As a bird lover it’s never nice to see a bird attacking another bird with the intention of killing it, especially when it’s an uneven fight.
But sentiments don’t count in nature and it is difficult to tell what circumstances bring on such behavior.
In the scene that I witnessed earlier this week, an adult male European Herring Gull attacked an adult male Eurasian Oystercatcher and wounded it so severely that I cannot imagine that it has survived this ordeal.
I did not see how this fight started, but my attention was drawn to an actively calling Oystercatcher and when I looked over I could see that a Herring Gull had grabbed it by its head with no intention of letting go.
The female partner of the Oystercatcher was nearby, trying to intervene but – unsurprisingly – with no effect.
After a long struggle the Oystercatcher became so tired that it could do nothing more than lie helplessly on the ground. The Herring Gull took the opportunity to repeatedly and visciously strike the Oystercatcher’s back with such force that it must have severely wounded it.
Somehow though, the Oystercatcher managed to upright itself twice in a last, feable attempt to defend itself only to collapse again and letting the Herring Gull do its thing.
I was able to take a short video of the last part of the fight. I leave it up to you to watch it, you may find it disturbing. The following images are taken from that video:
This all took place on the Forteiland in the port of IJmuiden, the Netherlands on 6 June 2016. It’s a small island and a breeding location for many Herring Gulls and a handful of Oystercatchers. It is also a place where bird research takes place and it therefore happened that both birds in this story were color-ringed on the same island where this scene took place, and only very recently for that matter: both on 27 May 2016.
The Herring Gull was ringed as Green Y.CBB:
The Oystercatcher was ringed as RG-OKCY (green ring on the right tibia, orange ring with code ‘K’ on the left tarsus and a blue ring with code ‘Y’ on the right tarsus).
The fact that both birds are ringed adds a whole new level to this story: we now know how this particular Oystercatcher came to its end (we would have missed its presence and perhaps would have recovered its body later without having known what happened to it) and it gives us yet another fascinating insight into the behavior of a Herring Gull.
To add some more context: Herring Gull YCBB is a breeding bird with a nest of 3 eggs so part of its motivation may well have been that it had some young chicks to feed.
The Oystercatcher had a nest of initially 4 and later 3 eggs and it was already unfortunate in that it had an inflamed leg at the time it was ringed. This might have had an influence on the female partner which started showing interest in a new male that had arrived recently. This may had already led to a divorce (with the female choosing a stronger partner for next year) and perhaps both males were fighting which the Herring Gull saw as an opportunity to get involved in.
All in all a sad but from a research point of view, interesting story.