Welcome to our presentation on “Birds and their wingspan ”.

1. Welcome to our presentation on “Birds and their wingspan”.

2. Evolution

3. Transitions started taking place drastically leading to weight of the bones getting lighter and the forelimbs got shorter due to which the bone structure changed and slowly the forelimbs started growing feathers. The ancient reptiles then became birds. Evolution chart of birds

4. Birds

5. Birds • Birds, also known as aves are a group of endothermic vertebrates, characterized by feathers, beaked jaws, the laying of hard shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the smallest bird Bee humming birds to the largest bird Ostrich. • The earliest recorded bird known to have taken flight is archaeopteryx. But there also was a strange bird called elephant bird which had no wings. • The digestive and respiratory system of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some water birds, have further evolved for swimming.

6. Lifestyle of birds • While a large number of birds feed on flower nectar, berries, nuts, seeds, tree sap, buds of trees and shrubs, there are various species that eat insects/worms. Some of them hunt and eat small animals, while some scavenge on dead animals. Availability of food is an important factor in determining their eating habits. • Most of the birds spend their time flying in search of food but many birds do not like ostriches, kiwi etc.

7. From saptarsi Mridul this slide is yours you will have to say the type of birds present in the following:-Mountain Rainforest Cold Arid and semi arid habitats and also give examples

8. Wings

9. Role of wings • The fundamentals of bird flight are similar to those of aircraft, in which the aerodynamic forces sustaining flight are lift and drag. Lift force is produced by the action of air flow on the wing, which is an airfoil. The airfoil is shaped such that the air provides a net upward force on the wing, while the movement of air is directed downward. Additional net lift may come from airflow around the bird's body in some species, especially during intermittent flight while the wings are folded or semi-folded. • Aerodynamic drag is the force opposite to the direction of motion, and hence it is the source of energy loss in flight. Their wings help to prevent the loss. So they initially star with a high kinetic energy which then decreases and eventually becomes constant.

10. Types of wings There are generally Four types of wings found among birds which are:- • Elliptical Wings:-It is mostly found among bats and other scrub birds. The wing beat is rapid and they are highly spotted behind primary and secondary feather which helps to prevent stalling. • High Speed Wings:- These wings are thin, strong and designed for speed the muscles have several fluids that prevent wear and tear. it is found in swallows, falcons etc. • Long Soaring Wings:-birds like albatross, terns and other sea birds have longer wings for soaring. They are mainly adapted for dynamic and high speed soaring. Birds with this kind of wings exploit the sea winds to maintain their direction as their tails are generally shorter. • Broad Soaring Wings:-These are generally found in Eagles, Hawks, etc. this type of wing has the strongest muscle and can support the bird in flight for very long duration of time without causing much pain. They help to glide very easily and

11. Wingspan • The wingspan (or just span) of a bird is the distance from one wingtip to the other wingtip. The term wingspan, more technically extent, is also used for other winged animals  • In humans, the term wingspan also refers to the arm span, which is distance between the length from one end of an individual's arms (measured at the fingertips) to the other when raised parallel to the ground at shoulder height at a 90º angle.

12. Tail

13. Influence of tail • The tail of the birds act as a stabilizer which maintains horizontal stability. Birds change their direction in mid air by twisting their tails. However elongated tails increase drag force and cause trouble in the management of speed in birds. For e.g.:-The tail of a peacock has a large surface area which increase the influence of friction on the bird. Hence they cannot fly with remarkable speed. • Bird tails are deceptively simple. Essentially, they're just a bunch of long feathers controlled by muscles at their base. There's more to them than meets the eye, though. Tail feathers are specialized plumage that's lighter and stiffer than body feathers.