Question

why all birds not seen in all seasons​

Answer 1

Answer:

Wet weather or a late spring, can all mean a lack of insects to forage for when the trees and hedgerows have long since been stripped of berries and seeds. So birds turn to our gardens in huge numbers to supplement their diet and even bring fledglings directly from the nest to the feeder.....

Birds may temporarily move out of areas to avoid droughts, floods, storms, exceptional heat and cold waves, and other unusual weather conditions. Predator populations. Foxes, birds of prey, cats, and other predators have fluctuating populations too.