Pigeons and blackbirds will pull a just emerged CBD seedling clean out of the ground to get at the seed husk still attached to it, and a bed of ten can be gone by breakfast. A cloche or a length of chicken wire bent into a tunnel for the first two weeks is all it takes. Cheap protection setups that survived a whole season, and the ones the birds worked around, are shown on https://calmcbdseeds.com. Once the seed leaves drop off the birds stop caring.