Eleonora’s Falcon: Easy or Difficult?

Summer with the Falcon of  Eleonora d’Arborea : are second-calendar year Eleonora’s Falcon easy or difficult to identify ?

by Andrea Corso

Summer time in the Mediterranean Basin has been since long time considered by local birders as an almost wasted time for our beloved passion. Too hot to go out birding for prolonged period but also too hot for many birds, which rather prefer to stay hidden in shade during most of the day-light, almost no migrants but the very first waders and sea birds forced many of us (including myself quite extensively) to start watching and sometimes even seriously studying dragonflies and damselflies for example. However, that summer is not a great period for birding is a belief  inherited from the old ornithological fashion in Italy: indeed some of the rarest sea birds, gulls, terns and waders have been found in summer in last years ( Franklin’s and Laughing Gulls turn mostly in July-August in Mediterranean, as do Lesser Crested, Sooty, Arctic and Roseate Terns, alongside with rare petrels and sea birds, with regular occurrence of Broad-billed Sandpiper, Terek Sandpiper and Red-necked Phalarope as well as the rarities among the waders).

Not only vagrants or migrants are best observed in summer, and among the most fascinating and localised species which are a summer speciality we could surely list the Eleonora’s Falcon, the elegant and majestic flier which the name is connected with one of those illuminated woman  of our history, Eleonora d’Arborea (http://en.wikipedia.org/wiki/Eleanor_of_Arborea).

Sitting quietly on a summer sunset over a sea steep cliff, volcanic or lime-stone variegated high wall, watching tens of those medium-sized falcon almost caressing the rocks on fast and hearth-breaking dives from up in the sky to almost touching the sea surface, screaming loudly in coro with so many different voices and calls-type (the species has one of the richest repertorio of all the raptors) or resting on a small colourful boat right below the islands’ cliffs where they breed watching their master air evolutions (I’ve seen so many raptors but still Eleonora’s remains one of the king of the blue sky) is something that at least once in a life a nature lover should experience. Adults are easy and most often seen at the breeding sites, but are second-calendar year so easily identify in the field? And are they really well-known by all European birders? They are seen on the breeding grounds as well but they are also prone to wonder a lot all around Europe and sometimes Western Palearctic as well (with several far out of range records).

If Ristow (2004)report that “undoubtedly the most reliable means of separating most juvenile Eleonora’s Falcon from most Hobbies lies in the size of the yellowish face pattern…”, then the answer to our fore above mentioned question is …not ! They are not well-known and deserve better treatment, in fact the face pattern being undoubtedly the least important character.

• FIRST STEP

 In any identification process, the very first step is a correct ageing of a bird, then the sexing when relevant and only then we could start to check characters to reach a reliable identification. Therefore, here below some ageing tips for Eleonora’s Falcon:

1. A 2^nd calendar-year (here after 2^nd cy) Eleonora’s Falcon is easily spotted on a breeding site by the pale looking, almost sandy or tawny, tail which appear paler than the rest of the upperparts, and among the palest “area” of the whole bird; the tail, also, appear barred! In adult birds the tail is very dark and almost concolour with the rest of the upperparts and is homogeneous appearing unbarred (few rusty or orangish-brown bars seen when fully spread and mostly from below) (Corso & Monterosso, 2000, 2004; Corso & Penna, 2009; Corso & Gustin, 2009). This character is helpful also when seen outside breeding grounds on a migration or vagrant context;
2. At the same time, the central tail feathers (R1 or T1) are most of the time moulted by late summer (but in many birds only by autumn) appearing than darker (being adult-type and fresher) and longer (adult’s rectrices are longer than juvenile ones, a unique case among Falco sp. in Europe where is rather the opposite) (Corso, 2022; Corso & Penna, 2009);
3. Also, the plumage is quite rugged, un-neat, rough, variegated due to a great contrast between old abraded juvenile retained feathers and darker, fresher, adult-type moulted one (Corso & Monterosso, 2000, 2004);
4. The tertials are abraded, duller and sandier, barred (Forsman 1999b; Corso & Monterosso, 2000, 2004; Ristow, 2004; Corso & Penna, 2009)
5. The underwing is paler, less dark toned, with barred remiges being mostly juvenile (or showing growing or just grown dark and homogeneous adult P4-P5) and therefore differing from the uniformly coloured and patterned adult’s remiges (and also, though less so, from the barely barred 1^st adult birds).

 IDENTIFICATION

 1) Tail pattern and colour: Probably the best way to distinguish a 2^nd cy Eleonora’s Falcon, also at distance, not only from adult and 1^st adult but also from similar species such as Hobby and Sooty Falcons (but not from the sometimes oddly similar Red-footed Falcon), is the pattern and colour of the tail. During 2^nd cy, up to the end of 1^st complete moult in wintering ground during their 2^nd winter, the whole tail is usually retained as above mentioned. Thus, the tail is heavily faded and abraded, with bleaching quite striking, and as a result, the tail indeed appear more or less obviously barred. This feature alone distinguish a 2^nd cy Eleonora’s of any morph from any aged Hobby and Sooty. The striking contrast between the paler, sandy or brownish-buff tail and the darker upperparts, is well visible at distance also and no such effect is found in any Hobby. Some 2^nd cy Hobby could show a slightly paler tail than upperparts (contrast never seen so in the uniformly coloured adults) and a slightly more barred uppertail, also barely on T1; indeed, some extremely faded and abraded 2^nd cy Hobby may show more visibly barred uppertail than usual, with even a few barring on inner web of central pair (T1) but the barring is visible at close up view and it never is as marked, complete all over the tail and obvious as in most 2^nd cy eleonorae, and its mostly seen with fully open tail, for example when spread on landing or while soaring (Small, 1992; Corso 2002; pers. obs.).

2) Tertials and scapulars: When still retained (up to the spring/summer of the 2^nd cy but often till the autumn) the pattern juvenile tertials, and less the lower scapulars, is also a very good identification (and ageing) character. Forsman (1999b) mention that on 2^nd cy birds, the tertials are faded and very abraded tertials, contrasting with the rest of the dark upperparts. Ristow (2004) report that the main differences with adult Eleonora’s and best identification character, alongside with size of the yellowish face pattern, from Hobby and Sooty, is the barred appearance of juvenile retained tertials and scapulars. Indeed, as for the tail feathers, abraded juvenile tertials appear rather or pretty barred, then contrary wise to the uniform tertials shown by 2^nd cy Hobby and Sooty. However, great care should be taken as this character is not easy to see in the field but at close range; further, I found several birds, chiefly in summer-autumn, with moulted tertials and scapulars, therefore showing the uniform adult-type pattern.   Even in some birds taken in wintering grounds in Madagascar, though extremely rarely, scapulars are mostly renewed while tertials are of mixed generation, old retained patterned and new unmarked one (birds at Tring Museum, UK – see figures). In any case, the barring over tertials and scapulars, also in fresh juvenile is variable, with some birds showing little visible barring having smaller pale notches along the webs.

3) Underwing: Variably dark and patterned underwing coverts depending on stage of the post-juvenile partial moult that is variable individually, usually just few new one or none in spring, later on in summer more and more to autumn (Corso & Penna, 2011). When complete moult start, any moulted new dark remiges (usually P4 or P4-P5) which would be protruding (being longer and fresher) and well showing, will ensure a very important ID character, differing in any morph from any Hobby which has always strikingly barred remiges (Forsman 1999a,b; Clark, 1999; Corso, 2002, Corso & Monterosso, 2000). During 2^nd cy,  underwing appear two-toned more than in fresh juvenile due to the faded remiges and the mixed new adult-type darker coverts. This contrast is lacking or far less conspicuous and striking in Hobby at any age and in any plumage, and also in Sooty at any age. Also highly important is the  broad dark trailing edge, well showing and well contrasting, distinguishing them from adult birds and from Hobby at any age and plumage (Forsman 1991 a,b; Conzemius, 2000; Corso, 2002; Corso & Monterosso, 2000, 2002). Indeed, Hobby in juvenile and 2^nd cy plumages do have a broader terminal bar, forming a terminal band along the secondaries, this being more extensive in some birds and more visible in faded individuals, but in any case it is always less striking and less contrasting with the rest of the remiges than in Eleonoar’s, having a more uniform underwing appearance, diffusely dull and uniformly marked. Surprisingly, Ristow (2004) seems to ignore all the above mentioned crucial characters, which under a good field view would make possible 100% of the identification of a 2^nd cy Eleonora’s compared to a Hobby or Sooty. Densely and conspicuously barred remiges distinguish 2^nd cy from 1^st adult where the pale barring is narrower and much duller, less marked and visible, mostly concentrated at the base of the remiges.

4) Body: see the photos’ captions for some comments on that.

5) Face pattern and bare parts: Ristow (2004)reportthat “undoubtedly the most reliable means of separating most juvenile Eleonora’s falcon from most Hobbies lies in the size of the yellowish face pattern…”. This is by no means true as the face pattern is variable both in colour hue and richness (though usually brighter and richer in eleonoare than in subbuteo but not so than in concolor) and in size of the pale patch; however under field condition, chiefly in flight bird, does not help at all. Further, in many (if not most) 2^nd cy birds in summer grounds, most of the head feathers would be moulted and therefore adult-like, then not useful any longer, or would be abraded and faded, therefore buffish-white or off-white. Same for the bill colour reported by same author as different from Hobby but indeed in most cases just the same.

 6) Flight style: after experience any skilled field birder would appreciate differences in flight style of Eleonora’s Falcon compared to any Hobby. Indeed, the former fly always, also when juvenile though less due to shorter hand and tail, more Tern-like, with very wide wing-beats, with hand going further up above the body level than in Hobby, then down, showing also a winnowing yet powerful flight. Hobby show a stiffer flight, more Peregrine-like, with stiffer and harder wing-beats, wing going less up to body level, hand moving more toward down then up, with a straighter fly. Sooty show an even more Tern-like flight with movements as a White-cheeked Tern, showing very wide and open elastic and soft though powerful wing-beats, with the body moving up and down during the direct fly, all the impression emphasized by the very long wings and short tail.

7) Structure in brief: Also, bill and feet structure are quite different from Hobby at any age and plumage, being always stronger, the former being higher and thicker, the flatter being bigger and stronger, with longer and more powerful fingers.

Conclusion

As shown by this short summary, after experience, Eleonora’s Falcon at any age and plumage, when seen reasonably well, is quite easy to age and to identify. To distinguish juvenile and 2^nd cy from same aged Hobby, the size and the colour of the yellowish face is by no means important as contrariwise reported by Ristow (2004). The tail pattern is in 2^nd cy by far the most reliable and easy to spot character, as well as the tertials pattern though this is often harder to see well under field condition and in some birds the pattern is mis-leading or the tertials have been already moulted by the time they are seen in Europe. Underwing pattern is a very good clinching character, chiefly if any new uniformly dark adult remiges has grown replacing the barred juvenile one. Silhouette and flight style are very relevant identification features with experience.

Photos 1-4 by Marc Thibault, Albaron , France, August 2006

1)      A perched pale morph 2^nd cy Eleonora’s Falcon showing perfectly the close resemblance to Hobby in some stage of this transitional plumage. Note the paler tail contrasting with upperparts which show narrow and numerous regular barring on the tail feathers; in a 2^nd cy Hobby the tail would be also paler when heavily faded/abraded but would appear homogeneous, lacking visible barring on the upperside of the tail or showing less numerous, differently shaped bars which are marked mostly on the inner webs and therefore visible only with fully spread tail. Note also the pale “spots or blotches” on the inner web of the inner greater coverts (GC) and lower scapulars (visible only on the one in which the inner web is exposed), and especially, note the diagnostic barred smaller tertials, while the longest tertial appear not so barred, showing indeed that this albeit good and clinching character is more variable than usually reported in literature and hard to be seen in good close up view. As regarding the structure, the tail is short being still wholly juvenile, but note the extremely long-winged appearance, with a very long and narrow primary projection; also, the feet appear strong and big. Note that contrary wise to what reported in some literature, the check patch is white or off white being abraded (and not creamy or buffy or yellowish as when in fresh juvenile plumage) and there is not any apparent and obvious difference to a Hobby, although, the face and head pattern is the closest to that species.

2)      The same bird a second before while landing: note importantly and diagnostically that all the tail feathers appear fully barred, in both outer and inner webs, with the central tail showing the least obvious barring but yet more than in any aged Hobby. Note also that there are numerous bars, many more than in Hobby. The bluish and fresh looking feathers sparse on mantle and scapular are the new adult-like feathers acquired during the just started post-juvenile partial moult.

3)      Same bird in flight from below: note in that photo the strong similarity to a 2^nd cy Hobby, chiefly on the white cheek patch contrasting with the rest of the underbody. Juvenile silhouette is closer to that of Hobby being the juvenile tail and juvenile wings shorter than on adult Eleonora’s Falcon. Note however, the two-toned contrasting underwing and the broad and remarkably obvious dark trailing edge to the wing.

4i. Same bird. Note again and more in this photo the contrasted two-toned underwing giving a Lanner-like looking to the bird, and the obvious and marked broad dark trailing edge well contrasting with the pale looking strongly barred remiges. In Hobby, the underwing is far more uniform, and although there is a dark and wider terminal bar to the remiges, this is not forming a such contrasting trailing edge, being usually less contrasting with the rest of the feathers.

4)      Same bird in flight from above: note the extremely well visible paler fully barred tail, which is visible and contrasting even at distance and in closed tail (not spread). This is the best and diagnostic character for both ageing and specific identification, differing from the uniform tail (mostly central tail feathers) of Hobby at any age and Sooty at any age. Note also, that some barring are barely visible on inner GC but not on tertials which indeed could often appear uniform, being therefore not so relevant ID character as believed by some authors if not seen very well and in very marked birds.

5-7 A pale morph 2^nd cy Eleonora’s Falcon, Spring 2006, Bologna, Emilia Romagna, Northern Italy (out of range record). William Vivarelli

5)      A side view of this 2^nd cy in which the barred and sandy tail is still very well visible and therefore diagnostic. First identified as a 2^nd cy Hobby by many ornithologists (due to the habitat and locality), this bird has later been correctly ID by me on this photo alone due to the tail pattern. The same happen regularly with many out of range records in N and C Italy.

6)      This bird appear rather pale and uniformly pattern on body and underwing too, with more colourful thigh-feathers and undertail, almost rusty orange, contrasting with the pale body which is dark streaked, giving to the bird a very Hobby-like appearance. However, note the broad and well contrasting dark trailing edge to the underwing and the numerous, regular and complete barring to the tail.

7)      Same as above

8)      A pale morph 2^nd cy (with unmarked undertail coverts, these would be rather dark barred/patterned in dark-morph juvenile and 2^nd cy), Tolfa Mountains, Lazio, July 2008. The complete moult has not yet started at all, with the whole wing and tail retained juvenile. Quite similar at a first glance to a Hobby, note however that in many Eleonora’s Falcon, already in 2^nd cy, the whole underbody appear warmly coloured, with diffuse orange or rusty-crème tinge not only limited on the undertail-coverts and thigh-feathers (as on Hobby) but also on the flanks, vent, belly and breast. In this richly coloured individual, the pale area on underwing are warmer and more rusty than usual, therefore the dark trailing edge is less contrasting, chiefly in some light. Note however the numerous, broad and striking barring all along the tail, in both inner and outer webs  eliminating any aged and plumaged Hobby and Sooty. The central tail pair (T1 or R1) is less obviously barred but yet more than on Hobby and Sooty.

9) Two spring Eleonora’s Falcon from Madagascar to show variability in tertials and tail barring. Usually, the birds with more strikingly barred tail are also more barred on tertials; note that in some birds the tertials appear uniform (being pale blotched only on one web) and the central tail feathers are barely barred. However, once spread, the tail appear always paler than the rest of the upperparts and show well a barred pattern. Photo © Natural History Museum, Tring (courtesy of NHM , Tring Staff).

 

10) A closer view to the barred tail pattern of a 2nd cy Eleonora’s Falcon from spring. In Summer and autumn the barring would be much more obvious also at distance, and the tail would be more abraded and therefore faded, appearing paler and sandier. Photo © Natural History Museum, Tring (courtesy of NHM , Tring Staff).

 

11)  A dark morph adult, from Sardinia, in summer. To show the very dark and uniform tail of adult, strikingly different from any 2^nd cy. Michele Mendi

12)  A pale morph adult female (greyish cere), Sardinia. To show uniformly coloured and patterned tertials, lacking obvious barring. A barely hint of bars are visible on the more abraded (having been moulted earlier) lower scapulars and inner greater coverts, while they are not yet showing up on the later moulted and therefore fresher tertials. Once abraded, on wintering ground, a hint of barring would be visible also in adult birds, but never as much as in the well-marked abraded juvenile and 2^nd cy. Michele Mendi

13)  A dark morph adult male (yellow cere), Sardinia. To show the wholly uniform upperparts including all tertials, scapulars and coverts. Also, note the fully homogeneous and dark tail, which do not contrast at all with the upperparts. Michele Mendi

14)  A pale morph adult male. Same as above. William Vivarelli

Acknowledgements

For the photos given I warmly thanks:

Michele Mendi http://www.pbase.com/michelemendi/root&page=all ;William Vivarelli http://www.vivarelli.net/ ; Roberto Ragno http://www.robertoragno.com/index.html and Marc Thibault. A warm thanks as usually to the whole most helpful and kindest stuff of the Tring, British Museum, UK.

References

Small, B. 1992. First-summer Hobbies in the New Forest. British Birds 85: 251-255.

Clark, W.S. 1999. A Field Guide to the raptors of Europe, the Middle East and North Africa.

Oxford University Press.

Conzemius, T. 2000. Hinweise zur Bestimmung des Eleonorefalken Falco elonorae in

Mitteleuropa. Limicola 14: 161-171.

Corso, A. 2002. Identificazione a distanza di quattro specie simili del genere Falco sp. www.ebnitalia.it.

Corso, A. & Monterosso G. 2000.  Eine unbeschriebene dunkle variante des baumfalke Falco subbuteo und ihre untersheidung vom eleonorenfalken F. eleonorae. Limicola 14 : 209-215.

Corso A. & Monterosso, G. 2004. Further comments on dark Hobbies in southern Italy. British Birds 97: 411-414.

Corso, A. & Gustin, M. 2009. Morph ratio of Eleonora’s Falcon Falco eleonorae in Sicilian islands. British Birds 102: 216.

Corso A. & Penna V., 2009. Dati sulla muta del Falco della Regina Falco eleonorae in Sicilia. Alula 16: 211-212.

Forsman, D. 1999a. The raptors of Europe and The Middle East: a handbook of field identification.   T & A D Poyser Ltd.

Forsman, D. 1999b. Identification of  Eleonora’s Falcon. Alula 4: 122-126.

Ristow, D. 2004. Exceptionally dark-plumaged Hobbies or normal Eleonora’s Falcon? British Birds 97: 406-410.