daft bird

[hobsonbear]

there is a blue tit in my garden (uk) that throws itself constantly up against the window at my back door.  at first i thought it was picking at insects or was attracted by its own reflection (there are plenty of other blue tits in the garden if it wants a mate) but i have watched it and can see neither.  it does this at my neighbour's back door window as well (the doors face in different directions).  i put a helium balloon on my back door and it stopped but came back when the balloon was away.  why is it doing this?

h

[Rystan]

More than likely it is the reflection after all. Birds are easily fooled by their own reflections. Males in particular recognize another male in the reflection and assume it is a competitor, and so will peck defiantly at the reflection to scare it off. Other birds find companionship in the reflection. Pet stores sell small mirrors for bird cages to keep them amused.

Your balloon, as a mysterious object, probably scared him away from the window, or otherwise blocked his view of his reflection. If it's driving you mad, you can spray your window on the outside with a good hair spray to cut the reflectivity but allow in the light (it will obstruct your view of your garden though).

[Robinia]

This question was also asked recently hobsonbear, must be a lot of it about!!......

http://www.theanswerbank.co.uk/Animals_and_Nature/Question98862.html

[Cetti]

The sap is definitely rising in the birdy world!

Look at Robinia's link and you will see that a tried and trusted deterrent is a silhouette of a hawk or other raptors. This also saves the birds from bad injuries.