Linaria cannabina - Sex spring

Linnaria cannabina - Sexing spring

Common Linnet

SEXING:

After the post-juv moult, sexing is generally straightforward based on colour and pattern of head, breast, and upperparts. If aged incorrectly, birds in completely juv plumage (with no moult contrasts) may be mistaken for ad females, but ground colour of head and body is warmer buff or brown and body feathers typically loosely textured.

According to Svensson (1992), many birds may be sexed already in juv plumage based on the amount of white in the outer vanes on the inner visible part of the inner PP, bordering tips of PC, but some birds ambiguous:

In males, white on innermost visible 5 mm of outer vanes of PP 7-9 reaches shaft or separated from shaft by a narrow black line (<0,5 mm).
In females, white on innermost visible 5 mm of outer vanes of PP 7-9 separated from shaft by a wider black line (>0,5 mm, generally 1 mm broad), roughly corresponding to half of total width of outer vane.
Some birds, presumably males (Svensson, 1992), are intermediate (black line generally 0,5-0,75 mm), and should be left unsexed.

After post-juvenile moult, the following criteria may be used:

Male:

Breast and forehead raspberry red, sometimes hidden by buff fringes in fresh autumn plumage. Some, typically younger birds, have very little red, more orange, yellowish, or even port-coloured markings, but these are rounded, never streaked.
Flanks warm buff or salmon pink.
Nape light grey, contrasting with deep chestnut, lightly streaked upperparts.

Female:

Head and breast without red, or with faint reddish markings. Breast always, usually conspicuously, streaked dark.
Nape greyish brown, showing weaker contrast towards upperparts than in males.
Feathers of mantle, LC and MC dull rufous or earth-brown, often streaked prominently along shafts.

3cy+ male May. Typical male showing unstreaked red breast and forehead. Exact tone of red may vary substantially. [DE62287]

2cy male May. Some males lack obvious red markings. Example showing golden-yellow breast, note similar pattern and distribution to previous bird, the real difference being the exact colour. Warm markings on forehead subdued but still present. [DA06049]

2cy female June. Typical female showing heavy dark streaking on breast and flanks, with at most very faint red tones adjoining streaks. [DC40185]

2cy female May. A somewhat trickier individual showing weak but obvious reddish tones to breast. Note, however, that all warm markings are adjacent to darks streaks - no feathers are pure red or orange with rounded pattern. When dealing with similar ambiguous birds, always make sure to assess amount of white in inner PP as an extra precaution. [DE62446]

2cy male May. Classic male with red breast and forehead, and warm buff, unstreaked flank. Note strong contrast between grey nape and chestnut back. [DB05198]

3cy+ male April. A bird with only weak red markings on breast and forehead, showing variation. [DB05130]

2cy male July. All red markings replaced by pure yellow, presumably due to diet. Birds like this are not too unusual and should not present trouble sexing. [CP46208]

2cy male April. Some males have virtually no red, either due to lack of pigmentation or caused by colour still hidden beneath pale fringes if feathers still relatively fresh. Note however warm unstreaked tone to breast and flanks, and strong contrast between nape and back. See also amount of white in inner primaries when dealing with similar birds. [DA03883]

2cy female May. Typical female showing streaked breast and forehead. Upperparts also prominently streaked along shafts, though this feature highly variable and generally present to some extent also in males. Nape brownish grey and back duller brown than in males, showing weaker contrast. [DB05196]

2cy female May. Showing variation - bird with slightly greyer head than previous. [DB05199]

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