Short tailed Hawk

Birds Name	Short-tailed hawk
Science Name	Buteo brachyurus
Domain	Eukaryota
Kingdom	Animalia
Phylum	Chordata
Class	Aves
Order	Accipitriformes
Family	Accipitridae
Genus	Buteo
Species	B.brachyurus

In the humid, sun-drenched expanses of the Florida peninsula, a raptor of singular grace and elusive behavior patrols the skies. The Short-tailed Hawk (Buteo brachyurus) stands as one of the most enigmatic and specialized members of the North American avifauna. Often described by ornithologists as a “phantom” due to its tendency to forage at the very limits of human vision, this species presents a unique case study in avian adaptation, ecological specialization, and biogeography. While it is a widespread neotropical species, ranging as far south as northern Argentina, its presence in the United States is almost entirely restricted to a disjunct, resident, and intra-state migratory population in Florida. This geographic isolation has created a distinct ecological enclave where the species has adapted to the specific hydrological and botanical rhythms of the Floridian landscape.

The Short-tailed Hawk challenges the conventional “Buteo” archetype. Unlike the Red-tailed Hawk (Buteo jamaicensis), which is frequently seen perched on roadside utility poles hunting mammals, or the Red-shouldered Hawk (Buteo lineatus), which hunts from perches in the sub-canopy of wet forests, the Short-tailed Hawk is an aerial specialist. It spends the vast majority of its day on the wing, utilizing a specific hunting strategy—a high-altitude still-hunt followed by a steep, vertical stoop—that is more reminiscent of a falcon than a buzzard. This behavior allows it to exploit a specific niche: small birds perched in the upper canopy of forests and edges, a resource largely unavailable to other sympatric raptors.

This report serves as an exhaustive examination of the Short-tailed Hawk, synthesized for an audience of expert birdwatchers, wildlife biologists, and conservationists. The analysis moves beyond basic identification to explore the intricate evolutionary pressures that have shaped its aerial-hunting lifestyle, its specialized diet of birds, and its reliance on specific wetland ecosystems such as cypress domes and mangrove forests. Through a rigorous review of biometric data, breeding phenology, and migration statistics, this document establishes a definitive profile of Buteo brachyurus, contrasting it with sympatric species such as the Broad-winged Hawk (Buteo platypterus) and Swainson’s Hawk (Buteo swainsoni) to highlight its unique niche. Furthermore, with the Florida population estimated at fewer than 500 individuals, the conservation implications of habitat loss and climate change are analyzed with urgency.

Description

The physical description of the Short-tailed Hawk reveals a bird evolutionarily sculpted for a specific aerial niche. It is a compact, trim raptor, often described as having a “big-headed” look, yet it possesses relatively long, broad wings that facilitate the static soaring required for its hunting method. Despite its common name, the tail is not notably short compared to other Buteos; rather, the name is something of a misnomer, potentially derived from early comparative studies with longer-tailed accipiters or other hawks. The tail length is average for its body size, but the folded wings reach the tip of the tail when perched, giving the bird a compact, truncated appearance.

Biometrics and Morphology

Biometrically, the Short-tailed Hawk is a medium-to-small Buteo, roughly the size of an American Crow (Corvus brachyrhynchos). Sexual dimorphism is present, as is typical in raptors (reversed sexual dimorphism), with females generally being larger and heavier than males. This size disparity is a critical adaptation in raptors, often associated with the differing roles of sexes during the nesting cycle, where the larger female defends the nest and incubates while the smaller, more agile male hunts. The degree of dimorphism in Buteo brachyurus allows the pair to exploit a slightly wider range of prey sizes, reducing intraspecific competition within the territory.

Data indicates that the total length of the species ranges from 39 to 44 cm (15.3–17.3 inches). The wingspan is disproportionately large for its body length, ranging from 83 to 103 cm (32.7–40.5 inches). This high aspect ratio and broad wing surface area create a low wing loading, which is the ratio of body mass to wing area. A low wing loading allows for effortless lift even in weak thermals, a critical adaptation for a bird that spends hours kiting in the humid, often heavy air of the subtropics. Weight measurements reveal a mass range of 385 to 515 g, with females averaging higher. One study noted an average mass of 441 g for the species, with females averaging 515 g and males significantly lighter at 392 g. This weight places them in a similar class to the Broad-winged Hawk but significantly lighter than the Red-shouldered Hawk, reflecting their reliance on buoyancy rather than brute force.

The structure of the bill and feet further reflects its dietary specialization. The bill is relatively small but sharply hooked, suitable for dismantling avian prey. The feet, however, are described as having longer toes and talons compared to other Buteos of similar size, such as the Broad-winged Hawk. This adaptation is thought to aid in grasping feathered prey, which requires a longer reach to penetrate the plumage and grip the body than is necessary for mammalian prey.

Table 1 illustrates the comparative biometrics of the Short-tailed Hawk against two similar species often confused with it: the Broad-winged Hawk and Swainson’s Hawk. The Short-tailed Hawk is generally larger and heavier than the Broad-winged Hawk but significantly smaller than the Swainson’s Hawk.

Biometric Comparison of Short-tailed, Broad-winged, and Swainson’s Hawks

Plumage Polymorphism

One of the most striking aspects of the Short-tailed Hawk is its distinct plumage polymorphism. The species occurs in two discreet color morphs: light and dark. Unlike the gradual variation seen in Red-tailed Hawks (which can range from krideri to harlani with many intermediates), Short-tailed Hawks are generally either fully dark or distinctly light, with few intermediates. This discrete polymorphism suggests a genetic basis that is maintained by balancing selection, although the exact ecological advantages of each morph in the Florida population remain a subject of study.

Dark Morph:

In Florida, the dark morph is the predominant form, accounting for approximately 80% of the population. This frequency contrasts sharply with populations in Mexico and Central America where light morphs may be more common or equally distributed. The dark morph bird is entirely sooty black or dark brown on the head, back, and underparts. The feathers often have a slight sheen in fresh plumage but can fade to a browner tone with wear. The key field mark for a soaring dark morph Short-tailed Hawk is the contrast between the black wing linings (underwing coverts) and the paler, silvery-gray flight feathers (remiges), which also feature distinct dark barring. This “two-toned” underwing is diagnostic. The tail is grayish with a bold subterminal band and narrower dark bands closer to the base. From a distance, a dark morph Short-tailed Hawk can resemble a Black Vulture (Coragyps atratus) due to its soaring behavior, dark plumage, and upturned wingtips, but its smaller head, feathered legs, and agile flight distinguish it.

Light Morph:

The light morph presents a starkly different appearance and is often considered one of the most beautiful Buteos. The upperparts are dark brown, similar to the dark morph, but the underparts are immaculate white. A defining characteristic of the light morph is the “hooded” appearance; the dark brown of the crown and ear coverts extends down the sides of the neck, creating a helmet-like effect that contrasts sharply with the pure white throat and breast. This lack of streaking or barring on the underparts is a critical identification feature, separating it from the Broad-winged Hawk, which typically shows heavy barring on the breast in adulthood, and the Red-tailed Hawk, which usually has a belly band. The underwings of the light morph show white linings that contrast with the darker flight feathers, though the contrast is less extreme than in the dark morph. The separation of the dark hood from the white throat is often visible even at a distance.

Identification of Color Morphs in Short-tailed Hawk

Identification in Flight

Field identification of the Short-tailed Hawk is notoriously difficult due to its habit of soaring at high altitudes, often appearing as a mere speck against the clouds. However, specific flight characteristics aid in identification. The bird soars on flat wings with the tips upturned in a dihedral, similar to a Turkey Vulture but more stable and less “tippy.” When gliding, the wings are held slightly forward, modifying the center of gravity. The silhouette is distinct: the wings are broad at the base but taper to a somewhat pointed tip, and the secondaries bulge, giving the trailing edge of the wing a curved appearance. This “pinched-in” look at the wing base separates it from the broader-winged silhouettes of other Buteos like the Red-tailed Hawk. The tail, while not exceedingly short, appears broad and fan-shaped when soaring, often fanned widely to maximize lift during kiting behavior.

Taxonomy

The taxonomic history of the Short-tailed Hawk is a narrative of confusion and eventual clarification, reflecting the challenges of classifying polymorphic species before the advent of modern genetics and field ornithology. Scientifically known as Buteo brachyurus, the species belongs to the family Accipitridae, a diverse group including eagles, hawks, kites, and harriers. The specific epithet brachyurus is derived from the Greek brachys (short) and oura (tail), reflecting the morphological trait that originally caught the attention of early naturalists, despite its relative inaccuracy as a field mark.

For over a century, the dark and light morphs were mistaken for separate species. The dark morph was formerly described as Buteo fuliginosus (the “Little Black Hawk”), while the light morph retained the name Buteo brachyurus. It was not until careful observations of mixed pairs—a dark male and a light female, or vice versa—nesting and producing young of both phases that ornithologists confirmed they were a single, polymorphic species. This realization resolved decades of taxonomic uncertainty regarding the “fuliginosus” type specimens collected in Florida. Historically, this confusion was compounded by the rarity of the bird and its elusive habits, which prevented the collection of large series of specimens for comparison.

Currently, two subspecies are recognized, divided geographically:

1. Buteo brachyurus fuliginosus: This subspecies occupies the northern portion of the range, including the population in Florida, as well as populations in Mexico and Central America down to Panama. The Florida population is noted to be slightly larger-bodied than its Central American counterparts and possesses more rufous coloration on the hindneck in light morphs. The name fuliginosus (sooty) nods to the prevalence of the dark morph in this subspecies, particularly in Florida.

2. Buteo brachyurus brachyurus: This subspecies is found in South America. It is distinguished by having less barring on the tail and lacking the rufous sides on the neck found in the northern subspecies. In the South American subspecies, the white-breasted phase is the more common form, contrasting with the dominance of the melanistic phase in the Florida population of B. b. fuliginosus.

A closely related taxon, the White-throated Hawk (Buteo albigula), found in the Andes and parts of Chile, was formerly considered a subspecies of the Short-tailed Hawk. However, distinct morphological and ecological differences—specifically B. albigula‘s adaptation to high-altitude temperate zones versus B. brachyurus‘s preference for tropical lowlands—have led to B. albigula being elevated to full species status. This separation highlights the Short-tailed Hawk’s identity as a lowland tropical specialist.

Distribution, Range, and Population

The Short-tailed Hawk is a neotropical species with a massive geographic range that extends from the southeastern United States through Mexico and Central America, down to northern Argentina and Brazil. However, its distribution within the United States is highly restricted, unique, and ecologically significant.

The Florida Enclave

In the US, the Short-tailed Hawk is almost exclusively a resident of Florida. This population is disjunct, separated by approximately 800 km of open water (the Gulf of Mexico) from the nearest populations in Mexico. The Florida population is considered a relict of a once broader distribution or a result of a colonization event across the Gulf of Mexico. This isolation has created a “founder effect,” likely contributing to the high frequency of the dark morph (melanism) in Florida compared to other parts of its range. This population is genetically isolated, with no regular gene flow occurring between Florida birds and the continental populations in Mexico.

Historically, the range in Florida was thought to be limited to the southern swamps—Big Cypress and the Everglades. However, modern data indicates a breeding range that encompasses much of the peninsula, extending north to north-central Florida. Breeding occurs in areas such as the Green Swamp, the Okeechobee region, the Kissimmee River valley, and various protected lands like the distinct cypress strands of the Everglades and Big Cypress National Preserve. The distribution is patchy, dictated by the presence of specific nesting habitats (mature swamp forests) adjacent to open foraging grounds.

Population Estimates

The population of Short-tailed Hawks in Florida is remarkably small, making it one of the rarest breeding raptors in the United States. Estimates consistently place the number of individuals at fewer than 500, with some sources suggesting as few as 250 breeding pairs. Despite this low number, the population is believed to be relatively stable. The density of the species is naturally low due to their large home ranges (1.2 to 1.6 miles in diameter) and specific habitat requirements. The rarity of the bird, combined with its secretive nesting habits in dense, remote swamps, makes accurate census data difficult to obtain, and it is likely that the population has always been small but secure within its niche.

Range Expansion and Vagrancy

While Florida remains the stronghold, there is evidence of range expansion or vagrancy in the southwestern United States. In recent years, Short-tailed Hawks have been sighted with increasing frequency in southern Texas, Arizona, and New Mexico. These individuals are likely vagrants from the Mexican populations of B. b. fuliginosus rather than dispersers from Florida. Nesting has been confirmed in southern Arizona, particularly in the “sky island” pine forests of the Chiricahua and Huachuca Mountains. This suggests a slow northward colonization is underway, distinct from the Florida population. These western birds are often light morphs, consistent with the Mexican population’s phenotype, further distinguishing them from the dark-morph-dominated Florida group.

Distribution and Population Status of Short-tailed Hawk

Habitat

The Short-tailed Hawk is a bird of the ecotone—the transitional zone between dense forest and open country. Its habitat requirements are complex, driven by its dual needs for secure nesting sites and open, prey-rich hunting grounds.

Breeding Habitat

For nesting, Short-tailed Hawks require mature, dense woodland stands. In Florida, they show a strong preference for wetland forests, which provide both the structural support for their large nests and a barrier against ground predators like raccoons. Key nesting habitats include:

• Cypress Domes and Strands: These are circular or linear depressions in the landscape filled with water and dominated by Bald Cypress (Taxodium distichum) or Pond Cypress (Taxodium ascendens). The dense canopy and hydrological isolation of these domes provide optimal protection. The “dome” shape results from smaller trees growing at the edges and larger trees in the deeper center, offering a range of canopy heights for nest placement.

• Mangrove Forests: In the coastal regions of the Everglades and the Florida Keys, Short-tailed Hawks nest in tall stands of Black Mangrove (Avicennia germinans) and Red Mangrove (Rhizophora mangle). These impenetrable forests are critical for the wintering population but also support breeding pairs in the extreme south.

• Pine Flatwoods and Hardwood Hammocks: While they prefer wet forests, they will also utilize stands of mature Slash Pines (Pinus elliottii) or oak hammocks (Live Oak, Quercus virginiana), provided they are adjacent to open foraging areas. The key factor is the presence of tall, straight trees that rise above the surrounding vegetation.

The structural characteristic of the nesting site is critical; they typically select tall trees near the edge of a forest patch or a clearing. This placement allows the hawk to launch directly into the air and gain altitude quickly, minimizing the energy expenditure of flapping flight through cluttered understory—a crucial adaptation for a long-winged soaring bird.

Foraging Habitat

While they nest in the forest, Short-tailed Hawks are birds of the open sky. Their foraging habitat consists of a mosaic of open country that supports high densities of small birds. This includes:

• Prairies and Savannas: The wet prairies of the Everglades and the dry prairies of central Florida are prime hunting grounds. These habitats teem with meadowlarks and sparrows.

• Forest Edges: The interface between the cypress dome and the sawgrass marsh is a favored patrol line. The aerodynamic lift created by wind hitting the forest wall aids their soaring.

• Agricultural Land and Suburbs: Surprisingly, Short-tailed Hawks have adapted to forage over pastures, edges of agricultural fields, and even suburban neighborhoods. Bird feeders in suburban areas attract high concentrations of passerines (doves, blackbirds), creating artificial “hotspots” for the hawk. This adaptability to human-altered landscapes is a positive indicator for their resilience.

The loss of cypress domes to urbanization is a critical habitat threat. Studies in Florida have shown that recruit size-class cypress trees decline with urban development, and the functionality of these domes is compromised by altered hydrology (drainage canals) and invasive species like Brazilian Pepper (Schinus terebenthifolius) and Melaleuca. This degradation reduces the availability of suitable nesting sites, forcing hawks into suboptimal habitats where reproductive success may be lower.

Behavior

The behavior of the Short-tailed Hawk is defined by its mastery of the air. It is arguably the most aerial of all North American Buteos, spending hours on the wing without landing, a lifestyle that has shaped its physiology and daily rhythm.

Flight and Aerodynamics

The primary mode of flight for the Short-tailed Hawk is static soaring. It utilizes thermal columns—rising masses of warm air generated by the sun heating the ground—to gain altitude. Once high in the air, often at altitudes of 250 to 800 feet (and occasionally up to 2000 feet), it engages in a behavior known as “kiting.” Kiting involves hanging nearly motionless in the air, facing into the wind, and using subtle adjustments of the wings and tail to maintain position relative to the ground. This behavior is distinct from the hovering of an American Kestrel (Falco sparverius), which requires active flapping. The Short-tailed Hawk’s broad wings and low wing loading allow it to kite with minimal energy expenditure, making it an efficient hunter of the high sky. By remaining motionless relative to the ground, it becomes less conspicuous to prey below, appearing as a fixed object rather than a moving threat.

The flight silhouette during soaring is characterized by wings held in a dihedral (V-shape), similar to a Turkey Vulture but less wobbly. This stability is crucial for spotting small prey from great heights. Unlike the Red-shouldered Hawk (Buteo lineatus), which has a frantic flap-and-glide flight style and hunts primarily from perches, the Short-tailed Hawk’s flight is smooth, composed, and enduring. It rarely perches in the open during the day, preferring to stay aloft or roost deep within the canopy.

Social and Territorial Behavior

Short-tailed Hawks are generally solitary birds outside of the breeding season and migration. They do not form large flocks like the thousands of Broad-winged Hawks seen during migration (“kettles”), although small groups of 3 to 11 individuals have been sighted migrating together in the Florida Keys. They are territorial during the breeding season, vigorously defending their nest sites against other raptors, including larger Red-tailed Hawks and eagles. Interestingly, they often engage in aerial displays that involve bounding swoops and exaggerated “butterfly” flight strokes—deep, slow wingbeats—to mark territory and court mates. These displays are one of the few times the birds become vocal and conspicuous.

Flight Style Comparison of Florida Buteos

Feeding

The Short-tailed Hawk is a specialist predator, a trait that sets it apart from the generalist Buteos of North America. Its diet is overwhelmingly dominated by birds, a specialization that has driven its evolution.

Avian Specialization

Research indicates that birds make up the vast majority of the Short-tailed Hawk’s diet. In Florida, studies have identified over 66 different bird species as prey. The size of prey ranges from small passerines like Blue-gray Gnatcatchers (Polioptila caerulea) and various warblers to larger birds such as Eastern Meadowlarks (Sturnella magna), Red-winged Blackbirds (Agelaius phoeniceus), and doves (Mourning Doves, Zenaida macroura; Common Ground Doves, Columbina passerina). In one detailed study of seven active nests, Eastern Meadowlarks and Red-winged Blackbirds accounted for over 50% of the identified prey items. This preference correlates with their hunting grounds over open prairies and marshes where these icterids are abundant and conspicuous.

While they are avian specialists, they are not strictly limited to birds. They have been recorded taking small rodents, lizards, snakes, frogs, and large insects, but these constitute a minor fraction of their intake compared to other hawks. For instance, the Red-tailed Hawk’s diet is approximately 86% mammals, whereas the Short-tailed Hawk’s diet is primarily avian. This dietary partition allows the Short-tailed Hawk to coexist with Red-shouldered and Red-tailed Hawks without significant competition.

Hunting Technique

The Short-tailed Hawk’s hunting strategy is a marvel of predatory efficiency known as aerial still-hunting. The hawk soars at high altitudes, often bordering the limits of visibility from the ground (up to 1,000 feet or more). It faces into the wind to remain stationary (kiting) while scanning the canopy or open ground below with acute binocular vision. Once prey is located—perhaps a meadowlark singing on a fence post or a dove perched in a treetop—the hawk initiates a stoop.

This stoop is a rapid, controlled dive with wings folded back, often at a steep angle (sometimes nearly vertical). The hawk builds up tremendous speed, allowing it to close the distance before the prey detects the threat. Unlike an Accipiter (like a Cooper’s Hawk), which relies on a horizontal chase through cover, the Short-tailed Hawk relies on the element of surprise from the “blind spot” directly above. It snatches the prey from its perch or the ground in a swift fly-by attack. This method allows it to exploit a niche—birds perched in the upper canopy or exposed on open ground—that is largely inaccessible to the understory-hunting Accipiters or the perch-hunting Buteos.

Table 5: Diet Composition Comparison by Primary Prey Class

Prey Species Frequency in Florida Short-tailed Hawk Nests (Sample Data from Ogden 1974 Study)

Breeding

The breeding biology of the Short-tailed Hawk in Florida is synchronized with the seasonal pulses of the subtropical climate, specifically the dry spring season which concentrates prey.

Nesting Phenology

The breeding season typically commences in late January or February, with courtship displays and nest building. This timing ensures that the period of highest food demand (feeding nestlings) coincides with the spring abundance of nesting passerines and their fledglings. Egg laying generally occurs from March to April. The incubation period lasts approximately 34 to 39 days. Unlike many other raptors where duties are shared, the incubation in Short-tailed Hawks is reportedly performed almost exclusively by the female. During this time, the male acts as the sole provider, hunting tirelessly to provision her with food. This division of labor underscores the high energy demands of incubation and the efficiency of the male’s specialized aerial hunting. The female’s larger size provides better heat retention for the eggs and formidable defense against predators.

Nest Construction and Clutch

Nests are bulky platforms constructed of sticks and twigs, often lined with fresh green leaves (such as wax myrtle or cypress sprigs) and Spanish moss. The lining of green leaves is a common behavior in Buteos, thought to serve a sanitary function or to signal nest occupancy. Nests are placed high in the canopy of tall trees, usually 30 to 60 feet above the ground, often near the very top but concealed within the foliage. Common nest trees include Bald Cypress, Slash Pines, and Mangroves.

The female lays a small clutch, typically consisting of 2 eggs (range 1-3). The eggs are pale bluish-white, sometimes with reddish-brown spotting, measuring approximately 50 x 40 mm. The hatching of the young is asynchronous, meaning they hatch in the order laid, often resulting in a size disparity between siblings. The nestlings are covered in white down at hatching. They grow rapidly, fed a diet of plucked birds delivered by the male and dismembered by the female. They fledge (leave the nest) after several weeks (estimated 5-6 weeks), though the exact duration of the nestling period is less well-documented than for more common species due to the difficulty of observing high canopy nests.

Breeding Phenology of Florida Buteos

Threats and Conservation

Despite a global classification of Least Concern by the IUCN due to its extensive range in South America, the Short-tailed Hawk faces significant conservation challenges in the United States. The Florida population is small, isolated, and reliant on specific habitats that are under intense pressure.

Habitat Loss and Degradation

The primary threat to the species in Florida is the loss of nesting habitat. The destruction of mature cypress domes for timber, agriculture (sugar cane, citrus), and urban development directly removes nesting sites. In the past, extensive logging of cypress swamps severely impacted the availability of tall nesting trees. Today, the drainage of wetlands for development continues to alter the hydrology of these ecosystems. Lower water tables allow predators (raccoons, snakes) access to nests that were once protected by a water moat. Furthermore, altered hydrology facilitates the invasion of exotic vegetation like Melaleuca and Brazilian Pepper, which can alter the forest structure and fire regimes, making habitats unsuitable for nesting. The replacement of native prairies with intensive agriculture or urbanization also reduces the prey base of meadowlarks and other grassland birds, forcing hawks to hunt in more marginal habitats.

Climate Change

Climate change poses a unique and existential threat to the Short-tailed Hawk in Florida. A significant portion of the population winters in the mangrove forests of the Everglades and the Florida Keys. These low-lying coastal habitats are extremely vulnerable to sea-level rise. Models predict that as sea levels rise, mangrove forests may be inundated or forced to retreat inland. However, inland retreat is often blocked by human development (seawalls, roads), leading to “coastal squeeze” and the loss of critical wintering habitat. Furthermore, increased frequency and intensity of hurricanes can destroy nest trees and directly kill individuals. For a population estimated at only 500 birds, a single catastrophic storm hitting a winter concentration could have devastating population-level effects.

Human Interaction

Direct human-caused mortality includes collisions with vehicles and windows, as well as illegal shooting. Although protected under the US Migratory Bird Treaty Act, these hawks are occasionally targeted by individuals who mistake them for other species or view them as threats, despite their diet consisting almost entirely of wild birds rather than poultry or game. The high incidence of dark morphs, which can look like vultures or “black hawks,” may sometimes confuse shooters or casual observers.

Migration

The migratory behavior of the Short-tailed Hawk in Florida is a fascinating example of “intra-state” migration. Unlike the Swainson’s Hawk, which undertakes a massive intercontinental migration from North America to Argentina (a round trip of over 12,000 miles), the Florida Short-tailed Hawk performs a much shorter, yet distinct, seasonal movement of only a few hundred miles.

The Florida Funnel

The migration is essentially a retreat from the northern and central breeding grounds of the Florida peninsula (north of Lake Okeechobee) to the southern tip of the state and the Florida Keys for the winter. Birds that breed in areas like the Green Swamp or Ocala National Forest move southward starting in October. They funnel down the peninsula, arriving in the Everglades and the Keys to spend the winter months. This concentration in the south is driven by prey availability; as winter sets in, the populations of wintering passerines (warblers, sparrows, buntings) from the rest of North America swell in southern Florida, providing an abundant food source for the hawks. They return north to their breeding grounds in February to establish territories. This “short-distance” migration strategy allows them to remain within the subtropical climate zone year-round.

Migration Monitoring

The Florida Keys Hawkwatch, located at Curry Hammock State Park in the Middle Keys, is the premier site for observing this migration. It is one of the few places where Short-tailed Hawks can be seen with some regularity. Data from this site indicates that Short-tailed Hawks are seen in small numbers, often mixed with other migrating raptors like Peregrine Falcons and Broad-winged Hawks. The peak of the southbound movement occurs in October, while the northbound return is noted in late February and March. Counts at the hawkwatch can reach up to 60 sightings over a season, providing a critical index for monitoring the population’s stability. While most individuals stop in the Keys, there is some evidence that a few may cross open water to Cuba or other Caribbean islands, although this is less common for the Florida subspecies compared to the truly migratory nature of some continental populations. The sight of a Short-tailed Hawk “kiting” over the mangroves of the Keys in winter is a prize for any birder.

Migration Statistics from Florida Keys Hawkwatch (Sample Data)

Conclusion

The Short-tailed Hawk remains one of the crown jewels of North American raptors. Its specific adaptation to aerial bird-hunting in the transition zones of the Neotropics has allowed it to carve out a unique existence in Florida. While its population is small, it appears resilient, maintaining a foothold in the cypress strands and mangrove coasts of the state. However, the phantom of the Florida sky is inextricably linked to the health of these wetlands. As Florida faces the dual pressures of rampant development and climate change, the future of Buteo brachyurus will depend on the continued preservation of the wilderness corridors—the cypress domes, the wet prairies, and the mangrove fringes—that allow it to migrate, hunt, and breed in the secluded canopy of the south. For the birder lucky enough to spot a dark silhouette kiting motionless over a cypress dome, the sight is a glimpse into a specialized and ancient lineage of avian predators, a ghost of the tropical sky that calls Florida home.