Burmese are usually larger, but I have seen all three subspecies and didn't notice Burmese having thicker necks. Often you will see photos of green peacocks with their neck looking big and other times it is skinnier. I think they just puff out the feathers some. When you see all three the major noticeable difference is Burmese are overall duller looking. The green on their neck is more muted in color and overall they are a darker looking bird especially when not in direct sunlight. I don't think they are Burmese they are either Javas, Imerators, or mixed subspecies if they are greens.
Burmese green at Rocking BAB:
Hens
Oh. Okay. Well I've googled Burmese and Javas and I would see some with thick necks and some with really skinny necks so I assumed that was the difference. But your information sounds a lot better and more accurate than my assumption.
