The simple answer is you do not need to, a lot of the time when we feel we are doing the right thing by the animal in providing food, we are actually inhibiting the animals natural dietary needs and intake.
There are many reasons for and against, feeding wildlife. However the main reason people feed native animals seems to be the same, to encourage animals into our daily lives!
This objective can be achieved in many different ways while still achieving the same goal. For example we can encourage native wildlife into our backyards through providing a water source, planting native trees, grasses & shrubs and providing nesting boxes and nesting materials.
Through following these simple tips, we are encouraging native animals to be a part of our lives whilst still following their natural instincts. We reduce the risk of spreading diseases, that can occur when a large number of animal congregate to feed close to humans.
We also keep the status quo present in all our surrounding eco systems, meaning smaller birds such as silver eyes or sun birds are still given the freedom to feed along with larger carnivorous birds such as kookaburras or crows.