Cover the seed with bird netting to keep away the birds. Bird netting and the stakes needed to hold it are available at garden centers and hardware stores; the netting is sold by the yard. This netting attaches to stakes and will allow the sun and water to reach your seeds but not the birds.
Order several bales of straw from a farm supply store. Spread the straw over the grass seed a few inches thick. Use as a natural cover to protect your newly seeded lawn from birds. The straw will gradually disappear as you mow and care for your new lawn.
Tie long colored cloth strips or ribbons to stakes placed in the newly seeded area. The stakes can be wooden or metal and stand 3 to 6 feet high. Wind blowing the cloths or ribbons will startle the birds and chase them away. This will only last a short while until the birds get used to it.
Tie several aluminum pie pans together on a tree limb or stake near the planted area. The noise and bright movement of the pans will startle the birds and keep them away. This is not an attractive method, but it is only needed for four weeks at the most.