Field Techniques for Biologists

• what must be considered before carrying out fieldwork?

  health and safety
• what aspects of fieldwork present a hazard?

  adverse weather, difficult terrain, problems associated with isolation and contact with harmful organisms
• definition of risk


  the likelihood of harm arising from exposure to a hazard
• what does a risk assessment involve?

  identifying control measures
• examples of control measures


  appropriate equipment, clothing, footwear and communication means
• how do you sample a species without counting every organism?

  take a number of samples from habitat and make the necessary assumption that the samples are representative of the general habitat
• how should sampling be carried out?

  in a way that minimises impact on wild species and habitats
• what considerations must be given when sampling?

  to the rare and vulnerable species and habitats protected by legislation
• what type of sampling is used when an area is very large, uniform and there's limited time?

  random sampling
• random sampling techniques


  large numbers of samples are taken from different positions within habitat
• what equipment is commonly used for random sampling?

  quadrat
• what type of sampling involves samples being taken at fixed intervals along a line?

  systematic sampling
• what technique is used in systematic sampling?

  doing transects in a line across an area where there are clear environmental gradients
• what is stratified sampling?


  when the population is divided into sub-populations
• what sampling technique is used to study avian populations?

  point count
• what techniques are used in point count?

  the observer records all individuals seen from a fixed point count location to compare with other point count locations or data from a different time of day
• examples of remote sensing

  satellite tracking and radio-tagging
• when is remote sensing used?

  to inform conservation biology and environmental management
• what sampling equipment is used for sessile and slow moving organisms?

  quadrats and line transects
• what sampling technique is used for mobile organisms?

  traps (e.g. pitfall traps) and nets
• what sampling equipment is used for elusive species?

  camera traps or scat sampling
• what procedure must be done after sampling?


  identification
• how can identification of an organism be made?

  classification guide, biological keys and analysis of DNA/protein
• what 2 ways can organisms be classified?

  taxonomy and phylogenetics
• definition of taxonomy


  the identification and naming of organisms and their classification into groups based on shared characteristics
• what is classic taxonomy based on?

  morphology
• what is binomial nomenclature?


  the formal system of naming species of living things by giving each a scientific name composed of 2 parts (genus and species)
• what is phylogenetics?


  the study of the evolutionary history and relationships among individuals or groups of organisms
• what heritable traits does phylogenetics use?

  morphology, DNA sequences and protein structure
• how is a phylogeny (phylogenetic tree) created?


  uses heritable traits to make inferences about an organism's evolutionary history
• what is a phylogeny?

  a diagrammatic hypothesis of an organism's relationship to other organisms
• what can genetic evidence reveal?

  an organism's relatedness obscured by divergent or convergent evolution
• what can model organisms do?

  allow for predictions and inferences to be made about the biology of an organism due to its taxonomic grouping
• examples of taxonomic groups

  nematodes, arthropods and chordates
• examples of model organisms

  the bacterium - e. coli, the flowering plant - arabidopsis thaliana, the nematode - c. elegans, the arthropod - drosophila melanogaster (fruit fly) and the chordates - mice/rats/zebrafish
• what is a model organism?

  organisms that have been well studied or are easily studied
• what can the presence, absence or abundance of an indicator species tell?

  gives information of environment qualities e.g. presence of pollutant
• what does a lower indicator species population indicate?

  the species is susceptible to an environmental factor
• what does an abundance of an indicator species indicate?

  the species is favoured by its conditions
• what method is used to estimate population size?

  mark and recapture