Field techniques for biologists

• Hazard


  Something that can cause harm
• Risk


  the likelihood of harm arising from exposure to a hazard
• Hazards in the field


  Terrain

  Weather conditions

  Isolation

  contact with harmful organisms
• Point counts


  A point count involves the observer recording all individuals seen from a fixed point count location. This can be compared to other point count locations or with data from the same location at a different time.
• Quadrats


  Common methods for sampling organisms which are slow-moving or stationary. The frame is laid down and a direct count of what is in the frame or a percentage cover can be estimated.
• Random Sampling


  no subjectivity as each member of the total population has an equal chance of being selected
• Systematic sampling


  samples which are chosen systematically or regularly. They are evenly or regularly distributed in a spatial or temporal context.
• line transect


  at specific point along a line the organisms present are recorded. The presence or absence of species could also be noted. Often plotted against the topography of the land to give more information on the habitat.
• Belt transect


  uses two parallel lines and records the plants found between the lines at given points
• Stratified sampling


  Used when the parent population or sampling frame is made up of different sub-sets of known size. The results should be proportionate and representative of the whole
• Pitfall trap


  for animals which are mobile
• Net


  size of net and mesh can directly affect what you can capture
• pan traps


  brightly coloured shallow dishes with a liquid that has a low surface tension. Attracts insects to fly in and drown
• Camera traps


  Elusive animals are difficult to trap and which contact should be avoided can be observed using camera traps which allow direct observations without interfering with the natural behaviour of the animal.
• Scat sampling


  an indirect method of sampling which can provide much information about the animals being studied
• identification methods


  classification guides, keys or analysis of DNA or proteins
• Classification methods


  taxonomy and phylogenetics
• three domain


  Archaea, Bacteria and Eukaryota
• King Phillip Came Over For Green Skittles, taxonomy classifications


  Kingdom

  Phylum

  Class

  Order

  Family

  Genus

  Species
• Plant kingdom divisions


  Liverworts, mosses, ferns, conifers and flowering plants
• Animal kingdom divisions


  chordata, arthropoda, nematoda, platyhelminthes and mollusca
• Familiarity with taxonomic groups


  allows predictions and interferences to be made about the biology of an organsim form better-known organisms
• Classification


  the grouping of living organisms according to similar structures and functions.
• Phylogenetics


  the study of evolutionary history and relationships amongst individuals groups of organisms. Phylogenetics is changing the traditional classification of many organisms.
• Phylogenetic trees/ Phylogeny


  The use of sequence data, morphology and protein structures has allowed more detailed of the relationships between organisms to be produced.
• identification in sampling


  key to getting exact and informative data
• Model organisms


  Used to obtain information that can be applied to species that applied to species that are more difficult to study directly. This is because model organisms are those that are either studied or have been well studied
• taxonomy


  where organisms are identified and named by classification groups determined by their shared characteristics
• indicator species


  presence, absence or abundance of particular indicator species can give information of environmental qualities, like the presence of pollutants
• susceptible species


  species that is absent or has a reduced population shows they are susceptible to some factor in the environment
• favoured species


  a species that is increasing or abundant is being favoured by the environmental conditions
• N=MC/R


  N= population

  M= number caputured and marked

  C= number captured in 2nd sample

  R= number recaptured
• assumptions made in mark and recapture


  all individuals have an equal chance of capture

  no immigration or emigration in time interval between 1st and 2nd sample

  Marked individuals can mix fully and randomly with the total population
• what can presence/absence/abundance tell us about the environment?


  gives information about conditions and allows monitoring of the ecosystem
• Banding


  often used on birds, attached to leg
• Ethical methods of marking


  Banding, Painting, Hair clipping, Tags, Surgical implantation
• Tagging


  used for remote tracking but must be securely attached and not interfere with the animals normal behaviour
• Surgical implantation


  prevents tags from interfering with the species but there are implications for the welfare and for the expertise required
• Painting


  non-toxic, biodegradeable paint must be used. IMportant to consider the impact of scent and colour on marking animals
• Hair clipping


  clearly identifiable section of hair removed can be used as a very effective form of identification. Care must be taken regarding the size of the clipping, distress to the animal, and social signals with the animals.