Several years ago they successfully identified the colours of its wing feathers, and now they've discovered a new type of contour feather that would have covered most of its body.
|
|
The data on grey morphs having the aforementioned advantages is also supported in Italian data.Koskenpato, K., Ahola, K., Karstinen, T., & Karell, P. (2016). Is the denser contour feather structure in pale grey than in pheomelanic brown tawny owls Strix aluco an adaptation to cold environments? Journal of Avian Biology, 47(1), 1-6.
|
|
This resulting feather is one with a tuft of branched barbs without a rachis. At stage IV, differentiated distal and proximal barbules produce a closed, pennaceous vane (a contour feather). A closed vane develops when pennulae on the distal barbules form a hooked shape to attach to the simpler proximal barbules of the adjacent barb. Stage V developmental novelties gave rise to additional structural diversity in the closed pennaceous feather.
|
|
5, Kilda-Verlag, Greven. Lead levels were difficult to estimate in Spanish owls due to the large number of feathers needed to estimate them, while dead Spanish owls had middling, variable levels of mercury concentrations.Debén, S., Fernández, J. Á., Aboal, J. R., & Carballeira, A. (2012). Evaluation of different contour feather types for biomonitoring lead exposure in Northern goshawk (Accipiter gentilis) and tawny owl (Strix aluco). Ecotoxicology and environmental safety, 85, 115-119.
|
|
In some cases there are differences in the UV reflectivity of feathers across sexes even though no differences in color are noted in the visible range. The wing feathers of male club-winged manakins Machaeropterus deliciosus have special structures that are used to produce sounds by stridulation. A contour feather from a Guinea fowl Some birds have a supply of powder down feathers which grow continuously, with small particles regularly breaking off from the ends of the barbules. These particles produce a powder that sifts through the feathers on the bird's body and acts as a waterproofing agent and a feather conditioner.
|
|
The body plumage of Archaeopteryx is less well documented and has only been properly researched in the well-preserved Berlin specimen. Thus, as more than one species seems to be involved, the research into the Berlin specimen's feathers does not necessarily hold true for the rest of the species of Archaeopteryx. In the Berlin specimen, there are "trousers" of well-developed feathers on the legs; some of these feathers seem to have a basic contour feather structure, but are somewhat decomposed (they lack barbicels as in ratites). In part they are firm and thus capable of supporting flight.
|
|
Parts of a feather: Feather structure of a blue-and-yellow macaw Anterior region of a contour feather from a rock pigeon, visualized using scanning electron microscopy. Interlocking barbules are clearly seen in the middle image. Feathers are among the most complex integumentary appendages found in vertebrates and are formed in tiny follicles in the epidermis, or outer skin layer, that produce keratin proteins. The β-keratins in feathers, beaks and claws — and the claws, scales and shells of reptiles — are composed of protein strands hydrogen-bonded into β-pleated sheets, which are then further twisted and crosslinked by disulfide bridges into structures even tougher than the α-keratins of mammalian hair, horns and hooves.
|
|