Behavioural plasticity and population connectivity: Contributors to the establishment of new pinniped breeding colonies

Abstract

Abstract Understanding the ecological and evolutionary processes that occur during range shift or (re‐)colonization is of critical importance for species whose ranges are changing due to human‐induced climate change or species such as New Zealand sea lions where their established colonies are significantly declining due to human impacts. The mechanisms underlying colonization are poorly understood. Observations are required to determine the processes that change individual's behaviour associated with colonization, but such observations are rare. Here, the establishment of a new breeding colony of New Zealand sea lions, Phocarctos hookeri, as they recolonized mainland New Zealand, an area from which they had been absent for ~200 years was investigated. There are differences in breeding location behaviour and population connectivity between established and establishing colonies of New Zealand sea lions. The recolonizing population is more dispersed with breeding locations that change annually and have more connections with other populations compared with established colonies and populations. The establishment of a new colony and the greater numbers of resightings between colonies means that for species' management, considerably more public education, habitat management, and protection is needed to ensure the safe return of New Zealand sea lions back on to mainland New Zealand.