The Lesser Spotted Eagles (Aquila pomarina) is a large Eastern European bird of prey. Like all typical eagles, it belongs to the family Accipitridae.
The typical eagles are often united with the buteos, sea eagles, and other more heavy-set Accipitridae, but more recently it appears as if they are less distinct from the more slender accipitrine hawks than believed.
Description
This is a medium-sized eagle, about 60 cm in length and with a wingspan of 150 cm.
Its head and wing coverts are pale brown and contrast with the generally dark plumage. The head and bill are small for an eagle.
There is usually a white patch on the upper wings, and even adults retain a clear-marked white V on the rump; the wing markings are absent, and the white V is not well-defined in the Greater Spotted Eagle.
The juvenile has less contrast in the wings, but the remiges (= flight feathers – typically only visible in flight) bear prominent white spots. It differs from Greater Spotted Eagle juveniles by a lack of wing covert* spotting and the presence of a cream-colored neck patch. (*Wing coverts are the feathers right above the wing feathers)
Calls / Vocalizations
The call is a dog-like yip.
The Lesser Spotted Eagle is not well-known for its complex songs, but it does have a distinct call, which has been described as a dog-like, sharp yip. This call is used for several reasons, including territorial defence and communication among mates, particularly during breeding season.
Bird enthusiasts can enjoy the thrill of hearing this call echo in an open area or lightly wooded areas, as it signals that this predator is nearby.
Systematics, Taxonomy, and Evolution
The birds formerly considered to be the resident Indian subspecies are now considered a separate species, the Indian Spotted Eagle (Aquila hastata), quite distinct and readily separable by morphological, behavioral, ecological, and DNA sequence data.
The European taxon is actually closer to the Greater Spotted Eagle; their common ancestor seems to have diverged around the middle Pliocene, perhaps some 3.6 million years ago (mya)[1], from the ancestors of the Indian birds. The “proto-Spotted Eagle” probably lived in the general region of Afghanistan, being split into a northern and a southern lineage when both glaciers and deserts advanced in Central Asia as the last ice age began.
The northern lineage subsequently separated into the eastern (Greater) and western (Lesser) species of today, probably around the Pliocene-Pleistocene boundary, not quite 2 mya.[2]
The spotted eagles as a group are quite distinct from the typical members of Aquila, the “true eagles”.
The present species hybridizes occasionally with the Greater Spotted Eagle. Hybrid birds are almost impossible to identify if not seen from up close.
Distribution and Ecology
The Lesser Spotted Eagle breeds in Central and Eastern Europe and southeastward to Turkey, and winters in Africa. This is a very wary species of open or lightly wooded country, in which it hunts small mammals and similar terrestrial prey.
This eagle lays 1–3 white buff-spotted eggs in a tree nest. As usual for eagles, only in breeding seasons with very abundant prey does more than one young fledge; however: the female starts incubating when the first egg has been laid, and thus the first young to hatch usually outgrows its clutchmate(s) and will kill and even eat them sooner or later.
Hunting and Diet
Lesser Spotted Eagles have a methodical style of hunting. They are highly skilled hunters. Lesser Spotted Eagles tend to fly lower and glide, sometimes hovering, as they search for small terrestrial creatures. According to Mammal Society, this species is well documented.
They eat primarily small mammals, such as voles and mice. These animals thrive in semi-forested and open landscapes. They hunt reptiles and amphibians, and sometimes birds and large insects. They rely on their keen eyesight, patience, and ability to silently swoop on unwitting prey. According to IUCN Red List, this species is well documented.
The adaptability of the prey in hunting contributes to its survival in different habitats. However, the availability of prey has a significant impact on breeding success and population.
Breeding Behavior and Life Cycle
Lesser Spotted Eagles’ breeding season occurs in spring and early summer when there is a large amount of prey available to feed their young.
The pairs build large nests in the trees and reuse nests that were built previously. Nests are usually made of sticks, and linings with soft materials provide a safe place for the eggs and chicks.
The eggs are white and have buff spots. It’s not uncommon for only one chick to survive to fledging. The first chick that hatches often kills or outcompetes its siblings, a behavior called siblicide. As soon as the egg is laid by the female, she begins to incubate it. This means that the first chick will hatch earlier than its siblings and gain a strength and size advantage.
The incubation period lasts 35-40 days. The female is responsible for the eggs while the male protects and provides food. Both parents will share the responsibility of feeding and caring for their chicks after hatching. This is until they reach fledgling age, which is around 8-10 weeks.
Prey availability is a major factor in successful breeding. When food is plentiful, many chicks may survive until fledging in years with abundant food, contributing to population growth.
Behaviour and Social Structure
During the breeding season, Lesser Spotted Eagles can be found alone or in pairs. In the absence of breeding, you may see them in loose groups. This is especially true during migration.
Cautious birds avoid human disturbances and prefer quieter habitats. They are territorial birds, and during breeding season, they will defend their nesting area from other eagles as well as intruders.
They have a strong, graceful flight with rounded, broad wings that allow them to fly in open areas as well as along forest edges. They will hover for a short time to concentrate on their prey before diving down with precision.
Conservation Status and Threats
The IUCN Red List currently lists the Lesser Spotted Eagle as Least Concern, in part due to the relatively large range of the species and its stable population. This does not mean that the species is safe.
Lesser Spotted Eagles face a number of challenges, including habitat degradation and loss. Deforestation, intensification of agriculture, urbanization, and infrastructure developments reduce suitable hunting and nesting habitats. Wetland draining and forest fragmentation have a major impact on their breeding success and the availability of prey.
Despite being less common, certain localities are still affected by persecution, such as illegal hunting or trapping.
Climate change is a growing threat that could alter habitat suitability and, therefore, prey populations in Europe and Africa. Survival rates may also be affected by changes in migration timing or stopover sites.
Conclusion
It may not have the dramatic plumage or imposing size of other eagles, but it is an amazing example of ecological balance, adaptation, and evolution. Its survival is dependent on the health and diversity of forests and open landscapes in two continents, as well as the delicate balance between prey, hab, and climate.
Lesser Spotted Eagles are a great challenge for bird enthusiasts and conservationists. They offer a chance to protect and study a silent hunter who quietly rules the skies of Europe and Africa.
Footnotes
- The estimate in Väli (2006) is certainly incorrect; it uses a molecular clock that is appropriate for small passerines with half the generation times of eagles.
- Parry et al. (2002), Rasmussen and Anderton (2005), Väli (2006)
- Väli and Lõhmus (2004)
