Field techniques for biologists

Hazard

A hazard is anything that poses a potential hard or threat to an individual or the environment

Risk

A risk is the likelihood of harm arising from exposure to a hazard

Risk assessment

A risk assessment involves identifying and evaluating hazards, and identifying control measures needed to minimise risk

Control measure

Control measures are ways to reduce the risk of hazards, which can include appropriate equipment, clothing, footwear and means of communication

Considerations when sampling

Sampling should be carried out in a manner that minimises impact on wild species and habitats, consideration must be given to rare and vulnerable species and habitats that are protected by legislation

Point counts

Involves the observer recording all individuals seen from a fixed location, which can be compared to counts from other locations or with data from the same location gathered at different times

Transects

Sampling lines laid across habitats affected by environmental gradients such as altitude, light intensity or tidal movements, where samples are collected at intervals called stations along the line

Line transect

Normally used to study the distribution of a single plant species and those individuals touching the line at a station are counted in the sample

Belt transect

Samples a wider zone along a transect and can be used to study a community of plants or sessile animals

Frame quadrats

Simple square frames of various sizes, sometimes subdivided into smaller squares used for estimating the percentage ground cover of species

Point quadrats

They have metal spikes that are pushed down into the plant community; individuals touching the spikes are counted in

Sampling mobile species

Capture techniques, such as traps and nets, are used to sample these species

Sampling elusive species

These species can be sampled directly using camera traps or an indirect method, such as scat sampling

Stratified sampling

Separate samples taken from different strata of the area being studied

Systematic sampling

Samples or sample sites taken at regular intervals

Random sampling

Samples or sample sites have an equal chance of being selected

Identification of species

Can be made using classification guides, dichotomous biological keys, or analysis of DNA or protein

Classification guides

Usually deal with a related group of species such as birds, dragonflies or butterflies, they are often illustrated and give identification details as well as information on distribution, diet, migration and breeding times

Dichotomous keys

Can be used to identify more difficult groups and are usually laid out as a series of questions with answers that lead the used further into the key and finally to the identification

Classifying organisms

Can be done with taxonomy and phylogenetics

Taxonomy

Involves the identification and naming of organisms and their classification into groups based on shared characteristics 

Classic taxonomy classification

Based on morphology

Morphology

Study of the shapes and structures within an organism

Phylogenetics

The study of the evolutionary history and relationships among individuals or groups of organisms, it is changing the traditional classification of many organisms