Unexpected plumage: immature Honey Buzzard
The BRC 2017 autumn count is a season of anniversary for which we receive many surprises! After getting 4 Eleonora’s Falcons, which is a higher total than all Eleonora’s we got since 2008, and the 1st Pallas’s Gulls actively migrating, an experienced counter of the team, John Wright, spotted on the 17th of September a European Honey Buzzard with an unusual shape during a day of slow migration. After taking pictures, a quick examination revealed very promising moult pattern.
The European Honey Buzzard Pernis apivorus is the most common raptor species migrating through Batumi bottleneck, with an average of 520.000 individuals counted per autumn. Peak-days regularly reach the bar of 100.000 birds. The record peak-day for the BRC is even higher, with an unforgettable 179.342 Honey Buzzards counted on 3rd September 2012.
So why do we show so much enthusiasm for a single of these birds? It appears that all Honey Buzzards spend their first year(s) of life in Africa. This long-distance migrant comes back to Europe once it reached the age of breeding. Despite this general rule few exceptions exist. There are a couple of known spring records here and there around the Mediterranean basin and some discussions about them (see Corso 2012, Pannucio and Agostini 2012). To our knowledge there are no claimed records of immature European Honey Buzzards in autumn, or at least no documented ones. This picture taken by Dr John is a rare opportunity to give a close look at what Honey Buzzards look like during the autumn of their 2nd calendar year.
First, the global appearance of the bird is striking because flight feathers show a clear contrast between worn and abraded juvenile feathers and freshly moulted adult-type feathers (detailed in Forsman’s book). This is totally unusual for autumn Honey Buzzards, unless you observe a bird with a damaged plumage.
2cy Honey Buzzard, Batumi, 17th September 2017. Photo by John Wright.
Another view of the bird showing the different feather generations.
2cy Honey Buzzard, Batumi, 17th September 2017. Photo by John Wright.
Here are examples of juvenile birds with damaged plumage that can be mistaken for 2cy birds if not watched closely. They show what is called fault bars, which are gaps in feathers that originate because of a lack of nutrition at the time that part of the feather was formed. The lack of nutrition during growth causes the barbs in that part of the feather to be very weak, such that quickly abrade, giving the feathers a strange appearance.
Juvenile Honey Buzzard showing fault bars, Batumi 2012. Photo by Aki Aintila.
Juvenile Honey Buzzard, Batumi 2012. Photo by Maël Sinoir.
Plumage description
The wing flight-feathers show various moult progress. Primaries show freshly moulted P1-5 and growing P6, while P7-10 are juvenile type. The juvenile outer fingers show a sharp contrast between dark fingers and white basis of the feather, which is a good tip to separate juveniles from tricky juvenile-like females. The pattern of newly moulted primaries suggest that the bird is a female. These feathers show a dark trailing edge combined with 3 rather broad bars spread across the feather, the outermost bar being close to the dark tip of the feather.
Secondaries are mostly of juvenile type, except the outermost of the right wing and the 2 outermost of the left wing which are freshly moulted. The juvenile type secondaries are typical of young Honey Buzzards, showing a bulging shape, being dark and showing 3 evenly spaced broad bars, lacking the dark trailing edge that most adults show.
The tail shape is also rather unique, with fresh inner and outer tail-feathers contrasting with pale brown juvenile feathers which are shorter because of abrasion. The new tail-feathers pattern is also in favour of a female bird, with a dark tip less solid than in males combined to 2 brown bars.
The head and upper breast are moulted, contrasting with the light brown belly and underwing coverts where few feathers are fresh, giving a mottled aspect to the bird. The iris was a dull yellowish-ochre and not as clean and bright as an adult and the bill was generally dull grey apart from a hint of pale yellowish at the base.
Let’s hope this record will bring some more attention on immature plumages of Honey Buzzards!
For more information check:
Corso, A, Pannucio, M & N. Agostini. 2012. The status of second-calendar-year Honey-Buzzards in Europe. British Birds 105(8): 484-486.
Forsman, D. 2016. Flight Identification of Raptors of Europe, North Africa and the Middle East. Bloomsbury.
Half-season report
Our 10th Autumn count kicked off at 17th August, with the coordination team and first volunteers arriving to our headquarters in Sakhalvasho a few days before. Even though the days are long, it’s always nice to see how the migration builds up and to see the first records for the season, whether it’s the first Osprey, Roller, or a Steppe Eagle.
The west is under control. Photo by Aki Aintila.
The first days can already be diverse and surprising. This year we were positively surprised by a total of 4 Eleonora’s Falcons! These birds, mostly 2nd cy, were observed between 21st August and 2nd September, all of the dark morph except the 3rd of the pale morph. We had a reason to party after seeing these beauties, since there are only two previous confirmed records of this species from Georgia!
Eleonora's Falcon 2cy. Photo by Bjorn Alards.
Once again, the Honey Buzzard migration started to build up towards the end of August. The first proper day was 22nd Aug with 20.000 Honeys. After that we had bit more modest days, and the migration really kicked off on 27th Aug with 37.000 Honey Buzzards, followed by almost another 37.000 the next day.
Honey Buzzard. Photo by Bjorn Alards.
As expected, the big days were going to hit us at the beginning of September. On the 2nd, we faced another slow morning with low clouds and the odd rain showers. In late afternoon, once another shower had passed and the visibility cleared, we suddenly faced the northern side of Station 1 full of raptors. Honey Buzzards everywhere! More and more birds started to head towards the coastline and streams grew larger and larger. By early afternoon, the sky in distant north was literally covered by buzzards. It was a 5 km wide kettle, a swarm of raptors. That day we had more than 9.000 raptors passing within 20 minutes and by the end of the day we reached a total of 70.000 Honey Buzzards!
Massive migration of Honey Buzzards. Photo by Aki Aintila.
Massive migration of Honey Buzzards. Photo by Aki Aintila.
More epic days followed, as we counted over 69.000 Honeys on the 3rd, 48.000 on the 5th and 66.000 on the 6th. Massive streams, shifting from overhead to the east, again to overhead and the west side, seemed to be everlasting from the midday to late afternoon. Even though some of us has witnessed this many times before, it never stops to amaze us.
Station 1. Photo by Aki Aintila.
The harriers came along with the Honey Buzzards. 2nd Sept was a good warm-up with 169 Montagu’s and 87 Marsh Harriers. Then, 5th of Sept, we got a nice late afternoon passage for harriers, constantly picking Montagu’s and Marsh Harriers from the HB stream. Then we knew that the next day was going to be good, if the weather stays clear. And so, the next morning the harrier show started immediately, and between 8 and 9 we had continuous streams of harriers over our stations! For the late afternoon, the harriers slowed down a bit, but then had another rush in late afternoon with the Honey Buzzards. We managed to positively identify, age and sex a good proportion of harriers, and daily totals from Station 1 include 458 Montagu’s, 25 Pallid, 278 Montagu’s/Pallid/Hen and 204 Marsh, a total of 965 harriers!
Marsh Harrier. Photo by Aki Aintila.
Montagu's Harrier. Photo by Bjorn Alards.
Pallid Harrier. Photo by Aki Aintila.
Roller migration has been rather low this season, as only 765 birds have been counted compare to the average years situated around 1.100 individuals. European Turtle Doves migration has as always been very entertaining. Small compact groups of fast-flying doves rushing at low heights around the count station can be quite challenging to count. Peak-day was 786 individuals the 31st of August for a season total almost reaching 1800 birds. Some lucky counters could observe during this peak day an Oriental Turtle Dove nicely sticking out of a European Turtle Doves flock. It is the second record for the BRC after a bird seen in very similar conditions on the 23rd of September 2016.
European Turtle Doves. Photo by Aki Aintila.
Some Large Eagles migrated early in the season again. Few adults Steppe Eagles were observed during the first weeks of the count along with some immatures, while first Greater Spotted and Eastern Imperial Eagles showed up in September.
It seems to be a rather low season for Crested Honey Buzzards, with 7 birds recorded so far plus some hybrids. This stunning male flew close to observers, showing a global European HB wing plumage, but the reddish iris, tail pattern and large hand with a long 6th finger suggest a hybrid bird.
Possible Hybrid Pernis. Photo by Aki Aintila.
Birding in the Chorokhi Delta has been a real pleasure this year. It is the very first year that shooting is banned in this major stopover site for birds. With a cloudy August, the place has been packed with passerines, with a Red-backed or Lesser Grey Shrike sitting on top of every bush, accompanied by hundreds of wagtails and wheatears. Little Crakes and Purple Swamphens have been occupying the fish ponds, and people who had the effort to scan wader flocks were rewarded with Broad-billed Sandpipers. And even on sunny days, there’s always something to see, especially the terns, gulls and shearwaters by the seaside.
The true gem of the beginning was found at 26th August, when a group for the team found an Egyptian Nightjar close to the shoreline! The bird was first flushed by a shepherd’s dog, then flying around the observers and giving close views. Another team managed to find it the following day – what a gift for the 10th count of BRC and congratulations to Jonas Schärer, Xu Shi and Jaime Escobar Toledo for this stunning bird!
Egyptian Nightjar. Photo by Simon Cavaillès.
We would like to thank our count coordinators (Hélène from France, Xu from China and Aki from Finland), volunteer counters (so far 24 volunteers from Netherlands, Estonia, Belgium, France, Spain, Germany, England, Switzerland - and Kenya!), organizers (Simon, Dries and Rafa) and all our supporters for all the efforts and making this season possible. Now we are heading towards the most diverse period of the season, and we’re preparing for the peak migrations of Black Kites, Booted Eagles, first good days for large eagles and observing up to 20 different species of raptors in a single day! Stay tuned!
Half a Million
Today added another 75.000 to the tally. Our volunteers have been counting for exactly 3 weeks now, and have reached a season total of 498.928 raptors! Almost half a million, right? Six more weeks to go, bring it!
The show started with harriers, between 7 and 8 o'clock a constant stream of Montagu's and Marsh over the station with many enjoyable Pallids. Also again a nice passage for Honey Buzzards with gigantic streams moving all around or spreading over the sky. Also and more Black Kites in the streams. Among these, today's highlights include 4 dark morph Marsh Harriers, adult Steppe Eagle and an adult Peregrine low overhead. Again, we want to dedicate this day to our friends who returned to home - this one is for Yves Dubois, Emmanuel Roy and Jonas Schärer thank you very much and see you again!
Steady stream of Honey Buzzards overhead. Photo by John Wright.