Individual differences in maternal behaviour in the grey seal (Halichoerus grypus) and the impact of disturbance at Donna Nook.

Abstract

The grey seal (Halichoerus grypus) is a semi-aquatic pinniped and a member of the family phocidae. On shore breeding colonies form around the UK during the autumn, on which female grey seals rear a single pup for up to 3 weeks. This study aimed to identify the presence, if any, of consistent individual differences (CIDs) in maternal behaviour of grey seals on the breeding colony at Donna Nook. Data collection was non-intrusive, using in-field focal videos, pup-check counts and proximity maps. In agreement with previous research on North Rona, results from the current study show CIDs in pup-check behaviour at Donna Nook. CIDs were present in time mothers spent interacting with their pup and time spent nursing. These findings provide preliminary evidence for the existence of grey seal personalities, or more specifically, mothering styles. There was no evidence that pup gender influenced maternal behavioural investment. There was evidence for habituation to human disturbance; females exposed to the public showed a lower duration of alert behaviour and no difference in duration of pup interaction compared to the restricted site. This habituation was no longer evident following exposure to sudden disturbance (in this case, an unforeseen tidal storm surge). A colony wide increase in pup-check duration and decrease in colony density was observed in the weeks following the storm surge. The results of this study highlight the scope for future research into the stability of these CIDs over numerous breeding seasons and effects of these differences on pup development. Perhaps most importantly, this study provides the first photographic identification catalogue for females at Donna Nook, an excellent basis for future research.