On 29 July 2014 Jan Zorgdrager and I came across Lesser Black-backed Gull Larus fuscus graellsii Yellow H.501 in Leiden, the Netherlands.
Ringed in Germany as a chick in 2007, H.501 is now in its 8th calendar year and a regular visitor of Leiden since at least 2009, especially during the post-breeding season when it spends several months here to almost fully complete the primary moult.
H.501 was part of a group of gulls that we attracted with some bread. True to form, H.501 immediately showed the aggressive behavior towards nearby gulls that we have come accustomed to see in this gull (see Yellow H.501 back in Leiden again – 20130728).
A few moments later our attention was drawn to another adult Lesser Black-backed Gull that was mew-calling nearby. This was the signal that H.501’s partner had arrived.
We already observed H.501 in the presence of a partner in July 2012 (see Do adult Lesser Black-backed Gulls pair up in August?), but not in 2013.
As was the case in 2012, H.501 and partner started to display pair-bonding behavior which consisted of walking side-by-side while mew-calling, grass-pulling and picking up loose objects such as twigs and feathers, and long-calling. In contrast to 2012, no choking was displayed although H.501 (a female when comparing the size with the partner) sat down once and looked as if to start the choking display.
Interesting to see also was that similar to 2012 (when we made the observations at the exact same spot, namely a local park) they frequently walked towards some trees, as if including such an object was part of the ritual.
We observed the display for some 10 minutes after which we had to leave, but it looked like it was to go on for some time.
It was fascinating to be able to observe this display again, which can best be seen in this video that Jan made:
Here is a selection of the photos I took that supplement the footage in the video. Welcome back H.501!
Is it the same partner?
I was able to take some photos of the partner showing a half-open wing but these don’t show enough of the primary pattern to say with certainty that it is the same partner as in 2012. From the few details that I can see I would say yes, but I cannot be fully sure yet. Hopefully it will stick around for a few days so that I can take some conclusive shots (in 2012 the partner stayed for about 2 weeks).