Björn Bergenholtz
(former alias "Calalp")
Let´s return to the identity of "Forskåhlii", and the original source itself ...
If we´re to dissect the description by Peter Forsskål (1775) in detail (following, trusting Laurent's translation, in post #7) ... versus today's Black Kite Milvus migrans and Yellow-billed Kite Milvus (migrans) aegyptius, as well as the Red Kite Milvus milvus, this is what we´ve got (at least, in my mind
) ...
• [Falco] "Forskåhlii" GMELIN 1788, based on Forsskål's "Falco cera pedibusque flavis, ..." (of 1775, without any binomial name), quoted (in divided parts), with comments, below:
HBW have the following measurements; Black Kite: 44-66 cm (incl. ssp. Yellow-billed Kite): contra Red Kite: 60-72 cm [here]. Note that other references claim the Head-tail measurements as: Black Kite: "48-58" or "55-60 cm" vs Red Kite "60-70" alt. "60-66 cm".
Looking at the Photos in Forsman's book I perceive the tips of primaries of aegyptius somewhat more pointed than the (six!?) ones on migrans. To me Mr Forsskål seems to have been a very sharp-eyed observant, more and more, for every sentence ... quite a "birder"!) I assume he had obtained a specimen, studied at close range.
[Even if not of interest regarding the ID of "Forskåhlii" itself, note that Forsman also cover field identification of the parasitus subspecies.]
This hieme/winter part is, to me, the most disturbing part of Forsskål's text. Note that Peter Forsskål spent more than a full year in Egypt (from 27 Sept. 1761 until 9 Oct. 1762). Could this quote possibly be read as it being (more) frequent/common in winter, as the numbers increased when European birds arrived/added to, or replaced, the local population? In the meaning (implied/as understood) Present ... versus (more) common, in winter?
Also noteworthy is that Forsskål (in "his" Descriptiones animalium/ "Fauna Arabica", on p.7), under the heading AVES MIGRATORI [Migrating birds], PER CONSTANTINOPOLIM [trough/over/via Constantinople/Istanbul], below; III. AUTOMNALES [in Autumn] listed "Milvus Falco" as "Septembri transit" (here) and (on the following page), under the heading AVES ALEXANDRIÆ. /I. PERMANENTES [BIRDS OF ALEXANDRIA /1. permanent, stationary, consisting alt. all-year] we (again?) find a "Falco Milvus" (but the opposite way around), with the Arabic name "Haddája"!?! Not sure if those two "Milvus Falco" vs "Falco Milvus" was intended as bionomial names or simply Latin text. Maybe Haddáj/ Haddája was used for any other Kite/s? Whatever Red/Black/Yellow-billed ones?
In my mind, this far, all of it (except maybe for the "Location" part), adds up strongly in favour of Gmelin's "Forskåhlii" (1788) being a synonym of Gmelin's own aegyptius, i.e. today's Yellow-billed Kite. I doubt this is the way Forsskål would have described any specimen of nominate migrans. If only he´d mentioned a dark iris ... but, well, one can´t have it all.
And, as always; don´t hesitate to question, or comment, any of the above!
Björn
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References:
Forsman, D. 1999. The Raptors of Europe and The Middle East - A Handbook of Field Identification. T. & A. D. Poyser
Forsman, D. 2016. Flight Identification of Raptors of Europe, North Africa and the Middle East. Bloomsbury/Helm (Helm Identification Guides).
Snow, D. W. & C. M. Perrins (Eds.). 1998. The Birds of the Western Palearctic. Concise Edition. Volume 1 Non-Passerines. Oxford University Press.
Svensson, L., K. Mullarney & D. Zetterström. 1999 (& 2009). Fågelguiden - Europas och Medelhavsområdets fåglar i fält. Bonnier Fakta (the Swedish original version of The field guide: Birds of Europe).
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If we´re to dissect the description by Peter Forsskål (1775) in detail (following, trusting Laurent's translation, in post #7) ... versus today's Black Kite Milvus migrans and Yellow-billed Kite Milvus (migrans) aegyptius, as well as the Red Kite Milvus milvus, this is what we´ve got (at least, in my mind
) ... • [Falco] "Forskåhlii" GMELIN 1788, based on Forsskål's "Falco cera pedibusque flavis, ..." (of 1775, without any binomial name), quoted (in divided parts), with comments, below:
Falco (in those days more or less equal of Raptor) ... all three Kites discussed (Black-, Yellow-billed and Red) have yellow cere and yellow feet. Both the Black and Yellow-billed Kite fits the description "ashy above", but only the Yellow-billed aegyptius (and the Red, of course) has ferrugineous lower parts. Forsskål's "Dark brown wings" excludes, in my mind, the Red Kite, and the "forked brown-barred tail" ... fits all, they all have (more or less) forked tails (less in flight, but certainly so when perched), least in migrans. Regarding "brown-barred", they all have more or less brown/dark-barred tails (most obvious below), even if I would say that the minute bars on the tail of the Red Kite are more blackish than brown. The "tail of the length of the body" is harder to determine, not knowing how the body was measured (and I haven´t found any reliable, comparable measurements of their tails vs "bodies" (incl. excl. head?) ... on this one I will pass. Clearly the Red Kite is the one Kite with the longest tail.
Indicating a bird less than, or just about, half a meter. This, of course, said with reservation for the unknown methods of measuring, as well as not knowing exactly what cubit Forsskål had in mind. Either way: the size talks in favour of either one of the two smaller Kites. Of those two aegyptius seems to be the smaller one (on average).
HBW have the following measurements; Black Kite: 44-66 cm (incl. ssp. Yellow-billed Kite): contra Red Kite: 60-72 cm [here]. Note that other references claim the Head-tail measurements as: Black Kite: "48-58" or "55-60 cm" vs Red Kite "60-70" alt. "60-66 cm".
Black Kite: Bill black, cere yellow. Yellow-billed Kite: Bill and cere yellow (adult). Red Kite: Bill greyish (paler by age), with black tip, cere yellow. "Bill and cere" talks (strongly) in favour of aegyptius (... from here onwards I´ve dropped the Red Kite).
Fits aegyptius better than migrans, as the former has a more reddish tone of the otherwise grey-brownish head. Also the one with most obvious "black in the middle". Black Kite's more dark-brownish. See photo here versus here. Both (of course) with "with isolated bristles towards the mouth".
Too vague, would fit either one.
Both the Black - and Yellow-billed Kite have "dark brown remiges", but interesting is that Forsskål mentioned "the 5 first ones narrowed towards the tip (i.e. the primaries) as Raptor expert Dick Forsman (2016), in his recent book Flight Identification of Raptors of Europe, North Africa and the Middle East (2016) points out that the Yellow-billed Kite (aegyptius) as: "Similar to Western Black Kite and often difficult to separate, except for diagnostic adults. Differ structurally from Western Black Kite in showing narrower wing and more pointed wingtip (only five fingers) and slightly more deeply forked tail, but ..." [here, with even more details].
Looking at the Photos in Forsman's book I perceive the tips of primaries of aegyptius somewhat more pointed than the (six!?) ones on migrans. To me Mr Forsskål seems to have been a very sharp-eyed observant, more and more, for every sentence ... quite a "birder"!) I assume he had obtained a specimen, studied at close range.
[Even if not of interest regarding the ID of "Forskåhlii" itself, note that Forsman also cover field identification of the parasitus subspecies.]
Fits aegyptius better than migrans.
Not useful as characteristic for either one.
Not useful as characteristic for either one. Couldn´t find any info regarding differences in numbers of retrices (tail feathers).
Not useful as characteristic for either one.
Not useful as characteristic for either one.
Distribution, numbers in Seasons, migration etc., etc. ... hard to find reliable info on species/subspecies level (due to the recent split/non-split situation). Anyone with better sources than I´ve found?
This hieme/winter part is, to me, the most disturbing part of Forsskål's text. Note that Peter Forsskål spent more than a full year in Egypt (from 27 Sept. 1761 until 9 Oct. 1762). Could this quote possibly be read as it being (more) frequent/common in winter, as the numbers increased when European birds arrived/added to, or replaced, the local population? In the meaning (implied/as understood) Present ... versus (more) common, in winter?
Also noteworthy is that Forsskål (in "his" Descriptiones animalium/ "Fauna Arabica", on p.7), under the heading AVES MIGRATORI [Migrating birds], PER CONSTANTINOPOLIM [trough/over/via Constantinople/Istanbul], below; III. AUTOMNALES [in Autumn] listed "Milvus Falco" as "Septembri transit" (here) and (on the following page), under the heading AVES ALEXANDRIÆ. /I. PERMANENTES [BIRDS OF ALEXANDRIA /1. permanent, stationary, consisting alt. all-year] we (again?) find a "Falco Milvus" (but the opposite way around), with the Arabic name "Haddája"!?! Not sure if those two "Milvus Falco" vs "Falco Milvus" was intended as bionomial names or simply Latin text. Maybe Haddáj/ Haddája was used for any other Kite/s? Whatever Red/Black/Yellow-billed ones?
Enough said.
Note that Svensson et al. points out that the ferrugineous lower part as one of the key characters of aegyptius contra the greyish-brown lower part of migrans (also parasitus is duller).
In my mind, this far, all of it (except maybe for the "Location" part), adds up strongly in favour of Gmelin's "Forskåhlii" (1788) being a synonym of Gmelin's own aegyptius, i.e. today's Yellow-billed Kite. I doubt this is the way Forsskål would have described any specimen of nominate migrans. If only he´d mentioned a dark iris ... but, well, one can´t have it all.
And, as always; don´t hesitate to question, or comment, any of the above!
Björn
________________________________________
References:
Forsman, D. 1999. The Raptors of Europe and The Middle East - A Handbook of Field Identification. T. & A. D. Poyser
Forsman, D. 2016. Flight Identification of Raptors of Europe, North Africa and the Middle East. Bloomsbury/Helm (Helm Identification Guides).
Snow, D. W. & C. M. Perrins (Eds.). 1998. The Birds of the Western Palearctic. Concise Edition. Volume 1 Non-Passerines. Oxford University Press.
Svensson, L., K. Mullarney & D. Zetterström. 1999 (& 2009). Fågelguiden - Europas och Medelhavsområdets fåglar i fält. Bonnier Fakta (the Swedish original version of The field guide: Birds of Europe).
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