OSLO BIRDER: Return of the Taiga Beans

This spring there were still 2 of the “Scottish” Taiga Bean Geese with functioning GPS collars one of which uses the Norwegian migration route and the other the Swedish route. During the summer a lack of plots led me to think the collars had stopped working but 05, the Norwegian bird, has come online again so the birds were maybe just in wilderness areas without mobile coverage.

05 who is a female and paired with a tagged bird V8 (they both were tagged on 5 Nov 2022) left her moulting grounds, close to the breeding areas in Sweden, before dawn on 24 August and arrived at a favoured field 4 and a half hours later. This favoured autumn field is one of the very first to be harvested and I think this is the reason it is chosen initially. There was a bit of a lag in the plots but once I was aware of her arrival on Monday I endeavoured to go find them on Wednesday. Sure enough they were on the same field and it was the only one in the area to have been harvested. It is right by a road and passing cars and lorries cause them no alarm but as soon as I stopped my car all their heads went up. They soon resumed feeding though but I chose not to leave the car which did rather reduce by viewing options.

Every time I counted the flock (both in the field and from pictures) I came up with a different number but have settled on 93 being the most accurate. I could only see three collars: 05, V8 and 27. 27 is a no longer functioning GPS collar which was ringed on 24 October 2019.

The number of collared birds is declining for every season (some lose their collars but still have leg rings which can only be seen in very favourable conditions which I did not have today as the stubble was too high and I did not have birds in flight at close range when photos can reveal the rings) but we are certainly losing a lot of birds to old age, predation and quite possibly hunting. This is also supported by a general decline in the number of birds using the area in both spring and autumn.

They can live quite a long time with one of the ringed birds, 6U, having been ringed on 12 Oct 2011 (when the first birds were ringed) and last seen (by me) on 30 March 2023 when it was at least 12 years old (I don’t know if it was a juv or adult when ringed). The flock size is declining year on year and although some birds maybe are choosing different routes there seems to be a real lack of reproductive success.

I usually find it difficult to pick out the young birds but the conditions yesterday were perfect for doing so. Unfortunately I forgot to do so whilst watching them but luckily took enough photos that I have been able to go through most of the flock and looks for juvs. What I found is worrying. The tagged bird 27 and his mate had 3 young but other that that I have only managed with certainty to find two single juveniles in the flock.

To the right is 27 whose watchful behaviour shows him to be a gander. To his right is his mate and then three juveniles

the same bird with another adult to the left

a single juvenile

and another juvenile

V8 and his mate with the GPS collar 05. These two can also be seen in the video (below) including how O5's collar moves up and down her neck which looks as though it must be quite uncomfortable