Avoidance of native versus non‐native predator odours by migrating whitebait and juveniles of the common galaxiid, galaxias maculatus

Abstract

Avoidance of predator odours by migrating Galaxias maculatus was studied in the laboratory using a two‐chamber choice tank. The odours of a native predator (short‐finned eel, Anguilla australis) and an introduced predator (rainbow trout, Oncorhynchus mykiss) were tested on both whitebait (i.e., new recruits) and juveniles. Both whitebait and juveniles exhibited avoidance behaviour when exposed to eel odours. There was no avoidance response from either the whitebait or juvenile G. maculatus when exposed to trout odours, which could suggest differences in the ability of G. maculatus to detect native and introduced predators. Observed negative effects of introduced predators on native species may be owing in part to the absence of innate avoidance behaviour in native prey species.

Keywords:

• olfactory cues
• predator avoidance
• introduced species
• choice experiments