Falconidae

Taxobox
name = Falcons and caracaras


image_width = 240px
image_caption = Brown Falcon "Falco berigora"
regnum = Animalia
phylum = Chordata
classis = Aves
ordo = Falconiformes
familia = Falconidae
familia_authority = Vigors, 1824
subdivision_ranks = Genera
subdivision = "Daptrius"
"Falco"
"Herpetotheres"
"Ibycter"
"Micrastur"
"Microhierax"
"Milvago"
"Phalcoboenus"
"Polihierax"
"Caracara"
"Spiziapteryx"
and see text.

The falcons and caracaras are around 60 species of diurnal birds of prey that comprise the family Falconidae. The family is divided into two subfamiles, Polyborinae, which includes the caracaras and forest falcons, and Falconinae, the falcons, kestrels and falconets.

Description and ecology

Falcons and caracaras are small to medium sized birds of prey, ranging in size from the Black-thighed Falconet, which can weight as little as 35 g, to the Gyrfalcon, which can weigh as much as 1735 g. They have strongly hooked bills, sharply curved talons and excellent eyesight. The plumage is usually composed of browns, whites, chestnut, black and grey, often with barring of patterning. There is little difference n the plumage of males and females, although a few species have some sexual dimorphism in boldness of plumage.

They differ from other Falconiformes in killing with their beaks instead of their feet. They have a "tooth" on the side of their beak for the purpose. The family has a cosmopolitan distribution across the world, absent only from the densest forest of central Africa, some remote oceanic islands, the high Arctic and Antarctica. Some species have exceptionally wide ranges, particularly the cosmopolitan Peregrine Falcon, which ranges from Greenland to Fiji and has the widest natural breeding distribution of any bird. Other species have more restricted distributions, particularly island endemics like the Mauritius Kestrel. Most habitat types are occupied, from tundra to rainforest and deserts, although they are generally more birds of open country and even forest species tend to prefer broken forest and forest edges. Some species, mostly in the genus "Falco", are fully migratory, with some species in Eurasia and wintering entirely in Africa, other species may be partly migratory. The Amur Falcon has one of the longest migrations, moving from East Asia to southern Africa.

Falcons and caracaras are carnivores, feeding on birds, small mammals, reptiles, insects and carrion. In popular imagination the falconids are fast flying predators, and while this is true of the genus "Falco" and some falconets other species, particularly the caracaras are more sedentary in their feeding. The forest-falcons of the Neotropics are generalist forest hunters. Several species, particularly the true falcons, will stash food supplies in caches. [Collopy M.W. (1977) "Food Caching by Female American Kestrels in Winter" "Condor" 79 (1): 63-68] They are solitary hunters and pairs guard territories, although they may form large flocks during migration. Some species are specialists, the Laughing Falcon specialises in snakes, others are more generalist.

The falcons and caracaras are generally solitary breeders, although around 10% of species are colonial, for example the Red-footed Falcon. [Ille, R.; Hoi, H.; Grinschgl, F. & F. Zink (2002) "Paternity assurance in two species of colonially breeding falcon: the kestrel "Falco tinnunculus" and the red-footed falcon "Falco vespertinus" "Etologica" 10 11-15] They are monogamous, although some caracaras may also employ alloparenting stratergies, where younger birds help adults (usually their parents) in raising the next brood of chicks. Nests are generally not built (except by the caracaras), but are co opted from other birds, for example African Pygmy-falcons nest in the nests of weavers, or on the ledges on cliffs. Around 2-4 eggs are laid, and mostly incubated by the female. Incubation times vary from species to species and are correlated with body size, lasting 28 days in smaller species and up to 35 days in larger species. Chicks fledge after 28-49 days, again varying with size.

Relations with humans

Falcons and caracaras have a complicated relationship with humans. In ancient Egypt they were deified in the form of Horus, the Sky and Sun God, and was the ancestor of the Pharaohs. Caracaras also formed part of the legends of the Aztecs, and are today the national emblems of Mexico. Falcons were important in the (formerly often royal) sport of Falconry. They have also been persecuted for their predation on game and farm animals, and that persecution has led to the extinction of at least one species, the Guadalupe Caracara. Several insular species have declined dramatically, none more so than the Mauritius Kestrel, which at one time numbered no more than four birds. Around four species of falcon are considered vulnerable to extinction by the IUCN, with one species, the Saker Falcon, listed as endangered.

Genera in taxonomic order

Family: Falconidae
* Genus "Daptrius" – Black Caracara
* Genus "Ibycter" – Red-throated Caracara (sometimes included in "Daptrius")
* Genus "Phalcoboenus" (4 species)
* Genus "Caracara" – crested caracaras (2 living species, 1 recently extinct)
* Genus "Milvago" – brown caracaras (2 species)
* Genus "Herpetotheres" – Laughing Falcon
* Genus "Micrastur" – forest falcons (7 species)
* Genus "Spiziapteryx" – Spot-winged Falconet
* Genus "Polihierax" – pygmy-falcons (2 species, includes "Neohierax")
* Genus "Microhierax" – typical falconets (5 species)
* Genus "Falco" – true falcons, hobbies and kestrels (around 37 species)

Fossil genera

*"Parvulivenator" (Early Eocene of England)
*"Stintonornis" (London Clay Early Eocene of England)
*"Badiostes" (Santa Cruz Early Miocene of Patagonia, Argentina)
*Falconidae gen. et sp. indet. (Early Miocene of Chubut, Argentina)
*Falconidae gen. et sp. indet. (Pinturas Early/Middle Miocene of Argentina)
*"Pediohierax" (Middle Miocene of Nebraska, USA) – formerly "Falco ramenta"
*Falconidae gen. et sp. indet. (Cerro Bandera Late Miocene of Neuquén, Argentina) [PVPH 465: a phalanx 1 of the middle toe. A caracara? Possibly belongs in extant genus.(Kramarz "et al." 2005)]
*"Sushkinia" pliocaena" (Early Pliocene of Pavlodar, Kazakhstan) – belongs in "Falco"?

External links

*http://www.soarinhawk.org/rehab/education/
* [http://ibc.hbw.com/ibc/phtml/familia.phtml?idFamilia=32 Falconidae videos] on the Internet Bird Collection
* [http://www.xeno-canto.org/browse.php?query=falconidae Falconidae sounds] in the xeno canto collection

Footnotes

References

* (2005): Estratigrafía y vertebrados (Aves y Mammalia) de la Formación Cerro Bandera, Mioceno Temprano de la Provincia del Neuquén, Argentina. "Revista geológica de Chile" 32(2): 273-291. [http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-02082005000200006&lng=es&nrm=iso HTML fulltext]