Decided against an early night and headed out at 11pm. Target was to hear River and Grasshopper Warbler that have been singing with 50m of each other. The River Warbler was first discovered 9 days ago then on Sunday a Grasshopper Warbler was found at the same site presumably attracted by its singing cousin. There was nothing special about the site as far as my human eyes could make out but obviously Locustella like it.
When I arrived there was already a couple there enjoying the bird and a lunar eclipse that I had been oblivious to (although I had registered that the moon was getting larger during my drive!). The Grasshopper Warbler was immediately audible and sang almost constantly for the next 30 minutes but the River Warbler sang only 3 times and for only about 10 seconds each time. Would have been easy to miss. Perhaps the River Warbler now has a mate and is nesting so has less need to sing?
Driving away from this site which was at the southern end of Nittedal I heard a Quail singing but a Thrush Nightingale that I found 2 weeks ago seems to have moved on.
I finished the night in Maridalen hoping that something exotic would have arrived but all I could find were 3 Marsh Warblers again. One was still near Brekke and there were now 2 singing within 250m of each other in Nesbukta.