I have spent a lot of time photographing Humpback Whales in the Pacific. I have seen some behaviours on which I would like some more information. Is a vertical stance by a humpback able to provide it with increased acoustic reception? (Some recent photos showing examples can be found among the web pages here: http://www.marinethemes.com/Tonga2006/index.html) I have photographed females that hang motionless in a head down position and generally (though not always) I have photographed singing males in a vertical or near vertical (head down) position. I assume that to some degree a vertical downward facing position would enable a male to bounce sound off the sea bed which could partially explain the usual singing position. Would a vertical position give an advantage when receiving sound? Spyhopping: Tourists are usually told that when a whale "spyhops" or raises it's head above the surface in a vertical or near vertical position, it is looking at the boat or other whales or in some way satisfying it's curiosity visually. However, I have rarely seen spyhops where the eye of a humpback is above the surface, as the eyes are situated well back from the snout. Almost all spyhops are done with 1/4 to 3/4 of the snout above the water (and sometimes less) so an above water visual check hardly seems to be an adequate explanation for this behaviour. Also, since a large part of the suspended planktonic animal/plant life is found in the top meter of sea water, it would be logical to think that it would be easier and more visually satisfying for a whale to be well below the denser and usually rough surface. I know that crocodiles have sensory pits around the mouth similar to the Ampullae of Lorenzini found in sharks, that are able to pick up surface vibrations which is why they may raise their snout to place these sensory pits on the water/air interface. Would a spyhopping whale be placing their jaw in the water/air interface to better pick up vibrations? Would a vertical humpback be using it's jaw or skeletal bones to detect or enhance sound waves travelling through the water? Any informed comments or references to articles would be much appreciated. With thanks, Kelvin Aitken.