[thedoc (OP)]

Vincent D. Mills  asked the Naked Scientists:
   
Most mornings after sunrise, there are some birds that land on my bedroom window and start tapping their beaks against the glass.  This has been happening for at least as long as I've been living at the house which is about 12 years.

I've looked on line and had seen some reasons described as the birds seeing their own reflection mirrored in the glass and perceive it as an intruder and that are trying to attack the image, Sometimes there are up to 4 birds doing this at the same time and they can get quite furious in their pecking of the glass.

I've tried a number of methods to stop this such as sticking pictures of a large bird, eagle or owl on inside of the window hoping that this would scare the birds off and this does not make any difference.  

Do you have any idea what the real reason is and how I could stop this.  

Cheers,

Vince Mills

What do you think?

[graham.d]

I thought the real reason was as described - that they see a reflection. It maybe that the act is not always a hostile one though. There is a pheasant that comes to the offices where I work and spends a lot of its life doing this - I am amazed it does not die of starvation. The glass goes to the ground and has a dark backing so it is not too bad as a mirror and there is nothing he can see through the glass as a result. Pheasant are particularly stupid birds though.

[menageriemanor]

This is usually only a problem low down at windows, where birds can stand and peck.  If you would like to help the birds, sticky tape paper along the bottom foot of effected windows.  or glue on with flour and water, or lightly spray, just to muck up reflection, that fake snow spray you can wash off. You can just paint on flour and water, tho you may have to redo after heavy rain. It only needs to be on during mating season.  I find a month is plenty, but I'm in Oz, different species.  I did have to put brown paper bags over both side mirrors of my car, for a fortnight, due to a cranky, horny, hungry, exhausted wagtail, that was determined to win and see his incredibly handsome rival off.

The only other reason I can think of, is they may see a fly or beetles or ants, on the inside of the glass, and the birds are trying to grab them.

[Origin]

We have learned that the main reason is that glass is not present in its natural habitat and doesn’t have an opportunity to learn about them.

For 9 long years Thedoc has been patiently waited in front of his computer for an answer.  Well today he got it and now he can move on with his life. 
In all seriousness though, since birds are born into a world that has glass, then it would seem that glass is part of a birds natural environment.

[Colin2B]

In all seriousness though, since birds are born into a world that has glass, then it would seem that glass is part of a birds natural environment.

Agreed. The answer is given early in the thread, reflections are not a regular part of the bird’s environment.
I have seen blackbirds getting agitated at the reflection in a pool of water.

[alancalverd]

Glass is a major part of every urban bird's upbringing, and unless your garden is populated entirely by migratory species, will have formed part of the early experience and tuition of every bird you see.

We know from the behavior of blue tits opening milk bottles, that birds learn very quickly and pass knowledge on within a flock.

So we must assume that they tap on windows for the same reason that you do: to request entry.

[Deecart]

In all seriousness though, since birds are born into a world that has glass, then it would seem that glass is part of a birds natural environment.

Seriously ?
Birds dont know glass.
But after millions of years of evolution they know water in liquid and solid form.
It is amazing to know that they dont even need to learn what water is.
So if a bird tap on a windows, he try to peck ice or drink water.
 
Conclusion : A bird taping on a window is a thirsty bird.
To verify this hypothesis, just put a water bowl near the window and see if they prefer the strange "ice" or the known water.

[Bored chemist]

Thanks, on behalf of the birds who will be offered a choice.