Why can granivorous birds at different periods of their lives occupy the place of consumers of the first and second orders in food chains?

1) granivorous birds feed on grains – they are consumers of the first order.
2) they feed their chicks with insects (animal food is richer in proteins for feeding offspring) – at this moment they are second-class consumers.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.