Yes, I thought it sounded rather other wordly as well, if it happens early morning it suggests that this is the call of the early riser, maybe like blackbirds, you know, chirruping as they are up before the rest of the world is? Will try and do some research to find out more, maybe it is the call to summon up the other g uineas high up in the Andes for breakfast?!
Kritiq have loads of pics of guineas on camera ( leads very helpfully packed in a box as yet undiscovered, so once I find them may be able to upload, also videos and pics on my phone, again have no extension leads so I could TEXT them to you!!! I really am such a technophobe) - Lizi was my favourite girl out of them all, she was such a sweetie. My daughter taught her to stair climb, and she was so responsive, intuitive etc, and was 'always there' - whenever I looked for her, she would be sitting waiting........ we had a spooky kind of connection, and I would dance with her, take her out and about etc etc, <beginning to sound rather sad> miss her so much. You are right about the collie resemblance, we have always had border collies from being young, and there is something so gorgeous about their markings.