Producers are plants that produce food through photosynthesis i.e. these are autotrophs.
There are plant-eating animals called herbivores as Rabbits, deer, pigeons, cows, buffaloes etc. and insects like grasshoppers, bees, butterflies and crickets also eat plants or plant products as fruits, flowers, pollen grains and plant juices. Such animals are called Primary Consumers.
Animals like tigers, lions, wolves, lizards, frogs eat the primary consumers. Birds vultures, kites, eagles eat the primary consumer, (i.e. These birds will eat the flesh of many birds like pigeons, sparrows.) These animals or birds are called Secondary Consumers.
Animals like snakes are eaten by the peacocks, they eat the secondary consumers and are called Tertiary Consumers.
Owls and eagles are top carnivores. So it is a Quaternary Consumer.