The last few days have been busy – we now have 5 females equipped with heart rate monitors; Norna, Sally, Jolie, Helga and Treble. All are doing well and caring for their pups. Looking after a pup on a crowded colony isn’t simply a case of providing the pup with adequate milk – the mothers have to make sure their pups do not wander off, make sure that neighbouring mothers don’t bite the pup, and make sure that any adult males don’t charge past and accidentally crush the pup. All this requires the mother to be pretty vigilant. But, from our previous studies, we know that some mums are more ‘watchful’ than others – the mums seem to have individually differing behavioural types, where some regularly check on their pups, whilst others do so very infrequently. Our work last year, and continuing this year, is to uncover the physiological basis of these differences in behaviour (or ‘personality’ if you like), through monitoring individual differences in heart rates.
Perhaps the most time consuming part of this work is the behavioural observations – essential to find out what the mothers actually do. Amy and Hayley have been busy watching our seals from dawn till dusk, collecting behavioural observations and video footage on all of our tagged mothers. This behavioural information will be used to assess how attentive the different mothers are of their pups, and to measure how much time each mothers spends in other activities, such as aggression with neighbours.
We will also be able to use these behavioural data to compare against the heart rate traces, to examine how heart rate changes with different behaviours, such as aggression with neighbours, and to get an indication of how stressful the breeding season is for these seals. What is more, we hope our behavioural and heart rate data will show us how each of these mothers differ in their ability to cope with the stress of a typical breeding season.