First sign of jungle animal’s pad (6)
I believe the answer is:
jotter
'pad' is the definition.
(I have seen 'Scribble pad' mean 'jotter' so perhaps 'pad' could also mean 'jotter')
'first sign of jungle animal's' is the wordplay.
'first sign of' says to take the initial letters.
'animal' becomes 'otter' (I've seen this before).
The initial letter of 'jungle' is 'j'.
'j'+'otter'='JOTTER'
(Other definitions for jotter that I've seen before include "Note pad" , "Scribble pad" , "Writing book for rough notes" , "Notepad" , "Small notebook" .)