...oh i see....there are other possible nocturnal predators around, too - dazzlenation....the bird that i had photographed looks a bit like a song thrush....although the song is as complex as a robin....and as loud as a blackbird, at night....hmmm....there's more than one birds' nest, in that tree....there used to be loads of them...anyway, having got onto the nightingale - the bird most commonly heard in the early hours...appears to be a nightingale...because it is quite a 'piercing' sound....see previous post....go figure:

BTO Bird ID - Nightingale and Other Night Singers - YouTube

and then we're back to T. S. Eliot, of course...i remember now...all a bit 'deja vu'....anyway, it is the tree that appears to be under attack...including heaven only knows, how many nests....which are now vulnerable to attack...after the protective leaves of that clinging vine foliage, had been killed off...and so yes, dazzlenation...the whole tree is kicking off, at night - now and then, as far as i am concerned:

and yes, it is the 'liquid bubbling' sound -at night, that really gets to me....because it is so loud - it almost sounds like 'warfare':