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!