What would happen? The ecosystem would remain stable because the red-tailed hawk would be replaced by increasing populations of elf owls as apex consumers. Food web is the network of different food chains operate in any ecosystem. A food chains consists of producer and different consumers. Apex predators (top carnivores) are top consumers. In a given image of food web of a desert ecosystem, red-tailed hawks are an apex consumer. If red-tailed hawks are removed from the given food web, the populations of elf owls will increase due to unavailable their predator and elf owls will become apex consumers and the ecosystem would remain stable.