thanks for your lovely comments

I've had a good look at the vases with children on and it's true that the way this vase is enamelled, along with the detail in it and the size of the picture which extends almost right around the vase, is a different quality I think.
I've attached a couple more pictures that should show the sheen on the enamel as the previous ones made it look very matt. It should be possible to see how the layers are created one by one with different detail on the picture.
Paul you're possibly right that it depicts a crane. I'm going to investigate habitat a little more and see if we can pin it to one or the other.
I've attached a link to some information on Japonisme from the Met Museum
http://www.metmuseum.org/toah/hd/jpon/hd_jpon.htmIt states within that information - 'After Japanese ports reopened to trade with the West in 1853, a tidal wave of foreign imports flooded European shores.' and 'Parisians saw their first formal exhibition of Japanese arts and crafts when Japan took a pavilion at the World's Fair of 1867. But already, shiploads of oriental bric-a-brac—including fans, kimonos, lacquers, bronzes, and silks—had begun pouring into England and France. '
I would imagine that information and style had filtered back very quickly Europe wide and it fits in with the dates given of 1860s-1870s.
With regards to whether this can be described as opaline glass, the answer is I don't know. It isn't the same as my mid 19thc white opaline glass that I believe is French. Neither is it as translucent as some green opaline I've had or still have both mid 19thc I believe. Nor is it exactly the same as a 19th century turquoisey blue opaline scent bottle I owned. All were more sheeny, not as densely coloured as this glass. Perhaps it might be called blue opaque glass? but you can see through it when you hold it to the light, I can see my fingers and the reverse of the bird and the decoration, so it's not opaque and is translucent. I still think it is 'opaline' glass.
There's a picture here of a vase sold by Alexia Amato that appears to be a similar type of glass
http://alexiaamatoantiques.com/sold5.asp?stock=O7I'll report back on the bird or if I find anything more

Thank you again for your help. I'm enjoying this vase a lot!
m