Hi Marion I can't help you with your question, you could be right about them sharpening their beaks or they could be getting something like grit out of the concrete.
My Flickr photos
In reply to Alan.:
hi Never seen them doing this before but its a very active thing sometimes 3 pecking away
In reply to marionspelman:
would they ues this for nesting material?
I'm not sure how they finish their nests off, with this dust mixed with saliva would make a hard finish of they leave it soft with moss etc.
Some birds that are seed eaters will eat grit to help break down the hard shell of certain seeds, not sure if Sparrows do it.
ty how do upload pictures from Iphone onto this site? maybe someone would know why?
You can add a photo as an attachment (there is another way but it means altering a setting on here) try clicking the "use rich formatting" link under the reply box and you should see the option to add an attachment.
do you possibly have ants that they could be eating ? and if not it would say it would be the grit from the concrete as there maybe a lime stone mix in it somewhere :D
In reply to Dale :
no ants dale.the floor in the garage was painted in a grey paint but they have pecked and chipped the paint off in little patches and pecking at the concrete below.. will try and get a picture and upload
That's really mysterious, Marion. So they first pecked the paint away, but isn't the concrete much harder? Do they actually manage to get something off? (Is already a bit of concrete missing now?) Lately I thought I saw birds (Goldfinches and Great Tits) pecking the grouting out of the walls, but then found out they were collecting cobwebs.
Yours is a different story, of course.
A photo would be great!
In reply to Martin A:
Hi Marion looking on the rspb site says they use grit from the concrete to help break down food in there stomachs and also sharpen there beaks.
We spend 90% of net income on conservation, public education and advocacy
The RSPB is a member of BirdLife International. Find out more about the partnership
© The Royal Society for the Protection of Birds (RSPB) is a registered charity: England and Wales no. 207076, Scotland no. SC037654