Falco cherrug

Geographic Range

Saker falcons (often simply called “sakers”) occur in the semi-desert and forest regions from Eastern Europe to central Asia, where they are the dominant “desert falcon.” Saker falcons migrate as far as northern parts of southern Asia and parts of Africa for the winter. Recently (in 1997), sakers have been observed breeding as far west as Germany.

• Biogeographic Regions
• palearctic palearctic
  • native native
• oriental oriental
  • native native

Habitat

Sakers occupy stick nests in trees, about 15 to 20 meters above the ground, in parklands and open forests at the edge of the tree line. No one has ever observed a saker falcon building its own stick nest; they generally occupy abandoned nests of other bird species, and sometimes even drive owners from an occupied nest. In the more rugged areas of their range, sakers have been known to use nests on cliff ledges, about 8 to 50 meters above the base.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• tundra tundra
• taiga taiga
• forest forest
• scrub forest scrub forest
• mountains mountains

Physical Description

Sakers exhibit great variation in color and pattern, ranging from a fairly uniform chocolate brown color to a cream or straw base with brown bars or streaks to brown-eyed leucistic individuals, which are especially prized by Arab falconers. In general, sakers have white or pale spots on the inner webs of their tail feathers, rather than the bars of color that are common among other desert falcons. As the underwing is usually pale, it has a translucent appearance when contrasted against the dark axillaries and primary tips.

Saker females are markedly larger than males; females typically weigh 970 to 1300 g (average 1135 g), have an average length of 55 cm, and a wingspan of 120 to 130 cm. Males usually weigh from 730 to 990 grams (average 840 g), are about 45 cm long on average, and have a wingspan of 100 to 110 cm.

As with other falcons, sakers have sharp, curved talons, used primarily for grasping prey. Sakers use their powerful, hooked beak to sever the prey’s vertebral column.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger

Reproduction

In order to attract females, male sakers engage in spectacular aerial displays, in common with many other members of the genus Falco . Male sakers soar over their territories, calling loudly. They end their display flights by landing on or near a suitable nesting site.

In closer encounters with a mate or prospective mate, sakers bow to each other, and many interactions incorporate some element of bowing. Males also often feed their mates during the nesting period. When wooing a potential mate, a male will fly around, dangling prey from his talons, or will bring it to the female in an attempt to prove that he is a good provider.

• Mating System
• monogamous monogamous

Sakers are generally two to three years old before they begin breeding. There can be 2 to 6 eggs per brood, but generally the number is between 3 and 5 (on average 4). After the third egg is laid, full incubation begins, and usually lasts for about 32 to 36 days. In general, as is true for most falcons, males offspring develop faster than females.

The young hatch with their eyes closed, but they open in a few days. They have two downy nestling plumages before attaining juvenile plumage. They attain adult plumage when a little over a year old, after their first annual molt.

Females reach sexual maturity about a year before males; they occasionally breed in their first year, but usually not until their second or third year, and some wait until their fourth year. Males, on the other hand, begin breeding in their second year at the very earliest; most wait until the third or fourth year, and some males don’t begin breeding until their fifth year.

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

Young sakers begin to fly at about 45 to 50 days of age, but remain within the nesting territory, dependent on their parents for food, for another 30 to 45 days, and occasionally longer. If they encounter a large localized source of food, brood mates may remain together for some time.

While still in the nest, chicks chirps to get a parent’s attention if they are isolated, cold, or hungry. In addition, females may make a soft “chip” noise to prompt their young to open their beaks to receive food. Mothers will pass over a chick that is begging but has a full crop in order to feed a chick that has not eaten enough. When a brood is well-fed, the chicks get along better than in a brood subject to food scarcity. In a well-fed brood, the chicks share food as well as explore with each other once they begin to fly. In contrast, when food is scarce, chicks guard their food from one another, and may even try to steal food from their parents. If a chick dies and the rest of the brood is hungry, they will eat their dead sibling, but fratricide has never been observed.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
• pre-hatching/birth
  • provisioning
    • male
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
  • protecting
    • male
    • female
• post-independence association with parents
• extended period of juvenile learning

Lifespan/Longevity

Falcons used for hunting are still subject to many of the same causes of mortality as those in the wild, including several bacterial and viral diseases, parasites, bumblefoot disease, lead and ammonium chloride poisoning, and injuries incurred from impacting or struggling with prey, to name a few.

Although most wild individuals are expected to live from 5 to 7 years, a few of these birds have been known to live for as long as 10 years. Captive animals tend to live longer than their wild counterparts. In captivity, sakers are expected to live from 15 to 20 years, but may reach a maximum age of about 25 years.

Behavior

Sakers are very aggressive; one of the reasons they are so prized by falconers is that once they have decided upon a target prey, they are very persistent. They have been known to follow their prey into brush, and in the past (in the Middle East) they were used to harry and attack large game, such as gazelle, until the saluki hounds could catch up and finish the animal off. Sakers are patient, relentless hunters. They hover in the air or sit on their perch for hours watching for prey and fixing the exact location of their target, until suddenly diving for the kill. Females are almost always dominant over males. They sometimes try to steal prey from each other.

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• migratory migratory
• solitary solitary
• territorial territorial

Home Range

Sakers are not social birds; they prefer not to establish their nests close to other nesting pairs. Unfortunately, due to habitat destruction, sakers are being forced to nest closer and closer together, much more so than they ever would otherwise. However, in areas where food is plentiful, sakers will nest closer together than in areas where food is scarce. Space between pairs ranges from three to four pairs in three acres to pairs being six miles or more apart in the mountainous areas and steppes. The average spacing is one pair every 2.5 to 3.5 miles.

Communication and Perception

As mentioned before, a female saker will make a “chip” noise to prompt her young to open their beaks for food, and they will chirp to get a parent’s attention. Male sakers call during their aerial displays in order to attract or impress a female, and if the female accepts the male, she may join in the calling at the end. Sakers may often call aggressively to drive off intruders from the nest or a freshly killed meal.

Sakers, like other falcons, communicate fairly often by posturing. The most aggressive display is the Upright Threat; the bird stands up straight, spreads its wings and fluffs out its facial feathers, hisses, cackles, and strikes with the feet. This display is used by adult falcons in defense of the young, and by feathered nestlings against nest intruders. Sakers also use bowing to appease a mate, and communicate submission with a modified version of bowing, in which the beak is pointed to the side.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic

• Other Communication Modes
• duets duets

• Perception Channels
• visual visual
• ultraviolet
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

During the breeding season, small mammals such as ground squirrels, hamsters, jerboas, gerbils, hares, and pikas may constitute 60 to 90% of a saker pair’s diet. At other times, ground-dwelling birds such as quail, sandgrouse, pheasants, and more aerial birds such as ducks, herons, and even other raptors (owls, kestrels, and harriers) can account for 30 to 50% of all prey, especially in more forested areas. Sakers may also eat large lizards.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates

• Animal Foods
• birds
• mammals
• amphibians
• reptiles
• insects

• Foraging Behavior
• stores or caches food stores or caches food

Predation

Sakers have no known predators in the wild, except humans.

Ecosystem Roles

Sakers are important predators of small mammals and medium-sized birds.

Economic Importance for Humans: Positive

Sakers are a favorite of Arab falconers.

• Positive Impacts
• pet trade pet trade
• ecotourism ecotourism
• controls pest population

Economic Importance for Humans: Negative

As with all falcons, sakers may prey upon species (such as pigeons) that humans value. They are not well liked by gamekeepers.

Conservation Status

The fact that female sakers, being larger, are preferred by falconers has led to a gender imbalance in wild populations, with males outnumbering females. In fact, about 90 percent of the almost 2,000 falcons trapped each year during the fall migration are females. These numbers cannot be reported with absolute certainty, because some sakers are illegally trapped and exported, especially in Mongolia, so it is impossible to know the true number of sakers taken from the wild each year. Juveniles are easier to train than adults, so most of the trapped sakers are around one year old. In addition, in the Middle East many falconers release their sakers because it is difficult to care for them during the hot summer months, and many trained birds escape. Basically, the number of sakers taken each year probably does not have a significant impact on the species, but the preference for female sakers does. In addition, sakers are affected by the use of pesticides (which contaminate their prey) and destruction of their habitat. A fairly recent estimate of the saker population in the wild is from 1982, when the population stood at about 100,000 pairs. That does not include juveniles, captive birds that may have later been released back into the wild, or pairs that ornithologists may have missed, so the estimate is probably on the low side. However, saker falcons an endangered.

Additional Links

Encyclopedia of Life

Contributors

Victoria Hekman (author), Michigan State University, Pamela Rasmussen (editor, instructor), Michigan State University, Nancy Shefferly (editor), Animal Diversity Web.

References

Anderson, S., J. Squires. 1997. The Praire Falcon (Section 3-Prairie Falcons and Other Raptors) . Austin: University of Texas Press.

Batdelgar, D., A. Parrot. 1998. The Illegal Export of Saker Falcons ( Falco cherrug ) in Mongolia. 5th World Conference on Birds of Prey and Owls: 64.

Baumgart, W. 1998. New Developments on the Western Border of the Saker falcon ( Falco cherrug ) range in Middle Europe. 5th World Conference on Birds of Prey and Owls: 17-18.

Cade, T. 1982. The Falcons of the World . London: Cornell University Press.

Naldo, J., J. Samour. 2004. Causes of Morbidity and Mortality in Falcons in Saudi Arabia. Journal of Avian Medicine and Surgery , 18/4: 229-241. Accessed April 22, 2005 at http://www.bioone.org/bioone/?request=get-document&issn=1082-6742&volume=018&issue=04&page=0229 .