A while ago a lady in Sweden email about something similar that had happened in Sweden. This is what she said –
” Something similiar happend here in southern sweden.
After a while the only understadble reason was a power cable – a bit from there likly disturbed the birds navigations.
We are disturbing nature in so many ways and kill so much life in waste for our relaxing lyxuis wayof leaving.
do you know how many birds die of trafic and poision everyday?? just on one week in sweden it dies more birds in traffic than several Sparrowhawks consume during their life!