Eleonora's Falcon

Maximum longevity: 11.2 years (wild)

Due to the limited distribution and colonial breeding habits of Eleonora’s falcons, they are very vulnerable. The main threats are an increase in tourism, especially the use of motorboats near colonies, which often results in distressed parent birds and reproductive failure. In the Aegean Sea, colonies are often raided by fisherman who take the young and eggs for food. Persecution of adult birds has also been recorded. The total population is currently estimated at 4,500 breeding pairs. As long as breeding colonies are protected from poaching by humans and from heavy tourism, Eleonora’s falcon populations will likely remain stable. A decrease in migrating passerines due to habitat loss in mainland Europe has been observed over the past century and falcon populations have dropped accordingly, but seem to be currently stable.

US Migratory Bird Act: no special status

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: least concern

Eleonora’s falcons have few natural predators as adults. Black rats (Rattus rattus) inhabit many islands that harbor falcon colonies and may feed on unguarded falcon eggs or nestlings. Peregrine falcons (Falco peregrinus), Lanner falcons (Falco biarmicus), and Eurasian eagle owls (Bubo bubo) have been known to prey on adult falcons. Cory’s shearwaters (Calonectris diomedea) often breed within falcon colonies and occasionally take young falcons.

Known Predators:

• Peregrine falcons (Falco peregrinus)
• Lanner falcons (Falco biarmicus)
• Eurasian eagle owls (Bubo bubo)
• Cory's shearwaters (Calonectris diomedea)
• black rats (Rattus rattus)

Eleonora’s falcons are medium-sized falcons, of similar length to peregrine falcons (F. peregrinus), but much lighter in weight and build. Like all other falcons, Eleonora’s falcons show reversed sexual size dimorphism, with females on average slightly larger than males. Males vary in length from 37 to 43 cm, females from 38.5 to 45.5 cm, and in weight, males range from 350 to 390 g, females from 340 to 460 g. The shortest wingspan measurement for an Eleonora’s falcon was 84 cm, while large females may have a wingspan of up to 103 cm. Eleonora’s falcons have long, narrow wings that exceed the tip of the long tail when folded. There are two color morphs, a light and a dark morph. Dark morph birds are all brown, and may appear black from a distance. The male’s cere is yellow in color while the female’s is blue-gray. Light morph birds are also dark brown above and buff to rufous below with dark streaking. The light morph also shows the typical dark moustache stripe.

Range mass: 340 to 460 g.

Range length: 370 to 455 mm.

Range wingspan: 840 to 1030 mm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic

Sexual Dimorphism: female larger

There is no information available on lifespan in Falco eleonorae.

Average lifespan
Status: wild: 6.0 years.

Eleonora’s falcons commonly breed on the ground on small, rocky, undisturbed islands with little vegetation. On larger islands, such as Sicily and Sardinia, and on the mainland in Africa and Turkey, they seek inaccessible coastal cliffs to breed. They hunt over the open sea, as well as over wetlands, grasslands, and sometimes woodlands. Nest sites are found from sea-level to an elevation of 2,000 meters.

Range elevation: 0 to 2000 m.

Habitat Regions: temperate ; tropical ; terrestrial

Terrestrial Biomes: savanna or grassland ; forest

Aquatic Biomes: coastal

Wetlands: marsh ; swamp

Eleonora’s falcons are distributed throughout the Mediterranean region, including the Canary Islands, Morocco, Algeria, Tunisia, the Balearic Islands, Sicily, Sardinia, Croatia, islands in the Aegean Sea, Crete, Cyprus, and Turkey. All breeding sites lie between longitude 14°W to 33°E, and latitude 43°N to 28°N. Approximately 10% of Eleonora falcon populations breed on the Tilos Island chain. All populations winter in Madagascar and the Mascarene Islands.

Biogeographic Regions: palearctic (Native ); ethiopian (Native ); mediterranean sea (Native )

Eleonora’s falcons feed primarily on flying insects. During the breeding season, however, these falcons switch their hunting behavior and concentrate solely on migrating passerine birds. Over 100 species have been recorded as prey of Eleonora’s falcons. To hunt, falcons fly out to sea utilizing vertical winds for soaring, and may hunt close to sea level or up to a height of 1,000 m. Several falcons often hunt together spaced several hundred meters apart, creating a barrier which makes it harder for migrating birds to stay undetected. Eleonora’s falcons are also known to hunt until well after sunset. These falcons usually stoop down on their prey, but sometimes pursue it for longer distances. Insects are also caught and eaten in flight. During the breeding season excess prey is often cached and retrieved later. Male falcons do most of the bird-hunting during the breeding season, leaving females to incubate eggs and nestlings.

Animal Foods: birds; insects

Foraging Behavior: stores or caches food

Primary Diet: carnivore (Eats terrestrial vertebrates, Insectivore )

Eleonora’s falcons play an important role in the migration of millions of small birds, mainly passerines from their Palearctic breeding grounds to African wintering areas. Falcons prey on migrating passerines, preferring small, juvenile birds. It is estimated that all Eleonora’s falcon colonies combined catch about two million migrating birds in a single breeding season. This, however, only represents 0.02 to 0.04% of the total number of migrating birds. Falco eleonorae is also important in regulating prey species populations throughout their range.

Eleonora’s falcons, like other raptors, are important bioindicators of healthy environments. They further help to reduce pest species, such as grasshoppers and rodents that cause damage to human crops.

Positive Impacts: research and education; controls pest population

There are no negative impacts of Eleonara's falcons on humans.

Eleonora’s falcons are highly vocal and seem to have a wider range of vocalizations than other falcons. Vocal communication is especially common during the pre-mating season. Some common calls include recognition, territorial, display, copulation, greeting, prey transfer demand, prey arrival, alarm, and distress calls. Chuckles can also be heard by brooding falcons upon arrival of the mate. The young give a variety of calls to indicate discomfort, hunger, alarm, or excitement.

Eleonora's falcons, like other falcons, have especially keen vision, used in capturing prey.

Communication Channels: visual ; acoustic

Perception Channels: visual ; tactile ; acoustic ; chemical

Eleonora’s falcons are monogamous, colonial breeders. Aerial displays by male falcons begin as soon as the birds arrive on nesting sites.

Mating System: monogamous

Breeding sites are occupied starting in late April, though breeding does not start until late July. The young hatch in late August to early September at the beginning of the migration period of most small, Palearctic birds. The nest is located on the ground or on a cliff, often in a small cavity or under a small bush, sheltered from wind. Clutch size ranges from 1 to 4 eggs, rarely 5. Incubation lasts between 28 and 30 days, and the young fledge after another 35 to 40 days. Average productivity differs among different colonies and can range from 1.26 fledglings per year to 2.6 young per year. Young males usually remain near their parents’ home range, while females disperse farther.

Breeding interval: Eleonora's falcons breed once yearly.

Breeding season: Breeding occurs in late July.

Range eggs per season: 1 to 5.

Range time to hatching: 28 to 30 days.

Range fledging age: 35 to 40 days.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous

As in most other falcon species, both males and females contribute to incubating, protecting, and nourishing their offspring.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Male, Female); pre-hatching/birth (Provisioning: Male, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Protecting: Male, Female); pre-independence (Provisioning: Male, Female)

Eleonora's falcon breeds later in the year than almost any other northern Hemisphere bird (5) (9), a behaviour that is linked to the species' other unusual feature, its seasonal switch in diet. For most of the year, Eleonora's falcon feeds mainly on large flying insects, such as butterflies, beetles, locusts, dragonflies, and flying ants and termites, with prey usually caught and eaten in flight. However, during the breeding season the diet switches to small migrant birds, passing on the autumn migration from Europe to Africa (2) (5) (8) (9). Breeding late in the year allows Eleonora's falcon to raise its chicks on this seasonal glut of food (5) (9). Birds are caught in the air, with hunting usually taking place over the sea, where a number of falcons may hover, forming a 'barrier' to intercept passing prey (2) (5) (8). Eleonora's falcon arrives in its breeding areas in late April to May, and typically nests in colonies of around 10 to 300 breeding pairs (2) (8). The nest is located in a hole or ledge on a cliff, or on the ground, under a bush or crevice (2). Between one and four eggs are laid, between July and August (2) (5) (8), and hatch after an incubation period of 28 to 30 days. The female performs most of the incubation and guards the chicks during the first few weeks, while the male carries out most of the hunting, bringing food back to the nest (2) (5). Fledging occurs after around 37 to 40 days, the young Eleonora's falcons leaving the colony around two weeks later (2) (8), and reaching sexual maturity at two to three years old (2). Eleonora's falcon leaves its breeding areas from October to November, its arrival in the winter quarters then coinciding with the rainy season, when insect prey is abundant (2).

A number of conservation measures are in place for Eleonora's falcon. In addition to restrictions on international trade in the species under the Convention on International Trade in Endangered Species (CITES) (4), Eleonora's falcon is listed on Appendix II of the Convention on Migratory Species (CMS or Bonn Convention), which aims to conserve migratory species throughout their range (11), and is also covered under a range of European legislation (12) (13). In 1999, an Action Plan was drawn up by BirdLife International, with the aim of evaluating and addressing the threats to Eleonora's falcon. Conservation measures proposed included promoting appropriate policies on tourism and coastal management, as well as increasing protection of colonies, avoiding introductions of predators onto islands, increasing public awareness, and ensuring habitat protection in the winter quarters and along the migration route. The need for further research into Eleonora's falcon numbers, breeding success and migration habits was also highlighted (8). Over 80 percent of the global population of Eleonora's falcon breeds in Greece, and in 2003 the Life-Nature 2003 Project was set up. This aimed to promote conservation of the species in Greece and throughout Europe, as well as to perform further research into its ecology and behaviour, and to put into place many of the actions described in the species Action Plan (9). The project has so far met with much success, performing the first ever global population census of Eleonora's falcon, undertaking many public awareness campaigns, and reducing nest predation through rat eradication programmes (9) (14) (15). Simple measures to reduce human presence around colonies have also been shown to have positive effects (10), and could be further used to protect this unique bird of prey.

One of the last bird species in Europe to be discovered by science, and noted for its late breeding season and unusual feeding habits (5), Eleonora's falcon is a fairly large and slender falcon, with long, narrow wings and a relatively long, rounded tail (3). The species occurs in two quite different colour phases, a light and a dark form. The less common dark form is dark brown to slate black all over, often with a cream throat, and sometimes a reddish tinge on the lower underparts. Faint grey to buff bars can sometimes be seen on the tail. In contrast, the light form is dark only on the back, with white or cream cheeks and throat, a dark 'moustache' stripe on the face, and buff underparts, which become more reddish lower down, with black streaks (2) (3) (5) (6). The vent is usually plain, and the greyish tail may have reddish-brown bars, with a dark tip (3). The degree of streaking, and of shading from buff to reddish-brown on the belly, may vary between individuals, and intermediates between the dark and light forms also occur (2) (5). Eleonora's falcon can be distinguished from other, similar falcon species by the dark underwing-coverts, which contrast with paler flight feathers (2) (5) (6). Slightly larger than the male (2), the female Eleonora's falcon is otherwise similar in appearance, though may be slightly browner in the dark form (3). The female also has pale blue facial skin, rather than yellow as in the male (3) (5). The juvenile usually resembles the light form of the adult, but is generally browner and paler, with barring on the underwing, and more distinct bars on the tail (2) (3) (5) (6). The call of Eleonora's falcon is a harsh keya, extended into kje-kje-kje-kjah (6).

Typically inhabiting rocky islands and islets in the Mediterranean, Eleonora's falcon prefers to breed on sea cliffs or on flat, quiet islets, usually only appearing on the mainland to hunt, or during migration. Hunting may take place in coastal marshes, lakes or woodland. In the winter range in Madagascar, Eleonora's falcon may be found in and around wetland, forest, open woodland, paddyfields and lakes, at elevations of up to 2,000 to 3,000 metres (2) (3) (6) (8).

Eleonora's falcon breeds on islands and rocky coasts in the Mediterranean, from the Canary Islands and northwest Morocco, east to the Greek islands and Cyprus (2) (5) (7), with Europe constituting over 95 percent of the species' global breeding range (7). Eleonora's falcon is also vagrant in parts of southern, western and central Europe (6) (7). The species spends the winter mainly in Madagascar, but also in parts of East Africa and the Mascarene Islands (2) (5) (7).

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (4).

Eleonora's falcon is thought to have undergone a decline in recent years (7) (9), and is classified as Rare at the European level (8). The world population of Eleonora's falcon is concentrated in a relatively small number of colonies, meaning the loss of a single colony can have a significant impact on the global population of this falcon. The species also shows high fidelity to its breeding sites, which can mean re-colonisation of a colony is unlikely once it has been abandoned (8). Threats to Eleonora's falcon come mainly in the form of human disturbance at its breeding sites. Modern transport and the development of infrastructure for tourism mean that these previously inaccessible sites are now within easy reach of tourist resorts, and human disturbance near colonies is thought to cause the falcons to abandon their eggs, or to move to more remote sites (2) (8) (9) (10). Introduction of other species to the breeding islands is also a threat, with introduced cats and rats feeding on eggs as well as chicks and adult birds (8) (9), and introduced livestock disturbing the birds from their nests (8). Game species have also been introduced to some islands, and undisciplined hunting dogs sometimes kill nestlings (8). Some direct persecution of Eleonora's falcon does occur, in the form of shooting of the adult birds and collection of eggs and chicks, but is not usually specifically aimed at this species (2) (8). However, hunting may occur in the winter range in Madagascar, and habitat loss and degradation here is a further problem (8). The species may also suffer from poisoning by agricultural pesticides (9).

Regular passage visitor.

Eleonora's falcon (Falco eleonorae) is a medium-sized falcon. It belongs to the hobby group, a rather close-knit number of similar falcons often considered a subgenus Hypotriorchis. The sooty falcon is sometimes considered its closest relative, but while they certainly belong to the same lineage, they do not seem to be close sister species. The English name and the species name eleonorae commemorate Eleanor of Arborea, Queen or Lady-Judge (Juighissa) and national heroine of Sardinia, who in 1392, under the jurisdiction conferred by the Carta de Logu, became the first ruler in history to grant protection to hawk and falcon nests against illegal hunters. The genus name falco is from Late Latin falx, falcis, a sickle, referring to the claws of the bird.