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.
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Figure 1 – Annette at work. Not a bad job? (photo M.
Kavelaars).
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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.
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Figure 2 – A puffin with a newly deployed geolocator
on its right leg (photo M. Kavelaars).
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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.
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Figure 3 – Two examples of the migratory journeys of
Skomer puffins (the lines represent approximate trajectories, ± 180 km. Puffins
do not fly across land).
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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!
Annette
(for more info on my research or
my contact details see here)
