Lesser spotted eagle

Lesser Spotted Eagle
Scientific classification
Kingdom Information
Domain	Eukaryota
Kingdom	Animalia
Subkingdom	Bilateria
Branch	Deuterostomia
Phylum Information
Phylum	Chordata
Sub-phylum	Vertebrata
Infraphylum	Gnathostomata
Class Information
Superclass	Tetrapoda
Class	Aves
Sub-class	Neornithes
Infra-class	Neoaves
Order Information
Order	Accipitriformes
Sub-order	Accipitres
Family Information
Superfamily	Accipitroidea
Family	Accipitridae
Sub-family	Aquilinae
Genus Information
Genus	Clanga
Species Information
Species	C. pomerina
Synonyms	Aquila pomerina
Population statistics
Population	40,000-60,000 (2016 est.)
Conservation status	Least concern

The lesser spotted eagle (Clanga pomarina) is a species of bird of prey of the family Accipitridae, and found throughout eastern Europe.

Description

The lesser spotted eagle is medium-sized, about 21.7 to 26.4 inches in length, a wingspan of 57.5 to 66.2 inches, and weigh between 2.5 to 4.8 pounds. Females are 15% larger than males. Adult birds are a dark brown overall, marked with a warmer, lighter brown to cream on the feather tips of the head and upper and lower wing coverts; the primary and secondary flight feathers are a monochrome dark brown-gray. The inner wing base is whitish, while the upper tail covert bears a white "V" mark. The iris is orange-yellow, the toes are yellow, and the the beak is yellow and black. Juvenile birds are generally a darker brown in color, but with a rusty to creamy-yellow diffuse spot on the neck, and white spots on the flight feathers. The iris is brown. Juveniles do not gain their adult plumage until after three years of age.

The call has been described as a quick "chee-up" or "hee-up", similar to the yips of a small dog.

Range

The lesser spotted eagle breeds within east-central Europe, from Poland eastwards towards the Baltic States and eastern Russia, south to the northern limit of the Balkans. Scattered breeding areas occur on the western and southern side of the Balkans, central Germany, Greece, Turkey, and northern Iran. Migration routes over the Balkans and into the Middle East take them to their winter range in east-central Africa, south to the edge of the Namib and Kalahari deserts and northern South Africa.

Habitat

In the northern area of its range (Germany, Poland, Baltic States, Russia) it inhabits wet lowlands with deciduous and mixed forests and adjacent wet meadows and bogs. From Slovakia and Hungary and further south, however, it lives in the mostly dry hills and mountains, loosely populated with deciduous forest and interspersed with meadows, up to an elevation of 4,900 feet. In the southern are of its range (northeastern Greece) it lives almost exclusively in dry pine forests at heights between 300 and 900 feet, avoiding deciduous forests if they are present. Within its winter range in Africa, the habitats there consist primarily of moist, open or slightly-forested savannas.

Reproduction

Courtship usually begins immediately upon arrival at the nesting site, with the male showing persistent wave flights, moving downwards at the highest point of a "wave" with wings attached, and then ascending to the next wave with the momentum gained. In addition, it has a flutter flight, in which the wings are quickly flapped. Mating usually take place after these courtship flights in an area near the nest.

The nests are built on trees in the forest and mostly in its edge zone and built by the nesting pair; often they will have several nests constructed within their territory, and rarely will they take over the abandoned nests of other bird species. The selected tree species depends on the available offer. The nests can have very different sizes, depending on the natural conditions and age. A study in Lithuania found nest diameters between 2 and 4 feet or more, with an average diameter of about 3 feet. The nest is built of sticks, and lined with green branches.

In Central Europe, egg laying takes place at the end of April to mid-May. The clutch usually consists of two eggs, with three laid rarely; the laying interval is 3 to 4 days. The eggs are spotted brownish or purple on a white background. Cainism is innate, and takes place regardless of the food availability; the first hatched chick will kill the second chick, which is ultimately consumed. After 38 to 41 days in the nest, the chicks are fledged by the end of July to mid-August. Until their departure around mid-September, they are fed by the parents and only occasionally hunt independently.

Taxonomy

Until quite recently the spotted eagles of the genus Clanga were included with the true eagles of the genus Aquila, with the lesser spotted eagle classified into two subspecies: Aquila pomarina pomarina, and Aquila pomarina hastata, an eagle restricted to the Indian subcontinent. Morphological, anatomical and breeding biological characteristics from studies in 2002, as well as behavioral characteristics caused the Indian spotted eagle to be classified as a distinct species, Aquila hastata. These studies also included the determination of a so-called "sister relationship" occurring between A. pomarina and A. clanga, which, as of 2005 made them distinctive genetically from other species of genus Aquila. Further studies among diurnal raptors led to a revision of Aquila, resulting in the split of spotted eagles into their own separate genus, Clanga, a name taken from the ancient Greek word κλαγγή, ("clang" or "scream"), and refers to the piercing cries the birds make.

Hybridization

This sister-relationship study showed that the lesser spotted eagle and the greater spotted eagle are not completely isolated from each other, although the gene flow apparently only occurs in the direction of the lesser spotted eagle. About 8% of the phenotypic lesser spotted eagles examined had haplotypes of the greater spotted eagle in the mitochondrial DNA (mtDNA), which was only passed on via the maternal line. Examinations of the nuclear DNA showed, however, that the lesser spotted eagles with the greater spotted eagle haplotypes in the mtDNA lie genetically between the samples of individuals of both species, in which the haplotypes of the mtDNA matched the phenotypes. This suggests that these lesser spotted eagles with greater spotted eagle mtDNA are either direct descendants of a mixed pair of greater spotted eagle females and greater spotted eagle males (F1 hybrids) or descendants of a female hybrid with male greater spotted eagle, seemingly confirmed in an Estonian study.

The results suggest that mixed pairs mainly consist of greater spotted eagle females, and lesser spotted eagle males, and that the hybrid females in turn breed with male greater spotted eagles. The first assumption agrees with the observations of mixed pairs available so far; the second assumption is plausible, since this is the only way to guarantee the difference in size between the couple partners. Finally, the relatively high percentage of lesser spotted eagles with spotted haplotypes indicates that at least individual lesser spotted eagles regularly form mixed pairs with greater spotted eagles far west of the closed distribution area of ​​the species.

References

• Drobelis, Eugenijus: On the Biology of the Lesser Spotted Eagle Aquila pomarina in Lithuania; Meyburg, B. U. & Chancellor, R. D. (editors): Eagle Studies. WWGBP, Berlin, London, Paris 1996