Caprimulgus europaeus - Autumn

AGE – BEST CRITERIA:

1cy birds show a fresh and uniform plumage where most wing feathers (e.g. alula, PC and SS) are pale tipped or fringed buffish. 2cy+ birds shows a rather worn plumage and most wing feathers lack the pale tips. Most adult birds are not possible to age further than 2cy+ due to the complete pre-breeding moult. However, quite a few individuals arrest their pre-breeding moult before completion and the post-breeding moult is rather limited (and does usually not include any wing feathers). Hence, feathers retained in the pre-breeding moult (often found in alula or SS) are still useful during autumn as they usually can be assigned to either juvenile or adult type, and thereby gives the possibility to separate some 2cy and 3cy+ birds.

Note that remiges within the same generation in some birds may appear rather different in colour tones, wear and length (e.g. the inner PP may appear browner and more worn than the outer PP, or single SS may be slightly longer/shorter than adjecent feathers) and this should not be inferred as a moult limit.

1cy:

Whole wing is fresh and uniform. Body sometimes appearing rather downy.
Most wing-feathers, and most obvious the alula, PC and SS, show pale buffis tips or fringes.
Tail shows rounded but not flat-ended RR with variably buff tips, as in wing.
Do not show any white markings on wing and tail (as seen in adult males).

2cy+:

Wing rather worn.
Most feathers in alula, PC, PP and SS show dark (brownish to dark grey-brown) tips.
Uniformly pre-breeding alula and SS with no moult contrast within these feather groups.
RR are broad and appear flat-ended.
Males show white markings on wing and tail.
Some may show single retained (bleached and worn) LC, MC or GC, but these feathers are difficult to specify as being of juvenile or adult type.

2cy:

As 2cy+ but show at least one retained alula or SS of juvenile type.

3cy+:

As 2cy+ but show at least one retained alula or SS of adult type.

Note that several of the below photos are from spring. These have been included here since the post-breeding moult is rather restricted and does not prevent the same characters being used during autumn as well.

1cy September. Note fresh and pale-tipped AL feathers and PC. [4632304]

1cy August, showing variation in the pattern of PC and AL. [4610217]

2cy+ May (male). Most birds, like this one, perform a complete pre-breeding moult and can not be aged further than 2cy+. Note that AL and PC are uniform pre-breeding (more or less identical in pattern, wear and ground colour) and show an adult pattern lacking pale tips. [4610730]

2cy+ May (male), showing variation in the pattern and wear of the pre-breeding AL and PC. [4610125]

2cy May (female). Some birds arrested their pre-breeding moult during winter and show two generations of wing feathers. Such birds can often be specified to either 2cy or 3cy+. This individual shows two generations of AL feathers. The inner two are pre-breeding (fresh with a dark brownish-black ground colour and a dark grey tip) while the outermost is much bleached and worn, which normally is the case with juvenile feathers after the first winter. Further, the pale fringe in the tip is visible and the feather shows a typically juvenile loose texture. [4610124]

2cy June (male). Another example of a bird that is possible to specify as 2cy. The AL feathers contains two different generations where the two outer feathers are juvenile (bleached, rather frayed, loose texture and the pale fringes are clearly visible). The innermost pre-breeding feather is fresh and dense in texture and show a dark brown-black ground colour. Note that the worn MC and GC still are difficult to discern from the newly moulted feathers. [4586328]

3cy+ May (male). Birds showing an arrested pre-breeding moult, where the retained feathers are of adult type, are possible to age as 3cy+. Note here that the AL contain two generations of feathers where the outermost is fresh with a dark brownish-black ground colour and a dark grey tip. The inner two (more than one year old) are pale medium-brown and show rather frayed tips. They are however similar in pattern and texture to the outermost feather and, more important, lack pale buff fringes. Note also one retained GC being much bleach and worn with rather similar pattern as the adjacent GC. [4611689]

3cy+ May (female). AL feathers of two generations where the outermost (retained) one is of adult type - pale medium-brown in ground colour, lacking pale buff fringe and somewhat worn and bleached at tip. The inner two are fresh with a dark brownish-black ground colour and dark grey tips, but still similar in pattern and texture to the retained outermost feather. Note also one retained LC and at least 2 GC being much bleached and worn. [4586319]

1cy September. Note the very fresh wing where most SS show pale tips. These pale tips may to a varying degree be intermixed with greyish vermiculation. [4632312]

1cy August, showing variation in wear and pattern of the juvenile SS. [4610217]

2cy+ May (male). Adult type SS with dark and rather worn tips. Birds that performed a complete pre-breeding moult (showing only one generation of feathers in the wing) are not possible to age further than 2cy+. Note that adult birds regularly show SS (of same generation) that differ somewhat in length and pattern. [4586311]

2cy+ May (male), showing variation in wear and pattern of the adult type SS. [4610730]

2cy June (male). A bird that arrested the pre-breeding moult, showing retained SS that allows a better specified ageing. Retained SS are of juvenile type, and usually stands out as being bleached and rather worn (even though inner SS are among the more protected feathers of the wing). Tips of juvenile SS are usually pale but may have worn off. Note that the general pattern of the juvenile SS does not necessarily have to differ much from adjacent moulted SS of adult type. [4586328]

2cy May (female), showing variation. Like the bird to the left, the retained SS are of juvenile type which proves the bird as a 2cy. [4586316]

3cy+ May (male). As in 2cy birds, retained feathers (paler and more worn) are found among the central SS. In 3cy+ howerer, these retained SS are of adult type. In this bird, the pattern is not identical with the adjacent feathers, but more important the tip is adult like dark, and not prominently pale as found on juvenile SS. [4586317]

3cy+ May (male). Another arrested pre-breeding moult with retained SS of adult type. The retained feathers are rather bleached and worn, but still show broad dark grey tips and similar structure and pattern as the adjacent moulted SS. [4586312]

Caprimulgus europaeus - autumn