In this article we will discuss about the origin of flight in birds. Birds constitute a very specialised group of vertebrates which have evolved from reptiles during Mesozoic era. The actual documentary records of the stages showing how such reptiles were transformed into birds are rare because of the non-availability of abundant avian fossils. Two fossil specimens of Archaeopteryx discovered [...]
In this article we will discuss about the Migration of Birds:- 1. Definition of Bird Migration 2. Types of Bird Migration 3. Causes 4. Guiding Mechanisms 5. Disadvantages. Contents: Definition of Bird Migration Types of Bird Migration Causes of Migration Guiding Mechanisms in Bird Navigation Disadvantages of Bird Migration 1. Definition of Bird Migration: The word "migration" has come from [...]
In this article we will discuss about the classification of birds. 1. Subclass Archaeornithes [Gk. Archios = ancient + ornithos = bird] [1 species, Jurassic, Bavaria]: i) This subclass includes most primitive, fossil birds of Jurassic period and are known from Germany. ii) Wings had primitive feathers. iii) Tail feathers were arranged in a row along each side of a [...]