The long period of sunny weather we have experienced in the Highlands this year, starting in April, seems to have increased the number of birds striking the house windows. The angle of the light hitting the windows, the light intensity and how bright it is in the room, all have an effect on how transparent the windows look. The birds, presumably, don't see the glass and believe they can fly-through the gap. I was dismayed when a juvenile song thrush (Turdus philomelos) struck the sitting room window, and died. I had to do something to combat the problem.