Apply precise ecology terms such as population, community, habitat, niche and ecosystem to biological scenarios and data in Cambridge A Level Biology questions, with mark-scheme support.
The natural ecosystem on Hawadax Island in Alaska was disrupted in the 1780s when brown rats, Rattus norvegicus, swam to the island from a sinking ship and then rapidly increased their population size.
The rats occupied a new niche on the island as predators. The rats ate the eggs and chicks of birds such as the black oystercatcher, Haematopus bachmani, and the glaucous-winged gull, Larus glaucescens. These birds make nests, lay eggs and rear their chicks on the beaches of the island.
Define the terms ecosystem and niche.
ecosystem
1 (self-contained unit containing) community of / all / different, organisms / populations / species, and their interactions ;
2 (with the) biotic and abiotic, environment / factors OR
with each other and with the physical environment ;
niche
role / function, of a species within its, ecosystem / habitat ;