Kids Learning Science

    

4th Standard Science Term-III

Life of Animals

Introduction 

    Have you ever wondered why a dog drools on seeing food?  Why cuckoo sings only during summer?  Why baby birds open their mouths when the mother returns to the nest? 

    Each animal has some unique behaviour.  Animal behaviour includes the activities of an animal and its interaction with other organisms.  E.g. Blinking, eating, walking and flying.

Group Behaviour in Animals

    Animals gain a lot of benefits by living together with other members of the same species.  The is called group behaviour.  Animals like tiger, bear etc live in solitary (alone).  Some animals live in small groups (E.g. Pride of a few lions) and some live as larger herd (E.g. Herd of thousands of wilde beest).

    Group behaviour is also called social behaviour.  Members of the group work together to find food, defend themselves and look after the young ones.  The main purpose of group behaviour is to help animals survive in nature.  E.g. All the fish in a school move together, following their leader in the front.  Staying in a group helps the small fish appear big.

Group behaviour in Bees

    When insects live together, they often follow a hierarchy.  E.g. Bees have one queen bee in every hive.  There are a few male bees called drones.  There are hundreds of female bees, which are the worker bees.

Nesting Behaviour in Birds

    Birds are very different from each other.  They live in different places, eat different foods and have different life styles.  Some birds permanently live in groups while others come together only during the breeding season.  Birds also live in groups.

  

  Not all the bird species build nests.   Some of them lay their eggs on the ground or in gap between rocks.  Most of the birds build their own nests carefully like engineers.  They build nests for their young ones.  Some weave leaves, some use twigs, some build with thorns then pad it with soft materials.

Group behaviour in Elephants

    Elephant group is called Herd or Parade.  For each group there is a female head, which leads the group towards the availability of food, water and safety.  The leader fights for their group.   All animals in a group obey the command of their leader.  Older animals teach manners and life skills to young ones.  Like elephants deer, bisons and monkeys also live in groups.

Animals and their Group Names

Animal         Group name         Animal         Group name         Animal            Group name

Lion         Pride                         Fish                School                      Ant               ColonyWolf         Pack                         Sheep              Flock                        Owl             Parliament

Advantages of Group behaviour in animals

S.No.        Group behaviour                            Example

1.               Procuring food                                 Hunting and sharing in lions.

2.               Taking care of young ones               Female elephant takes care of its calf.

3.                Protection from predators               Wildebeests make sounds to alert their group.

4.               Division of labour                            Honey bees collect nectar, build comb and clean hive etc

5.               Energy conservation                        Birds fly in "V" shape to reduce wind resistance

Adaptations in Animals

    Adaptation is the most essential factor of all living beings.  The changes in  an animal's behaviour to adjust with its habitat is called adaptation.  If an organism fails to  adapt to the particular environment, its survival is difficult. 

    All animals have special body parts to live in a particular place at a particular time.  E.g. Giraffes have developed very long necks because of their environmental demands.

Some more examples of adaptations are given below.

Tigers and Zebras have lines so they can hide themselves.  

Camels have broad feet to walk in the desert.

Fish have gills to breathe in the water and fins to  swim.

Elephants have long and large trunk to get their food.

There are three basic types of adaptations seen in animals.  They are, 

1. Structural adaptations

    Changes in the physical features of the animal are called structural adaptations.  E.g. Polar bears living in cold climate have physical adaptations, such as thick fur and short ears to reduce heat loss.

2. Physiological adaptations

    Changes in the functions of the animal's body are called physiological adaptations.  E.g. Dog shivers to generate more heat when it is cold and pants when it is hot.

3. Behavioural adaptations

    Changes in the behavioural activities of the animal are behavioural adaptations.  E.g. Birds migrate to avoid adverse conditions.

Structure of Insects

    Insects have three main body regions.  They are;

    Head, thorax, and the abdomen.  All parts of the insect are inside and exoskeleton.

• Head The main visible parts on the head are the large compound eyes, the antennae (feelers) and the mouth parts.
• Thorax The thorax is the middle region of the body.  It bears three pairs of legs and two pairs of wings.
• Abdomen The abdomen is the last part of the insect's body.  Abdomen of  the insects has clear segmentation.

    Insects have differences in structures like wings, legs, antennae and mouthparts.  The legs are modified for walking, jumping, digging or swimming.  

    Most of the insects have wings which can be folded flat over their body.  E.g. Bug.  There are some insects which cannot fold their wings.  E.g. Dragonfly.  Some insects are wingless.  E.g. Silverfish.

Special senses in Ants and Bats

    Some animals have well development special senses.  These special senses help the animals experience the world around them.

Ants

    Ants have sense of sight, smell, taste and touch.  Ants have organs of smell and taste in their antennae.  They feel the vibrations in the ground through their feet.  Ants have a good sense of smell.

Bats

    Bats have a good sense of hearing.  They use sound navigation.  They produce ultrasonic sound which helps the bats find their way at night and find out the objects on their path.  This is called "Echolocation".

    Vampire bats feed on the blood of their prey.  Vampire bats have heat-detecting noses which allow them to find their prey.

Animal Active at Night

    Some animals sleep in the day time and are very active at night.  A good example is cat at your home.  Not only small animals but also some birds are active at night.  Such animals are called Nocturnal animals.  E.g. Owl, Bat.

    Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight.

Parental Care

    Efforts taken by the adult to take care of their young ones is called Parental care.  Parental care increases the survival rate and improves the quality of young one. It also increases the reproductive success of animals.

Kangaroo

    Kangaroo is well known for parental care.  Female kangaroo carries its baby in its pouch.  The pouch provides a safe place for the young ones to stay until they grow large enough to survive outside on their own.

Cow 

    Cow gives milk and protects its calf from the enemies.  Mother and calf communicate with each other through a sound.  Calves respond to the calls from their own mother by calling back.

Human beings

    Humans promote and support the physical, emotional, social and intellectual development of their child.  The human infant is completely helpless at birth.  Mother takes good care of the baby by feeding, helping to sleep and making comfortable with clothes etc.  Through proper parenting the child is taught whatever needed to live successfully in the society.