Aquila rapax

Geographic Range

Tawny eagles occur from Romania east to southern Russia and Mongolia, and south through India and much of Africa.

• Biogeographic Regions
• palearctic palearctic
  • native native
• ethiopian ethiopian
  • native native

Habitat

Tawny eagles favor arid climates but occupy a wide range of habitats including deserts, steppes, open savannah, open grassland, mountainous regions, and cultivated steppes. The tend to avoid dense forests.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland
• mountains mountains

• Other Habitat Features
• agricultural agricultural

Physical Description

Aquila rapax plumage varies from very dark brown to light brown shades with blackish flight feathers and tail, light colored stripes or bars on the wings, and a pale lower back. Tawny eagles with darker shades of brown generally have tawny coloration on the body, distinguishing them from similar species of eagles, which lack any tawny coloration. The eyes are brown and the beak is yellow with a dark tip. Females are typically larger than males, otherwise the sexes are similar. Immature tawny eagles are paler and more streaked than are adults, sometimes "blonde" (white). Tawny eagles were thought to be synonymous with steppe eagles ( Aquila nipalensis ). Steppe eagles are larger than tawny eagles (up to twice the size in weight) and are darker in color.

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

• Sexual Dimorphism
• female larger

Reproduction

Tawny eagles are monogamous, pairing for life. Behavior prior to and during mating varies for this species, but usually involves undulating displays made by the male followed by mutual soaring displays. Epigamic display, display that occurs during breeding, may involve high circling, alone or in pairs, over the nesting site. The male may perform a series of "pot hooks" which involves a series of gradual dives and swoops, with little to no wing flapping. The female may turn over and present her claws in response to the male swooping over her. Males and females may lock claws in flight. Actual mating usually occurs at or near the nesting site.

• Mating System
• monogamous monogamous

Tawny eagles breed once yearly. Breeding season varies by geographic location, but typically occurs from April to July. Males and females both build the nest. Males collect nest material, while females assemble the nest. Nests are usually in trees or telephone poles and are occupied for one to three years before they are abandoned. Female tawny eagles lay one to three eggs at three day intervals and incubate them for approximately 45 days. Although males primarily feed offspring while they are young, both parents bring food during fledging, which occurs at approximately 76 to 85 days old. Tawny eagles begin to fly around ten weeks, but chicks remain in the nest for approximately 5 more weeks after their first flight and remain reliant on their parents for food during this period. After that, the young become independent. Siblings are aggressive towards one another, many times resulting in the death of the younger hatchling, usually within the first few days of hatching.

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

Female tawny eagles generally incubate the eggs, occasionally assisted by males. For the first ten days females remain by the nest, brooding day and night, and males may also brood or shade the chicks from the sun. After 7 days females leave the chicks for extended periods, but stay near the nest to protect them. They continue to perch near the nest for approximately forty days. At fifty days, neither males nor females are near the nest during the day. Males brings most of the food for the chicks, but may be assisted by females after fifty days. Chicks make their first flight around 84 days old and may remain in the nest for up to forty days after the first flight. However, some young remain with the parents until the following breeding season.

• Parental Investment
• altricial altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • protecting
    • male
    • female
• pre-weaning/fledging
  • provisioning
    • male
    • female
  • protecting
    • male
    • female
• pre-independence
  • provisioning
    • male
    • female

Lifespan/Longevity

The lifespan of adult eagles is difficult to determine in the wild. The oldest golden eagles, also in the genus Aquila , are recorded to have lived for sixty years. The average lifespan of golden eagles is 18 years, and they live approximately 40 to 45 years in captivity. The lifespan of tawny eagles may be similar to these values. In East Africa it is estimated that the lifespan of tawny eagles is 16 years on average, assuming that there is a 75% mortality rate before sexual maturity. Eagles live much longer in captivity, rarely reaching the same ages in the wild due to the high mortality rate within the first twelve months of life.

Behavior

Tawny eagles are gregarious outside of the breeding season. Groups of at least twenty are commonly observed, especially when large amounts of food are locally available (such as swarms of locusts and large populations of rats). Tawny eagles spend time near water where they can drink freely. Tawny eagles normally fly only when thermals can assist in soaring, and usually perch in trees during the day, especially in heavy rain. Tawny eagles, like most other eagles, are diurnal. Some populations of tawny eagles are migratory but many are not.

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• migratory migratory
• sedentary sedentary
• territorial territorial
• social social

Home Range

Tawny eagles tend to occupy the same territory for many years, sometimes even decades, in pairs. Territories are usually fairly far apart (20 km^2) to avoid food stealing by neighboring tawny eagles. Territories may range from 25 to 100 km^2 in area, most are 35-55 km^2.

Communication and Perception

Tawny eagles are generally fairly silent, except when aggravated or displaying. Their call can be described as a sharp kwok kwok . Occasionally tawny eagles will call during acts of piracy. Females may call from the nest, soliciting food. In general, vision is acute among eagles, and is likely to be their most important sense. They are able to see prey clearly at distances and up close. Their acute vision may also help in establishing territories. Hearing is also an important sense for tawny eagles, as it helps them locate prey when they are hunting.

• Communication Channels
• visual visual
• acoustic acoustic

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

Food Habits

Tawny eagles are generalist carnivores, they will eat insects, carrion, and small animals such as rodents. They are the only type of eagle that scavenge from humans regularly. Tawny eagles are also well known for robbing prey from other raptors, even birds much larger than they are.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates

• Animal Foods
• mammals
• carrion carrion
• insects

Predation

Nest predation by crows occurs more regularly in the nests of tawny eagles than in other species, possibly due to the openness of the nest site. There is very little other information on other predators or behaviors to prevent predation in tawny eagles. Tawny eagles are large birds of prey once they reach adulthood, they are probably do not have many predators.

Ecosystem Roles

Tawny eagles are primary predators. They are also piratical and opportunistic. They will steal prey from other animals as well as scavenge already dead prey.

Economic Importance for Humans: Positive

Tawny eagles are important members of the ecosystems in which they live.

Economic Importance for Humans: Negative

Tawny eagles are piratical and steal and scavenge food from other animals and humans. They may occasionally take domestic livestock, although not often enough to have a significant negative impact on humans.

Conservation Status

The current IUCN Red List status of this species is "lower risk/least concern."

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Joslyn Westphal (author), Kalamazoo College, Ann Fraser (editor, instructor), Kalamazoo College.

References

Brown, L., D. Amadon. 1968. Eagles, Hawks, and Falcons of the World . New York, NY: McGraw-Hill Book Company.

Brown, L. 1977. Eagles of the World . New York, NY: Universe Books.

Brown, L., E. Urban, K. Newman. 1982. The Birds of Africa Vol. 1 . London: Academic Press Inc.

Burton, P. 1983. Vanishing Eagles . New York, NY: Dodd, Mead & Company, Inc.

Campbell, B. 1983. The Dictionary of Birds in Color . New York, NY: Exeter Books.

Channing, K. 2006. "The Hawk Conservancy Trust" (On-line). Accessed October 15, 2006 at http://www.hawk-conservancy.org/priors/frodo.shtml .

Clancey, P. 1964. Birds of Natal and Zululand . London: Oliver and Boyd Ltd.

Knystautas, A. 1993. Birds of Russia . London: Harper Collins Publishers.

Love, J. 1989. Eagles . London: Whittet Books Ltd.

Maclean, G. 1988. Robert's Birds of Southern Africa . London: New Holland Publishers Ltd.

Sedgewick County Zoo. 2006. "Sedgwick County Zoo" (On-line). Golden Eagle. Accessed November 09, 2006 at http://www.scz.org/animals/e/golden.html .