Sampling methods in biodiversity

What is a quadrat and how is it used in biodiversity sampling

• A quadrat is a square plot used to sample and study the distribution of organisms.

• It’s recommended to sample about 10% of an area for effective analysis.

Why are quadrats particularly useful

• They help study ecological requirements and are effective for organisms whose habitat preferences are well-known.

• Indicator species can be assessed through quadrat surveys.

What are the two belt transects

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What are indicator species

Examples

• Species whose presence, absence, or abundance reflects a specific environmental condition, helping assess the health of an ecosystem.

• Frogs (pollution indicators), lichens (air quality indicators).

indirect sampling

• Estimating animal presence without seeing them directly

Why is indirect sampling used for mammals

• Mammals are often widely dispersed, secretive and elusive; indirect methods avoid disturbing them and still provide information about their presence

What are the pros and cons of indirect sampling

Pros

• preferable when direct sampling is difficult or could cause undue harm to the organisms involved

Cons

• provides a ‘best guess’ of population attributes but estimates made this way are less accurate than those made using other methods

Name some indirect signs used to detect mammals

• Scats

• tracks

• burrows

• food remains

• skulls

• skins

What is spotlighting

• Using a high-powered torch to observe nocturnal mammals. Caution is needed to avoid disturbing habitats

What is direct observation in biodiversity studies

• Watching and recording animal behavior or presence without intermediate indicators

What is live trapping? Why is it restricted?

• Capturing animals alive to collect detailed data like weight, sex, and genetic profiles.

• It can interfere with animals’ lives and usually requires permits.

What is Mark & Recapture method

• A technique where animals are captured, marked, and released, and later a second capture helps estimate population size

what is the equation for mark and recapture

N = (number initially marked x number of individuals captured in 2nd sample) / number of marked individuals recaptured in 2nd sample

What is necessary for accurate Mark & Recapture studies

• Ideally 20% of the population should be marked, but marking small or mobile animals can be difficult

How are birds sampled differently from mammals

• Birds are easier to locate through direct observation and by listening to their calls

What does point sampling, random transect and non-random transect look like

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What ethical principles must be followed in biodiversity studies involving animals

• Beneficence – the welfare of research participants must be a primary goal. Ethics approval is usually required.

• Acting for the benefit of others; avoiding harm

What are two major threats to global conservation efforts

• Poaching and habitat destruction.

How can conservation be improved according to social justice ideas

• Empowering local communities to participate actively in conservation efforts

Why is poverty a key issue in conservation

• Poverty can drive illegal activities like poaching; addressing social justice improves conservation outcomes

sampling bias

• When samples do not accurately represent the whole area or population, affecting the reliability of results