Question

below is a food web from joshua tree national park, a desert ecosystem in southern california. which organisms are tertiary consumers in this food web? select all that apply. red - tailed hawk kit fox rattlesnake desert woodrat grasshopper

Explanation:

Tertiary consumers are organisms that eat secondary consumers. In a food web, they are at a higher trophic level.

• The red - tailed hawk preys on organisms that may be secondary consumers (e.g., it could eat a rattlesnake which is a secondary or tertiary consumer depending on the chain).
• The kit fox also preys on smaller consumers. For example, it might eat a grasshopper mouse (which could be a secondary consumer if it eats a grasshopper).
• The rattlesnake can prey on desert woodrats (which are primary consumers if they eat plants like creosote bush). So, when the rattlesnake eats a primary consumer, it is a secondary consumer, but if it eats a secondary consumer (e.g., if there is a chain where a small secondary - level predator is present), it can be a tertiary consumer. In the context of this food web, considering the available prey - predator relationships shown, it can be classified as a tertiary consumer.
• The desert woodrat is a primary consumer as it likely feeds on plants (e.g., creosote bush).
• The grasshopper is a primary consumer as it feeds on plants.

Answer:

red - tailed hawk, kit fox, rattlesnake