Making tracks

One of the most exciting aspects of the field season is getting to download the data from the GPS tags and seeing where the gannets have been.  As in previous years, we left the tags on for 7 to 10 days allowing us to record multiple trips from each bird.

A popular foraging location for many of the gannets this year has been the Fladen Ground, a large fishing area in the middle of the North Sea between Scotland and Norway.

This gannet made 5 trips to the Fladen Ground in 10 days, covering an average of 670 km on each journey (each trip is a different colour). To put this in perspective, this is the equivalent to you making a round trip from Leeds to Bristol for your food shop – every 2 days!


In complete contrast, other gannets have been staying much closer to the colony. This male only went a maximum of 35 km from Bass Rock when it went up to St Andrews, however it still managed to cover between 90 and 200 km during each of these four trips.


This female gannet also chose to forage close to shore but instead headed south to the coast of Northumberland. During the yellow trip she covered a distance of 375 km and spent time foraging close to Holy Island. During the pink trip she spent time foraging close to the Farne Islands in areas that shags forage for sandeels.



It’s always fascinating to see the variation in foraging strategies used by gannets who are neighbours at the colony. Establishing why they have developed these individual strategies is something I and other researchers are hoping to try and understand a little better.




The newest member of Team Gannet

Sadly this will be the last summer I get to spend working with the Bass Rock gannets. But fear not, the blogs will be continuing as Ruth Jeavons, and from October Chris Pollock, will be continuing the research in pursuit of their PhD’s. So for this post I’m handing over to Ruth to introduce herself and her research.


I am currently spending a hot, but windy, afternoon looking out to sea at the white crests preventing us from landing on Bass Rock today. What better excuse to sit down with an excellent cup of coffee, piece of carrot cake, and introduce myself?!

I’m Ruth, a 1st year NERC DTP PhD student at the University of Leeds, studying the foraging effort and behaviour of breeding gannets. Despite officially being half way through the field season, it’s only just beginning for me in terms of getting my hands on some actual data…

Very excited to be retrieving a GPS logger from one of the birds tagged in April (Photo – Emily Thornton)

Like Jude, I am attaching data-logging devices to the birds to see what’s going on whilst they’re out at sea. In addition to GPS loggers to see where they go, I’m using accelerometers. These measure movement, in the form of acceleration, in three directions (see below!) From this it’s possible to work out body postures and behaviours that we simply wouldn’t be able to see otherwise. For example, the angle of a dive, or individual wingbeats during flight and underwater. As movement is associated with using energy, accelerometry data can also be used as an indication of how energetically costly some activities are to gannets. These are some of the things I hope to look at during my PhD… But for now, it’s all about getting that data!

I have always been a big fan of fieldwork and have been lucky enough to work in some amazing places, but Bass Rock fieldwork is like nothing else I’ve ever experienced! As everyone says, the senses are utterly assaulted one way or another by the 150,000 birds. From getting to know the ideal distance to stay away from a path side nest to avoid a jab to the calf, to the ever constant ‘is it raining? Oh, nope, that’s not rain’, it’s a one of a kind experience!

One of the more vocal and feisty path side birds – one to avoid getting too close to! (Photo – Ruth Jeavons)

I am attaching accelerometers to the backs of the gannets rather than the tail, which involves the fiddly task of manoeuvring small feathers, positioning tape under them at the base and then laying the device on top before wrapping it up nice and securely… Sounds simple? I didn’t so! To be on the safe side I made some dummy devices out of fimo (basically playdough that hardens in the oven for anyone not familiar!) and attached them to some pioneering participants. Two out of three birds were seen 6 days later with their dummy devices still attached, so I went ahead and deployed 4 of the real things on our next trip, with a clear conscience!

Accelerometer attached to the back and GPS logger to the tail (Photo – Ruth Jeavons)

As the newbie in the team, I’ve had a lot of firsts this field season; First trip to Bass in April, first bird caught (B262 you trooper), first dummy device attached and re-sighted (B066 you star), first real device attached (B295 you legend)… The list (and excitement!!) is endless, but I’m still waiting on the biggest first… Which leads back to hoping for a calm day to be able to retrieve some devices and download the first of my data!

Season so far

We are now four weeks in to our eight week gannet tracking season, so how have we been getting on?

A quagmire

It’s been an interesting summer so far, after such a promising May, June, as you may have seen in the last blog, brought wind, rain and stormy seas. The wild weather has been a bit of a disaster for many seabirds, this blog from Isle of May describes the conditions their seabirds have been experiencing.

The storm over the 29/30th June certainly caused gannet nests to fail on the Bass. Many of the nests on the flatter areas of the rock succumbed to the quagmire of mud and guano which is created during heavy rain, however those on the steeper ledges, the prime locations, have fared much better.

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Tough year for gannets and researchers

So the gannets have been having a tough year and as a result so are we! You would think on a colony of 150,000 gannets it would be easy to catch and tag a few of them, but unfortunately for us it isn’t quite the case. The first limitation we face is that it is only possible to access a very small area within the breeding population (many of the gannets below the chapel are non-breeders), secondly we can then only catch birds we can reach with a 6 m pole, thirdly we need to know the sex of the birds we catch [see this blog on why sexing gannets is a tricky business] and fourthly they need to be feeding chicks. Because we work on one of the flatter areas of the colony, many of the nests have failed this year, making it much harder than usual to meet all the criteria.

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Interesting tracks

It hasn’t all been stormy seas and rain though. The chicks that survived are now a good size with many now standing tall next to their parents tentatively flapping their newly discovered wings. The birds we have managed to track so far have given us some interesting foraging tracks, with lots of activity close in to the coastline, so we’re just keeping our fingers crossed that we get some more calm seas and light winds over the next few weeks to allow us to track a few more.

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Summer storms

For the seabirds in the Firth of Forth, June 2017 has been a shocking month. Reported as being the wettest June on record in parts of Fife, the impact of all that rain was very evident when we made our first trip over to the Bass on the 19th June. The part of the colony within which we work appeared to have many failed nesting attempts with adult gannets standing around on empty territories instead of sitting tight incubating eggs or brooding young chicks.

New year, new team

The University of Leeds research team this year comprises myself, Ruth Jeavons who is embarking on her first summer of PhD field work and two MSc students Emily Thornton and Solange Ponce. Our first two visits, as last year, were made with the objective of spotting as many of the previously colour-ringed birds as possible and to establish their breeding stage – were they incubating eggs, brooding chicks or not breeding/failed.

Weather watching

Since those first visits the east coast has been battered by strong winds making trips out to the Bass almost impossible. A small window in the weather on Monday 26th allowed us to get on for a morning and attach loggers to the first birds this summer but since then the wind has howled and today has seen the coast inundated with heavy rain to accompany the winds.

This clip was shot on my phone from the Seabird Centre … can you make out the Bass in the distance?

A small positive

How the rest of the summer will turn out is anyone’s guess. What is certain though is that after today’s weather there will have been yet more chicks and eggs lost.

It will be interesting to see how the adult gannets respond to this bad weather when out foraging. As a far-ranging seabird their ability to adapt to environmental change has allowed them to be one of the few species of UK seabirds not to be suffering from long-term breeding failures. Being able to track their foraging behaviour during this unseasonable weather may give us some insights into how they adapt and how they might fare in our changing climate.

Battles on Bass Rock

By mid-April almost all the gannets have returned to Bass Rock and tensions are high. Fights are common with birds on the edge of the colony trying to establish themselves on a territory.  In between catching and GPS tagging we would watch these fights unfold in awe of the brutal blows they inflict one another. The dogged determination they show in trying to win is unbelievable. Just when you think one bird is down and out, bam, it strikes back with even more purpose than before.

The photos below document one such fight. The bird with the colour ring is B116, a young bird we ringed in 2015 when it was in it’s 4th year. These two must have been fighting for at least 20 minutes, locked beak to beak, jabbing at each other, grabbing the backs of each others necks only pausing for a second or two before resuming their intense power struggle. If you look closely at the pictures you’ll see how B116 causes its opponents bill to splinter. At one point the neighbouring bird got involved but soon turned away and left them to it!

Eventually B116 appeared to come out as the winner but not before blood was split.

During these fights the birds spread their wings widely which allows them to balance and prevent themselves being pushed backwards.

The ornithologist Brian Nelson describes perfectly in his book The Gannet, how the winner of such fights is “often not content with winning; he prevents his rival from disengaging, pursues him and renews the fight even when it could have ended.” It’s therefore not surprising that we see a fair number of gannets with battle wounds. However they are incredibly resilient, I  am just in awe of their robustness in the wake of such ferocious fights and what look to be quite severe injuries.



Early season success

Our return visits to the Bass certainly didn’t disappoint!

If you read the previous blog, you’ll know we put out some GPS loggers on gannets in April this year in a first attempt at finding out how they behave early in the breeding season before they are constrained by incubating eggs or feeding chicks.

The weather and tides dictated the days we were able to go back to retrieve the loggers and fortunately they gave us a two day window, a week after the deployment, to try and get them all back.

With huge relief, four of the birds were waiting for us on the first morning so we were quickly into the process of catching and removing tags. Unfortunately though, two of the four were about to leave on foraging trips at the same time and so frustratingly one of them managed to get away before we could retrieve it’s tag.


Hoping that wasn’t to be the last time we’d see B154, we then had 6.5 hours to spot colour-ringed birds and indulge ourselves with observing and photographing the day-to-day life on a gannet colony. At this time of year is even more frenetic than in the summer with birds trying to establish and defend territories, copulate, meet and greet and steal nesting material; it really was intense out there with some truly ferocious fighting witnessed. I’ll blog another time about the ‘battles on the Bass’. Then, just in the nick of time before we had to head down to get on the boat, our old friend B099 (we have tagged him in the summers of 2015 and 2016) returned with his GPS!

The trip back across the Forth was slightly more exhilarating than usual with Jack Dale of Forth Wild demonstrating some superior boat handling skills to get us back into Seacliff harbour on a high tide. We than had an hour and a half to hunker down out of the wind and watch the male gannets come into Seacliff bay to collect seaweed before the tide was low enough to safely walk back to the beach.

April high tide at Seacliff harbour (Photo: Jude Lane)

The high tide preventing us from getting back to the beach (Photo: Jude Lane)

Day two was a more slow and steady day with nerves creeping in at times as we pondered about the prospect of not getting any more tags back. Thankfully though we did, the gannets just appeared more sporadically throughout the day, keeping us on our toes and looking through our binoculars for the entire 10 hours we were there. We were well rewarded for our efforts though as by the end of the (cold and windy) day we had successfully retrieved all but one of the GPS devices we’d deployed including, with much relief, B154, the ‘one that got away’ the day before!

So it was with big smiles that we headed back to Seacliff, not only had we shown that catching at this time of the year on the Bass can be done but we also now have some great data to crunch to see whether the Bass gannets are behaving differently during the pre-laying period to when they are feeding chicks!

A Gannet tracking first?!

My first field work blog of the year is a little earlier than usual. This is because, excitingly, we are attempting to gather some slightly different data this year.

As I explained in Gannet Grabbing, the GPS tagging of adult gannets has traditionally taken place during the period of the breeding season when the birds are feeding chicks. At this stage the gannets are almost guaranteed to return to the nest, allowing them to be re-caught to retrieve the loggers. This has given us a really fabulous insight into where the gannets are going during the summer months when they are feeding chicks but we know very little about their behaviour during the remaining 10 months of the year.

This year we are going to attempt to change that and see if we can get GPS data from adult gannets making foraging trips in April before they lay their eggs and begin incubation.

So why are we interested in doing this? If successful, it will be very exciting as no-one has managed to gather data on gannet foraging trips during this stage of the breeding season before. During the chick-rearing period we know adults are repeatable in their foraging behaviour with individuals consistently returning to the same areas presumably because they know they will find prey there – see last summer’s post about B037. Their time away from the colony is constrained by the need to return with food for the chick so their foraging trips need to be as efficient as possible in terms of time and energy expenditure. When there is no chick to feed we don’t know whether they are repeatable in their foraging trip destinations or whether they are able to be more flexible in the amount of time they spend away from the colony.


I use the words ‘attempt’ and ‘if successful’ as we are as yet unsure whether it will be possible to catch the gannets in April. When gannets have chicks they will remain with the chick and avoid straying into the territories of neighbours who will give them a hard time. With no chick to protect and potentially less aggressive neighbours (as they also have no chicks) the gannets may simply run or fly off! If we do catch them and attach the loggers the second question mark lies over whether we’ll be able to re-catch them again for much the same reasons plus the fact they will be wiser to being caught when they see the pole approach for a second time!


So keep your fingers crossed for us and hopefully my next post will be able to bring news of a successful April tagging trip!


Hot rock

“UK weather: Britain is hotter than Saudi Arabia as country sizzles in 35C heat” was the Mirror’s headline on 19th July this year. It probably wasn’t quite 35C in the Firth of Forth but it was still pretty hot!

The early morning trip across from Seacliff was magical … the sea was as calm as I’ve ever seen it, the sun shone and the gannets soared.

Beckie and I didn’t get much tagging or colour ringing done that day, it was too hot for both us and the birds, but I did take some footage and made it into a short movie you might enjoy.






Gannets in the Guardian

A couple of weeks ago we were lucky to be joined by freelance journalist Louise Gray on one of our tagging trips.

Having seen this blog she came out onto the Bass with us for the day and wrote a piece which was published as the Guardian’s Country Diary feature.

If you missed it you can read it here

She has also written a great blog about her experience which includes her really interesting family connection with the rock and the lobster fishermen who take us over to the rock. You can read it here.



The Shags of Bass Rock

I’m going to revisit the theme of colour ringing in this blog and give you another example of how they are used in sea bird research.

Since 1973 the Centre for Ecology and Hydrology (CEH) have been running a long-term study on 5 species of sea birds that live on the Isle of May.  One of the biggest studies of its type in the world, the project involves using colour rings to follow individuals and learn about survival, breeding success and behaviour. One of the five study species is the shag. CEH colour ring over 90% of breeding shags and their off-spring every year on the Isle of May with the aim of establishing where they spend the winter. You can read more about the study here.

Now it might be hard to believe, but Bass Rock is not just home to gannets.  Look closely at the lower sections of the steep cliffs and rocky outcrops and you’ll spot kitiwakes, razorbills, guillemots, herring gulls, fulmars and the beautiful green-eyed shags.

On our first visit over to Bass this year, Beckie and I noticed a female shag (female shags hiss as they shake their heads at you, the males honk) wearing a colour ring breeding up on the prison wall. We couldn’t read the code at time as the ring was at the wrong angle, however the next day we got lucky …


White PSP breeding on Bass Rock – she has at least two chicks in the hole in the wall behind her

It’s not a great photo as I quickly snapped it on my phone but if you peer closely, or zoom in on it’s right leg, you can see it reads ‘PSP’. I excitedly reported the sighting to CEH through their dedicated email address ( and a week later got a lovely reply.

It’s turned out to be quite an exciting record as White PSP hasn’t been seen since she fledged from the Isle of May in 2003. I guess it’s no wonder if she’s been hiding in the prison wall for 13 years!

But our colour-ringed shag sightings didn’t end there.

I’ll save you the long story but on another visit we were locked out of the rock and had an hour to hang around the landings before we could get in. Just as we got settled on the path I spotted a shag with a red colour ring, on a ledge, just a few meters above the sea. I scrambled for my camera and quickly took a picture before it made the leap. It was Red LXA.


Red LXA just above the east landing on Bass Rock

Shortly afterwards by the south landing I spotted Blue AJX and later in the day Green AZE.

Again, I excitedly reported the sightings to CEH and got another lovely reply with details of where and when the birds had been ringed and of other sightings:

Green AZE was ringed as a chick on Craigleith in 2014. It made a trip over to the Isle of May in October 2014 but hasn’t been seen since.

Blue AJX was also ringed on the Isle of May in 2014, it was seen three times during the winter on the May and at St Monans in Fife but again, has not been seen since October 2014.

Red LXA was ringed as a chick on Inchmickery (another of the Firth of Forth islands just north of Edinburgh) in 2010. She was then not seen until 2014 when she had an unsuccessful nesting attempt on the Isle of May. In 2015 she returned to the Isle of May and raised three chicks. Earlier this summer she was recorded on an early nest but wasn’t seen after 9th May – maybe she fancied a change of scenery and that’s why she turned up on Bass in mid-July!

Finding out these little life histories of the birds you’ve seen is so interesting and rewarding and provides extremely valuable information for the BTO, CEH and other researchers working to understand more about the ecology of these birds. So keep your eyes peeled for colour rings when out walking on beaches or visiting seabird colonies and report your sightings!