The tuatara is a rare reptile endemic to New Zealand. The diagram below shows a food web involving the tuatara on an offshore island. 
How many secondary consumers are in this food web?
Ferrets are described as both predators and competitors of tuatara. Explain why.
Biomass is lost as it passes through this food web. Which two of the following processes cause a loss of biomass from the food web? Options: egestion, growth, photosynthesis, respiration.
Ferrets were introduced to New Zealand by farmers to control rabbit pests in their fields. Which term describes this type of pest control? Options: Abiotic control, Biological control, Chemical control, Genetic control.
Female ferrets can breed up to 2 times each year and produce 6 offspring each time, while the tuatara lays about 10 eggs only once every 2 to 4 years. Explain why the ferrets almost caused the tuatara to become extinct.
Suggest why these tuatara have survived on this offshore island.
Suggest why scientists are against a plan to build a bridge to allow tourists to visit this island.