Misidentification of Juvenile Honey-buzzard
Here's some notes on Forsman's text: Misidentification of Juvenile Honey-buzzard at p.302 Separating Common Buzzard and European Honey-buzzard, in: Dick Forsman, Flight Identification of Raptors of Europe, North Africa and the Middle East, Christopher Helm (2016).
The article laments the very limited experience that most European birders have with juvenile Honey-buzzard. “It is the juvenile honey-buzzard, in particular, which remains unknown to many birders and causes a lot of confusion. In fact, this is probably the most often misidentified raptor in the Western Palearctic. The explanation is probably the short period that juvenile European Honey-buzzards are available to European birders. They are visible only for a few weeks each autumn before they leave Europe, not to return again until they are in full adult plumage nearly two years later.”
There is no excuse for not identifying an adult Honey-buzzard but the juvenile needs a different approach: "Adults and juveniles are so different, in shape, proportions and plumage, that they could easily be seen as belonging to different species by the unaware. While the adult Honey-buzzard is a most distinctive bird, with diagnostic shape and plumage, and easily told from Common Buzzard, autumn juvenile honey-buzzards appear much more similar to Common Buzzards, especially from a distance, when plumage details cannot be seen."
Experienced observers note in the juvenile European Honey-buzzard:
flat wings
relaxed and somewhat slower wingbeats
protruding chest
slightly elevated head in active flight
absence of kink in wing in frontal views
pinched in wing-base
more bulging arm
narrower hand
fuller tail in soar
wings pressed forward more in flight in soar
Plumage differences are used by some to clinch identification:
sparser, broader barring of the remiges
paler markings on the greater coverts, not on the median coverts
Bare part differences are also of use:
bill a bright yellow with just a dark tip
dark brown eye lacking a clear dark pupil
Comments by NR:
The quote “While the adult Honey-buzzard is a most distinctive bird, with diagnostic shape and plumage, and easily told from Common Buzzard” does not hold with all British birders. I believe male Honey-buzzard are picked out readily but females, because of their overall duller plumage and heavier build, are confusable by some with Common Buzzard.
There is another challenge not mentioned, that of identifying a juvenile Honey-buzzard that is just fledged, in its breeding area. Because their remiges and tail feathers are still growing, they appear more compact than older juveniles: their proportions are even closer to Common Buzzard. Further the uneven primary growth could be read as primary moult, thus suggesting adult Common Buzzard to the novice. This interesting further complication will be the subject of a new page directly.
There is little doubt that many British birders are unable to identify juvenile Honey-buzzard unless there is plenty of moral support as in the major movements of 2000 and 2008. Counts by NR show that the autumn emigration from Britain extends through the second half of September until early November. Birds on the move are as Forsman describes them, so it is a significant failure of British birders to keep up with the literature and improve their ability in the field. The many 'buzzard' reported on Trektellen moving broadly S in autumn along the spine of England, in NR's view, are the migratory Honey-buzzard rather than the mainly sedentary Common Buzzard within Britain as claimed; ringing returns suggest the Common Buzzard is a very limited migrant within Britain. This will also be the subject of a new page.
The tail bands are not noted as a distinguishing feature between juvenile Honey-buzzard and Common Buzzard. As also found in my studies, the tail bands of the juvenile Honey-buzzard are very variable, often not showing the 3 bands of the adults. Yet how many British record committees appreciate this? Past decisions on juvenile Honey-buzzard may need revision. This is another study underway by NR to determine the frequency of the various tail patterns. A preliminary view is that 4 evenly-spaced tail-bands are fairly frequent. The results will be reported on another new page.
Nick Rossiter 2017