With reference to Indian elephants, consider the following statements :

1. The leader of an elephant group is a female.
2. The maximum gestation period can be 22 months.
3. An elephant can normally go on calving till the age of 40 years only.
4. Among the States in India, the highest elephant population is in Kerala. Which of the statements given above is/are correct?

Statement 1 is correct: The oldest female elephant always leads an elephant herd. This matriarchal structure is typical for Indian elephants.

Statement 2 is correct: Elephants have the longest gestation period of all mammals, averaging 640 to 660 days (approximately 22 months).

Statement 3 is not correct: Female elephants can live for 60 to 70 years and can continue to reproduce until at least the age of 65 years, although fertility declines after age 50. The statement that they can only calve until 40 years is incorrect.

Statement 4 is not correct: Karnataka has the highest elephant population among South Indian states, with 6,049 elephants, followed by Kerala. Therefore, Kerala does not have the highest elephant population in India.

Hence, only statements 1 and 2 are correct.