Category Archives: a) Vultures and Eagles

Tawny Eagle identification by Barak Granit

First, a short introduction (by YP):

Tawny Eagle Aquila rapax is rather poorly known in the WP. It is widespread in Africa and S Asia, but now with the North African population probably extirpated, the only breeding population is perhaps in the southern Arabian Peninsula, though I have managed to find no recent evidence of this. Ssp. belisarius breeds across the Sahel Region and sub-Saharan Africa. It is generally sedentary, but some individuals disperse, occasionally to long distances. It seems to occur as a rare visitor to S Arabia, Egypt, Israel and perhaps also S Morocco. It is unclear whether WP occurrences involve also birds from the Asian subspecies vindhiana.

A recent individual that was found in Israel a couple of weeks ago sparked an interesting ID exercise. Barak Granit, one of Israel’s top birders, was involved in the identification process, and wrote a nice identification article that first appeared on the Israeli Birding Portal. It is reproduced here:

Tawny Eagle Identification by Barak Granit

On July 14th, Olga Chagina posted on her Facebook page a series of images of an Aquila sp. she took south of Kibbutz Ze’elim in the northwestern Negev (not far from the famous Urim powerline), seeking for ID Help. Initial responses called for Steppe Eagle while others suggested Lesser Spotted. Itai Shanni was the first to call for Tawny Eagle – a species with only five previous national records, four of which in the same general area. Shortly after Itai’s opinion appeared on FB, I supported Itai’s identification as Tawny Eagle and pointed out some diagnostic identification features. These are Olga’s first photos:

Tawny Eagle, Zeelim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

Tawny Eagle, Zeelim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

Later on, Dick Forsman approved the identification. This is not an ‘Identification article’ proper – identification features of Tawny Eagle are available in literature. I review here the status of Tawny Eagle in Israel, and point out the key features that separated this individual from similar species.

Status in Israel

Tawny Eagle was first recorded in Israel on 1st November 1992 at Urim (Shirihai, Harris and Williams). Subsequent records came from the same locality: one on 22nd November 1996 (Aldersons), and one on 21st December 1997. Information about these records are in Hadoram Shirihai’s book Bird of Israel (1996) and in volume 21(1) of Sandgrouse, dedicated to fifty new species Hadoram had found in Israel.

Between January 1999 and March 2000 a Tawny Eagle was seen occasionally around Urim-Zeelim, by different birders including James Smith, Trevor Ellery, Eyal Shochat and others. On December 17th, 2000 while conducting a wintering raptor survey I finally locked on that bird. During the following weeks we were amazed to discover that it had built a huge nest (!) on one of the Eucalyptus trees by Urim’s gas station. Moreover, soon after a (probable) female Eastern Imperial Eagle showed some interest in becoming a partner, and it was observed perched by the nest and it even collected some nesting material.

Eventually, no breeding occurred but that bird enabled a close look at the species’ key features. It is possible that this bird was the same bird seen in 1996 and 1997 or perhaps even the same bird from 1992 that ranged in the area for almost a decade. We’ll never know.

13 years later, in early August 2013, Ezra Hadad photographed a Tawny Eagle near Bet-Kama in the northern Negev, some 20 km east of Urim. This bird was seen again by several birders over next few days.

Key features seen on Olga’s photos

Tawny eagle is a highly variable species. In Israel we don’t have records of the easy creamy-buff morph or the more difficult dark morph. All the birds recorded involved tawny-brown individuals. In this respect confusion might happen with Steppe Eagle, especially sub-adult birds which lack already the broad white greater coverts and with Lesser Spotted Eagle. Here I give the main ID pointers that could be seen in the first set of photos. Hopefully this will refine the ‘Search Image’ for local and visiting birders in Israel.

  1. Ageing the bird – the bird is in active moult, growing outer primaries while the outermost primary being paler and pointed, thus unreplaced yet, indicating a 3rd calendar bird (hatched in 2014). Actually correct ageing was enough to eliminate other species of the same age: Steppe Eagle still shows a broad white line on the greater coverts at this age; and Lesser Spotted still shows some whitish undertail coverts.
  1. Structure: Large headed with somewhat shortish wings compared with the long wings of Steppe or the more well-proportioned Lesser Spotted. When perched, tail looks rather short as well and the whole ‘weight’ of the bird is moved forward. The Bill is large compared to Lesser Spotted but the gape-line is only medium-long reaching the centre of the Eye, not as long as in Steppe.
Tawny Eagle, Zeelim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

In flight the wings are typically pressed forward and although it was not clear if that feature was a result of a photo that caught it during active wingbeats, the effect could be noted.

Tawny Eagle, Ze'elim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

  1. Partially black greater coverts – contrary to Lesser Spotted and Steppe, the black GC are more solid and prominent. Actually the prominent black GC are similar to that of fulvescens Greater Spotted Eagle which in general, at least the intermediate morph can look quite similar!
Tawny Eagle, Ze'elim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

  1. Barring on flight feathers – every Aquila Eagle has a unique barring pattern which enables diagnostic identification (see in Dick Forsman’s new raptor ID book). In Lesser Spotted, the dark barring extends along all the feathers to the trailing edge. In sub-adult Steppe (from 4th year plumage) the barring is well developed and first adult feathers show a broad black trailing edge. On Olga’s photos it is clear that the barring doesn’t reach the trailing edge, thus covers only inner part of the feather (as in juvenile and immature Great Spotted), but also that the bars are faint, unlike all other species.
Tawny Eagle, Ze'elim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

Tawny Eagle, Ze'elim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

  1. Almost entirely plain tail feathers – unlike in any of the similar species. This is a very important feature.
  1. Paler ‘wedges’ on inner primaries – that was actually a good example of how a good feature was hard to detect in a too-close photo. Later on, when flight photos from greater distance became available, this feature was easily noted: somewhat resembling juvenile / immature Eastern Imperial Eagle though fainter, Tawny Eagle has paler inner primaries that create pale ‘wedges’. On the first set of photos this pattern was difficult to see.
  1. General plumage tones – the plain ground colour of the belly, trousers (lacking any spots typical in both Spotted Eagle species) and undertail coverts are unique for Tawny Eagle. Personally when seeing the first set of photos I hesitated on this feature the most, since it was hard to tell if it was the real colour or a result of light-effect of low evening sun. However, the entirely tawny and plain undertail coverts convinced me that the tones seen in the photos were close to reality.
Tawny Eagle, Ze'elim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

Many of these features were confirmed later by Dick Forsman, who also added the elongated shape of the nostril as in Steppe and unlike ‘spotted’ eagles that have a round nostril.

Tawny Eagle, Ze'elim, NW Negev, Israel, July 2016

Tawny Eagle, Ze’elim, NW Negev, Israel, July 2016

Itai Shanni also pointed out the contrast from above between the paler median coverts to the much darker greater coverts.

Tawny Eagle, Zeelim, NW Negev, Israel, July 2016

Tawny Eagle, Zeelim, NW Negev, Israel, July 2016

This individual is still present in the same area, and became very popular during the first two weeks of its stay among Israel birders and photographers.

Many thanks to the photographers Olga, Ezra, Eldad, Avi and Meir who contributed their superb photos to this article.

Griffon and Rüppell’s Vultures

More on ID of tricky ones

Guillermo Rodriguez Lazaro

Hi Yoav and Martin,

I saw your post about the Israeli vulture in the Birding Frontiers blog and thought that perhaps I could provide some light about this bird.

Vulture sp., Gamla NR, N Israel, 4 August 2014. Photo by Shachar Alterman. Now thought to be an odd Griffon Vulture.

Vulture sp., Gamla NR, N Israel, 4 August 2014. Photo by Shachar Alterman. Now thought to be an odd Griffon Vulture.

The second photo (underparts) shows an indisputable Griffon (repeated above), definitely ruling out Rüppell’s The complete absence of white edges in wing coverts (not only GCs but also in MCs) is diagnostic. Other features which don’t indicate Rüppell’s are the shape and color of the axillary feathers, absence of white edges in UTCs, strong contrast between black GCs and much lighter MCs, etc… I attach a photo of a classic erlangeri adult from below from northern Ethiopia for comparison.

Rüppell’s Vulture, adult ssp. erlangeri, N. Ethiopia, Guillermo Rodriguez Lazaro

Rüppell’s Vulture, adult ssp. erlangeri, N. Ethiopia, Guillermo Rodriguez Lazaro

So, as pointed in your post, only the upper parts resemble Rüppell’s, I think that mainly due to the presence of two-rows of dark wing coverts, a feature typical of Rüppell’s (which usually has present 2-3 rows). Additionally the bird’s overall colour is perhaps unusually greyish for Griffon, but this species presents a high variation in this trait and I feel it isn’t a strong feature to discard Griffon. In my opinion, your bird doesn’t fit well one of the striking “pale morphs” Rüppell’s which from time to time are observed in NE Africa (it’s too patterned and browner above), so we should compare with the more classic erlangeri adults.

In both Griffon and Rüppell’s all wing coverts present a dark feather center with a pale edge. In Griffon, only the greater coverts present an extension of black large enough to be visible, whereas in the median coverts the dark part is very limited (due to the broad pale edge) and it’s usually not visible. In Rüppell’s, the pale edge is much finer and thus the dark centre of the feather is exposed and very obvious in the upperwing. However, I’ve found that a few Griffons (Spanish breeders at least; I’m not sure if it is an individual characteristic or just the result of a certain state of moult, though the first option is more likely since these birds seem to present also more patterned scapulars) can show two rows.

Vulture Sp., Gamla NR, N Israel, 15 July 2014. Photo by Eitan Kaufman. Now considered to be an odd Griffon Vulture.

Vulture Sp., Gamla NR, N Israel, 15 July 2014. Photo by Eitan Kaufman. Now considered to be an odd Griffon Vulture.

In my opinion, your bird is one of these odd Griffons. Detailed analysis of the upperparts pattern shows that the feather edge of the second row (median coverts) is too broad, and concolorous (cream coloured) with the rest of the wing, whilst it is usually whiter and thinner in Rüppell’s. The wing looks very uniform and with the characteristic griffon-colour of the species, instead of the more browner/greyer appereance of erlangeri Rüppell’s. I also attach one photo of an adult erlangeri (again from N Ethiopia), in which these features are evident.

Rüppell’s Vulture, adult ssp. erlangeri, N. Ethiopia, Pablo Garcia

Rüppell’s Vulture, adult ssp. erlangeri, N. Ethiopia, Pablo Garcia

Taking into account these points, I don’t find consistent reasons for considering a Rüppell’s here but just a slightly unusual Griffon. Other characters also support this id, eg the bird silhouette and the blue skin around the auriculars which provides the characteristic Griffon head pattern.

The option of a hybrid is, in my opinion, even more complex: as far as I know there aren’t proved records, though there is at least one suspected individual from Spain which certainly ticks all the boxes:

Apparent hybrid click HERE
Hope these comments are interesting for you and help to clinch the id.

Best regards
Guillermo

Rüppell’s Vulture or hybrid

or  What?

Yoav Perlman

On July 15th, Eitan and Judith Kaufman went birding at the scenic Gamla NR in N Israel . This reserve is well-known for its vultures that often fly past the lookout at very close range. Among the Eurasian Griffons, they noticed this very striking-looking vulture, that made one quick pass in front of them:

Vulture Sp., Gamla NR, N Israel, 15 July 2014. Photo by Eitan Kaufman.

Vulture Sp., Gamla NR, N Israel, 15 July 2014. Photo by Eitan Kaufman.

 

They sent the photo to several Israeli birders, and immediately the alarm bells went off – from above this bird looked very good for  Rüppell’s Vulture. Hot on the heels after the first Rüppell’s for Israel that was found in May 2014 by Ezra Hadad in C Israel but unfortunately was non-twitchable, we were all hoping that this bird shows better. The image was sent to Dick Forsman, who agreed that this bird had a good potential to be an adult Rüppell’s Vulture of the NE African race erlangeri, but he did clearly state that some bird are virtually impossible to separate from Eurasian Griffon, and that hybrids are known from Ethiopia.

Next morning quite a few birders assembled at the Gamla lookout, and when the air heated up and the vultures left their roost, soon the suspect was relocated. from above it looked very good, but from below – oh no! Pretty identical to Eurasian Griffon! Very plain from below, too plain, especially the undertail coverts. This bird stayed around Gamla for a couple more weeks. This image is by Shachar Alterman:

Vulture sp., Gamla NR, N Israel, 4 August 2014. Photo by Shachar Alterman.

Vulture sp., Gamla NR, N Israel, 4 August 2014. Photo by Shachar Alterman.

Googling Ethiopian Rüppell’s Vultures images, I found none that have completely ‘blank’ underparts like this bird. erlangeri is less striking than the C African race rueppellii, but surely pure erlangeri cannot be so plain from below? I wonder if anyone has images of known hybrids either from E Africa of elsewhere in Africa. Have any hybrids wandered into Europe via Gibraltar? Certainly worth looking out for.

Here are some ‘real’ Rüppell’s Vultures:

This is the first for Israel, found and photographed by Ezra Hadad, 5 May 2014. It was on the move with two other Eurasian Griffons and was not seen subsequently. This is a younger bird – probably 3cy – note especially the undertail coverts:

Rüppell's Vulture, Gva'ot Gad, NR, C Israel, 5 May 2014. Photo by Ezra Hadad. The first for Israel.

Rüppell’s Vulture, Gva’ot Gad, NR, C Israel, 5 May 2014. Photo by Ezra Hadad. The first for Israel.

Here is an adult Rüppell’s from Portugal, with an Eurasian Griffon, by Rami Mizrahi, November 2011:

Rüppell's Vulture (left) and Eurasian Griffon (right), Portugal, November 2011. Photo by Rami Mizrachi.

Rüppell’s Vulture (left) and Eurasian Griffon (right), Portugal, November 2011. Photo by Rami Mizrachi.

 

And a few from Kenya, December 2008:

Rüppell's Vulture of nominate race rueppellii, Masai Mara, Kenya, December 2008.

Rüppell’s Vulture of nominate race rueppellii, Masai Mara, Kenya, December 2008.

Rüppell's Vultures with African White-backed Vultures G. africanus, Masai Mara, Kenya, December 2008.

Rüppell’s Vultures with African White-backed Vultures G. africanus, Masai Mara, Kenya, December 2008.

The pale “FULVESCENS-LIKE” plumage of Lesser Spotted Eagle

Andrea Corso & Michele Viganò

MISC birding team

 

Very few birders and ornithologists acknowledge that Lesser Spotted Eagle has a much paler plumage than the common dark one which is similar to that shown by the Greater Spotted Eagle (chiefly in the eastern populations).
 

 

Juvenile Lesser Spotted Eagle Aquila pomarina photographed north of Ardahan, North_Eastern Turkey,June 2014 by Igor Maiorano- THE MISC.  Note the impressive resemblance with the imperial eagles, chiefly with a faded juv. Spanish Imperial Egle Aquila adalberti : in particular note the extremely pale (much paler than usual) underwing coverts strikingly contrasting with the remiges, the very dark looking tail obviously contrasting with the vent and underbody in general, the well defined dark streaking to the breast forming as a darker breast band, the paler head with a darkish eye-line or eye-mask all characters shared with Imperials. As differences note however the very well marked and visible double pale commas at “wrist”, the less marked and striking pale “window” on inner primaries compared to both Eastern and Spanish Imperial Eagles (though it is usually less obvious in the latter!), the different wing formula with shorter and rounder, less protruding P4 (7th primary) and not projecting at all P3, the numerous and conspicuous dark barring to the whole remiges, and other minor characters as described in the text.

Juvenile Lesser Spotted Eagle Aquila pomarina photographed north of Ardahan, North_Eastern Turkey,June 2014 by Igor Maiorano- THE MISC. Note the impressive resemblance with the imperial eagles, chiefly with a faded juv. Spanish Imperial Egle Aquila adalberti : in particular note the extremely pale (much paler than usual) underwing coverts strikingly contrasting with the remiges, the very dark looking tail obviously contrasting with the vent and underbody in general, the well defined dark streaking to the breast forming as a darker breast band, the paler head with a darkish eye-line or eye-mask all characters shared with Imperials. As differences note however the very well marked and visible double pale commas at “wrist”, the less marked and striking pale “window” on inner primaries compared to both Eastern and Spanish Imperial Eagles (though it is usually less obvious in the latter!), the different wing formula with shorter and rounder, less protruding P4 (7th primary) and not projecting at all P3, the numerous and conspicuous dark barring to the whole remiges, and other minor characters as described in the text.

 

While raptor watching in the last 30 years, one of us  (AC) noticed that among the usual plumage of Lesser Spotted Eagle (Aquila pomarina) there was a much paler plumage not shown or even not cited in any field guide, handbook or publication. Indeed, all birders and ornithologist know about the fulvescens plumage in Greater Spotted Eagle (Aquila clanga) as well as its many pale and intermediate plumages of the Eastern range of distribution (paler birds are commoner among eastern populations).

In fact, this rare paler variant of LSE plumage, being so little known, is often wrongly identified in the field by even the keen birder, sometimes as fulvescens or other times as juvenile Aquila heliaca or juv. adalberti. For this reason we would like now here to give a short description on it and some hints and tips for its identification.

We noted this plumage during autumn migration in Israel as well as during breeding season in Eastern Turkey (near Ardahan and Kars).  Also the skins found in museums were from Eastern Turkey and the Middle East.

Description

A pale variant of the usual plumage of Lesser Spotted Eagle, found both in juvenile (more frequently) than in immature or near adult birds ( no adult yet observed). The whole body appears visibly paler than the usual coloured birds, ranging from tawny-buff or buffy-cream or isabelline, paler on both under and upperwing and on head, being off white or creamy-white on lower belly, vent and undertail coverts. Usually the “thighs” appear darker, pale brownish, as well as most of the time there is a noticeable dark streaked breast band as in Spanish Imperial Eagle (Aquila adalberti) or in Eastern Imperial Eagle. All in all, the general appearance is very similar to that of a juvenile Spanish Imperial Eagle. Remiges and tail are like in the normal plumage, showing a regular and thick dark barring, with numerous bars; the inner primaries pale “window” could (or not) looks more obvious, again recalling more what is seen in juvenile heliaca. On the underwing, greater coverts (GC) and primary coverts (PC) are darker than the rest of the coverts, appearing as a dark band across the mid-wing; they are white-tipped. There is an obvious double pale comma at wrist. Pattern of upperwing is similar to that of underwing. In 2CY, faded birds are even much paler. Older birds (immatures) are similar to juvenile and appear much paler than equivalent plumage in typical pomarina (showing various moult stages and abrasion of course, differently from juvenile).

Juvenile Lesser Spotted Eagle Aquila pomarina photographed north of Ardahan, North_Eastern Turkey,June 2014 by Michele Viganò – THE MISC.  Note in this angle the darker carpal patch and “trousers” or “thighs” , not usually shown by the imperial eagles. Darker carpal patch and pale double commas are very striking.

Juvenile Lesser Spotted Eagle Aquila pomarina photographed north of Ardahan, North_Eastern Turkey,June 2014 by Michele Viganò – THE MISC. Note in this angle the darker carpal patch and “trousers” or “thighs” , not usually shown by the imperial eagles. Darker carpal patch and pale double commas are very striking.

 

Identification

These pale variants could appear extremely similar to GSE fulvescens and even more to juvenile Eastern Imperial Eagle and Spanish IE. They are best told for:

  1. fulvescens: flatter wings during soaring and gliding, longer tail and neck/head, narrower wings and “hand” (more pointed wing-tip), typical LSE wing formula (less obvious in juvenile birds where the wing formula become is similar in both species). Plumage even paler in fulvescens, with contrast dark-pale more striking, more orangish in fresh bird (Ruddy Shelduck-like) and more pale creamy or off white-creamy in faded birds. Different flight feathers pattern, as for typical plumage, with a different dark barring. When shown (not all birds do), double pale comma distinctive of LSE.
  2. Imperial Eagles in juv. plumage (Spanish and Eastern): similar flight style showing to these species, both soaring and gliding being similar. Wings of the Imperials appear longer, narrower and more pointed, fingered primaries more numerous, narrower and longer, head and neck heavier, tail even longer. The pale rump-uppertail coverts patch on Imperials is wider and more conspicuous than in pale plumage LSE. Pattern of dark barring is similar but often, dark bars on the Imperials are wider and less numerous (but variable). Important characters are the darker, almost solid black, remiges in both Eastern Imperial and even more visibly in Spanish Imperial, with therefore the pale “window” on inner primaries much more striking and obvious at distance compared to pale variant LSE. Also, very hardly there is any pale comma on wrist in the Imperials (chiefly, it is extremely rare in Spanish) and there is no dark carpal patch on them (or only a hint of dark blotching to carpal area). When perched structure is of course very different, with stronger, heavier and higher bill of Imperials, oval, oblong nostril instead of small and round as in LSE, thicker, fuller and wider “thighs” on the Imperials, stronger legs and feet, bigger, heavier body held more horizontally (LSE appearing often more upright) and so on.
Juvenile Lesser Spotted Eagle Aquila pomarina photographed north of Ardahan, North_Eastern Turkey,June 2014 by Michele Viganò – THE MISC. As for the imperial eagles, note in this pale plumage the contrasting paler head, the dark breast band and very pale body and underwing coverts. Note the very flat looking soaring, with very flat wings although the “hands” are held pressed downwards. Darker carpal patch and pale double commas are visible.

Juvenile Lesser Spotted Eagle Aquila pomarina photographed north of Ardahan, North_Eastern Turkey,June 2014 by Michele Viganò – THE MISC. As for the imperial eagles, note in this pale plumage the contrasting paler head, the dark breast band and very pale body and underwing coverts. Note the very flat looking soaring, with very flat wings although the “hands” are held pressed downwards. Darker carpal patch and pale double commas are visible.

Conclusions

All in all, this plumage is not shown or discussed in most (or all) field guides, so it deserves great attention as indeed it poses serious ID problems when not seen well or if not bearing in mind the differences with fulvescens or even more with the juvenile Eastern Imperial Eagle and possibly more Spanish Imperial Eagle. In a “vagrant context”, when facing with outside range records of these eagles, the possibility of this paler variant pomarina should be taken into consideration.

 

 

Spanish Imperial Eagle – Variation in juveniles and immatures

Spanish Imperial Eagle (Aquila adalberti). Valladolid, June 2011. Photographer: Juan Sagardía
A young adult female Spanish Imperial Eagle. A stunning bird, for sure, particularly if seen this well! Adults are relatively straightforward to Identify, but some juveniles, and especially immature birds, can be very difficult to tell apart from Easterns.

By Dani López-Velasco

I was recently asked about an interesting looking immature (presumably a 4cy) Imperial Eagle sp. seen in Sweden, and I thought it was about time to share some photos, and comments, on variation within juvenile and immature Spanish Imperial Eagles (Aquila adalberti).

First, a photo of the Swedish bird, taken by Lasse Olsson, from the Surfbirds gallery.

Imperial Eagle sp, probably 4cy Eastern. Sweden, July 2012. Photographer: Lasse Olsson. Photo taken from Surfbirds gallery

I am, by no means, an expert on the 2 Imperial Eagles, although I have seen quite a few Easterns, mainly in Oman, and of course plenty of Spanish over here in Spain (mainly adults and juveniles of the latter though; it’s not easy at all to see immature birds, as they wander around a lot).

But I will try to offer some visual information on variation and ID pitfalls of juvenile and immature Spanish Imperial Eagles, which can perhaps be useful for future records.

I´m not completely sure of the ID of the swedish bird. It is most likely an Eastern, typically lacking any warm rufous colouration on the immature-type underparts and underwing coverts. However, based on my experience, it might be difficult to rule out with certainty a Spanish. Some of them can be scarily similar. See for yourself after checking some of the photos below…

Most fresh juveniles, and full-grown adult SIE, are relatively easy to identify. However, some juveniles can be more difficult than what has been published. They can be quite similar to some Easterns, and, above all,  worn birds can be extremely similar to pale belisarius Tawny Eagles (Aquila rapax), and also to fulvescens Greater Spotted Eagles (Aquila clanga).

Many, if not all, of the recent Tawny Eagle records from Morocco refer, in fact, to wandering juvenile Spanish Imperial Eagles!

Separating immature (mainly 3-5cy) Spanish from Eastern, before the first obvious and diagnostic white feathers on the leading edge of the wing start to appear, usually by late 4cy-5cy,  can be very difficult, or even impossible in some cases.  Especially on birds lacking warm rufous immature-type feathers on the head, underparts and underwing coverts. And these birds exist. Differences in structure (Spanish looking more “compact”, with proportionally shorter and broader wings, and a longer tail than Eastern, and showing a heavier bill and more robust head/neck) are somewhat variable, and probably of little use in the field for separating both species.

The ID criteria still has te be worked out, and an in-depth study, mainly with known-age birds, is badly needed, especially for separating the most difficult, intermediate transitional plumages .

So here are a few photos of some tricky plumages of SIE:

  • Most fresh juvenile Spanish Imperial Eagles show uniformly rich warm rofous, almost unstreaked, underparts. Upperparts usually lack many distinct pale spots or streaks. Thus, they are very different to juvenile Eastern Imperials. See 2 photos below of typical juvenile adalberti.

Spanish Imperial Eagle (Aquila adalberti). Fresh Juvenile. Valladolid, July 2012. Photographer: Juan Sagardía.
A typical juvenile SIE, showing uniformly warm rufous colouration on the underparts, with very little streaking on the chest.

Spanish Imperial Eagle (Aquila adalberti). Juvenile. Ávila, February 2012. Photographer: Juan Sagardía.
Another typical juvenile, with no streaking on the chest, and plain rufous underparts and underwing coverts. The photo was taken in a mountain area of central Spain, certainly less sunny  in the winter than southern Spain or Morocco. Therefore, the plumage state of the bird is still good, not worn or bleached at all being February. Birds wintering in more southerly, sunnier, areas are more prone to bleaching, and by mid winter can be already very worn and whitish.

  • However, some juveniles can show quite extensive evenly dark and pale streaking on the breast, much more so than what´s depicted on most of the guides, and can lack the warm rufous colour of the classic birds, having a  paler, colder, background colour instead. They can also show striking whitish tips to the median and lesser coverts, and also obvious pale spots and streaks on the mantle and scapulars.

Thus, they can be relatively similar to juvenile Eastern Imperials to the unaware observer. Note though that they tend to show little streaking on the underwing coverts, less streaking on the upper-belly, and almost none on the lower breast, than classic heliaca. See some examples of such birds below:

Spanish Imperial Eagle (Aquila adalberti). Central Spain, Autumn 2011. Photographer: Juan Pablo Fuentes Serrano
A juvenile SIE with notorious streaking on the upper breast.

Spanish Imperial Eagle (Aquila adalberti). Central Spain, Autumn 2011. Photographer: Juan Pablo Fuentes Serrano
Note the overall pale and cold background colour of this bird, and also the striking pale tips to all the wing coverts.

Spanish Imperial Eagle (Aquila adalberti). Juveniles. Photographer: Jose Luis Rodriguez. Photo taken from Jose Luis Rodriguez website.
Note the heavy upper breast streaking of the juvenile on the left, similar to that of Eastern.

Spanish Imperial Eagle (Aquila adalberti). Juvenile. Photo: Jose Luis Rodriguez.
A fairly pale bird, with obvious streaking on the upper breast. Note however little streaking on the underwing coverts, unlike heliaca.

A typical juvenile Eastern, for comparison:

Eastern Imperial Eagle (Aquila heliaca). Juvenile. January 2011. Oman. Photographer: Daniel López- Velasco

Below, a darker, and more rufous, Eastern, but with very heavy streaking on the breast and underwing coverts. Such heavy streaking, especially on the lower breast and underwing coverts, shouldn´t be found even in the more streaked extremes of juvenile Spanish.

Eastern Imperial Eagle (Aquila heliaca). Juvenile. January 2011. Oman. Photographer: Daniel López-Velasco

From above, certain birds can be almost identical. See the 2 shots below, both taken in January, showing a juvenile Spanish on the left, and a juvenile Eastern on the right.

Left – Spanish Imperial Eagle (Aquila adalberti). Juvenile. Avila. January 2010. Photographer: Juan Sagardia. Right – Eastern Imperial Eagle (Aquila heliaca). Juvenile. Oman. January 2011. Photographer: Daniel López Velasco
Note the similarities between these 2 birds, although the white tips of the upperwing GCs are broader in the Eastern. A view of the underparts should ID both, though.

  • Apart from the previous pitfall, worn juvenile Spanish Imperials, especially those wintering in more southerly, sunny, latitudes, can be quite bleached in winter and spring, and can look very pale, with cold sandy-buff or even whitish upperparts, and also very pale, worn, upperwing coverts. They can be very similar to pale belisarius Tawny Eagles, and also to fulvescens GSE.

Left -Tawny Eagle (Aquila rapax), Namibia. Photographer: Ignacio Yufera. Photo taken from Ignacio´s website. Right – Spanish Imperial Eagle (Aquila adalbert). Juvenile. Southern Spain, December 2009. Photograher: Javier García.
Note the great similarities between a pale Tawny Eagle , on the left, and a bleached, pale sandy juvenile Spanish Imperial, on the right. No wonder how some of the latter have been wrongly identified as Tawny over the last few years in Morocco. For a correct identification, note smaller size and more compact structure of Tawny, with a shorter tail and shorter wings. Perched, Tawny lacks SIE´s tail/wingtip projection. It also lacks any streaking on the upper breast, usually evident even on worn SIE (see photo). Pale Tawny usually lacks obvious whitish tips to the wing coverts, mantle and scapulars, and they don’t usually show such a noticeable pale, inner primaries window as in Imperial. However, some of the differences can be difficult to judge, and good views and photos would help a lot with the identification.

Spanish Imperial Eagle (Aquila adalberti). Juvenile. Southern Spain. December 2011. Photographer: José Arcadio.
Another example of an already bleached, pale sandy buff juvenile SIE.

Some older, worn birds, in spring, such as the 3cy below, can show uniformly pale underparts, and very worn wing coverts, and can still be very similar, like bleached juveniles, to fulvescens GSE.

Apart from size and structure differences, fulvescens tends to show a more obvious pale crescent on the base of the primaries, more solidly black, almost complete, undersurface of greater coverts, and more uniformly looking dark primaries, with only a diffuse pale inner primaries window.

Left – fulvescens Greater Spotted Eagle (Aquila clanga). India. Photographer: Tejas Soni / Indian Nature Watch. Right – Spanish Imperial Eagle (Aquila adalberti). worn 3cy. June 2009. Southern Spain. Photographer: Antonio Cavadas.
Mainly bleached Juvenile, but also worn, older Spanish Imperials, such as the 3cy on the right, can be very similar to fulvescens GSE. The pale, sandy buff colour of both, upperwing pattern, etc… are almost identical. Good views, mainly of the underwing pattern (fulvescens showing more solidly black, almost complete, under-surface of the greater coverts, and usually lacking a prominent inner primaries pale window), as well as a correct judgement of size/structure, are essential for telling them apart.

  • Immature Spanish, mainly 3cy-5cy,until they start to show pure white feathers on the leading edge of the wing, are in some cases, as already commented, very difficult to separate from Eastern. At least, on actual knowledge.  More work is needed to try to improve this in the future..

They can show obvious dark/pale streaking on the breast, and on the older ages, a mix of dark brown adult- type  feathers and pale, yellowish, whitish,  rufous or buffy, immature-type feathers. The ones with warmer, rufous, immature type feathers, being somewhat easier to ID. But some of them with a cold looking, yellowish, background colour,  Thus, very similar to Eastern.

Some examples of different age classes of Spanish Imperial below, showing variation. There are few published pics of these plumages, so they might be of interest.

…and compare with some Easterns. Similar, aren’t they..?

Spanish Imperial Eagle (Aquila adalberti). 3cy. 31-7-2011. Navarra. Photographer: José Ardaiz.
Note 2 moult waves on the primaries of this 3cy, and the 2 outermost juvenile primaries. The bird shows notorious dark and pale streaking on the upper breast, but the head, part of the underparts and underwing coverts are typically warm rufous.

Spanish Imperial Eagle (Aquila adalberti). 3cy. 4-6-2011. Aragon. Photographer: Alberto Bueno.
Another 3cy, more advanced in terms of primary moult, with no juvenile primaries left, than the above bird. Note, again, obvious streaking on the chest, and relatively cold looking underparts and underwing coverts. See, however, the fairly warm rufous head of this individual, typical of Spanish.

Eastern Imperial Eagle (Aquila heliaca). 3cy. January 2011. Oman. Photographer: Daniel Lopez-Velasco.
For comparison, A 3cy Eastern from January. Outer primaries still juvenile, thus very worn and ragged. Note the heavier streaking on the breast and underwing coverts compared to the above 3cy Spanish.

Spanish Imperial Eagle (Aquila adalberti). Presumed 4cy. Central Spain. Photographer: Jose Luis Rodriguez. Photo taken from Jose Luis Rodriguez website.
This presumed 4cy bird (not possible to confirm the ageing on this photo alone), still, apparently, with no white on the leading edge of the wing, is probably impossible, on actual knowledge, to separate with confidence from the corresponding plumage of Eastern. ID mainly based on location.

Spanish Imperial Eagle (Aquila adalberti). Presumed 5cy. Photographer: Jose Luis Rodriguez.
The first white feathers on the leading edge have already appeared, which helps separate it from Eastern.

Spanish Imperial Eagle (Aquila adalberti). Presumed 5cy. 25-5-2011. Central Spain. Photographer: Antonio Cavadas.
If no pure white feathers on the leading edge of the wing can be seen (and beware of light effects), then the ID of birds like this one can be very tricky.

Spanish Imperial Eagle (Aquila adalberti). Presumed 5cy. 14-6-2011. Valladolid. Photographer: Juan Sagardia

And below, a 5cy Eastern, from Oman. Note how scarily similar the bird is to the above 2 Spanish.

Eastern Imperial Eagle (Aquila heliaca). 5cy. January 2011. Oman. Photographer: Daniel López-Velasco

There are already records of Spanish Imperials in France, and even in the Netherlands , so any vagrant Imperial Eagle should be fully checked and documented, just in case…

And last, thanks to Juan Sagardía and Guillermo Rodriguez for his comments and input on the subject.