What can best described as grey talcum powder is covering everything inside the nesting burrows. It is effectively dander produced we believe as the chicks transition from their down to feathers and it is getting everywhere including on the inside of the camera cases in front of the lens. This builds up quite quickly so now even though we are able to record for days at a time without intervention the dust builds up quickly on the lens making the video stream look progressively muddy and will require a cleaning it looks like every other day at the stage. Will try bringing compressed air so as to avoid having to take the camera case apart each time.