3rd Class Science Birds Birds

LEARNING OBJECTIVES

This lesson will help you to: -

• study different types of birds.
• observe the feathers of different birds.
• learn about various shapes and features of the beak and claws.
• know about the nest of different birds.

Real Life Examples

• Many birds fly together in flocks. Flocks are so prevalent in some bird species that these groups of birds have special names, such as a raft of ducks, a charm of finches,

a horde of ravens etc.

• Birds make a variety of calls, songs and nonverbal sounds with a language as complex as any spoken words.

Amazing Facts

• Geese save energy by flying in a V- formation.
• A woodpecker can peck 20 times a second.
• The Humming birds are the only birds that can fly backwards.
• parrots are the longest- living birds. They can reach an age of up to 100 years
• An ostrich’s eye is bigger than its brain.

QUICK CONCEPT REVIEW

Birds and their Habitats

Birds live in different habitats.

Forests, farmlands, lakes, rivers, coasts etc., all have their own characteristic birds.

The habitats of birds in our country (India) can be divided into the following broad types:-

(a) In forest areas

(b) Near water bodies

(c) In farms

BIRDS AND THEIR MOVEMENT: MIGRATION

• Very few birds have a lifestyle without physical activity.
• Birds move in search of food and good weather condition.
• Birds migrate towards areas like nesting sites, food source etc.

For example. Birds such as ducks and geese along with other birds come to wetlands in September-October and leave in March- April.

BIRDS AND THEIR HOME-NESTS

• Birds make different types of nests with different styles.
• Not all birds make their nest. Some birds, instead lay their eggs in other birds nest's. For example Cuckoos simply lay their eggs in the nest of the host species and play no further role in rearing their young ones.                                
• Birds make their nests using branches, twigs and leaves etc.
• The mother bird lays eggs in the nest and sits on them to keep them warm. After a few days, the eggs hatch and the baby bird comes out. The parents feed them for some days. Then the baby birds open their eyes, develop feathers and learn to fly and finally leave the nest.

BIRDS AND THEIR BEAUTIFUL FEATHERS

• The body of a bird is covered with different types of feathers.

      (a) The small, light and fluffy feathers which cover their body and keep them warm, are called down feathers.

      (b) The long and stiff feathers present on their wings and tails are called flight feathers. They help the birds to fly.

Birds shed their feathers from time to time and new feathers grow in their place.

• The feathers of birds serve a variety of functions.
• Feathers are essential for flying.
• They also help birds in maintaining their body temperature.
• The colors and patterns produced by the feathers provide camouflage in some species and colorful display in others.
• Feathers do many jobs for birds. Soft down feathers keep them warm, wing feathers allow flight and tail feathers are used for steering.

BIRDS AND THEIR BEAKS

• All birds have differently shaped beaks.
• The most important function of a bird beak is feeding and it is thus shaped according to what a bird eats.
• The beaks form one of the characteristics to identify birds.
• Beaks are multi-functional. They are used to fight, protect, assemble food and eat, and groom and build nests for birds.
• The beaks are also engaged to guard, qualify and consume their food and so the exterior is fitting to the food.

Historical Preview

• The evolution of birds is thought to have begun in the Jurassic period.
• The birds have had mythological significance to their names, such that many constellations are named after them. Example- pavo (a peacock), Columba (a dove), Aquila (an eagle) etc.

Misconcept/ Concept

Misconcept: Birds have teeth in their beaks that they use to tear the food.

Concept: Birds do not have teeth.

Misconcept: Bird’s legs have “knees” that bend the bottom of their legs backwards (similar to human’s knees).

Concept: Bird’s legs have “ankles” that bend the bottom of their legs forward.

Misconcept: parent birds will abandon a nest if it has been touched by humans.

Concept: Birds may abandon a nest if humans approach a nest too often because other predators may be led to the nest by the scent.

Misconcept: Birds migrate because it’s cold (to avoid freezing).

Concept: Birds migrate toward areas of increasing or higher resources like nesting sites, food etc. Both environmental (temperature, day light) and genetic factors are involved in migration.

Misconcept: Penguins are only black and white.

Concept: Some penguin species are black and white, but others have shades of black, white, greys, blues, yellows, and oranges species may have red eyes, brightly coloured feathers, bright orange beaks, or pink feet.

• The beaks are also engaged to guard. Qualify and consume their food and so the exterior is fitting to the food

A cone shaped beak is found in many birds such as finches and grosbeaks. It is a strong beak used for cracking seeds.

Thin, slender, pointed beaks are found mainly in insect eaters. They are used to pick insects off leaves, twigs, and bark. Warbler is a good example.

Woodpeckers have strong beaks which taper to the tip, forming a chisel for pecking holes in trees for food or nests. Most feed on insects which live under the bark.

Hummingbirds have long, tubular beak that resemble straws, which they use to sip nectar from flowers.

Mergansers,   specialized   for eating fish, have sharp tooth-like structures on the edge of the beak to hold fish tightly.

Hawks, owls, and other birds which catch and kill live prey, have sharp, "hooked" beaks. These are used to bite the skull or neck and also to tear the body into pieces small enough to swallow.

The edges of a Mallard?s beak are fringed to strain plants, seeds, and small animals from mud and water.

Beaks which are flat and wide at the base are found in birds which catch insects in flight, such as flycatchers. These birds also often have "whiskers," which are actually modified feathers, at the corners of the mouth, which effectively widens the mouth opening, allowing more effective capture of prey.

BIRDS - THEIR FEET AND CLAWS

• Birds have feet of many different shapes and sizes depending upon their habitat.
• Like the shape of their beaks, the anatomy of bird’s feet also tells about the ecology of different species of birds.
• Claws help in catching, holding and eating the food.
• They also help in walking, swimming, climbing and perching.                               
• They help protect the birds from their enemies.

Song Birds or Perching Birds (warblers, thrushes, wrens, etc.)    Have    independent, flexible toes, with one pointing backwards, ideal for grasping perches. When perching birds sit, a tendon on the backside of the ankle automatically flexes locking their toes around the branch. With feet locked, sleeping birds don't fall. As the bird stands up its feet releases.

Woodpeckers have two toes pointing forwards and two backwards; for climbing up, down, and sideways on tree trunks.

Water Birds such as ducks have webbing between their toes for swimming. GULLS also have feet similar to these. This is the reason why they don't sink while walking in the soft sand or mud near the water's edge.

Wading Birds. The long toes of herons, which spreads the bird's weight over a large surface area, facilitates walking on soft surfaces near the water's edge (where wading birds like to eat).  

Raptors such as hawks, eagles, and owls use large claws (called talons) to capture, kill, and carry prey with their feet.

Pheasants and chickens use their strong feet to scratch the dirt and leaf litter to uncover seeds and insects.

Strong-legged flightless birds, like the cassowary, protect themselves by kicking with their powerful feet and sharp claws.  

Real Life Examples

• Kingfisher, the name itself tells, that it eats fishes and dives deep into the water to catch it with its long beak.
• Woodpecker, as the name suggests, it pecks the wood with its strong beak.