1a, 1b, 1c, 1d, 1e: Field Techniques Flashcards
Aspects of fieldwork which could be a hazard:
- adverse weather conditions
- difficult terrain
- problems associated with isolation
- contact with harmful organisms
Sampling should be carried out in a manner which…
Minimises impact on wild species and habitats
When sampling wild organisms, considerations should be given to…
- rare/vulnerable species
- habitats which are protected by legislation
What is the point count technique
- a point count involves the observer recording all individual seen from a fixed point count location
- this can be compared to other point count locations or with data from the same location gathered at other times.
What sampling method is used for plants and other sessile or slow-moving organisms
Quadrants of a suitable size and shape, or transects.
How to sample mobile species
Using capture techniques such as traps and nets
How can elusive species be sampled
- Directly using camera traps
- indirectly using scat sampling
What is random sampling
- Individuals selected from the larger population must be chosen completely by chance
- Minimises the effect of bias which may affect a non-random sample
What is stratified sampling
- population being sampled is split into sub populations
- individuals are then randomly selected from each sub-population
What is systematic sampling
- taken at regular intervals (eg in transect)
- more likely to reveal nest sites (eg than a random search)
Identification of an organism in a sample can be made using:
- classification guides
- biological keys
- analysis of DNA or protein
What is taxonomy?
- the identification and naming of organisms
- their classification of into groups based on shared characteristics
(Classic taxonomy classification is based on morphology)
Phylogenetics definition
The study of the evolutionary history and relationships among individuals or groups of organisms.
Phylogenetics uses heritable traits such as __________, _____________ and _____________ to make inferences about an organisms evolutionary history and create a phylogenetic tree
Morphology, DNA sequences and protein structure
Advantage of genetic evidence in seeing relatedness
Genetic evidence can reveal relatedness obscured by divergent or convergence evolution
What is divergent evolution
Accumulation of differences between closely related populations leading to speciation.
What is convergent evolution
Independent evolution of similar features in species of different periods in time
(Creates analogue structures)
What does familiarity with taxonomic groupings allow?
Predictions and inferences to be made about the biology of an organism from better known (model) organisms.
Examples of taxonomic groups
Nematodes, arthropods and chordates
What are model organisms
Those that are either easily studied or have been well studied
Examples of model organisms
- bacterium e. Coli
- flowering plant arabidopsis thaliana
- nematode C. elegans
- arthropod drosophila melanogaster
- mice, rats and zebrafish
Why are model organisms useful
Information obtained from them can be applied to other species that are more difficult to study directly
Presence, absence or abundance of indicator species can give…
Information of environmental qualities, such as the presence of a pollutant
How can an absence or reduced population be used to monitor an ecosystem?
- absence or reduced population indicates a species is susceptible to some factor in the environment
- abundance or increased population indicates it is favoured by the conditions
Assumptions made in the Mark and Recapture technique for estimating population size
- all individuals have an equal chance of recapture
- there is no immigration or emigration
- individuals that are remarked and released can mix full and randomly with the total population
(Sampling methods used each time are identical)
Examples of marking animals
- banding
- tagging
- surgical implantation
- painting
- hair clipping
The method of marking and subsequent observation must…
Minimise the impact on the study species
Measurements used to quantify animal behaviour
- latency (time between the stimulus occurring and the response behaviour)
- frequency (number of times a behaviour occurs within the observation period)
- duration ( length of time each behaviour occurs during the observation period)
What does an ethogram do
An ethogram of the behaviours shown by a species in a wild context allows the construction of time budgets
An ethogram lists species-specific behaviours to be observed and recorded in the study
Why are ethograms useful
Recording the duration of each of the behaviours in the ethogram (together with the total time of observation) allows the proportion of time spent on each behaviour to be calculated in the time budget
Importance of avoiding anthropomorphism
anthropomorphism can lead to invalid conclusions
What is anthropomorphism
The attribution of human traits, emotions or intentions to non human entities
Eg dolphins ‘smiling’
