User:DmitrySA/Drafts/Steppe eagle

The Steppe Eagle (Aquila nipalensis) is a bird of prey. Like all eagles, it belongs to the family Accipitridae. It was once considered to be closely related to the non-migratory tawny eagle (Aquila rapax) and the two forms have previously been treated as conspecific. They were split based on pronounced differences in morphology and anatomy. Two molecular studies, each based on a very small number of genes, indicate that the species are distinct but disagree over how closely related they are.

Description
This is a large eagle with long broad wings and rounded tail. Sexual dimorphism is expressed in the size of a bird – females are larger than males. Males are about 65-77 cm in length and has a wingspan of 174-199 cm, weight is about 2.2-4.6 kg. Females are 75-89 cm in length, 192-262 cm in wingspan and 3.5-5.5 kg weight.

Adult birds (6 years and older) are dark-brown, often with a ochreous spot on back of the head, blackish primaries with brown-grey strokes on the inner part of vexillums. Tail feathers are dark-brown with prominent wide grey bars. Iris is nut-brown, beak is dark grey, claws are black, cere and legs are yellow. A gape that extends beyond the center of the eye is a characteristic feature of the Steppe eagle. In contrast to any other eagle species (and Tawny Eagle as well), in Steppe Eagle the distance from the beak point to the nostril is much shorter than the distance from the nostrils to the angle of mouth. Nostrils have an oval shape, that is a feature that could help to set Steppe eagle apart from Greater Spotted.

Надо картинку с клювом и размеченными расстояниями.

In soaring Steppe Eagle keeps it wings strait in plane. Tops of the wings could be lowered. This is also a good field feature of Steppe Eagle.

The call of the steppe eagle sounds like a crow barking, but it is rather a silent bird.

Аудиозапись с криком Феникса из Симбирского Центра Спасения.

Steppe Eagle is listed as endangered species in IUCN Red List.

Classification
According to the latest research and DNA-analysis steppe eagles from northern Eurasia (Aquila nipalensis) and steppe eagle from Africa and India (Aquila rapax) – are separate species. Previously both species were listed under A.rapax name. Nowadays Steppe Eagle is an English name of Aquila nipalensis only, and Aquila rapax is named Tawny Eagle. Both species look quite similar.

This species has two subspecies. The eastern subspecies A. n. nipalensis is larger and darker than the European and Central Asian A. n. orientalis. The intergradation zone of both subspecies lay in Altai Mountains region of Russia, Mongolia and Kazakhstan.

Moulting
There are four age-related plumages in Steppe Eagle.

Plumage of birds before 1 year old (fledgling, underyearling) are brown, with big ochrous strokes and light fringes of primary-coverts, light ends of secondaries and tail feathers. On the underwing, a broad juvenile band formed by whitish underwing primary-coverts is prominent.

Иллюстрация сеголетка

Juvenile plumage (1 year) — the overall coloration getting lighter and become light-brown. Bars on feathers became more prominent (иллюстрация с пером). Light fringes of feathers on the upper part of body become worn and less noticeable. Juvenile band on the underwing is broad and prominent.

Иллюстрация 1 year

Sub-adult plumage (2-5 years) is even more lighter than juvenile – from very light-brown, reddish-brown to pale yellow. The elder bird is the less light feather fringes and ochreous strokes are in its plumage, and finally they totally disappear. Light fringes of greater coverts forming thin white line at the edges of coverts are the most durable but they will be also obliterated by age. Juvenile band is still present in this plumage, but between white feathers some feathers with dark centers appear. Each molt new feathers with dark centers replace white ones and juvenile band become discrete.

Иллюстрация subadult

At the age of four plumage of sub-adult birds begins to get darker again. Brown feathers appeared on the light background.

Adult plumage (from 6 years and older) is single-colour dark-brown, without juvenile band, with prominent bars on flight and tail feathers. On back of the head forms an ochreous spot.

Иллюстрация adult

Individual birds show a range of variation in plumage colour.

Juvenile band is a good field feature of Steppe Eagles before 5 years old.

Distribution and population numbers
The current distribution range of the Steppe Eagle covers steppe regions of Kazakhstan (22 000 – 31 000 breeding pairs), whole area of Mongolia (1500 – 2000 breeding pairs), northern part of China from Manchuria to Khingan (400-600 breeding pairs) and southern borders of Russia (2100-3100 breeding pairs). A small isolated population exists in Turkey (less than 10 breeding pairs).

The total worldwide estimation of the breeding population of the Steppe Eagle is 26 000 – 37 000 breeding pairs.

Steppe Eagle in Russia
In the western part of Russia, Steppe Eagle breeds in Kalmykia, Volgograd Region, Saratov Region, Orenburg Region. Population number in this area is about 850-1350 breeding pairs. Few more pairs could be found in Astrakhan, Rostov and Samara Regions. Each year number of Steppe Eagles decline in these regions.

In Siberia Steppe Eagle breeds in Altai-Sayan Ecoregion (Altai Krai, Altai Republic, Khakassia and Tyva Republic) and south-eastern part of Transbaikal (Irkutsk Region, Buryatia Republic and Zabaykalsky Krai). Altai-Sayan ecoregion holds the biggest population of Steppe Eagle in Russia (1000-1400 breeding pairs). According to the latest data this population is stable. Transbaikal population is consists of 240-280 breeding pairs and this number gets lower every year.

It is worth to mention that apart from Altai-Sayan Ecoregion, all other breeding areas of Steppe Eagle in Russia are only margins of the major breeding areas in neighboring countries – Kazakhstan and Mongolia.

Nesting habits
Steppe Eagle is a typical resident of steppe and semi-desert habitats. Its nests could be located in any suitable places – on the ground, on rocks, on trees, on human-made objects like pylons of powerlines, ruins of dwellings, abandoned agricultural machinery. As a nesting material Steppe Eagles mostly prefer dry twigs and animal bones. Nest size is 0.8-2 m in diameter. Height of a nest could vary depending on its location. Nests located on ground, on slopes or on low trees are 10-50 cm height. However, nests located on cliffs or in bifurcations of high trees like larches could reach 4 m in height. On the other hand, it is often when Steppe Eagles lay eggs strait on the ground marking nesting site with only 3-5 twigs.

Фото гнезда из костей, фото гнезда без всего.

Another characteristic feature of Steppe Eagle’s nest is presence of specific bedding made of human-made or natural litter like rag, paper, polyethylene, ropes or dung and shed wool and hair of animals.

Breeding territory of a pair of Steppe eagles covers about 3.5 km in diameter.

In areas where Steppe Eagle is a migrant species pairs return to their breeding sites in the middle of March. For two week pairs display and repair nests, and then start laying and incubating eggs. Eggs of Steppe Eagles are white with ochreous and clay-colored dots, 62.8-80.1 cm x 48.9-60.5 cm size. There are 1-4 eggs in the clutch. Female lay one egg in 2-5 days. Incubation starts from the very first egg and last for 39-45 days, thus eaglets also hatch with several days difference.

Фото с кладкой

After hatching nestlings remain in the nest for 58-65 days before fledge. Young eagles left the nest, but their primaries and tail feathers continue growth and reach their full size only in 10-15 days after fledge. In the nest, nestlings change two down plumages and molt in juvenile plumage before fledge. Molting from the first to the second down plumage that is thicker and denser then the first one occurs on 7-13 day after hatch. On 17th day primaries and tail feathers covered in feather sheath start growth, and soon after - covert and contour feathers. For five weeks lasts intensive feather growth, so 51-55 days old eaglet is fully dressed in brown feathers but its head that remains some down. Last bits of down from around base of the beak and supercilium disappear on 61-65 day of eaglet’s life. At this age, young eagle begins to fly, but it will keep in the close vicinity of its nest until primaries and tail feathers are fully grown. It is not self-reliant and still depends on its parents who continue to feed young bird.

Steppe Eagles could mate at the age of three for females and two for males. However, the optimal age for mating is 6 years for females and 5 for males.

Table 1. Breeding terms of Steppe Eagles in Russia and Kazakhstan

Migration and wintering
European population of Steppe Eagle winter in north-eastern, eastern, central and southern parts of Africa. Important waypoints of migration route are Georgia (Batumi) and Israel (Eilat).

Birds from Volga region and Aral-Caspian region winter in countries of Persian Gulf mostly in Saudi Arabia, and in Africa (Botswana, South Africa, Zimbabwe, Euphoria, Chad and Sudan). Eagles from central Kazakhstan winter near Persian Gulf only.

Eastern subspecies of Steppe Eagle winter in India and Pakistan. Birds from Altai-Sayan population and Kazakhstan pass through Uzbekistan, Turkmenistan and Afghanistan. Birds from Mongolia reach wintering sites via China and Nepal.

Картинка с путём Завы.

Chinese population of Steppe Eagle that breed in the northern part of the country winter in the south of China.

Historical reference
Until end of XIX – beginning of XX century, Steppe eagle was the most abundant eagle species in Northern Eurasia and its breeding territories extend much wider then today. Breeding range stretched from lower Danube river through Slovakia, Hungary, Rumania, Moldova and Ukraine, covered steppe zone of European part of Russia and spread east through Kazakhstan and Mongolia to China, and steppes of southern and western Siberia. Southern borders of its range lay in Turkmenistan.

Human activities and business development in XX century resulted in catastrophic decline of breeding range and population number of this species. At the first place, there were ploughing up virgin steppes and widespread using of pesticides which effect on steppe eagles appear to be very negative. In USSR in 1940-1960 mass campaigns against birds of prey, fish-eating and other “bad” species (like crows and ravens) had very negative consequences for Steppe Eagle.

At the beginning of 1980th Steppe Eagle disappeared in Ukraine and to the west from its borders. Thus, western limits of Steppe Eagle’s breeding range moved to the steppes of Kalmykia Republic of Russia.

In European part of Russia breeding range also changed dramatically. In 1990th species disappeared from Samara and Chelyabinsk regions, as well as from Bashkiria Republic. On the rest of its breeding range population number declined 6-10 times.

Population dynamics of Steppe Eagle from 1960th to 2012. Image from rrrcn.ru ©Igor Karyakin

Estimations of 2012 showed that population size of Steppe Eagle in Europe declined 94% more against 1990th (from 15 000 – 25 000 pairs in 1990th to 866-1375 pairs in 2012).

In Kazakhstan and Mongolia Steppe Eagle population also declined, even though breeding range did not change.

Diet
Diet of Steppe Eagle mostly consists of colonial borrowing rodents and small lagomorphs – at the first place susliks (Spermophilus dauricus, Spermophilus pygmaeus, Spermophilus undulatus) and pikas (Ochotona dauurica, Ochotona alpina, Ochotona pallasi). In areas, rich with these species Steppe Eagle forms dense and vast breeding populations.

Rodents of a bigger size like Spermophilus major, Spermophilus erythrogenys, Spermophilus fulvus, and Mongolian (Meriones unguiculatus) and Great Gerbils (Rhombomys opimus), as well as smaller rodents – Steppe Pika (Ochotona pusilla), Yellow Steppe Lemming (Eolagurus luteus) and Brandt’s Vole (Lasiopodomys brandtii) - are suboptimal prey species, so Steppe Eagle do not form big colonies in territories rich with these rodents.

Another species that could be found in ration of Steppe Eagle are different kind of gallinaceous (Altai Snowcock, Rock Ptarmigan, Willow Ptarmigan, Grey Partridge), crows (Magpie, Hooded Crow, Carrion Crow), some small mustelids (Weasel and Stoat), and young Marmots (Marmota sp.) and hares.

Картинка с гнездом степня с тушей заи, можно и с сусликами

Conservation status
Critical decline of population in Russia brought Steppe Eagle to the pages of USSR Red Book at the end of XX century, and later to the Russian Red Book and Red Books of most former union republics.

In Europe, however, Steppe Eagle was added to the Red List only in 2015 as critically endangered (CR) species.

No species action for species conservation were done.

Russia and Kazakhstan
Russian Raptors Research and Conservation Network conduct annual monitoring of Steppe Eagle populations in Russia and Kazakhstan and ring nestlings. Since there are two ringing centers in Russia, each bird is ringed with two rings – aluminum ring with sign “Moskwa” and numbers on the right leg, and color plastic ring with sign “www.rrrcn.ru” and numbers on the left. Фотка кольца

Plastic rings could be easily detected from a distance and can be read even on soaring or perching bird unlike metal ones. Many valuable information on movement of ringed bird could be gained from plastic rings via pictures from birdwatchers and nature photographers. This information helps ornithologists to understand migration routes and terms, to track resettlement, changes in population number, study treats and lifespan of birds, and forms a background for organizing conservation studies and actions.

Russian Raptor Research and Conservation Network would be grateful for any information about encounters with ringer steppe eagle that could be send via online form on the web-page http://rrrcn.ru/en/ringing. Except ring code that consists of letters and numbers other relevant information is date of observation, place of observation (geographical coordinates, name of the closest settlement, railway station, km of highway), and circumstances (either bird was photographed in flight / perching / on a nest / on a carcass of prey or found wounded / dead / killed by poacher or only ring was found).

Color schemes for plastic rings in Russia and Kazakhstan

Treats
Nowadays, three main treats for the Steppe Eagle in Russia and Kazakhstan are: Treats that were critical in the past and lead to a sharp decline of Steppe Eagle population in Russia and Kazakhstan in 1950-1980 such as habitat lost due to intensive land use, poisoning by pesticides and direct persecution by human are not so critical today.
 * 1) Food shortage;
 * 2) Electrocution on powerlines;
 * 3) Destruction of nests and killing of broods by steppe fires and spring dry grass burnings.

Main causes for nowadays treats are:
 * 1) Crisis in livestock farming after dissolution of the Soviet Union led to significant decrease of grazing in all countries of former Soviet Union. Overgrowing on pastures resulted in fast population decline of borrowing rodents, such as susliks, that are the main prey species for Steppe Eagle. Other prey species that managed to adapt to the new no-grazing conditions and continued to inhabit former pastures became less accessible for eagles due to high grass canopy. Thus, significant decline of Steppe Eagle population happened caused by the shortage of prey.
 * 2) Reduced grazing also results in another treat – an increased fire hazard in steppe areas. Accumulation of highly inflammable died off parts and particles of steppe grasses increases the frequency of wild fires in the hot season. And since Steppe Eagles’ nests are mostly located directly on the ground or close to it, steppe fires lead to high mortality among nestlings and unhatched eggs. Spring controlled burns that are used as a regulatory measure to reduce the number of residues of dry grasses are also disastrous for clutches of Steppe Eagle since its breeding season starts already in April.
 * 3) Pylons of power lines are often used by Birds of Prey as a perch. In open landscapes pylons could be the only elevated elements of the landscape. Medium voltage power lines (6-10kV) are the most common since they are used in transmission lines between settlements, agricultural facilities, facilities of extractive industry (gas and oil extraction) and cell sites. Modern medium-voltage power lines are fitted with concrete pylons with metal crossarms and upright insulators. Such pylons are very dangerous for birds because distance between grounded crossarms and wire under tension is only 40 cm or less, thus any bird with wingspan from 80 cm and more could touch by a chance the wire when it flies up, which will lead to a short circuit and death of the bird. Steppe eagle considered as a species that is most vulnerable for electrocutions on powerlines  . In Kazakhstan, up to 10% of Steppe Eagle population dies on powerlines in spring and 25-30% (including juveniles) during the breeding season.

Steppe Eagles and chemicals
Steppe eagles are very sensitive to agricultural chemicals. Several cases of mass mortality of Steppe eagles caused by use of agricultural pesticides or veterinary drugs are known.

Poisoning of Steppe Eagles by bromadialone
In 2002 Steppe Eagle populations in Mongolia and in Tuva Republic of Russia were poisoned by rodenticide Bromadialone that was used in Mongolia in 2001-20012 against Brandt’s Vole. Poisoning occurs when eagles consume dead poisoned rodent. In Russia, this pesticide wasn’t used, however eagles from Tuva population were poisoned as well since they get on the territory of Mongolia during seasonal movements. Eagles from Altai Region and Khakassia were not affected by this chemical since their migration routes left Mongolia aside. However, Steppe Eagle population in Tuva was destroyed, population in Mongolia sharply decreased. Today, bromadialone is banned in Mongolia.

Poisoning of Steppe Eagles by diclofenac
Diclofenac is a non-steroid anti-inflammatory drug that is used in livestock veterinary. From 1990th this drug caused mass mortality of vultures in India and Southern Asia. Neurotoxic effect on vultures was revealed for this drug in 2004, and in 2014 same effect of the drug on Steppe Eagles was detected. It is not ruled out that diclofenac is toxic for other birds of prey as well.

Bird get poisoned after consuming meat of a dead livestock that was treated with a diclofenac soon before its death. Raptor died on 1-2 day after poisoning from acute kidney failure. Fowl, crows and New World vultures (Cathartidae) are not sensitive to diclofenac at all and even high doses of this drug are not lethal for them.

There is a safe analog of diclofenac named meloxicam.

In 2004 BirdLife International and several other birds conservation organizations adopted a Manifesto of Saving Asia’s from Extinction that postulate removal of diclofenac from areas inhabited by vultures. From 2006, manufacture and veterinary use of diclofenac is banned in India, Nepal and Pakistan. However, from 2013 diclofenac is manufactured in Spain and could be legally used in Spain and Italy.

Economic importance
Steppe Eagle benefit to agriculture since its diet mostly consists of borrowing rodent and pikas that considered as pests.

Steppe Eagle is not used as a hunting bird. Traditionally people use Golden Eagle that is bigger in size.

Studies and researches
In Russia Steppe Eagle is studied by Russian Raptors Research and Conservation Network under support of UNDP/GEF and Russian Geographical Society (project “Eales of Russia” - . Since 2005 NGO “Siberian Environmental Center” and after 2015 LTD “SibEcoCenter” issued a bilingual periodical on-line journal “Raptors conservation” . This journal is dedicated to actual treats and conservation issues on Birds of Prey and Owls with special attention to studies and conservation tusks on Steppe Eagle.

Interesting facts
Lifetime of Steppe Eagle in captivity is 40-50 years.

Steppe Eagles form monogamous pairs. But it is not due to personal affection of mates, but because of their common affection to one breeding territory and nest. Mates do not winter together and meet each other only when they return to their breeding site.

In captivity Steppe Eagle consume about 1 kg of meet per day.

Steppe Eagle is depicted on the national flag of Kazakhstan.