Hook Avoidance Induced by Private and Social Learning in Common Carp

Abstract It is essential for fish to respond appropriately when faced with a threatening situation. Accordingly, fish are able to reduce predation risk through learning. In addition to privately learned experiences, fish can acquire social information about a threat by observing the response of conspecifics and use such public information to adapt future behavior through learning. It is unclear if social learning can also influence the behavioral response of fish when faced with human‐induced threats in the form of angling. Using an experimental approach in the laboratory, we examined the influence of private (i.e., direct experience of hooking) and social information on angling vulnerability in Common Carp Cyprinus carpio —a species regularly exposed to catch‐and‐release angling. Compared with control groups, individuals with direct or social experience of catch‐and‐release angling expressed significantly elevated hook avoidance behavior during a short‐term vulnerability assessment hours after a catch‐and‐release experience. In the medium‐term vulnerability assessment, conducted within days after the threat event, fish with direct hooking experience continued to exhibit decreased angling vulnerability, whereas the social experience of catch and release did not consistently reduce angling vulnerability compared with controls. Yet, in a subsequent trial within days after the threat exposure, we found that fish with direct hooking experience and fish with only social hooking experience were both more cautious towards bait (corn) in the presence of a sham rig (i.e., a hookless rig with bait) than when only exposed to bait without a rig. Collectively, these results indicated that the combined influence of direct and social experience of catch‐and‐release angling induced a hook avoidance behavior in Common Carp. The extent to which the phenomenon of social hook avoidance learning exists in other recreationally targeted fish species and in the wild deserves further attention because of the potential to affect catch rates and population‐level catchability.