Netting / covering seedlings

We have planted some peas, broad beans, onions and lettuce. 

Peas and beans we put netting over to discourage pigeons

Onions some fleece and lettuce have their own individual pop bottles as temporary mini greenhouses.

Are they all necessary? Good idea/bad idea ?

All opinions welcome.

Oh peas are definitely in need of netting here - there's the Corvid5 of jackdaws and the site squadron of sparrows who love the hedges that have grown up over the years!