Ethology And Its Methods || Animal Behaviour

 ETHOLOGY AND ITS METHODS

 

The various aspects related with animal behavior can be studied by applying the following methods -

1. Under natural conditions.

2. Experimental Analysis

3. Statistical Analysis

1. Under Natural Conditions: -

The best way of studying animal behavior is under natural conditions. Observation may be in the form of field notes, checklist of behavior patterns, tape recorders, motion pictures etc. While studying animal behavior in natural surroundings circadian rhythms and seasonal cycles are taken into consideration.

2. Experimental Analysis: -

Experiments are conducted in two ways viz.

Field experiment and Laboratory experiment –

(A) Field Experiment: - These are performed with least disturbance to the animal. The first phase involves a thorough description of all aspects of the animal under observation. For this binocular and infrared devices are required when more than one individuals are to be observed, it is desirable to make cinematographic or portable T.V. recording. In field experiment it is most essential to identify the animal correctly.

For the next phase of study following aspects of study are more important.

(a) Protective Behavior: - It involves defensive behavior against predators like camouflage (a form of visual deception) and threat (a form of communication that usually occurs in situation involving mild aggregation and fear).

 

(b) Social System: - It is the most complicated behavior as the animal under study occupies the same ethological niche and competition tends to be more among members of the same species. Social behavior makes it possible for the individual of a community to make adjustments between the antagonistic tendency to cluster and to disperse in a way that suits them the best. This social system in animal can only be reveal by field study in the natural habitat. The most appropriate approach to study behavior is on comparative basis.

 (c) Communication: - The conclusion derived from comparative observation can be tested experimentally by studying "Fixed Action Patterns (FAP or stereotype pattern) which are similar to reflexes.

It is now established that many FAP’s are controlled by brain, e.g. rapid escape response of squid and crayfish. The fight of locus and the song of cricket.

Some FAP sub serves the purpose of communication within a species. Examples of communications are numerous viz. song in birds, whales and crickets; flashing in fire flies and deep sea fishes, tail wagging in dog, roaring in lions, hissing in snakes, and cats and waiving of arms in men and jumping spiders.

To investigate these signal one should study the consistency of the reaction of an animal, while attempting to manipulate behavior by presenting it with the essential features of different signals.

Nervous and hormonal system affects the animal behavior thus giving a large number variable. This can be reduced by keeping animals in captivating and using them in laboratory studies.

(B) Laboratory Experiment: -

Laboratory studies can be done adopting the following methods –

(a) Measurement of behavior by direct observation : -  According of preliminary observations may be in the form of notes, recording on tape recorders and photographic recordings.

The analysis of behavior requires proper categorizations of behavior patterns. In simple behavioral studies, the records maintained on paper tape or video films are satisfactory but complex behavioral patterns can directly be observed by using event recorders, which registers sequences of events continuously for a period of time.

(b)Automatic Measures: - Operant method is the most Common automatic method. It mainly consists of training an animal to perform a task to obtain a reward. It is a psychological process of learning e.g. Rat may be trained to press a lever or a pigeon to peck at pink to obtain a food reward.

(c) Control: - Control is essential for experimental studies. These are of two types –

(i) Control of experimental region: - In this case the control animal and the experimental animals are tested simultaneously. When the experimental animals response, the same consequences is given to both the animals, e.g. a monkey which receives electrical shocks for making inerrant responses for a simple task develop gastric ulture, while its control remained healthy because he did not had to make decisions though it also received the shocks.

(ii) Control of Environment: - Experimental data usually shows variability. Food and water availability and ambient temperature all should be controlled in the animals environment. Following precautions should be taken before performing the experiment –

·        Control an experimental animal should be tested. Simultaneously.

·        It is based to rotate the order on repeated test.

·        Every individual behaves in a different manner, therefore only those animals should be taken which match to the maximum extend.

·        Social Environment should be maintained constant by raising animals in isolation.

·        As like temperature and noise affect the animals, they should be controlled.

·        To achieve accuracy of the tests, test should be carefully repeated.

3. Statistical Analysis: -

After performing the field or laboratory experiment the data is reduced to numerical values by statistical methods. Arithmetic Mean is usually sufficient and should be accompanied by some measure of variability.

Descriptive statistical data are used to help draw inference concerning conditions which draw about the change in statistical value

E.g. it is known that density of animals may be related to geographical conditions. (Latitude Longitude, Altitude).

 

Climate and other ecological aspects:-

Suppose we have data showing relative population densities of a species for a period of 10 years and a systematic shift out of 1 region into another was observed. The shift may be related to certain ecological factors and thus be able to predict that when certain aspects of the ecology changed, there would be a movement out of a particular region.

Advantages and disadvantages of three methods: -

Method	Advantages	Disadvantages
Natural	Best way to gain knowledge and concerning natural behavior patterns, both Individual and social variables for future experimental analysis may be isolated.	Lack of controls may lead to ambiguity in interpretation.
Experimental	Rigid control over environmental events. Ability to manipulate variables in systematic manner. Excellent for isolations of relevant antedecont conditions.	Artificiality of laboratory conditions may be affect generality of findings.
Statistical Analysis	Excellent for population descriptions. Relationship among many measures can be determined techniques by correlation techniques.	Lack of control leads to difficulty in interpretations.

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