Wildlife sampling methods Lecture 7 part 2

Question 1

What can Survey results do?

Answer 1

Identify priority areas for species protection

Develop conservation management strategies

Help mitigate threats

Question 2

What is Non-invasive monitoring ideal for?

Answer 2

Ideal for estimating abundance

Trends

Question 3

What does invasive monitoring involve?

Answer 3

Trapping

Collaring

Disease transmission from humans

Question 4

List the Non-invasive survey methods

Answer 4

Interviews

Index counts

Direct and indirect distance sampling methods

Capture-recapture methods (Inv or uninv)

Line/point and Strip/quadrat transects

Question 5

List the aspects of Capture - recapture with camera traps

Answer 5

Effective tool for monitoring terrestrial mammals - precise density estimates

Enable population estimates- Social, demographic structures, movement patterns

Presence/absence of arboreal spp.- Monitoring tool

Effective at small spatial scales - 200km

Larger areas - transects or genetic censuses

Question 6

What are the different scales of monitoring or assessing populations?

Answer 6

Site level

Protected area

Regional

National

Continental

Different methods are appropriate at different scales

Question 7

What will you need to gather information on?

Answer 7

Survey species

Area to be covered - Behavioural, ecological characteristics of the target species. Ranging patterns, habitat requirement

Map of the survey area- vegetation, topographical hydrological

Previous data

Answer: Why, what, how, where, when, how often?

Question 8

Why is it important to survey?

Answer 8

Reason is defined by survey objectives:

To estimate -

Distribution

Abundance

Population trend

Population structure

Question 9

What questions can the information of spatial distribution of a species answer?

Answer 9

Can help answer questions on whether

A species. Is restricted to a particular area or habitat type

Question 10

What is species occurrence influenced by?

Answer 10

Species Occurence is influenced by environmental, anthropogenic or temporal factors. For example: Seasonal variation in food abundances.

Question 11

In relation to abundance, what different measures can be estimated?

Answer 11

Relative abundance

Index, encounters rate of signs, per unit distance - caution needed when interpreting these results between sites or habitats

Absolute abundance: Total number of individuals in the survey area

Density- Absolute abundance divided by the size of the survey area (Number of individuals per km2).

Question 12

What is population trend for?

Answer 12

For informing and assessing effectiveness of conservation management decisions

Aimt to estimate trend over several years

Need to be repeated over a no. of years.

Question 13

Explain population structure

Answer 13

Requires obtaining info on the age and sex classes of the individuals sampled

Maybe easy when surveying directly

More challenging when surveying for indirect signs - difficult to assign age and sex classes

Provides useful insights into reproductive health of a popln, immigration and emigration patterns, population trends and population viability

Question 14

What does Ecological censuses investigate?

Answer 14

Site importance

Population size of a species

Habitat requirements of a sp.

Reason for species’ decline

Habitat management

Population dynamics

Question 15

Give examples of Census

Answer 15

Ecological status of 6 parks in sandwell

BSc project - GCN poplns in pools in Fibbersley LNR

EIA for a development

BTO thrush survey

RSPB garden bird survey

Question 16

Describe the importance of a site for a range of species

Answer 16

Provide a spp. List with a rough estimate of abundance

Use a wide range of different techniques

Sample in as many habitats as possible

Over a wide period of time

Over different weather conditions

Document the area searched

Question 17

How do you monitor population changes?

Answer 17

Monitor the fate of a species of conservation interest

Not necessary to have an absolute population estimate

Relative measure of abundance may be sufficient

Ensure exactly the same techniques are used each time

Must ensure that comparisons are valid

May also be necessary to measure env variables at the same time.

Question 18

How do you determine population dynamics?

Answer 18

Measure life history parameters

Estimate the population size

Consider a range of questions:

Why does the population fluctuate from year to year

What determines the level of abundance?

How strong is density dependence and at what stage does it operate

What are the consequences of competitors, herbivores or predators on the population?

Question 19

How do you determine habitat requirements?

Answer 19

Not necessary to have absolute population estimates

Can’t just visit all the best sites

Need to be able to compare sites where species. Are absent

Could use a random collection of points

May need to asses prey abundances, predator abundance, nesting sites, habitat structure, env. Variables

Could be presence/ absence or relative density

Question 20

How do you determine why species have declined?

Answer 20

Could use the previously mentioned methodology and try to determine whether factors have changed or…

Compare the sites in which the species still occurs with sites where it has disappeared

Estimate life history parameters

Asses the limiting factors - determine if they have changed

Question 21

What is involved with monitoring habitat management?

Answer 21

Need to learn from the results of the management that has carried out

Need to be sure that the right conclusions are drawn

Management experiments need to be controlled, randomised and replicated

Replication is required

Question 22

Why must you sample?

Answer 22

Not possible to count all individuals within a given population (Population = total number of a particular species in definite area)

Aim to select a small representation of the total population

Must divide the area into sampling units of equal size

Sampling units must be distinct, must not overlap, must be of the same size and each unit must be chosen at random from the whole population

A group of units is selected and will be representative of the whole population

Question 23

What is sampling and how does it work?

Answer 23

Collecting data from a representative sample of the population (A collection of all the items about which we want to know some characteristics).

Often may require a sample from a TARGET population

The sample must be representative of the WHOLE population and not be biased in any way

The sample must be as representative as possible

Must collect as many samples as is feasible in the time available

Question 24

What does sampling cont involve?

Answer 24

Samples must be independent of one another

May be constrained by TIME and COST

The point of sampling is to deduce information about the entire population

Need to make inferences

The sample must be free from bias

The optimum sample is one which maximises precision per unit cost

Question 25

How do you decide on a sampling strategy?

Answer 25

Selecting a sample involves the formulation of rules and procedures, by which members of the population are included in the sample

The chosen sample is then measured using defined procedures to obtain the relevant data

Good sampling design should provide valid estimates of the population of data you are investigating

2 primary types: Random and purpose (information- rich)

Question 26

How does Random sampling work?

Answer 26

Overcomes biases

Divide the area into blocks

Stratified random sampling

Question 27

List the types of distribution of individuals

Answer 27

Homogeneous (Uniform) - evenly distributed

Patchy- showing a clustered distribution

Gradient - a distribution that varies smoothly over the sampling area

Stratified - showing a distribution which discret levels or strata

Question 28

List the different distribution types

Answer 28

Random distribution

Aggregations Regular distribution

Patch distribution

Distribution in the form of a gradient, with

Showing a steeper gradient than ^

Question 29

What is the sampling protocol?

Answer 29

Should decide on this before an investigation proceeds

The main aspects to be determined are:

The position of the sample

The size and shape of the sample area

The number of sampling units in each sample

Need to know the likely distribution of the units under investigation

Question 30

Truly representative samples should normally?

Answer 30

Taken at random, or in a way that ensures that every member of the population has an equal chance of being selected

Large enough to provide sufficient precision in estimating population parameters

Unbiased by the sampling procedure or equipment

Should use the resources efficiently

Question 31

Explain Bias

Answer 31

Intentional bias

Conduct during optimal conditions of the sampling method and for the species studied

Time of day, year, weather conditions should be considered

Consistent bias - objective of relative abundance surveys

Unbiased/ precise estimates - objective of absolute abundance surveys

Question 32

Give examples of Bias

Answer 32

• Effort bias
• Habitat bias
• Species/sex/age/class bias
• Density bias
• Activity bias
• Seasonal bias
• Time of day bias
• Tidal rhythm bias
• Weather bias

Question 33

How does identifying individuals work?

Answer 33

May be essential in some studies

BUT may be impossible within a group

Need to be distinguish reliably between one another

Resulting data is then more informative- can distinguish differences in known individuals

All individuals in a species. Do not behave in the same “species-typical” way.

Question 34

Marking methods identify by?

Answer 34

• Tagging
• Banding
• Transponders
• Micro chipping
• Notching
• Tattooing
• Dye marking
• Clipping
• Branding

Question 35

What can marking alter?

Answer 35

marking it may alter its behaviour or that of the others with which it interacts

Question 36

What is the problem with identification in the field?

Answer 36

Marking presents problems
May need traps, nets, drugs
Some forms of marking don’t last long
Traps need to be monitored

Question 37

What do you need to do to identify in the field?

Answer 37

Need to minimise stress - Reasons are scientific and ethical

Some species. Individuals have distinct markings - stripes, noses, ears, whisker spots, fins, tails, bills, scale patterns

Some acquire distinctive marks

Can be difficult

Requires verifiable demonstration of you ability to distinguish between the individuals

Question 38

Whats involved with tracking in the field?

Answer 38

Various techniques enable individuals to be tracked over long distances

Radio transmitters

Low level radiation

Collars can be fitted with GPS and data loggers

Question 39

Explain individual distinctiveness

Answer 39

Animals have distinct personalities

These can be rated reliably - capture overall patterns

For example bold or timid, aggressive or submissive

Question 40

List observations what than be differences in individuals behaviours

Answer 40

Statistical techniques are used primarily for drawing inferences about populations

Aim to remove the troublesome effects of differences in behaviour

Emphasise what members of the population have in common

Some differences in individuals are of biological significance

Can’t generalise to all members of a gp even on age or sex

2 or more reproductive tactics may be present within populations

Animals possess developmental plasticity to respond to environmental conditions in early life

Studies involving measurements of behaviour should take variations into account. For example categorise or ID them

Question 41

List the rules and methods of defining a group

Answer 41

Rules are usually implicit but should be made as explicit as possible

Assess how animals are distributed in spaces

Observe relative distances between individuals

Distance used depends on species. Sensory capabilities and their environment

Distinguish between groups and parties

The criterion distance could be the distance to the nearest neighbour

May be distributed bimodally

Definition of together will depend on the study:

Problems of definition vary between species

Collective pattern may be the most appropriate unit of measurement