The former Springwatch presenter said natural wild food can be scarce in the summer breeding season:
"People still seem surprised when I tell them that during the summer months we should actually increase the amount of food we put out for the birds.
"There are more birds around and every time the youngsters leave the nest they add to the numbers in the garden. A new family may be one or two, maybe half a dozen. Plus, the parents are still around and they are pretty worn out.
"Even before the youngsters arrive, they have been working hard to build a nest. Then they lay and incubate the eggs, perhaps the least hectic time but the parents still need to feed themselves. The quality of the food will affect the health of the offspring. Ironically, the healthier the nestlings are, the hungrier they look - their frantic begging for more uses up energy which can only be replaced by more food."
Oddie, who now works as a Haith’s bird food representative added:
"The chicks that are barely moving are the ones in danger. It might be illness, or hunger, or even starvation. The ones that get the food are the survivors. The responsibility is with the parents.
"Every daylight minute they must search for food, feed the young and then find more. It really is the survival of the fittest."