An ecologist wants to estimate the size of the population of field crickets on a large area of heathland.
Which method would be most suitable?
Lay a transect line across the heathland and record the crickets touching the line at fixed intervals.
Set pitfall traps across the heathland for one night and use the total number caught as the population size.
Catch and harmlessly mark a first sample, release them, then catch a second sample and count the marked crickets.
Place quadrats at random coordinates, count the crickets in each quadrat and scale up the mean count.
109 exam-style questions on OCR GCSE Biology 6.1 Monitoring and maintaining the environment, covering 6.1.1 Field investigation of distribution and abundance, 6.1.2 Human interactions and biodiversity, 6.1.3 Maintaining biodiversity, and 6.1.4 Environmental change and distribution of organisms. Each one has a worked solution and a mark scheme showing where the marks go.