Question

The population of birds inhabiting the dense forests of Coorg in Karnataka is large as compared to the population of elephants in the same forests.

1. Identify and briefly explain the types of survivorship curves represented by the species mentioned above. [2]
2. State any one reason for the survivorship pattern followed by each of the species mentioned above. [2]

Answer 1

1. • Elephants (Type I Curve): This curve shows high survival rates in early and middle life, followed by a rapid decline in old age. A large percentage of the population survives to reach their maximum physiological lifespan.
   • Birds (Type II Curve): This curve represents a constant mortality rate throughout the organism’s entire lifespan. The probability of dying remains uniform at any age interval, resulting in a diagonal linear decline.
2. • Reason for Elephants (Type I): Elephants invest significant energy into extensive parental care, protecting and nurturing their few offspring over many years, which shields young calves from early predation and disease.
   • Reason for Birds (Type II): Birds face continuous environmental pressures, such as constant predation, hunting, weather extremes, and disease, which affect individuals equally regardless of whether they are young or adult.