Turdus pilaris - autumn

Fieldfare / Björktrast

AGE - BEST CRITERIA:

In 1cy, a moult contrast is present in GC, most often in the central part of the arm. Adult birds show a uniform and freshly moulted plumage.
 
1cy: 
  • Most birds include 3-7 inner GC in the post-juvenile moult. The inner post-juvenile coverts are often slightly longer, more fresh and dense, in contrast to outer, shorter, slightly more worn juvenile coverts that also show a less colorful pattern and often a thin pale (brownish-)grey or whitish edge and tip.
  • Juvenile RR are generally slightly more worn, narrow and more pointed, but difficult birds are sometimes seen. The structure is often helpful, with the juvenile feathers being slightly less dense, less glossy and somewhat paler brownish. A few birds may include R1 in the post-juvenile moult, showing two generations of RR.
  • Juvenile PC are often slightly more brownish, narrower, less dense and more loose/frayed than in adult.
  • Most birds show uniformly juvenile tertials, but some have included single (or rarely all three) feathers. The pattern of the juvenile and post-juvenile generations are rather similar, but generally somewhat more colorful in the latter. The general structure and state of wear gives further help in the assessment.

2cy+:
  • Whole plumage fresh, lacking moult contrasts.
  • GC, PC and tertials are dense, fresh and colourful.
  • RR are generally slightly broader, more blunt tipped and often in better condition.
1cy November (male). GC1-3 are unmoulted juvenile (shorter, less dense, less colourful and with pale brownish-grey edges and tips) in contrast to post-juvenile GC4-9 (slightly longer, more fresh/dense, more colorful and lacking the pale grey edges and tips). [4632757]
1cy November (female), showing variation with GC1-6 juvenile in contrast to inner post-juvenile GC7-10. [4632843]
2cy+ November (male). Fresh adult wing showing uniform, broad and rather dense GC and lack of any moult contrasts. [4632756]
2cy+ November (female), showing variation of the adult wing. [4632758]
1cy November (male). Juvenile RR are generally slightly more narrow and more pointed than in adult, but there is a variation in shape and difficult birds are sometimes seen. The structure is often helpful: less dense, less glossy and somewhat paler brownish than post-juvenile (or post-breeding) feathers. [4632761]
1cy June. Most birds include no RR in the moult, but a few may show a single RR (often R1). This bird shows a dominantly juvenile tail but with left R3 and right R1-2 post-juvenile (and growing). This is rather exceptional and is likey caused by accidental loss of feathers rather than true moult. Note also the still juvenile upper-tail coverts. [4611701]
2cy+ November (male). Adult RR are generally slightly broader, more blunt tipped and often in better condition. [4632756]
2cy+ October (female), showing variation. [4609547]
1cy November (male). Juvenile PC are often slightly narrower, less dense and a slightly browner (less cold grey) hue. [4632757]
1cy November (female), showing variation. [4632760]
2cy+ November (male). Adult PC are slightly more dense, fresh and often a bit broader and somewhat colder grey. [4632756]
2cy+ November (female), showing variation. [4632758]
1cy November (male). Most 1cy, like this one, do not include tertials in the post-juvenile moult. Note the rather narrow, slightly worn and less colorful feathers compared to the adult ones below. [4632757]
1cy November (male), showing variation in the uniformly juvenile tertials. [4632783]
2cy+ November (male). Adult tertials are generally slightly broader, more colorful and less worn. [4632756]
2cy+ October (female), showing variation of adult tertials. [4609547]
More Turdus pilaris:
Sexing autumn and spring
Ageing spring

Moult
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