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ESA Certified Ecologist Biodiversity Science & Conservation: practice questions

ESA Certified Ecologist (Ecologist-in-Training, Ecologist, Senior Ecologist) · USA · Ecological Society of America

Original practice questions written to the published syllabus · not past papers
10worked here, free
28written to this exam in this subject
12syllabus units

What this subject covers

What biodiversity is, how it is measured, why it is being lost and how it is conserved, from IUCN Red List categories and protected areas to the Kunming-Montreal Global Biodiversity Framework.

In the exams: ICAR AICE subject 71 Unit 2 (whole unit); GATE ES Section 8 (biodiversity); UGC NET Unit 3; UPSC CSE Prelims environment (heavily asked)

What ESA Certified Ecologist asks from it

UGC NET Environmental Sciences (Unit 3) and professional ecologists (ESA Certified Ecologist)

Biodiversity measurement, conservation biology concepts (MVP, PVA, SLOSS, extinction vortex), drivers of loss, invasive species management and conservation planning.

Where the 28 questions fall

How our questions for ESA Certified Ecologist spread across the units of Biodiversity Science & Conservation. Difficulty: 0 easy, 5 medium, 23 hard.

Measuring biodiversity: alpha, beta, gamma diversity and indices4
Population viability and minimum viable population4
Island biogeography and species-area relationships3
IUCN Red List categories and criteria3
In-situ conservation: protected areas, biosphere reserves3
Invasive alien species management3
Biogeographic realms and biodiversity hotspots2
Values of biodiversity: use, non-use, intrinsic2
Levels of biodiversity: genetic, species, ecosystem1
Drivers of biodiversity loss: land-use change, overexploitation, climate, pollution, invasive species1
Ex-situ conservation: zoos, botanic gardens, seed and gene banks1
Convention on Biological Diversity and the Kunming-Montreal Global Biodiversity Framework1

10 practice questions, worked

Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.

1 · Measuring biodiversity: alpha, beta, gamma diversity and indices · medium

What does environmental DNA (eDNA) metabarcoding allow ecologists to do?

  1. Measure the age of trees from their DNA without coring
  2. Clone extinct species from fossil DNA in museum collections
  3. Detect species from DNA traces in water or soil samples
  4. Change the DNA of invasive species to make them sterile
Answer and working

C. Detect species from DNA traces in water or soil samples

eDNA metabarcoding sequences DNA shed into the environment to detect which species are present, aiding surveys of fish, amphibians and soil biota. It does not date trees, clone extinct species or edit genomes.

Further reading: Biodiversity monitoring literature

2 · Biogeographic realms and biodiversity hotspots · hard

Which is a common criticism of hotspot-based prioritisation?

  1. It is biased towards plant endemism
  2. It ignores plants and is based solely on the distribution of large mammals
  3. It gives priority only to areas with no human population at all
  4. It cannot be mapped because hotspots have no defined boundaries
Answer and working

A. It is biased towards plant endemism

Critics note that hotspots rely on plant endemism and habitat loss, overlooking wilderness, marine areas, low-endemism ecosystems and ecosystem services; complementary approaches such as Key Biodiversity Areas address some gaps. Hotspots are plant-based, include populated areas and are mapped.

Further reading: Hotspot critiques

3 · Biogeographic realms and biodiversity hotspots · hard

In systematic conservation planning, what does 'complementarity' mean?

  1. Choosing sites that duplicate the species of existing reserves
  2. Selecting the largest sites regardless of their species content
  3. Adding sites that contain species or ecosystems not already protected
  4. Protecting only sites that are already owned by the government
Answer and working

C. Adding sites that contain species or ecosystems not already protected

Complementarity selects sites that add the most unrepresented biodiversity, achieving targets efficiently. Duplicating existing reserves, choosing by size alone or by ownership does not.

Further reading: Margules and Pressey 2000

4 · Drivers of biodiversity loss: land-use change, overexploitation, climate, pollution, invasive species · hard

Why does acting only on direct drivers often fail to halt biodiversity loss?

  1. Direct drivers have no measurable effect on any species population
  2. Indirect drivers are fixed by nature and cannot be changed by policy
  3. Indirect drivers keep creating pressures
  4. Biodiversity loss stops automatically once protected areas reach 10 %
Answer and working

C. Indirect drivers keep creating pressures

Land conversion, exploitation and pollution are driven by demand, trade, technology, governance and values; without addressing these, pressures shift elsewhere. Direct drivers clearly matter, indirect drivers are policy-sensitive, and no threshold of protection stops loss automatically.

Further reading: IPBES Global Assessment 2019

5 · Island biogeography and species-area relationships · hard

What was the 'SLOSS' debate about?

  1. Whether species-area slopes should usually be measured on linear rather than on logarithmic axes
  2. Whether soil loss or species loss should be the priority in watersheds
  3. Whether slow or swift population declines should be listed by IUCN
  4. Whether a single large or several small reserves of equal total area conserve more species
Answer and working

D. Whether a single large or several small reserves of equal total area conserve more species

SLOSS asked whether one large reserve or several small ones of the same total area are better; the answer depends on species, habitats and threats. The other expansions are invented.

Further reading: Diamond 1975; Simberloff and Abele 1976

6 · Population viability and minimum viable population · medium

What does the original '50/500 rule' of conservation genetics state?

  1. Ne ≥ 50 avoids short-term inbreeding; Ne ≥ 500 keeps evolutionary potential
  2. Census size ≥ 500 for mammals; ≥ 50 for birds in all reserves
  3. Reserves must be 50 km² for small species and 500 km² for large mammal species
  4. Populations need 50 % females and 500 offspring every year
Answer and working

A. Ne ≥ 50 avoids short-term inbreeding; Ne ≥ 500 keeps evolutionary potential

Franklin and Soulé (1980) proposed effective sizes of 50 and 500; Frankham and colleagues (2014) argued for 100 and 1000. The other statements are invented.

Further reading: Franklin 1980; Frankham et al. 2014

7 · Population viability and minimum viable population · hard

What is the 'extinction vortex'?

  1. The spiral of ocean currents that carries extinct species' remains
  2. A legal procedure that lists species as extinct after 50 years
  3. A rapid increase in population when predators are removed
  4. Mutually reinforcing small-population processes that drive further decline
Answer and working

D. Mutually reinforcing small-population processes that drive further decline

Gilpin and Soulé described how inbreeding, drift, demographic and environmental stochasticity reinforce each other as populations shrink. The other options are unrelated.

Further reading: Gilpin and Soulé 1986

8 · Population viability and minimum viable population · medium

What is the main practical use of population viability analysis (PVA)?

  1. Predicting the exact year a species will go extinct with certainty
  2. Comparing the effect of management options on extinction risk
  3. Counting individuals in the field without any survey
  4. Classifying species automatically as Least Concern
Answer and working

B. Comparing the effect of management options on extinction risk

PVA models are uncertain, so they are most useful for ranking options such as reducing poaching or translocating animals. They do not give certain dates, replace surveys or classify species automatically (though they inform criterion E).

Further reading: Primack, Essentials of Conservation Biology

9 · IUCN Red List categories and criteria · hard

Why can a species be globally Least Concern yet legally protected in India?

  1. The Red List is a binding international law that overrides national laws
  2. India uses the Red List categories directly as its legal schedules
  3. They are separate: global science versus national law
  4. Least Concern species cannot be protected by any national law
Answer and working

C. They are separate: global science versus national law

IUCN assessments are scientific and global; Wildlife (Protection) Act schedules reflect national status, trade and cultural considerations. The Red List is not law, India does not copy it into schedules, and national law can protect any species.

Further reading: IUCN; Wildlife (Protection) Act

10 · Invasive alien species management · hard

What does Kunming-Montreal target 6 aim for regarding invasive alien species?

  1. Eradicating every invasive species on every continent by 2025
  2. Cutting introduction and establishment rates by at least 50 % by 2030
  3. Introducing new species to replace extinct ones by 2030
  4. Stopping all international trade in plants and animals
Answer and working

B. Cutting introduction and establishment rates by at least 50 % by 2030

Target 6 aims to reduce rates of introduction and establishment of other known or potential invasive alien species by at least 50 % by 2030 and to eradicate or control them, especially on islands. The other aims are unrealistic or invented.

Further reading: Kunming-Montreal GBF 2022

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Read the subject

Biodiversity Science & ConservationThe full study manual, free ESA Certified EcologistFormat, sections and how it has changed

More ESA Certified Ecologist practice

Ecosystem Services & Pollinators in Agricultural LandscapesLandscape Ecology, Protected Areas & Human-Wildlife InteractionsResearch Methods in Environmental & Sustainability Science

Biodiversity Science & Conservation for other exams

UGC NET · IndiaUPSC Civil Services Examination · IndiaICAR AICE-JRF/SRF · IndiaGATE · IndiaGATE · India

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