the most useful identifying call

loud 2-part call of cock
repeated twice

Thanks to Dinah and John
(WFS) for the ID

no editing - the cock emitted this pair of
2-part calls in this time scale

cocks call much more than hens
and much less often when caged as a pair

(cage of 4 unpaired birds)

quiet twitter mixed with very quiet call,
almost like a quiet 'tchee'. 

Once heard you can't mistake the 'tchee'
for another quiet call -
a pip or more normal bird-like twitter

'tchee' answered immediately by the mate
This quiet call hasn't recorded well.

It seems this is a close contact call

More importantly, almost always
emitted between bonded pairs

(from aviary of paired birds)

How to get them to call?

1 - the sound of running water
2 - when turn off the vacuum cleaner after cleaning their cage
3 - when Lavender chicks fledge (bit hard to arrange that one but the birdroom goes mad)
4 - let another Lavender loose to fly around the birdroom (works a treat)

Determining cocks is fairly straightforward - a few minor irritations

Firstly, cocks can be suppressed when in the company of a more dominant cock
Remove the dominant cock and another may well burst into 'song'.  I have direct experience of this.
So, identify a cock bird, remove him and wait a week or so to see if another declares himself

Secondly - there are variations.  Some cocks make it harder by only doing the first of the two part call
(but they will come out of their shell if they are the only cock in the cage)

Thirdly - some cocks seem to be shy/ quiet
(but they will come out of their shell if they are the only cock in the cage)

Fourth - cocks in a settled pair, housed alone, call very infrequently (if at all)

To hear the variation of the cocks' calls go to - 'cock call variation?'