If it is not indicated in the title, you can use it, then you have written it correctly, because the example given in the book is

Grass-> rabbit

It is said that this is the simplest food chain.

As for the second layer, it is wrong to say that the food chain only has producers and consumers.

Animals in the living area are divided into terrestrial organisms, freshwater organisms and marine organisms.

The birds used are all terrestrial creatures.