Animals dash -- first signs of dry season (6)
I believe the answer is:
elands
'animals' is the definition.
(I've seen this before)
'dash first signs of dry season' is the wordplay.
'dash' becomes 'elan' ('elan' can be a synonym of 'dash'**).
'first signs of' says to take the initial letters.
The first letters of 'dry season' is 'ds'.
'elan'+'ds'='ELANDS'
(Other definitions for elands that I've seen before include "Animals" , "Large African antelopes" , "African antelopes with twisted horns" .)