Monday, 22 August 2016

The Secret Life of Skomer’s Sea Shores

Hi, my name is Cerren and I am one of the Long Term Volunteers here on Skomer for the second half of the season. I had never been to Skomer before, but so far I have enjoyed every second! Each day has been so different and enjoyable.

Skomer is home to an impressive array of wildlife, and most people associate the island with its large colonies of seabirds, however, little attention is given to the shore life of Skomer. As I am currently reading Marine Biology with Oceanography at university, I have a keen interest in marine life and decided to go rockpooling in the intertidal zone along the beaches of Skomer. The intertidal zone, the area between the high and low tide, is one of the harshest environments for animals to survive in because of the changing environmental conditions. The animals living there have to cope with the stresses of changing salinity as it rains, the temperature as the sun heats the rockpools, long periods out of water as the tide recedes, and the mechanical strength of the waves. As a result, the fauna living in the intertidal zone have undergone some fascinating adaptations!

Cornish lumpsucker (Photo: P. Reufsteck)

Even though North Haven beach seems like a simple pile of rocks and boulders- it is teeming with life! Under the first rock I turned over, I found three shore clingfish also known as Cornish lumpsuckers. These fish have remarkable adaptations for example their pelvic fins have fused together to form suckers which help them to remain stuck to the rocks on exposed shores. They are also covered in a layer of mucous which allows them to remain hydrated during periods out of water. Some other species that I found included the broad-clawed porcelain crab which has flattened hairy claws to catch small particles in the water, sea mats which look like tiny bubble-wrap on top of kelp but they are actually a colony of individual bryozoans and by-the-wind sailors which are free-floating hydrozoans from the same phylum as jellyfish (the cnidarians). Like the jellyfish, by-the wind sailors also have stinging cells called nematocysts which they use to stun their prey.

By-the-wind sailor (Photo: J. Milborrow)

Normally, the public don’t have access to the beaches on Skomer to minimise disturbance to wildlife, but on Wednesday, I held a seashore spectacular family day activity. It was a very successful day with a great turn out of people. Around 15 children and their parents joined me for a two hour session of rock pooling on North Haven beach. The children loved finding the variety of invertebrates and vertebrates along the shore. Some of the species that were found included compass jellyfish, by-the wind sailors, keelworms, barnacles, limpets, topshells, dog whelk, anemones, shannies, blennies and common shore crab. Their favourite animals by far were the crabs therefore we all decided to have a competition to find the largest crab on the beach (the winner found a 5cm common shore crab).

Edible crab (Photo: C. Richards)

Next time you go to a rocky shore, check under the rocks to see what fascinating creatures you can find, but remember to place the rocks back gently where you found them!

(Long Term Volunteer)

Monday, 15 August 2016

Celtic Deep trip

We try and take a few trips out each year to see some wildlife and give our volunteers a bit of a treat. On the evening of Saturday 13th of August we took a trip out to the Celtic Deep, which lies around 25 miles SW of Skomer, to look for seabirds (especially storm petrels) and cetaceans. As you can see we were successful. We saw over 40 Storm Petrels, plenty of Common Dolphins, as well as two Great Skuas and a Sooty Shearwater, and everyone involved had a wonderful time. What an amazing area we live in!

European Storm Petrel
Playful Common Dolphins

Thursday, 4 August 2016

Amazing amount of Shearwaters cruising past my kitchen

Have a look at this video I took  from my kitchen yesterday evening.

(Skomer Warden)

Monday, 25 July 2016

The fascinating migration of the Skomer Puffins

My name is Annette and I’m a researcher at the University of Oxford. I have been doing research on Skomer since 2011, first as a research assistant, then as a PhD student, and now as a fully-fledged postdoctoral researcher. I am lucky enough to come and spend some time on the island each year (for up to 5 months when I’m really lucky), to study the seabirds on the island. Some of you may have met me, when I’m not up in the middle of the night tracking shearwaters, awake at dawn observing puffins, or with my arm down a burrow in the middle of the day, I’m usually working on my computer in the library. Over the last 5 years I have been working with Manx shearwaters, guillemots, razorbills and kittiwakes, but my main study species during my PhD was the Atlantic puffin. 

Figure 1 – Annette at work. Not a bad job? (photo M. Kavelaars).

We are approaching the end of July, when young pufflings fledge from their burrow in the middle of the night and adults gather on the clifftops of Skomer, ready to leave the island until next spring. Finding out where they are heading off and what they are be up to for the next 8 months were one the main objectives of my PhD. To answer these questions, year after year, I attached miniature trackers on a plastic ring around the leg of breeding adult puffins, and recaptured them a year later to download data from the devices. The loggers, called geolocators, weigh less than 2g and measure light levels (from which we can infer approximate position) and saltwater immersion (the proportion of time spent wet for each 10 minute block, which helps us identify sitting, flying and foraging behaviour when the birds are at sea). The devices are tiny (Figure 2), all birds are only manipulated (very cautiously) once a year, and they do not seem disturbed by the study, as their survival rate and breeding success is comparable to those of undisturbed puffins. 

Figure 2 – A puffin with a newly deployed geolocator on its right leg (photo M. Kavelaars).

So what did I learn from the data collected by these geolocators? Well, after tracking about a dozen birds each year for multiple years, I obtained a good picture of where the adult puffins go and spend the autumn and winter after they leave Skomer. And this picture is really quite astonishing. They seem to go pretty much everywhere (in the North Atlantic). Not only was I surprised to see that puffins, with their stubby little wings (which make flight very energy-demanding), could migrate thousands of miles away from their colony, but I was also amazed to see that puffins which had been breeding in burrows a few meters apart were spending the winter in completely different places. Indeed, individual Skomer puffins migrate to a whole range of different places. Some will remain around the UK and Ireland, others will venture westwards to the Atlantic Ocean, near Iceland, Greeland or even, in one particular case, to Newfoundland (Canada) and the Labrador Sea. Later in the winter, some birds will then move towards the French and Iberian coast, and about 20% will even go and spend a few months in the Mediterranean. Tracking the same individuals for multiple years also showed that puffins are very consistent in their migratory journeys, and keep following the same route, year after year. A few examples are presented in Figure 3.

Figure 3 – Two examples of the migratory journeys of Skomer puffins (the lines represent approximate trajectories, ± 180 km. Puffins do not fly across land).
Many questions remain unanswered regarding these striking migratory patterns. How do these routes develop? Do young puffins inherit their parents’ routes? Are some routes better than others?  While I don’t have space here to develop on all the results I found, this study was published early this year in an Open Access paper you can all access here and you can find a few more answers in the paper (not all, unfortunately!). For example, puffins visiting the Mediterranean Sea seem to spend more time foraging overwinter, and to have a higher breeding success than others. I invite you to have a read if you want to know more!
Puffin population worldwide are declining and they were recently classified by the IUCN as endangered. What do these migratory patterns mean for puffin conservation? This diversity of routes makes it more difficult to pinpoint a single area which is critical to the winter survival of all Skomer puffins, but it may perhaps also enable the Skomer population to be more resilient; for example if dramatic storms or oil spills affect puffins off the coast of Ireland in winter, only a proportion of them would be affected, as many others would be visiting other areas far away. Future puffin conservation however should most likely rely on multi-colony studies, as the migratory patterns of Skomer puffins may not reflect that of other puffins (e.g. puffins from the East coast of Scotland mostly winter in the North Sea). Nonetheless, the more we learn about these fascinating birds, the more we will be able to protect them from the many threats which they are or will face, and so it is important to continue these studies in the long term. I am about to start a new 3-year research position at Oxford to pursue this research – so keep an eye on this blog for further puffin discoveries!

(for more info on my research or my contact details see here)