Denne unge blå Glente havde - som det kan ses - sortagtige armsvingfjer ligesom håndsvingfjer.
Et hurtigt check i litteraturen antyder, at dette er mindre kendt. De fleste steder vises adult og juvenil med de samme hvide armsvingfjer, blot W.S. Clarks rovfuglebog fra 1999 skriver "secondaries greyish" for ungfuglenes vedkommende.
Små kendetegn findes fortsat hos de europæiske rovfugle, men så mørke armsvingfjer, kontra hvide, må siges at være en iøjnefaldende karakter. På afstand giver det jo undervingen et helt andet udseende end man ser illustreret i øvrigt.
Ung blå Glente kan altså have langt mørkere tegnet undervinge end man almindeligvis antager. Værd at have i tankerne ved besøg i artens udbredelsesområde, eller hvis en ungfugl skulle driste sig nordpå.

Dear Klaus,
are the dark secondaries typical for 2nd cy? in april 2006 we (4 belgian birders) had a 2nd cy black-shouldered kite in the Göksu-delta, Turkey, and that bird also had dark underside of the secondaries. this seemed strange to us as we thought the underside of the secondaries was always light greyisch (no contrast with the rest of the underwing). some pics of this bird can be seen on this page: http://natuur-forum.be/topic.asp?TOPIC_ID=4009&whichpage=2

grtz
pieter

Hi Pieter,

The dark secondaries, as seen here, is regular up to 2nd cal. year. There is probably som evariation, with the palest birds hardly different from adults, and the darkest patterned birds showing almost as dark secondaries as primary tips.

I have seen this darker-than-expected secondaries in a number of birds in recent years. This is a character hardly described in the litterature, although Clark - in his book on WP raptors -mentions "secondaries greyish" for young birds.

grtz
Klaus
PS! Pieter, I am most interested in including some of your observations in my Turkish report (Maj 2005,2006 and 2007)which is constantly updated. Hope you could e-mail me concerning this.

Dear Klaus,

thanks for the quick and clear answer. so in your opinion darkish (underside of) secondaries is solely individual variation in 2nd CY and is not regional (for example more in asian birds?)?

i will try to translate our Turkey sightings to english as soon as possible so i can send them to you. i will make it still in 2007, i think.
the black-shouldered kite we saw was on 24 and 25 of april 2006 in the southern part of the Göksu-delta. it should be the 11th for Turkey (according to Emin Yogurtcuoglu).

grtz
pieter

Dear Pieter

Thanks a lot -when posting your turkish sightings, please mail on

klausmalling@gmail.com

It is stillnot known, if the darkish surface to the secondaries is more frequent in Asian than in African/Iberian birds. I first notes the character while in India Jan./Feb. 2006,where we saw a good number of the species.
Could anyone supply with more details?

Season´s greetings
Klaus

Peter Adriaens, who was with me in Turkey when we saw the bird, also noticed the dark secondaries in Malaysia last winter.

grtz
pieter