16. Conducting Behaviour Observations Flashcards
What two levels of decisions must be made?
- Sampling Rules
- specifies which subjects to watch and when
- eg. ad libitum (aka everything), focal sampling, scan sampling and behaviour sampling - Recording Rules
- specifies how the behaviour is recorded
- eg. continuous, one-zero sampling
What is ad libitum sampling?
Means that no systematic constraints are placed on what is recorded and when
- Simply note whatever is visible and seems relevant at the time; eg. preliminary observations, just sitting and watching the animals
- Caveat: observations biased towards behaviour patterns and individuals which happen to be most conspicuous (not always catching rare and subtle behaviours)
What are the 4 sampling rules?
- Ad libitum sampling
- Focal (animal) sampling
- Scan sampling
- Behaviour sampling
What is focal (animal) sampling?
- Means observing one individual (or one dyad, one litter or some other unit) for a specified amount of time and recording all instances of its behaviour (usually for several different categories of behaviour)
- Handy means of studying large groups
- Caveat: can be difficult under field conditions or when focal animals are out of view
What is scan sampling?
- Means that a whole group of subjects is rapidly scanned, or “censused”, at regular intervals and the behaviour of each individual at that instant is recorded
- A single scan can take a few seconds or a few minutes (depending on the amount of information being gathered for each individual)
- Can be used in combination with other samplingmeans
- Caveat: usually restricts the observer to a limited number of behaviour categories
What is behaviour sampling?
- Means watching the whole group and recording each occurrence of a particular type of behaviour, together with details of which individuals were involved
- Used for rare but significant behaviours (eg. fights or copulations)
What are the two basic types of recording rules?
- Continuous recording
- Aims to provide an exact and faithful record of the behaviour, measuring true frequencies and durations and the times at which behaviour patterns stopped and started
- Could be a video or an observer - Time sampling
- Involves sampling the behaviour periodically, but makes it possible to record several categories of behaviour simultaneously
- Less information is preserved and an exact record of the behaviour is not necessarily obtained
What are the two principle types of time sampling?
- Instantaneous sampling
- not taking any info during the sample interval, getting it exactly at the sample point “beep”
2 One-zero sampling
- take nothing on the “beep”, gathering info at the interval
What are sample intervals? What are sample points?
Sample intervals
- An observation session is divided up into successive, short periods of time called sample intervals
Sample point
- The instant of time at the end of each sample interval is referred to as a sample point
Ex. a 30 min observation period may be divided into 2 minute sample intervals, giving 15 sample points
- Provides information on duration of behaviour
What is continuous recording?
Each occurrence of the behaviour pattern is recorded, together with information about its time of occurrence
- Exact record; times at which each instance of the behaviour patter occurred (for events), or began and ended (for states)
- Provides information on duration and frequency of behaviour
- Necessary to analyze sequences of behaviour
How is instantaneous sampling (a type of time sampling) conducted?
With this sampling method the observation session is divided into short sample intervals
- On the instant of each sample point (“beep”), a record is made of whether or not a given behaviour pattern is occurring at that moment
- Score obtained is expressed as the proportion of all sample points
eg. 30 min recording session divided into 15 sec intervals. A behaviour occurred 40 out of 120 sample points = 0.33 - Used to record behavioural states that can equivocally be said to be occurring or not occurring at any instant in time
- eg. body posture, orientation, proximity, body contact, locomotor activity etc.
How is one-zero sampling (a type of time sampling) conducted?
Referred to as “fixed-interval time span sampling”, with recording session divided into short sample intervals
On the instant of each sample (“beep”), you record whether or not the behaviour patter has occurred during the preceding sample interval
- Irrespective of how often, or for how long, the behaviour pattern has occurred DURING that sample interval
- Data is expressed as the proportion of all sample intervals during which the behaviour pattern occurred
eg. behaviour occurred during 50 out of 120 15 sec sample intervals in a 30 min session, the score would be 50/120 = 0.42 - Caveat: should only be used with very short sampling intervals if other sampling methods do not sufficiently capture a behaviour’s occurrence
What does the size of the sample interval depend on?
- Number of behaviour categories being observed at once
- Nature of the behaviour
- Shorter sample intervals provide a more accurate time-sample record, but are more difficult for recording several categories of beahviour
- Striking a balance is important…partly based on trial and error/previous experience (30sec to 2min is common in livestock species)
What are 3 types of recording mediums?
- Video recordings
- Can be continuous or scan sampled
- Permanent record of behaviour (in case you want to go back later)
- Not always “fastest” or most efficient use of time - Verbal descriptions
- In the form of long-hand written notes or dictated
- Useful during pilot studies and preliminary observations - Automatic recording devices
- May involve some engineering and technology, but has ability to generate a lot of data (which can be automatically summarized depending on the software)
Check (observation) sheets
- Basic pen and pencil method
- Cheap, flexible and surprisingly powerful way to record observations - Basic design
- Columns and rows
- Categories of behaviour along the top, sample intervals along the side
- Can be modified and adapted for the study (custom made)
- Easy to modify after preliminary observations
