What makes Bluebirds look blue? (1 Viewer)

I'm so sorry to ask this question but I've been reading and reading online over the last few days about what causes birds like blue jays and buntings to be blue and most of what I've read said that it is due to scattering of blue light by modified cells in their feathers, which is known as Tyndell scattering, right?
Upon further research I came across another page that had as the headline
"The Myth of the Tyndell Effect in Blue Bird Feathers" basically what is being suggested in this write up is that the blue color in birds like blue jays, buntings and so forth is due to an interference of light not scattering of blue light here is the link to that article http://www.euronet.nl/users/hnl/tyndall.htm

I'm looking for true facts on the matter as it is a part of research paper I'm doing, what is accepted in peer reviewed scientific journals on the matter of what makes birds like buntings or blue jays blue in color?

Thanks in advance to any help that anyone can help me with.

I've always heard that it was an interference effect, caused by the very specific spacing (at a microscopic level) of bars of melanin in the feathers. I believe that this same effect is responsible for the brilliant greens, reds, and other colours that are apparent in hummingbird's feathers, and in many other groups as well. (One thing I've never been able to grasp is why a hummingbird's plumage goes black when viewed from the wrong angle, but not the Blue Jay's; but that's a whole other question.)

This scattering theory is complete news to me, I've never even seen it mentioned before I saw that paper you linked to.

Thats interesting I had not given it any thought but I was aware in British butterflies green and blue pigments do not exist, it must be the same phenomenon , Structural Colouration