The falcons and caracaras are around 65 species of Diurnality birds of prey that make up the family Falconidae (representing all extant species in the order Falconiformes). The family likely originated in South America during the Paleocene and is divided into three subfamilies: Herpetotherinae, which includes the laughing falcon and ; Polyborinae, which includes the spot-winged falconet and the caracaras; and Falconinae, the and ( Falco) and falconets ( Microhierax).
Description
Falcons and caracaras are small to medium-sized birds of prey, ranging in size from the black-thighed falconet, which can weigh as little as , to the
gyrfalcon, which can weigh as much as . 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 in the plumage of males and females, although a few species have some sexual dimorphism in boldness of plumage.
Distribution and habitat
The family has a cosmopolitan distribution across the world, absent only from the densest forests 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
endemism like the Mauritius kestrel. Most habitat types are occupied, from
tundra to
rainforest and
, 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 summering 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.
Behaviour
Diet and feeding
Falcons and caracaras are carnivores, feeding on birds, small mammals including bats,
[Mikula, P., Morelli, F., Lučan, R. K., Jones, D. N., & Tryjanowski, P. (2016). Bats as prey of diurnal birds: a global perspective. Mammal Review.] 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
of the
Neotropics are generalist forest hunters. Several species, particularly the true falcons, will stash food supplies in caches.
They are solitary hunters and pairs guard territories, although they may form large flocks during
bird migration. Some species are specialists, such as the
laughing falcon, which specialises in
, and the red-throated caracara, which mainly feeds on the
of
and
; others are more generalist in their diet.
Breeding
The falcons and caracaras are generally solitary breeders, although around 10% of species are
bird colony, for example the red-footed falcon.
They are monogamous, although some caracaras may also employ
alloparenting strategies, 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
nest in the nests of
Ploceidae, or on the ledges on cliffs. Around 2–4 eggs are laid, and mostly
avian incubation 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 who was the ancestor of the
. Caracaras also formed part of the legends of the
. 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 five species of falcon are considered vulnerable to extinction by the
IUCN, including the
saker falcon.
Taxonomy and systematics
The family Falconidae was introduced by the English zoologist William Elford Leach in a guide to the contents of the
British Museum published in 1819.
[ The name of the author is not specified in the document, Leach was the Keeper of Zoology at the time.] The family is composed of three main branches: the
Microhierax and true
falcons, the caracaras, and the
. Differences exist between authorities in how these are grouped into subfamilies. Also, the placement of the
laughing falcon (
Herpetotheres) and the spot-winged falconet (
Spiziapteryx) varies. One common approach uses two subfamilies
Polyborinae and Falconinae. The first contains the caracaras, forest falcons, and laughing falcon. All species in this group are native to the
Americas.
The composition of Falconidae is disputed, and Polyborninae is not featured in the American Ornithologists' Union checklists for North and South American birds that are produced by its Classification Committees (NACC and SACC). The Check-list of North American Birds considers the laughing falcon a true falcon (Falconinae) and replaces Polyborinae with Caracarinae and Forest falcon. On the other hand, the Check-list of South American Birds classifies all caracaras as true falcons and puts the laughing falcon and forest falcons into the subfamily Herpetotherinae.
Falconinae, in its traditional classification, contains the falcons, falconets, and Polihierax. Depending on the authority, Falconinae may also include the caracaras and/or the laughing falcon.
Phylogeny
The following cladogram is based on a comprehensive molecular phylogenetic study of the Falconidae by Jérôme Fuchs and collaborators that was published in 2015. The number of species is taken from the list of birds maintained by Frank Gill,
Pamela Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).
Fuchs and collaborators recommended that the genus
Daptrius should be expanded to include the genera
Phalcoboenus and
Milvago due to the shallow genetic divergence. This change has been adopted by the Clements Checklist but not by the IOC.
List of genera
Below is list of the subfamilies and genera of the Falconidae.[
]
|
|
|
| Herpetotheres – laughing falcon | |
|
| Caracara – crested caracara | |
| Ibycter |
-
Red-throated caracara, Ibycter americanus
|
| Milvago – brown caracaras |
-
Yellow-headed caracara, Milvago chimachima
-
Chimango caracara, Milvago chimango
|
| Daptrius | |
| Phalcoboenus |
-
Carunculated caracara, Phalcoboenus carunculatus
-
Mountain caracara, Phalcoboenus megalopterus
-
White-throated caracara, Phalcoboenus albogularis
-
Striated caracara, Phalcoboenus australis
|
|
| Polihierax | |
| Neohierax |
-
White-rumped falcon, Neohierax insignis
|
| Falcon – true falcons, hobbies and kestrels |
-
Lesser kestrel, Falco naumanni
-
Common kestrel, Falco tinnunculus
-
Rock kestrel, Falco rupicolus
-
Malagasy kestrel, Falco newtoni
-
Mauritius kestrel, Falco punctatus
-
†Reunion kestrel, Falco duboisi
-
Seychelles kestrel, Falco araeus
-
Spotted kestrel, Falco moluccensis
-
Nankeen kestrel or Australian kestrel, Falco cenchroides
-
American kestrel or "sparrow hawk", Falco sparverius
-
Greater kestrel, Falco rupicoloides
-
Fox kestrel, Falco alopex
-
Grey kestrel, Falco ardosiaceus
-
Dickinson's kestrel, Falco dickinsoni
-
Banded kestrel, Falco zoniventris
-
Red-necked falcon, Falco chicquera
-
Red-footed falcon, Falco vespertinus
-
Amur falcon, Falco amurensis
-
Eleonora's falcon, ''Falco eleonorae
-
Sooty falcon, Falco concolor
-
Aplomado falcon, Falco femoralis
-
Merlin or "pigeon hawk", Falco columbarius
-
Bat falcon, Falco rufigularis
-
Orange-breasted falcon, Falco deiroleucus
-
Eurasian hobby, Falco subbuteo
-
African hobby, Falco cuvierii
-
Oriental hobby, Falco severus
-
Australian hobby or little falcon, Falco longipennis
-
New Zealand falcon or karearea, Falco novaeseelandiae
-
Brown falcon, Falco berigora
-
Grey falcon, Falco hypoleucos
-
Black falcon, Falco subniger
-
Lanner falcon, Falco biarmicus
-
Laggar falcon, Falco jugger
-
Saker falcon, Falco cherrug
-
Gyrfalcon, Falco rusticolus
-
Prairie falcon, Falco mexicanus
-
Peregrine falcon, Falco peregrinus
-
Taita falcon, Falco fasciinucha
|
|
Fossil genera
-
Badiostes (Santa Cruz Early Miocene of Patagonia, Argentina)
-
Falconidae gen. et sp. indet. (Early Miocene of Chubut Province, Argentina)
-
Falconidae gen. et sp. indet. (Pinturas Early/Middle Miocene of Argentina)
-
Pediohierax (Middle Miocene of Nebraska, US) – formerly Falco ramenta
-
Falconidae gen. et sp. indet. (Cerro Bandera Late Miocene of Neuquén, Argentina)
[PVPH 465: a phalanges 1 of the middle toe. A caracara? Possibly belongs in extant genus. Kramarz, Alejandro: Garrido, Alberto; Forasiepi, Analía; Bond, Mariano & Tambussi, Claudia (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. HTML fulltext]
-
"Sushkinia" pliocaena (Early Pliocene of Pavlodar, Kazakhstan) – belongs in Falco?
-
Thegornis (Miocene of South America)
External links