Sheet 02MigrationKlaipėda
Counting the October finch passage at Ventė Cape
The mainland shore narrows to a point here, and birds that have been moving down the coast all night have to leave the land somewhere. On a good October morning you do not so much find the migration as stand in the middle of it and try to keep up.
- Logged
- Typed up
- Reading
- 9 minutes
- Coast
- Klaipėda County
Why the cape collects them
The geography does the work. The spit runs south-west from the city for the better part of a hundred kilometres with the open sea on one side and the lagoon on the other, so a bird moving along it in the dark has a strip of pine and sand a few hundred metres wide to work with. The cape reaches out into the lagoon from the mainland shore opposite, and the two lines of moving birds meet somewhere over the water off the point. What comes past in the morning is the overnight traffic of two coasts, compressed into one piece of sky.
That compression is why almost nobody at the cape walks anywhere in October. You stand at the end of the track with your back to the wind and let the morning come past you. There are large funnel traps for ringing in the willows behind, and on a heavy day the people working them are busy from first light until the middle of the morning, which tells you as much about the passage as the sky does. I keep well clear of the traps and count from the open ground, where the view down the shoreline is longest.
The first three hours, and what comes after
Visible migration here is a morning business and a short one. On a still October day the movement starts as soon as there is enough light to hold a flock against the sky, builds for an hour, holds for two, and is thin by ten o'clock. A light easterly with high cloud puts the birds low and keeps them coming; a strong westerly moves everything inland, and the same three hours then produce a tenth of the birds. I have stopped going out at all when the forecast promises south-west and mild.
Late morning is not wasted, though it belongs to different birds. Once the air has warmed, sparrowhawks and buzzards come up off the spit and cross high, and a white-tailed eagle over the lagoon will hold my attention for a quarter of an hour whether or not it is going anywhere in particular. Cranes pass in October too, usually between ten and one, in long lines that you hear before you manage to find them. The finches have gone by then, and the handwriting in the notebook changes at about that point on the page.
Counting a river of chaffinches
Counting finches properly is a skill I am still bad at. The birds come over in loose parties, some of thirty and some of four hundred, and they do not wait for anybody. What works for me is counting the first ten in a flock, seeing how much sky that block occupies, then stepping it across the rest. It is the standard method and everybody uses it because nothing better exists. Every count goes into five-minute blocks with the direction written beside it, since a single total for the morning with no shape to it is close to useless in March.
The harder part is the split. Chaffinch and brambling move together, and at any distance the flocks are one thing to the eye and two to the ear. I record what I am sure of by call, estimate the ratio from the flocks that pass close, and write the estimate down as an estimate with the sample size next to it. On the sixth of October last year I logged roughly eleven thousand finches in four hours and could honestly assign fewer than nine hundred of them to a species.
Noted on the sheet
- Count ten, measure the block of sky, step it across the flock
- Five-minute blocks with direction, never one morning total
- Split by call on the close flocks, then apply the ratio honestly
- Write the sample size next to any ratio you estimated
The totals I no longer trust
Two things wreck a morning's figures, and both of them are me. The first is birds that come out to the point, think better of the crossing, and go back up the coast to try again; count them out and count them in and the total doubles. The second is the gap between seeing something and writing it down, which widens with every minute I put it off. A tally kept in a numb hand at four degrees is not a pleasure, and the totals from the mornings when I was cold are visibly rounder than the rest.
None of this makes the counts worthless, but it does decide what they are for. I use them to compare mornings against other mornings under the same wind, and to answer the one question that matters to me in February, which is whether that was a normal October or not. Anything finer belongs to people with more observers and a proper protocol. My figures are one person's arithmetic, done standing up, in the cold, with a pencil that gave out at nine.