why is it orange? I have been attempting to delve deeper into crossbill colouration:
Ref 1
Season-, sex-, and age-specific accumulation of plasma carotenoid pigments in free-ranging white-winged crossbills Loxia leucoptera
Abstract:
Many birds acquire carotenoid pigments from foods and deposit these pigments into feathers and bare-parts to become sexually attractive, but little work has been done on the interindividual and temporal variability in the types and amounts of carotenoids that free-ranging individuals have available for use in coloration or other functions (e.g., in immunomodulation). To address this issue, we studied intra-annual variation in plasma carotenoid profiles of juvenile and adult white-winged crossbills Loxia leucoptera of both sexes. Adult male crossbills exhibit bright red carotenoid-based plumage pigmentation, whereas females uniformly display drab yellow feather coloration and juvenile males only occasionally display some orange or pink color. Yellow xanthophylls (e.g., lutein, zeaxanthin) were predominant in plasma of birds from both sexes and age classes throughout the year. Plasma xanthophylls levels tended to be highest in the summer, when crossbills increase seed consumption for breeding as well as supplement their diet with insects. Blood accumulation of three other, less common plasma carotenoids, cryptoxanthin, rubixanthin, and gazaniaxanthin-varied in a highly season-, sex-, and age-dependent fashion. These carotenoids were virtually absent in juvenile or adult female plasma at all times of year and were only present in male plasma, at higher concentrations in adults than juveniles, during the period of feather growth (Sept.–Nov.). These pigments have been reported as valuable precursors of the metabolically derived red pigments (e.g., 3-hydroxy-echinenone, 4-oxo-rubixanthin, and 4-oxo-gazaniaxanthin, respectively) that appear in the plumage of male crossbills. These findings suggest that male crossbills either adopt a season-specific foraging strategy to acquire foods rich in these pigments at the time they are needed to develop red coloration, or have a unique physiological ability to metabolically produce these pigments or absorb them from food during molt, in order to maximize color production.
this is the text from BWPi
Adult Male
Moults: mainly September–December (complete). Head, back, rump, and underparts to end of flanks and belly mainly brilliant cerise-pink, more uniform in tone than L. curvirostra but at close range showing (a) dusky lores, cheeks, and ear-coverts, (b) dusky-grey cast on mantle and round shoulder, (c) blackish marks on scapulars, (d) dusky-black upper flanks, and (e) black upper tail-coverts tipped pink-white. In flight, pink appears brightest on rump. Wings basically black, strongly patterned with (a) white forewing-panel, formed by pinkish to white tips to lesser coverts and virtually white median coverts, (b) broad white wing-bar, formed by pinkish-white distal halves to inner feathers and broad tips to rest (and thus narrowing towards primary coverts), (c) striking white tips and pink-white fringes to tertials and innermost secondaries, and (d) duller, apparently pale grey tips and fringes to other flight-feathers. Underwing off-white. Tail black, with white fringes. Belly, vent, and under tail-coverts white, under tail-coverts streaked brown-black. With wear, pink plumage becomes almost carmine and all pale tips and fringes reduce in size or are lost. Bird thus looks even more immaculate, with virtually black scapulars making wings seem larger and wing markings reduced to narrower panel and bar on coverts and isolated white tips on tertials. Bill noticeably more slender than in L. curvirostra, looking less crossed due to elongation of less curved points of mandibles; dark horn above, pale horn below. Eye dark brown, seemingly set nearer bill than in L. curvirostra. Legs blackish-brown.
Adult Female
Head, back, and underparts to end of flanks and belly basically greenish-brown, with quite heavy brown-black streaks emphasized by cleaner fringes than in L.e.curvirostra. Lower back, rump, and all but longest upper tail-coverts quite bright greenish-yellow, with faint dusky marks; area noticeably paler than dull yellowish-olive rump of fem L. curvirostra. Rear underparts dusky-white, sharply spotted brown-black on under tail-coverts. Longest upper tail-coverts, wings, and tail as male, but ground-colour less fully black, while white tips and fringes tinged yellow, not pink.
Juvenile
Resembles fem but ground-colour of head and body noticeably buff-brown, with sharper streaks above than in L. curvirostra and whiter centre to breast and underbody, with as many spots as streaks. Wings dusky-black, with forewing panel almost as large as adult but wing-bar distinctly narrower; both marks more discrete than exceptional diffuse whitish marks shown by a few L. curvirostra.
First-year
Male has mixture of adult and juvenile colours, showing pale crimson, brown, and yellow fringes and dark feather-centres on head and body, these largest on back which appears noticeably dark. White wing markings retain yellow (not pink) cast.
Clearly the above does not fit with the Broughton bird or several others found on the web in images; but is the orange plumage a feature of a first-summer male or could it occur in adult males?
Song notes from BWPi are just about spot on -- I heard the redpoll like calls but at first assumed they were from a nearby redpoll and did not attribute them to the two-barred
Song better-developed and more musical than L. curvirostra: long, rich, varied tremolos and trills recalling domesticated Canary Serinus canaria, Redpoll Carduelis flammea, and Siskin Carduelis spinus. Calls (perched and in flight) often disyllabic like L. curvirostra but distinctly higher pitched, drier, and less metallic. 3 main types: 'kip-kip' or 'tyip tyip'; 'chut-chut' suggesting C. flammea; remarkable sound like toy trumpet.
Food section from BWPi does not mention Scots Pine but the Broughton bird fed regularly on this species last weekend at least; feeding methods suggested below as same in all 3 crossbill sp but subtle differences obvious between Parrot, cutting off cones and carrying away to hold in feet and break open, Common mix of above and maibly feeding on cones in situ and 2 barred always seemingly acrobatic in hanging onto cones to extract seeds
Food
Conifer seeds, principally of larch Larix and spruce Picea; some invertebrates in breeding season. Larch is main food in some parts of range (e.g. eastern Russia: Dementiev and Gladkov 1954; Danilov et al. 1984), spruce in others (e.g. Fenno-Scandia, Murmansk region of north-west Russia: Svärdson 1957; Kokhanov and Gaev 1970; Pulliainen 1971, Pulliainen 1972); differences presumably due to distribution and abundance of these trees. Foraging methods identical to Crossbill L. curvirostra and Parrot Crossbill L. pytyopsittacus when all 3 species watched together in Murmansk region and Finnish Lapland (Kokhanov and Gaev 1970; Pulliainen 1972); for details, see L. curvirostra. Probably more readily hangs on cones to extract seeds, taking them less often to perch than other Loxia (Bannerman 1953a; Bent 1968; Kokhanov and Gaev 1970). For details of handling, bill morphology, efficiency, etc., see Kokhanov and Gaev 1970 and Benkman 1987b, Benkman 1988d, Benkman 1989a. Thinner bill more suitable for extracting seeds from between thin and relatively short cone scales, e.g. larch and spruce (Newton 1967a; Benkman 1987b). Nesting pair in cemetery in Berlin (Germany) often foraged in broad-leaved trees, e.g. fed on seeds of birch Betula, hanging head-down, although conifers available (Fischer et al. 1992). In eastern Siberia, fed in alders Alnus with Redpoll Carduelis flammea, and also picked up seeds from ground and rubbish-tips near houses (Mezhennyi 1979; Morozov 1984), and in Finland fed on spruce seeds lying on branches (Pulliainen 1972). In North America, away from conifers, recorded feeding in alder and birch, taking seeds on sunflower Helianthus plants and on herbs in fields and on roadsides, eating various berries and fruits, as well as insects and larvae, sometimes taken from behind bark; also seen feeding on snails (Gastropoda) on tideline (Bent 1968). In central and eastern USA, in winter, has acquired habit of extracting seeds from fruit of sweetgum Liquidambar tree, using ability to hang upside-down and make powerful use of bill; will also hang from neighbouring twig to pull fruit in with foot; may have learned technique from American Goldfinch Carduelis tristis (George 1968). Caught insects in flight in captivity (Massoth 1989, which see for captive diet). Ate decayed wood from wall of hut, presumably for minerals (Sundin 1988); many accounts of fondness for salt, etc. (Bent 1968). In captive trials, seed-husking time ranged from average 0·9 s per seed for spruce (n = 459) to 8·4 s for one species of pine (n = 337); more efficient than L. curvirostra when foraging in spruce and extracting seeds from open cones, less efficient in pines and in handling closed cones (Benkman 1987b, which see for many details).
Plumages of first-adult and moults from BWPi
None seem quite accurate
First adult
Highly variable, as in 1st adult L. curvirostra. Advanced birds similar to adult, but juvenile flight-feathers, tail, usually all tertials, and often at least outer greater upper wing-coverts retained. In more retarded birds, many juvenile wing-coverts retained, as well as scattered juvenile feathering on body (especially on neck and belly); in male, plumage mixture of red (like adult male), green-yellow (like adult fem), and juvenile. Head and body of advanced 1st adult male orange- or rosy-red, less bright and less deep rosy than in adult male; tertials and feather-bases on body browner, less blackish, bases more exposed, especially on hindneck, scapulars, and side of head and breast; rump bright light pink-red. Head and body of 1st adult fem greyer than in adult fem, less extensively tinged yellow-green or buff-green rather than extensively green-yellow; feather-centres paler, greyer, less contrasting; rump patch narrower, less pure bright lemon-yellow. In 1st adults with inner greater coverts or a few tertials new, some contrast in abrasion and in extent and pattern of white between these and retained juvenile coverts (see Svensson 1992); when coverts and tertials all juvenile, white tips partly wear off, especially white on tertials and outer greater coverts of fem sometimes completely lost. Also, white fringes along tips of tail- and flight-feathers liable to wear off; often no clear white fringe along inner web of t6, in contrast to adult. Shape of tail-feathers not reliable for ageing. For difference from rubrifasciata variant of L. curvirostra, see Recognition (below).
Bare parts
Adult, First Adult, Juvenile
Iris brown or dark brown. Bill dark horn-grey to greyish-black, darkest on culmen and tip of upper mandible; cutting edges paler horn-grey or buff-grey. Leg and foot dark plumbeous-horn to greyish-black. (BMNH, ZMA.)
Moults
Adult Post-breeding
Complete; primaries descendent. Timing erratic, depending on local breeding season; June–November (Pyle et al. 1987); mainly September–November (Svensson 1992). In birds examined, plumage worn in 2 from July (but moult just completed in single bird from captivity then); body strongly abraded but primary moult just started in one from 14 September (primary moult score c. 8 ) and in one from 28 September (primary score 24 ; inner 4 primaries and 2 central pairs of tail-feathers new, outer 4 primaries and 3 pairs of tail-feathers old) ; plumage fresh in 2 from October–November and in 3 birds from December (BMNH, RMNH, ZFMK, ZMA). In Murmansk area (Russia), 2 birds not yet in moult July, but 5 from October all in moult; completed in 4 birds from November (Kokhanov and Gaev 1970). Occasionally, limited pre-breeding moult, March–April (Pyle et al. 1987).
Post-juvenile
Partial: head, body, and lesser as well as some to all median and greater upper wing-coverts; occasionally, a few tertials. Starts shortly after fledging, and timing thus as variable as breeding season. Moult June–November (Pyle et al. 1987). In north-west Russia, less than c. 15% of 35 birds examined September in moult, but 40–100% of samples from October–November (total n = 45) (Rymkevich 1990). In birds examined, plumage of some still largely juvenile in September, in others mainly 1st adult by then (BMNH, RMNH, ZFMK, ZMA).
Broughton bird appears to have replaced all of its greater and median coverts judging by the width of the white tips, and also all its tertials and flight feathers that appear blackish rather than worn and brown toned as they would be if they were juvenile feathers and the tips of the primaries and secondaries also appear fresh and not abraded; the lower scapulars are largely black centred -- the orange colour is mixed with some patches of red and this was quite similar to two of the Broomhead birds but they seemed to show more red and less orange in their body plumage; those birds were considered to be the juveniles that arrived there the previous autumn so it seems logical that the Broughton bird is indeed a first-summer male but one that has undergone a rather more extensive moult than described in BWP
any comments from ringer or crossbill experts alike appreciated
links to photos of Broughton and Broomhead birds
Broughton
http://pewit.blogspot.co.uk/2014/02/two ... lincs.html Broomhead:
http://pewit.blogspot.co.uk/2013/12/two ... bills.html
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