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.

This slideshow requires JavaScript.

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.

This slideshow requires JavaScript.

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.

This slideshow requires JavaScript.

 

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 …

WhitePSP

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 (shags@ceh.ac.uk) 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.

redLXA

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!

 

 

Catching, tagging and measuring

It’s been a busy last few weeks collecting data from the Bass rock gannets.

As I’ve not had much time to sit down and write anything I thought that I’d just share some pictures with you.

When we fit a gannet with a GPS logger and altimeter, we not only fit it with two identification rings but we also take the opportunity to take some quick and basic biometric measurements from it. These measurements not only provide an indication of the condition of the individuals we are tracking but they will also allow us to look at relationships between size and behaviour.

The whole process from catching to releasing take no more than about 10 minutes and is documented in the photos below (taken on a number of different days!)

Click on an image to see a larger version with a description of what is taking place.

 

Meet B037

Meet B037, or 1446262 as I affectionately know him (1446262 is his BTO ring number)!

B037 in 2016. Photo Jude Lane

B037 was first ringed and GPS tracked in 2010. Although we tracked some immature gannets last year, prior to that all tracking had been of breeding adults as they are far easier to re-catch and remove data loggers from. As gannets don’t breed until they are at least 5 years of age we know that B037 was at least 5 years old in 2010.

Last year he was breeding again so we GPS tracked him for a second time. We also gathered flight height data from him. As you can see from the photo above, he’s back at the colony again this year although sadly it looks as though his breeding attempt has failed.

Tracking the same bird in multiple years is really exciting. The data gathered from the trips can tell us how repeatable individuals are in their foraging behaviour and allows us to compare their behaviour with others in the colony. We can also look at how behaviour can be affected by weather conditions and other environmental variables in different years.

Here you can see the tracks of B037’s foraging trips in 2010 (pink) and 2015 (blue).

 

We recorded 3 trips from him in 2010 and 8 in 2015. His trip durations were slightly longer in 2010 (25 hours average) than in 2015 (23 hours average). Corresponding with that, he covered a greater distance on each trip in 2010 (538 km average) than in 2015 (470 km average).

So this part of the data I am gathering and analysing again this year (I’ll blog more on flight height later in the summer). Hopefully I’ll be able to tag some of the birds I tracked last year so that I can see how consistent they are in how high they fly as well as seeing if they are going to the same places.