Ethology (Animal Behaviour)
Ethology means the study of animal Behaviour. Heini Hediger was the first scientist called as the “Father of Zoo Biology”, who emphasized the need of application of ethology to captive wild animal management.
Causation of Ethology (Animal Behaviour)
There are two types of causations- Proximate causation and Ultimate causation.
- Proximate type: (eg. Singing of bird in spring) Hormonal, neural and stimulus specific factors act inside the animal body.
- Ultimate type: (eg. Proximity of a prospective mate) It emphasizes the reasons that are responsible for the occurrence of the earlier phase.
Distance and Space
Distances and spaces are more important in terms of ethology of wild animals.
Distance
- Individual distance: it is the personal space or distance that an animal prefers between itself and other members of its own species.
- Social distance: it is the one which an animal maintains with other members of its social group. It provides cohesiveness to the group.
- Critical distance: if this is violated and if there is no place or route to escape, animal may threaten or attack the opposing individual.
- Flight distance: if it is violated bird or animal will run or move away.
Space
Space or Territory is a fixed area from which intruders are excluded by some combination of advertisement, threat or attack. Aggression may be revealed if territory is violated especially by the members of its own species.
Types of Behaviour
- Aggression
- Reproductive behaviour
- Parental care
- Developmental behavior
- Vices
Aggression
The major causes are given below:
- Competition of males for successful selection of females.
- Conflict over food resources.
- Conflict over infants.
- Disturbance of social organization (crowding, territorial disputes).
- Temporal distortions (eg. Reduced time for feeding).
- Incompatible artificial composition of groups.
- Distortion of social role.
- Reduction of ecological functions.
Aggression is often related with musth in an elephants (The musth related behaviour includes the followings; Disobedience, Aggression, Tendency to attack, Frequent urination, Frequent trumpeting etc.,)
Reproductive Behaviour
Understanding of biology is a must to understand about the reproductive behaviour of the wild animals. The reasons for abnormal reproductive behaviour:
- Improper social group composition.
- Improper space availability.
- Failure of niche based requirements.
Niche
For example, Need of two nest boxes is a must for reproductive success in case of female tree shrews.
For example, Provision of nest box newly at the start of the breeding season may enhance the courtship behavior of some avian species.
Composition of social group
To enhance the characteristic mating system of the particular wild animal species, there should be an adequate composition of the concerned social group.
Females have more parental investment than males. Examples for differences in parental investment among sexes:
- In grizzly bears and tigers, males have home range which may overlap the territory of more females. Hence more offspring can be produced.
- Most of the time birds may reveal monogamy unlike mammals.
Parental Care and Maternal care
Placenta is the major pathway for intersection of mother with the fetus. The behavioral development in fetus is influenced my mother due to following:
- neuro endocrine changes.
- Ingestion of chemicals / drugs affecting the developing brain.
- Altered circulation through the placenta.
- Altered maternal diet.
Birth
The hormones regulating pregnancy and parturition are same in most of the mammals like estrogen, progesterone and prolactin. However, in animals like chimpanzees, progesterone does not reduce as it does in other primates.
Post-partum
Vocalization, olfactory stimuli and infant activity regulate the interactions between the offspring and mother. Though lactation is dependent on prolactin and milk let down is dependent of oxytocin, the performance of nursing behavior does not depend on all these hormones.
Maternal attachment
This is being carried out by the following:
- licking
- nursing
- vision
- audition
Imprinting
It is the special form of filial attachment occurring during a precise and sensitive period. ( eg. For few hours after hatching in some species of birds.)
Maternal aggression
Most common behavior observed.
Eg-Attack of gaur on carnivores attempting to predate on the young ones or calves.
The pregnant and lactating wild animals exhibit intense aggressive behavior.
Alloparenting
Alloparenting means the care taking of an infant by individuals other than the mother.This means the aunting behaviour. Mostly the close relatives are involved with this type of behavior.
Developmental Behavior
Social deprivation
Altered behavior due to social deprivation is commonly observed in non-human primates like rhesus macaques. The following behaviors get affected.
- eating behaviour
- drinking behaviour
- reaction to pain
- explorative behaviour
- maternal motivation and skill
Imprinting
Imprinting is a genetically programmed learning, observed in birds as well as in many mammals. Imprinting occurs during a relatively short, well defined period of time usually early in the life of the individual.
Behavioural Disorders
Stereotyped Behaviour
Repetition of motor acts is caused by a variety of reasons especially the boredom. Examples of stereotyped motor acts are given below:
- rocking
- repetitive somersaulting
- repetitive head tossing or weaving
- repetitive bouncing in place
- repetitive pacing
Displaced activities
Displaced activities is the inappropriate activity due to strong activation of innate behaviour by stimulus. Eg. When primate fails in attracting visitors during begging, it engages in grooming and scratching themselves.
Feeding disorders
For example, Food wasting behaviour in captive raccoons and Plucking of entire feathers of chicken by ocelots.
Vices
Stereotyping, usage of stools, spitting on persons etc.
