The ice machine-chilled fizzy stuff was cracked open yesterday for celebrating a colleague’s successful Ph.D. viva (congratulations, ‘Dr. Perrett’), and, somehow, the chat turned to observations I’ve been mentally post-it-noting.
My route into work takes me down the hill, through the Sports Centre and through the cemetery. On mornings when the caffeine has hit properly, and I have my eyes open, and am not trying to avoid sighting solitary magpies, I sometimes notice a still flock of seagulls gathered in the centre circle of one of the two adjacent football/hockey all-weather pitches. The gulls are not always there (neither am I), although I’ve not yet deduced any correlation with the weather – seagulls inland, stormy at sea and all that (I live close to the coast, so you often see them anyway); but I observe this in the morning, when there are relatively fewer people at the Sports Centre; and always on the same pitch, and always in or around the centre circle. Why so?
A few (un- or over-)obvious suggestions were mooted. The surface of the pitches have sand on them, which makes the surface relatively ‘warm’. Well, they are all-weather pitches, and so perhaps provide for a more comfortable morning snooze. Okay, so why always the one pitch? Well, safety in numbers means it is more sensible to stick together rather than spread themselves out across the two available to them; and the larger the group, more effective is the harassment of any potential predator which might enter the playing area without the referees permission. But why always the same pitch? I figure because the pitches are fenced, providing a guard against ground predation; and the chosen pitch is between the fenced running track and the other fenced pitch; therefore, the number of barriers to ground predators is increased. Also the chosen pitch is further from the block housing the changing facilities, so is the more peaceful and, again, safer option with the widest view. Okay, so why do they always amass in the centre circle, the most unsheltered area? Why not in one of the goalmouths or by one of the fences? Presumably because lingering by a fence means limiting escape options; in the event of any air predators appearing, more easily spotted from the 360 degree openness of the centre, it is advantageous to keep all potential exits available.
That’s about all we could come up with (but the inebriating effects of fizzy stuff are pretty quick, and we couldn’t be bothered to ‘work’ at it). And no, I’m not going to ask Google. Any bird behaviourists out there able to help out this bird brain?