Auk tracking and the island count
Post date: Jun 22, 2014 6:15:31 PM
As I always seem to be writing at the start of these updates: work is progressing well on the island.
The auk tracking work on the island has reached completion; over the past few weeks Steve Dodd (RSPB) has managed to deploy and retrieve GPS devices from both razorbills and guillemots. All in all, tracks from 14 razorbills and 11 guillemots were collected. This work is a continuation of tracking which has been carried out over the last five years. Such repeated annual tracking of these birds is particularly valuable in that it allows us to gather insights into the between year variability in foraging distributions during the chick rearing periods. Furthermore, with the data feeding in to the wider RSPB STAR project, the data we are gathering is not only valuable in looking at Puffin Island specific variation, but will also be useful in identifying between island variation in foraging distributions of these species around the UK.
Sample tracks from razorbills and guillemots. Click to enlarge!
At a glance, the two species don’t seem to be as separated in foraging distributions this year as in previous years, however without any formal analysis yet completed, much of this is conjecture. A sample of tracks from the two species is shown above. We will also be carrying this work out on kittiwakes in the coming weeks.
Another annually repeated, important piece of work is the full island seabird population count, which was also carried out recently. On the 12th of June, a group of us set off around Puffin Island to conduct this count, which is organised by Natural Resources Wales, and aims to gather visual estimates of the seabird populations on the island; such counts allow us to elucidate population trends over time. I'm pleased to note that with flat calm conditions, counting the birds went smoothly, and unlike last year, everyone managed to retain their breakfast. When doing boat-based counts, each species presents its own difficulties, for example nesting cormorants are often difficult to spot in the vegetation, and low density of fulmars nesting in often difficult to spot areas makes them challenging. Guillemots, however are probably the most difficult to count; this is largely due to them being the most abundant species, and due to them nesting in vast groups which makes counting individuals troublesome. So naturally muggins here was assigned to count them, but luckily so was Steve Dodd, and I am pleased (and mildly surprised) to say that we got similar numbers across the island, giving us a degree of confidence in the counts we made. The final numbers aren’t available to me yet, but I’ll be sure to post them as soon as I know. In light of the winter storms, which have been the talk of many seabird researchers, the final numbers should be interesting.
A small section of the Guillemot colony. Impressive to look at, a pain to count.
The winter storms resulted in abnormally high numbers of ring recoveries from Puffin Island (as with many other locations), thus highlighting the importance of the ringing work on the island. With that in mind, I’m pleased to say that the first of this year’s SCAN ringing group days on the island took place on June 14th, with large numbers of shag and razorbill chicks being ringed across the island. In my mind, by ringing a relatively high proportion of chicks on what is essentially quite a small island population, ringing work on Puffin Island is particularly valuable (I may be slightly biased though).
A Razorbill chick - Good numbers (albeit of larger chicks than this!) were ringed recently.
Our work on the kittiwakes is also moving forward. Being later than the auks, we still have a slight wait before we see the first chicks on the island (shouldn't be long now though! Hopefully…). Currently the backbone of the work we are carrying out on the kittiwakes revolves around the remote cameras placed around the island. I may sound like a broken record, banging on about how useful remote cameras are (which I like to think does actually reflect their importance, rather than lazy writing on my part…), but the potential information they can record in an objective manor, across pretty much all taxa, especially centrally placed foragers such as seabirds, is extensive. We've recently been colour marking an individual from each pair in camera shot (currently 22 kittiwakes are colour marked, therefore 22 nests), which allows us to further enhance the information collected by the cameras. Colour marking the kittiwakes is essentially the equivalent of introducing some identifiable dimorphism to our study birds, thus allowing us to look at partitioning of effort between the individuals within the pair. I will soon be deploying accelerometers on adult kittiwakes which will further add to our knowledge of these birds by allowing me to determine the behaviours of these birds when away from the nests.
An image from one of the remote cameras, note the colour marked kittiwake on the right hand side.
Furthermore, since the last update, a paper from Louise Soanes et al. regarding GPS tracking of shags on Puffin Island has been published. The paper is available via Open access (a wonderful thing) here: http://link.springer.com/article/10.1007%2Fs00227-014-2422-x
It’s encouraging to see work from the island being published; as part of the scientific literature, the work adds to current scientific understanding and will effectively inform future studies.
Louise is also currently working in the Caribbean, with her project website being available here: http://www.caribbeanseabirds.org.uk/ Well worth a look! Although I bet she misses the welsh sunshine.
A Shag with chicks - the subject of the recently published paper.