<< Did you mean the blueish part? >>
The 2 / 3 bits actually - the 'sky' right at the top of the image and then the (different coloured) bit above the GH's abdomen, right side of the pic.
I'd assumed the topmost parts were intended as 'sky', but (to me) they seem somewhat incongruous with the overall nature of the pic.
Considering the 'busy-ness' of the image (which I like), to have 3 (relatively small, but high contrast) featureless areas tends to draw the eye to them (or the interface between them and the subject matter) to the detriment (imo) of the overall viewing experience.
If, with a 'normal' pic, the intention is to isolate the subject from the bg, then this often involves fairly large areas of (oof?) bg - eg sky or foliage ... and this generally works well - but the situation here seems different because of the areas involved.
Also, the 'sliver' above the abdomen is *very* sharply defined / cut out ... and again tends to 'draw the eye' and makes me wonder why it's there / what's it for?
As regards the bg in general - some techniques I've used in the past (as well as blurring and changing scale - as you've done) involve the use of desaturation (complete / partial), median, posterize and add noise.
These allow the subject matter and the background to still be graphically 'linked' - but also allows for a series / group / sequence of images to have a common theme - or 'corporate identity' of some sort
Depending on techniques used, then parts of the bg may not be instantly recogniseable - but not making things easy for the viewer - ie getting them to figure stuff out a bit may also be useful sometimes.
(When I saw the 'desaturated bg trick' for the first time (photoshop 3 wow book - p89) ... I thought 'that's got some mileage' (or kms for you

) as a technique.)
Since you're creating (rather than capturing) an image and thus (imo) 'truthfulness / integrity' may be compromised / adjusted for artistic impact I'd suggest 'anything goes' as regards available techniques?
At the end of the day this is very subjective territory
pp