observing & measuring behavior

ethology

the biological study of behavior

historical focus of behavior study

before ethology, scientists studied behavior from a psychological viewpoint, mainly to understand human behavior

ethology pioneers

-von Frisch, Tinbergen, and Lorenz

-shifted focus to understanding animal behavior for its own sake

three approaches to studying animal behavior

1.observational

2.experimental

3.comparative

observational approach

observing animals in nature, a lab, or a controlled environment and noting what they are doing

limitation of observational approach

risk of assuming when none exists

experimental approach

controlled experiments that manipulate variables to establish causation and better understand specific behaviors

comparative approach

compares behaviors across species, often using evolutionary history to explain how and why behaviors exits

comparative approach and extinct species

behaviors of extinct species can sometimes be inferred by comparing behaviors across living species

presence/absence of behavior

recording whether or not a behavior occurs

frequency of behavior

how often the behavior occurs

duration of behavior

how long the animal performs the behavior before stopping

intensity of behavior

the strength or focus with which the animal performs the behavior

timing of behavior

when the behavior occurs

• ex: time of day, relation to feeding, socializing, etc

latency of behavior

the amount of time before the behavior occurs again after its last occurence

why record behavior objectively?

-prevents incorrect assumptions

-reduces bias

-ensures accurate data interpretation by others

example of correct recording

the chicken is standing with an elongated neck, body upright, and flapping its wings up and down without taking flight (objective & descriptive)

levels of descriptive detail in behavior recording

-individual muscle movements

-muscle group movements

-whole limb movements

-parts of body relative to each other

-whole animal movements

-effect on environment

-effect on another individual

what is an ethogram?

a list and description of behaviors performed by particular individuals in a particular environment

are ethograms universal?

-no, they are contextual to the species and environment

-no single “correct” ethogram exists

factors influencing ethograms

must be individualized to the animal and environment

• ex: rat in a cage vs rat in a sewer

states in ethograms

long-duration behaviors with distinct start and stop points

• ex: resting, grooming, etc

events in ethograms

short-duration behaviors with less clear boundaries

• ex: pecking, wing flaps

events within states

events occur during longer states

• ex: pecking while foraging

mutual exclusivity in ethograms

behaviors should be described in a way that prevents overlap or confusion between categories

four main sampling methodologies

1.ad-libtium behavior recording

2.conspicuous/continuous behavior recording

3.point/instantaneous/scan sampling

4.period occurrence (one-zero) sampling

ad-libitum recording definiton

-opportunistic recording of behaviors without constraints

-observer notes deemed relevant

pros of ad-lib recording

-useful for early stage of observation

-allows capturing unexpected behaviors

cons of ad-lib recording

-biased → depends on observer judgement

-not reliable for quantitative data collection

conspicuous/continuous recording definition

continuous observation while recording only predetermined behaviors of interest

pros of continuous recording

-useful for capturing rare behaviors

-can also be automated with technology

cons of continuous recording

-ignores other potentially important behaviors

-observer focus is limited to selected behaviors

point/instantaneous/scan sampling definition

recording behaviors at regular, predetermined time points to see if a behavior of interest is at that instant

pros of scan sampling

-efficient for observing large groups with limited personnel

-reduces continuous observation workload

cons of scan sampling

-misses rare or short-duration events

-difficult to confirm behaviors requiring time to identify

one-zero sampling definition

recording whether a behavior occurred (1 = yes, 0 = no) within a set time interval

pros of one-zero sampling

-captures rare events

-easy to record quickly

cons of one-zero sampling

-does not capture duration or frequency accurately

-requires short observation intervals for reliability

ad-lib recording (pecking example)

observer notes when the chicken pecks, whenever noticed

continuous recording (pecking example)

observer tracks every instance of pecking behavior continuously (possibly with video)

instantaneous/scan sampling (pecking example)

at each set time point, observer records whether or not the chicken is pecking at that moment

one-zero sampling (pecking example)

within each time interval, observer records whether pecking occured at all (1) or did not occur (0)