We’re over half way through the field season now and have already recovered all 16 of our first set of deployed heart rate tags and accelerometers. That’s because the mothers are nearing the stage of weaning their pups. The pups are born around 19kg, but after 18 to 20 days of feeding on the fat rich milk of their mothers, the pups can weigh anywhere between about 40 and 70kg!
Several of our mums have already left their pups to fend for themselves as the mums head off back to sea to feed up again – ready for next year! But, towards the end of their lactation period, around day 16, the mothers come into oestrus, and that’s when the males get interested, competing for the chance to sire next year’s pups.
This means that the males are much more in evidence now. There are of course the dominant, resident males who hold loose territories (for want of a more descriptive term) amongst the groups of females, and seek to fend off other males. But, elsewhere, there are many more subordinate males slinking around the periphery of the colony trying to find one or a few isolated females on the edge of the breeding grounds. These males are quite mobile and pop up pretty much anywhere on the island – as at Zoe’s hide (see Zoe’s last blog!). It all adds to the entertainment when sitting huddled in a wee dell on the island; trying to do your video observations on the females, whilst sheltering from the wind and rain, and all of a sudden a male appears right behind you! Especially in the weather we’ve had of late, since Monday we’ve had rain, or gales, or rain and gales, all making the task of observing the seals a little more challenging!