From Ally Bunning's Field Notes:
Starling Murmurations – Eynsham, Oxfordshire.
25/01/23 1 hour. Sunset 16.40. Weather misty/drizzly and overcast.
I had been planning to pop over to Eynsham to take in the spectacular and mesmerising, murmurations. The flock had started to grow considerably since mid December, and were increasing by the day. I live only a couple of miles away from Eynsham as the crow or should I say Starlings fly!
I joined two lovely friends, Moth Clark and Jane Tomlinson a couple who have been visiting most afternoons.
I had mentioned, I would try a count, if the circumstances allowed.
Jane had previously guesstimated 10,000+/-.
I really wasn’t expecting the numbers counted into the main roost! We took up position about 30-40m away from the tree and bush roosts, with not a starling in the sky and waited a good 5-10 minutes. Then a sprinkling of small groups flew in 10, 20, 40 etc. I thought this is going to be easy! No murmuration and they were going straight down to the roost. Then 100, 300, 700, 1000, 3000 arrived in minutes! I looked over at Jane and Moth, with eyebrows raised! At this point, Moth kindly offered to keep an eye on the few small flocks flying back out of the roost, and on their return let me know, to stop any double counting.
The count went on rising quickly to 7000 then 11000. I looked at Jane and said, “I think there may be a few more than the 10000 estimated!”
Please accept my apologies if you were there and tried to speak to me, and I came across a bit abrupt or dismissive! I was having to use every ounce of concentration to count!
I continued counting in lots of 100’s and 1000’s as the skies filled and they cycloned down into the roost, ending at 23000 +/-. I have always been an underestimater and the flocks coming in low over the roofs from the North were not counted, as they were not in clear sight.
How do I go about counting a flock that size?
You count 10 birds, making sure they have a good spacing, not tight together, (this will help to stop overestimations) and then memorise the area they take up. Now 10 x 5 and 10 x 10 to get 50 and 100 spacing, repeat this again with the 100’s to count your 1000’s. It can take a lot of concentration! The birds need to be flying in one direction or stationery. I personally would find a murmuration impossible to count. It is a bit of an art I suppose but with practice and getting your eye in, anyone can do it. Try it out on a photograph of a flock or on a small flock that are stationery in a field to start with, then you can judge by doing a literal count afterwards, if you underestimate or overestimate.
In the Winter our resident flocks are joined by huge flocks from Northern Europe. Starlings can travel from as far away as Russia, Lithuania, Latvia, Estonia and other countries. A lot of these countries have declining breeding populations, as we do in the UK…. you wouldn’t know it in Oxfordshire! Their decline has been connected to a number of factors including loss of habitat, lack of food due to insecticides, extreme heat conditions, making it harder to catch invertebrates who in turn will reproduce less in arid soil conditions. Their preferred food choice are leatherjackets (the crane flies larvae) and earthworms.
Lastly, the combined flocks should have peaked in December-January and after this will slowly disperse, with the visitors returning to Europe completely in March.
Have a look at this link, it shows the movement of Starling over one year.