Mortar is found on all brick homes. It is a mixture of lime, cement, sand and water. Mortar is applied between each brick to hold them in place. Over time, this mortar can crumble and chip off. Loose mortar is a target for many different types of birds, but particularly sparrows. These birds do not get enough calcium in their diet necessary for egg production. Breeding sparrows eat loose mortar for the calcium. Even if the mortar is not loose, the birds may attempt to go after it. There are a few techniques to keep those birds away from your mortar.
Locate all of the loose mortar and place fake snakes around the spots where there is the most amount of loose mortar. Spread out the snakes around the entire area. This will help scare the birds away from the mortar.
Place an artificial owl near the porch. The birds will see this as a predator and it will help keep them away. Position an owl in a tree in the yard. This will help prevent the birds from building a nest in the area. Set an owl at each corner of the porch also.
Fill up small containers full of sand and place them near the trees in your yard. The birds will eat the sand instead of the mortar. Spread out the containers around the yard and refill them when necessary.
Monitor the birds and move the snakes and owls as necessary to different locations. Add more to the area if the mortar is spread out.