I know you all want to be kept updated with those gripping Common Gull counts I'm doing. If you don't know about this exciting project, well, last winter there were almost no Common Gulls on my usual stretch of river, which was very odd. So this winter I decided to count them. And I have been doing. So, here's a nifty plot showing the numbers of Common Gulls plotted against the number of all species of gulls present ... the flock size. With occasional counts of 30-40 ish, things are back to normal so far, though they do fluctuate right down to zero sometimes. I wasn't expecting to get anything else of interest out of it, but look ... there seems to be a fairly good correlation between the number of Commons and the total flock size. OK. I thought. But then I thought again. If there is a correlation, then why ? Why should a bigger flock of gulls have more Common Gulls in it ? Those Common Gulls are winter visitors ... and I'm presuming they've all pretty much arrived by now .... so why would there be more of that local population turning up when there's more of the others? Well, one thing is, they seem to be roosting/resting there. When I turn up to count them, the vast majority of them aren't feeding. So maybe the "total flock" splits and goes to other roosts/resting sites sometimes. And if they did that species-randomly, you would, on average, get similar proportions of each species each time., but split up into smaller flocks in different places. Roughly. It's a possible scenario. I certainly don't think that the Common Gulls look around and think ...hey, there's too many of us in this flock ..... you lot over there .... bog off somewhere else. No. Or .... hey, we're not very well represented here ... wake up, Bernard, go and fetch some of the others from that lot down the river . About a dozen will do. No. Any other ideas would be welcome .......... [email protected] Here's a fine Einstürzende Neubauten song , " Nagomy Karabach" ... brooding, that's what it is ! By the way, there's some comedy programme which seems to be about birds tonight at 11:15 pm.... it doesn't look too promising but you never know ...
0 Comments
Leave a Reply. |
AuthorThat's the author up there ... I was young and sprightly then. Archives
October 2022
|