Possible Clues:

• They may be heightened
• Picks up some grouse's nests on the way back
• Perceives by sight and hearing
• Taste et al.
• Vision and scent, e.g.
• They can be overloaded
• Picker-uppers?
• Hearing and sight
• We have five, though some claim six
• Said to be only five of them if you count the people, by the sound of it