900 meters (3,000 feet) but can reach 1,700 meters (5,600 feet) and occasionally up to 2,000 meters (6,500 feet) in the Himalayas.
Mostly sedentary, it forms social family groups that perch high on snags above the canopy and sometimes engage in communal hunting and preening. Its diet consists primarily of large insects such as butterflies, moths, dragonflies, and beetles, but it is also capable of taking small birds, lizards, and even tiny mammals.
The collared falconet readily uses partially cleared forest and other disturbed habitats, showing a high tolerance for human-altered landscapes. While it is fairly common in some regions, it tends to occur in low densities and is often patchily distributed. Its broad range and adaptable habits ensure its long-term stability, with no major threats currently affecting the species.
Pygmy falcon (Polihierax semitorquatus)
- Body length: As small as 18 cm (7.1 in).
- Weight: As little as 44 g (1.6 oz).
- Wingspan: As short as 34 cm (13.4 in).
- Where found: Eastern and southern Africa; arid and semi-arid savanna, scrub, and thornbush with scattered trees.
- Conservation status: Least Concern.

The pygmy falcon is the smallest falcon in Africa and the tiniest raptor on the continent, measuring just 18 centimeters (7.1 inches) in length with a wingspan of only 34 centimeters (13.4 inches). The lightest individuals, mainly from southern populations, can weigh as little as 44 grams (1.6 ounces).
Compact and slightly chunkier than the Asian falconets, it resembles a shrike in size but retains the predatory agility of a falcon. Its relatively short but broad wings and a fast, direct flight allow quick, low-level dashes from an exposed perch, well-suited to open savanna landscapes.
This species is found from northeastern Democratic Republic of the Congo and South Sudan through Ethiopia, Somalia, and Kenya to southern Tanzania, and separately from southern Angola and Namibia to northwestern South Africa. It inhabits arid and semi-arid savanna, thorn scrub, and steppe with sparse ground cover and scattered trees, typically up to 1,600 meters (5,250 feet).
Uniquely, it relies on the elaborate communal nests of weaver birds – particularly the sociable weaver (Philetairus socius) in southern Africa and the white-headed buffalo-weaver (Dinemellia dinemelli) in the northeast, for both roosting and breeding. Pairs or family groups often share chambers within a single nest mass, sometimes staying inside for long hours during cold winter nights. The diet is dominated by small lizards and large insects, though it occasionally takes rodents, small birds, or the chicks of its weaver hosts.
Although generally tied to the distribution of its host weavers, the pygmy falcon has benefited in parts of southern Africa from the expansion of sociable weaver nests onto utility poles and other man-made structures. It remains widespread and locally common, showing stable populations across much of its range, with no significant threats currently impacting the species.
Seychelles kestrel (Falco araeus)
- Body length: As small as 15 cm (5.9 in).
- Weight: Around 73 g (2.6 oz).
- Wingspan: As short as 44 cm (17.3 in).
- Where found: Granitic islands of Seychelles – in secondary forest, plantations, and urban areas with cliffs or tall trees.
- Conservation status: Vulnerable.

The Seychelles kestrel is the smallest member of the genus Falco, measuring just 15 centimeters (5.9 inches) in length with a wingspan of 44 centimeters (17.3 inches). Males are slightly smaller than females and average around 73 grams (2.6 ounces), making it not only the tiniest kestrel but also the smallest true falcon.
Slender and lightweight, it is adapted for quick, direct flights between perches rather than the hovering typical of many kestrels. Its hunting style relies on rapid dashes from concealed or open perches to snatch prey from foliage, trunks, or the ground – a strategy well suited to the mixed habitats of its island home.
This island endemic occurs only on the Granitic islands of the Seychelles, with most of the population concentrated on Mahe and its satellites, as well as Silhouette and smaller numbers on Praslin following reintroduction. It inhabits dense secondary forest with cliffs, but also uses coconut plantations, gardens, and even buildings, ranging from sea level up to 900 meters (3,000 feet). The diet is dominated by native lizards such as skinks and day geckos, but it also takes insects, small birds, mice, and occasionally frogs or chameleons.
The Seychelles kestrel has shown some adaptability to human-modified landscapes, including nesting in urban areas and plantations. However, it still faces competition for nest sites from introduced barn owls (Tyto alba) and common mynas (Acridotheres tristis), along with predation by black rats and feral cats.
The kestrel’s population, though reduced from its historical distribution, has been stabilized through conservation efforts such as reintroductions, nest-box programs, and habitat protection. Despite its resilience across several islands, its restricted range and ongoing local pressures continue to leave the species vulnerable.
American kestrel (Falco sparverius)
- Body length: As small as 22 cm (8.7 in).
- Weight: As little as 80 g (2.8 oz).
- Wingspan: As short as 51 cm (20 in).
- Where found: Throughout the Americas from Alaska to southern South America – open country, grasslands, agricultural areas, and urban edges.
- Conservation status: Least Concern.

The American kestrel is the smallest falcon in the Americas, measuring just 22 centimeters (8.7 inches) in length with a wingspan of 51 centimeters (20 inches). Males are slightly smaller and can weigh as little as 80 grams (2.8 ounces), yet they retain the sleek, pointed-wing silhouette of larger falcon species.
This diminutive predator combines agile hovering flight with rapid, direct pounces from exposed perches, a versatile hunting style suited to open habitats. Despite its small size, it is highly adaptable, ranging from grasslands to desert scrub and even city edges, where utility wires often serve as hunting perches.
This species occurs across an immense range, breeding from Alaska and Canada through the United States, Mexico, the Caribbean, and much of South America. It favors open areas with short ground vegetation and scattered trees or structures that provide perches and cavity nest sites. The diet varies with season and location but is dominated by insects such as grasshoppers and beetles, supplemented by small rodents, birds, reptiles, and occasionally amphibians.
While the kestrel remains widespread and locally common, populations in parts of North America have shown long-term declines due to loss of nesting cavities, pesticide use reducing prey availability, and intensification of “clean” farming practices. Nevertheless, its broad range and high adaptability keep it secure at the continental scale, though continued habitat management is important to prevent further declines.
Merlin (Falco columbarius)
- Body length: As small as 24 cm (9.4 in).
- Weight: As little as 125 g (4.4 oz).
- Wingspan: As short as 53 cm (20.9 in).
- Where found: Widespread across northern Eurasia and North America – open moorlands, boreal forest edges, grasslands, and coastal areas.
- Conservation status: Least Concern.

The merlin is the smallest falcon in Europe, measuring just 24 centimeters (9.4 inches) in length with a wingspan of 53 centimeters (20.9 inches). Adult males are up to 30% lighter than females, typically weighing around 160 grams (5.6 ounces), but the tiniest individuals can weigh as little as 125 grams (4.4 ounces).
Despite its compact build, the merlin is a powerful aerial hunter, built for fast, low-level pursuits rather than high-altitude stoops. It flies with rapid wingbeats, hugging the ground or weaving through low vegetation to surprise its prey.
This species breeds across northern Eurasia from Iceland and Scandinavia east to Siberia, favoring open moorlands, tundra edges, and fragmented boreal forests. In winter, it disperses southward across much of Europe, where it frequents coastal mudflats, farmland, and urban edges to hunt small birds. In North America, it is widespread in the boreal zone and prairie regions, also wintering far south into Central and South America. Merlins rely heavily on small birds such as pipits, larks, and sparrows, capturing most prey in midair during short, surprise attacks.
Although historically affected by pesticide contamination and habitat changes, populations have stabilized following bans on organochlorines, and the species remains secure overall. Local threats such as nest disturbance, habitat loss, and collisions with man-made structures persist but have not caused major global declines.
Nankeen kestrel (Falco cenchroides)
- Body length: As small as 28 cm (11 in).
- Weight: As little as 121 g (4.3 oz).
- Wingspan: As short as 62 cm (24.4 in).
- Where found: Australia, Tasmania, and nearby islands; open grasslands, farmland, savanna, and lightly wooded areas.
- Conservation status: Least Concern.

The nankeen kestrel is the smallest falcon in Australia, measuring just 28 centimeters (11 inches) in length with a wingspan of 62 centimeters (24.4 inches). Adult males are noticeably smaller than females, and the lightest individuals can weigh only 121 grams (4.3 ounces).
Despite its modest size, this kestrel is highly effective in open habitats, hunting by hovering on rapid wingbeats or scanning from exposed perches. Its flight is buoyant and agile, allowing precise pounces on prey in grasslands and farmland, where it is a familiar sight.
This widespread species ranges across mainland Australia, Tasmania, and offshore islands, and even reaches New Guinea and parts of Indonesia as a migrant. It thrives in a variety of lightly wooded and treeless habitats, from coastal plains and agricultural fields to semi-arid savanna. Its diet is diverse, including insects such as grasshoppers and beetles, small mammals like mice, lizards, and occasionally small birds.
Unlike many raptors, the nankeen kestrel has benefited from habitat changes caused by agriculture and forest clearing, as well as the availability of introduced prey. Today it remains one of Australia’s most abundant birds of prey, secure across its vast range with no significant conservation concerns.
Barred forest falcon (Micrastur ruficollis)
- Body length: As small as 31 cm (12.2 in).
- Weight: As little as 144 g (5.1 oz).
- Wingspan: As short as 46 cm (18.1 in).
- Where found: From southern Mexico to northern Argentina – in humid tropical forests, forest edges, and foothill woodlands.
- Conservation status: Least Concern.

The barred forest falcon is the smallest member of the genus Micrastur (forest falcons), measuring just 31 centimeters (12.2 inches) in length, with males weighing around 144 grams (5.1 ounces) and spanning 46 centimeters (18.1 inches) across the wings.
Unlike open-country falcons with long, pointed wings, this species has shorter, rounded wings and a long tail, an adaptation for maneuvering silently through dense tropical forest. Its hunting style relies on stealth and short bursts of flight between shaded perches, enabling it to ambush prey in the dimly lit understory.
This elusive raptor ranges widely from southern Mexico through Central America and across much of the Amazon Basin to northern Argentina. It inhabits mature tropical forests, edges, and secondary growth, often favoring areas with a broken canopy and dense cover. Its diet is dominated by lizards, supplemented by small birds, mammals, amphibians, and arthropods, with opportunistic hunting methods ranging from still hunting to ambushing prey flushed by army ant swarms.
Though largely sedentary and locally fairly common in many parts of its range, the barred forest-falcon remains poorly studied due to its secretive nature. Habitat loss from deforestation poses a potential threat, but its wide range and tolerance of secondary forests help keep populations relatively secure.
Small size, same fierce spirit
From the tiny falconets of Southeast Asia to the compact kestrels of islands and open plains, these species reveal just how versatile falcons can be, even at the smallest scale. Despite their reduced size, they remain capable hunters, adapted to very different habitats, from dense tropical forests to semi-deserts, grasslands, and urban areas.
While many of these falcons benefit from their flexibility and wide ranges, some, like the Seychelles kestrel, remain vulnerable due to limited distributions and introduced predators. Together, they show that even the smallest birds of prey retain the power, agility, and precision that define the falcon family.