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Sampling animals
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What do you remember? What is biodiversity? What is species richness? Whose formula can be used to put a figure on the biodiversity of an area? What is a transect? The variety of life The number of different species in an area Simpson’s index A line across a habitat; samples are taken along the line at points or using a quadrat
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Sampling animals There are many different ways to sample animals depending on the type of animal and habitat where it lives. Read pages 196 and 197 in the book and make a list of sampling techniques along with some examples of animals that could be sampled in that way.
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What is this and what type of animals could you sample with it?
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What is this and how does it work to sample animals in leaf litter?
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What is being sampled here? What should you control to allow for a reliable and repeatable sample?
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What is being sampled here?
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How is this sampling procedure done.
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Mark release and recapture MRR is used for animals where it is hard to know whether you have counted all the individuals in an area. They might move about too fast or be difficult to capture. Originally developed for use with ducks! Capture as many animals of the species as you can in a set time and area. Count them (value C 1 ) Mark them in a way that does not harm them or make them more obvious to predators eg rings on bird legs Release the captured individuals and allow them to mingle with the original population for a few days. Sample the population again in exactly the same way as before. Count the total number in the second sample( value C 2 )
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Mark release and recapture Then record the number in the second sample that are marked ( value C 3 ) The estimate of population size is based on the idea that the proportion of marked to total individuals in the second sample is the same as the proportion of individuals in the first sample to the total population. C1 = C3 Total population C2 Or to rearrange the equation Total population = C1 x C2 C3
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Try these 58 woodlice were captured in a pile of logs, marked with a spot of paint and released. In a similar sample two days later 47 woodlice were found of which 20 were marked with paint. Estimate the population size. Using a net 18 carp were fished from a lake in 1 hour. They were marked and returned to the lake. One week later 18 carp were again fished in the same time period but only 12 were marked what is the approximate population of carp in the lake? 75 moths were caught in a moth trap one evening, marked and released. The next evening the moth trap was set in the same place. 71 unmarked moths were found and 18 marked ones. What is the approximate population of moths?
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http://www.bbc.co.uk/nature/collections/p0085njx
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