Looks like we are quickly approaching the half way point to our season! There have been a lot of happenings in our research efforts over the last few weeks, let’s take a minute to give an update on the season.
Just before the weather began to turn today after a cold (for us), but dry few weeks, we tagged our twentieth adult female of the season! We’ve got tagged females across the entirety of the island now and get to experience a nice mix of locations, seals, and various terrain types that tend to change the intraspecific behavioural relationships among different aggregations across the island. While it might not feel like it to most of us in this country, this year has been relatively dry, which means that pools or mud holes are at a premium. For some females, mild and dry weather may mean that they are driven to commute if it gets too ‘hot’ – well, hot for a seal – as demonstrated in previous research efforts by the Twiss Lab.
As part of this year’s accelerometry work, we’ve been doubling up tags on a few of our repeat females from the last few seasons in an effort to better understand the energetics of behaviour during lactation. We’ve also been lucky to get more heart rate monitors out that in previous seasons as part of both Jodie’s MBIOL research as well as Dr. Twiss’ continued work looking into heart rate variability. Rocky has also made his yearly appearance among the colony!
Our earliest females have begun to leave the island after weaning their large, healthy pups – now referred to as weaners – after their 18 day lactation period. Hard to believe that we’ve been out here that long already! While this is the end of our research monitoring period for the females, our colleagues at Abertay University will be looking into how pollutants affect the fasting metabolism and physiology of their weaned pups during the two weeks they spend on the colony before they head off to sea (check out the PHATS team blog for more Kelly Robinson Science blog).
As our tags (accelerometer and heart rate monitors alike) begin to return home, the data is piling up. Jodie and Courtney have been hard at work, in between tagging and retrieval efforts, racking up the focal videos for us to decode over the winter and have logged just shy of 100 videos so far this season. We will be decoding these videos for many of the behaviours that we are featuring in the Behaviour of the Day posts to investigate their daily activity budgets in addition to aiding our research into accelerometry and heart rate variability.
The colony itself has been a-buzz with pups of all stages and their mums as well as large, powerful males defending their territories, jockeying for position on the edges, and copulating the females at the end of lactation that have reached estrus. In addition to seals, the island is a stop-over for many birds migrating for the approaching winter season (check out the CEH long-term bird study for their activities) – including a Long-eared Owl, Lapwings, and Woodcocks! These are wonderful additions to the normal mix of ubiquitous Greater Black-backed Gulls (sometimes a predator to the unattended pups of the island), Shags, chatty Oystercatchers, Wrens, and Short-eared Owls among many more that make you feel a bit like an old school naturalist observing life pass on the May. Jodie and Courtney were also lucky enough a few weeks ago to spot a Minke whale, the smallest of the filter-feeding baleen whales, transiting south along the eastern side of the island. It even did us the grace of breaching to say hello! (Sorry kids, no pictures as it was a bit too exciting).
More to come – data, seals, and blog posts! Stay tuned.