The Falconidae family, commonly known as falcons, is a group of birds of prey belonging to the order Falconiformes. This family includes some of the most well-known and admired raptors, such as the peregrine falcon, the marsh harrier, and the hobby. Members of the Falconidae family are renowned for their speed, flying abilities, and highly specialized hunting techniques. With about 60 species distributed worldwide, falcons occupy a variety of habitats, ranging from deserts to forests, and are known for their exceptional hunting skills.

Scientific Classification

• Kingdom: Animalia

• Phylum: Chordata

• Class: Aves

• Order: Falconiformes

• Family: Falconidae

Morphological Characteristics

Falcons are medium to large-sized birds characterized by their agile and robust bodies, long pointed wings, and curved beaks. Their morphology is perfectly adapted for hunting, with sharp eyesight, a hooked beak, and strong legs with sharp talons, making them effective predators. Their long, narrow wings give them remarkable speed in flight, which is one of the most distinctive features of these birds. The shape of their wings and tail varies by species, but all falcons possess excellent aerial maneuverability.

The plumage of falcons can vary widely between species, but generally includes tones of brown, gray, white, and black. Some falcons, like the peregrine falcon (Falco peregrinus), are easily recognized by their elegant plumage and distinct facial markings.

Behavior and Feeding Habits

Falcons are carnivorous predators, with a diet that primarily includes small birds, mammals, insects, and reptiles. Their ability to fly at high speeds and capture prey mid-air is among the most extraordinary in the animal kingdom. The peregrine falcon (Falco peregrinus), for example, is famous for its speed during its hunting dive, reaching speeds exceeding 300 km/h, making it the fastest animal in the world.

Falcons hunt in different ways depending on the species: some species, like the marsh harrier (Circus aeruginosus), prefer hunting in flight over open terrain, while others, like the hobby (Falco subbuteo), specialize in catching insects. During hunting, falcons use their keen vision to spot prey from great heights, executing rapid and precise attacks.

Habitat and Distribution

Falcons are found in a wide range of habitats around the world, including deserts, forests, mountain ranges, and urban areas. They are particularly common in open regions and landscapes that provide wide views, such as plains, agricultural fields, and coastal areas. Some species, like the peregrine falcon, are found in urban environments, nesting on skyscrapers or bridges.

Their geographic distribution is extensive, with falcons inhabiting nearly every continent except Antarctica. While some species, like the American kestrel (Falco sparverius), are sedentary, others are migratory, moving between more favorable habitats during hunting seasons or for breeding.

Reproduction

The breeding season for falcons varies by species and climate. Falcons are generally monogamous during the breeding season, and pairs form long-lasting bonds, sometimes for life. Their nests are usually built in high places, such as cliffs, tall trees, or artificial structures like bridges or skyscrapers. Falcons often use pre-existing nests built by other birds, but some species build their nests from scratch using twigs and other materials.

The female typically lays between 2 and 5 eggs, which are incubated by both parents for a period ranging from 28 to 35 days, depending on the species. Both parents take part in caring for the young, with the male usually assisting in food provisioning while the female incubates and protects the eggs. Once the chicks hatch, both parents work together to feed and protect them. The young falcons are generally cared for until they are fully fledged and able to fly, after which they may stay with their parents for a while to learn essential survival skills.

Conservation

Most falcon species are stable, but some are threatened due to habitat loss, pesticide contamination, and hunting. The peregrine falcon, for example, was severely impacted by the use of pesticides like DDT in the 1950s and 1960s, which caused a dramatic decline in its population. However, thanks to conservation efforts, the peregrine falcon population has significantly increased.

Species like the Juan Fernández Island falcon (Falco peregrinus fernandensis) are at risk, with their population confined to a small habitat. Conservation measures focus on protecting natural habitats, reducing pesticide use, and creating nature reserves.

Conclusion

The Falconidae family represents one of the most fascinating and adaptable groups of raptors. Falcons are formidable predators, with flying and hunting abilities that make them some of the most extraordinary birds. Their presence in a variety of habitats and their ability to adapt to urban environments make them a bird family of great interest to ornithologists and nature enthusiasts. Despite some challenges related to conservation, the peregrine falcon and other species have shown remarkable resilience, ensuring their place as symbols of speed and predatory skill in the animal kingdom.

References__________________________________________________________________________

Fargallo JA, Navarro-López J, Cantalapiedra JL, Pelegrin JS, Hernández Fernández M. Trophic Niche Breadth of Falconidae Species Predicts Biomic Specialisation but Not Range Size. Biology (Basel). 2022 Mar 29;11(4):522. doi: 10.3390/biology11040522. 

Abstract. Trophic niche breadth plays a key role in biogeographic distribution patterns. Theory posits that generalist strategies are favoured in a more heterogeneous set of environments across a spatio-temporal gradient of resources predictability, conferring individuals and species a greater capacity for colonising new habitats and thus expanding their distribution area. Using the family Falconidae (Aves, Falconiformes) as a model study, we tested the prediction that those species with a wider diet spectrum will have larger geographic range sizes and inhabit more biomes. We assessed the relationships between trophic breadth (diet richness and diversity) at different taxonomic resolutions of the prey (class and order), range size and biomic specialisation index (BSI; number of biomes inhabited) for the different species. Despite different diet breadth indexes and taxonomic resolutions defined differently the trophic niche of the clade and species, our findings revealed that trophic breadth was not a good predictor for range size but was for total environmental heterogeneity, with more diet-generalist species occupying a higher number of biomes. Diet breadth at the order taxonomic level showed a higher capacity of predicting BSI than at class level, and can be an important ecological trait explaining biogeographic patterns of the species.

Amin OM, Heckmann RA, Dallarés S, Constenla M, Rubini S. Description and molecular analysis of an Italian population of Centrorhynchus globo caudatus (Zeder, 1800) Lühe, 1911 (Acanthocephala: Centrorhynchidae) from Falco tinnunculus (Falconidae) and Buteo buteo (Accipitridae). J Helminthol. 2020 Oct 29;94:e207. doi: 10.1017/S0022149X20000887. 

Abstract. Centrorhynchus globocaudatus (Zeder, 1800) Lühe, 1911 (Centrorhynchidae) was reported in birds of prey. Our population from Falco tinnunculus Linnaeus (Falconidae) and Buteo buteo Linnaeus (Accipitridae) in northern Italy was morphologically distinct from others described elsewhere. The worms are elongate and cylindrical. Proboscis long, apically truncated and bare, with wider base and variably faint constriction at point of attachment of receptacle. Large anterior hooks well rooted; posterior spiniform hooks with reduced roots; transitional hooks with scutiform roots in-between. Four tubular cement glands extend into prominent ducts overlapping a large Saefftigen's pouch. Bursa large, with sensory plates. Vagina with laterally slit orifice in sub-ventral pit of globular terminal extension. Thick-shelled eggs ovoid without polar prolongation of fertilization membrane. In our specimens, proboscis hooks, receptacle, male reproductive system, and lemnisci especially in males varied in size from those from Ukraine, India, Egypt, Kyrgystan, Russia, Georgia, Armenia and Asian Soviet Republics. Our description of the Italian specimens includes new morphological information supported by scanning electron microscopy and microscope images, molecular analysis and energy dispersive X-ray analysis (EDXA) of hooks. Additional new details of proboscis hook roots, micropores and micropore distribution are described. Metal composition of hooks (EDXA) demonstrated high levels of calcium and phosphorous, and high levels of sulphur in core and cortical layers of eggs. The molecular profile based on sequences of 18S and cytochrome c oxidase 1 genes is also provided, as well as phylogenetic reconstructions including all available sequences of the family Centrorhynchidae, although further sequences are needed in order to clarify their phylogenetic relationships.

Fuchs J, Johnson JA, Mindell DP. Rapid diversification of falcons (Aves: Falconidae) due to expansion of open habitats in the Late Miocene. Mol Phylogenet Evol. 2015 Jan;82 Pt A:166-82. doi: 10.1016/j.ympev.2014.08.010. 

Abstract. Understanding how and why lineages diversify is central to understanding the origins of biological diversity. The avian family Falconidae (caracaras, forest-falcons, falcons) has an uneven distribution of species among multiple well-supported clades, and provides a useful system for testing hypotheses about diversification rate and correlation with environmental changes. We analyzed eight independent loci for 1-7 individuals from each of the 64 currently recognized Falconidae species, together with two fossil falconid temporal calibrations, to assess phylogeny, absolute divergence times and potential shifts in diversification rate. Our analyses supported similar diversification ages in the Early to Middle Miocene for the three traditional subfamilies, Herpetotherinae, Polyborinae and Falconinae. We estimated that divergences within the subfamily Falconinae began about 16mya and divergences within the most species-rich genus, Falco, including about 60% of all Falconidae species, began about 7.5mya. We found evidence for a significant increase in diversification rate at the basal phylogenetic node for the genus Falco, and the timing for this rate shift correlates generally with expansion of C4 grasslands beginning around the Miocene/Pliocene transition. Concomitantly, Falco lineages that are distributed primarily in grassland or savannah habitats, as opposed to woodlands, and exhibit migratory, as opposed to sedentary, behavior experienced a higher diversification rate.

Nishida C, Ishijima J, Kosaka A, Tanabe H, Habermann FA, Griffin DK, Matsuda Y. Characterization of chromosome structures of Falconinae (Falconidae, Falconiformes, Aves) by chromosome painting and delineation of chromosome rearrangements during their differentiation. Chromosome Res. 2008;16(1):171-81. doi: 10.1007/s10577-007-1210-6.

Abstract. Karyotypes of most bird species are characterized by around 2n = 80 chromosomes, comprising 7-10 pairs of large- and medium-sized macrochromosomes including sex chromosomes and numerous morphologically indistinguishable microchromosomes. The Falconinae of the Falconiformes has a different karyotype from the typical avian karyotype in low chromosome numbers, little size difference between macrochromosomes and a smaller number of microchromosomes. To characterize chromosome structures of Falconinae and to delineate the chromosome rearrangements that occurred in this subfamily, we conducted comparative chromosome painting with chicken chromosomes 1-9 and Z probes and microchromosome-specific probes, and chromosome mapping of the 18S-28S rRNA genes and telomeric (TTAGGG)( n ) sequences for common kestrel (Falco tinnunculus) (2n = 52), peregrine falcon (Falco peregrinus) (2n = 50) and merlin (Falco columbarius) (2n = 40). F. tinnunculus had the highest number of chromosomes and was considered to retain the ancestral karyotype of Falconinae; one and six centric fusions might have occurred in macrochromosomes of F. peregrinus and F. columbarius, respectively. Tandem fusions of microchromosomes to macrochromosomes and between microchromosomes were also frequently observed, and chromosomal locations of the rRNA genes ranged from two to seven pairs of chromosomes. These karyotypic features of Falconinae were relatively different from those of Accipitridae, indicating that the drastic chromosome rearrangements occurred independently in the lineages of Accipitridae and Falconinae.