India Environment Portal Knowledge for change

About us Contact us
downtoearth-subscribe

Browse by subjects

Lost manhood

  • 29/11/2006

Cover story special package

Croc can't go on | Tears for the crocodile | Pyrrhic victory | Where to live? | Lost manhood | Where to croc?



Bad numbers
Katerniaghat Wildlife Sanctuary
58 gharials: 28 adult females, 4 adult males, 8 sub-adults and 18 juveniles in 2006
 
National Chambal Sanctuary

323 gharials: 44 yearlings, 154 juveniles, 39 sub-adults, 82 adult females and 4 adult males in 2006
 
Son Gharial Sanctuary

25 gharials in a 160-km stretch of river in the sanctuary; only two nests (meaning two females) in 30 years
 
Ken Gharial Sanctuary

10 adult gharials. No adult males observed
Satkosia Gorge Wildlife Sanctuary
2 known gharials in 2006, despite about 700 being released since 1980
THE skewed sex ratio is not confined to Katerniaghat (see box: Bad numbers). Project Crocodile has been conspicous in giving the cold shoulder to the male gharial. Shrinking and fragmented habitat have increased competition among the males. "The social structure and behaviour of gharials is such that adult males try to push away sub-adults,' says Choudhary.

There are other reasons for the lopsided sex ratio. All crocodile species, including gharials, belong to a group of reptiles whose sex is determined by environmental temperatures and not just heritable chromosomes, according to a study by D C Deeming, published in Biological Sciences (Vol 322, No. 1208, December 1, 1988). Embryos need an optimum temperature of 32

  • Tags:

Related Content