Startling counts

As mentioned in the previous post there is always some discussion about numbers when flocks of birds gather. I generally tend to under estimate the size and photography is one way to get a better handle on numbers. This gathering was at Whittle Dene in 2001. I reckoned 40-50,000 birds at the time.When I got the slides back from developing (ah! the bad old good old days) I projected the most diverse shot onto a gridded A1 sheet of paper on the wall I found each 50mm vertical strip held 2.250 birds and that there were about 22,000 on the one sheet. There were four sheets of similar density plus stragglers around the edges therefore concluded the gathering was around 100,000. It lasted three or four days then they went elsewhere probably having killed the stand of Pine trees they were roosting in.
The gathering at Druridge was therefore gridded thus. The average density to the left half and far right is about 30 birds per square increasing to 45 then 60 toward the right centre. I count 100 at 30, 18 at 45 and 10 at 60. That makes 4410 birds plus stragglers and edges so likely 5000 and the flock was still building. The argument at the time was between 2000 and 5000 birds so the upper end appears correct and the end gathering would have been nearer 7,500.
Last night over 2000 Starlings flew over the Carr in groups of 10 - 250. Much easier to count but now I need to know where they are going to roost. Another good count of 14 owls in the air together was made by SWA yesterday morning. Just as spectacular and equalling the site record in recent times although 20 plus were recorded at Newcastle Airport during the seventies.