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Methodologies to determine the population density of organisms in a habitat
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In Details, the approaches that can be used to determine
the population size or density of organism in a habitat
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POPULATION DENSITY:
Let me start with asking a question
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Hence, population density is the number of individuals in a unit area at a given
time
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Commonly, this may be calculated
for example a country, city, another territory, or the entire world
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Therefore, the worldwide human
population density is around 7 billion ÷ 510 million = 13
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mile)
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miles) is taken into account
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Mark-recapture method
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Random Sampling with Quadrats
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Counting along Transects

Please move to the next page
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Mark-Recapture Method
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(Mobile animals or fast moving) e
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fish, birds
The Procedure:
a) Using a quantitative technique, organisms are captured unharmed
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c) The captured individuals are discretely marked or tagged in a way and then
release back to the environment
d) After leaving time for dispersal, the population is then recaptured, and another
count is made and recorded as C2
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e) The frequency C3 of marked animals recaptured in the second capture is
determined and recorded
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C1: Is the number captured, marked and released in first sample
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C3: Is the total marked individuals captured in second sample
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Methodologies to determine the population density of organisms in a habitat
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This type of population technique is luxurious, but very quick and as well time
saving method in which a sample of a low flying, flying machine is flown over a given
area and the animals are then counted
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It`s Benefits:
a) The chances of counting the animals more than once is reduced
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c) The method is quick and time saving as well
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b) Is not possible for organisms living in the dense forest
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d) It is costly
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Please move to the next page
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Random Sampling with Quadrats
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An area where the sampling is to be thru within the habitat is demarcated
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A one square meter (1m2) quadrat is randomly thrown within the demarcated area
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The number or frequency of individuals enclosed in the quadrat is determined by
counting and recorded as (f1)
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The n above shows the number of estimations
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fn/ Nm2
NOTE:
f = frequency of individuals in the whole quadrat
N = Number of estimations made
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b) The samples that has been taken is the representation of the whole population
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Methodologies to determine the population density of organisms in a habitat
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In this type of totalling we use a low flying aircraft which is flown over a
given period area while taking the photograph which are then developed and
counted
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Counting along Transects
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Formula:
a) The area where the sample is to be done is demarcated and its total
area is recorded as N
b) A rope or a tape stretched along a straight line across the habitat and the
number or the frequency of individuals which actually touch the tape or the
rope are then counted and recorded as P1
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Pn
Where n= serves as the number of attempts made in the method
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Methodologies to determine the population density of organisms in a habitat
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Pn / Nm2
P =Frequency of the individuals that touched the transect line
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Footnote:

A belt transect records all the species that are present between two
lines, and an interrupted belt transects records all those species present in a
number of quadrats places at fixed points along a line stretched across the
habitat
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Habibu Abdullahi Muhammad
+2348032721286
Habibuabdullahi25@yahoo

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