Asian Elephants - Stages of Reproduction
Reproduction & Breeding:
- Mounts last about 30 seconds
- Mating and births occur any time during year; may peak during heavy rains in some regions
- In captivity, estrus cycle lasts 13 to 14 weeks (if female is not pregnant)
- Females who have conceived or with young may have 4 - 5 years between estrus cycles
- Only one in five follicular cycles, each lasting 2-3 weeks, produce a fertile egg
- Males can breed at any time, not only when in musth (Hindu for "intoxicated")
- Musth levels of testosterone in male up to 20 times higher than normal
- Musth lasts about 4 months in wild males
- Females prefer musth males
Female Asian elephants bear a single calf (usually) after a gestation of more than a year and a half (18 to 22 months). Their estrus cycle is about 22 days, out of which they are receptive to copulation on only one day, the first day of estrus. There is no seasonality in their reproduction. Females on good quality habitats give birth every three to four years, while the interbirth interval can be much longer among females inhabiting poor quality areas.
Newborns weigh about 100 kg and can stand soon after birth. The infant may nurse from its mother or from other lactating females. After a few days it can follow its mother as she goes about her normal activities. Young begin to eat some grass after several months but may continue nursing for 18 months. They also eat their mother's dung, which contains nutrients as well as the symbiotic bacteria that aid in the digestion of cellulose.
Mothers continue to supervise their young for several years after weaning. Both sexes become sexually mature at about 14 years of age, but males cannot mate until they can dominate other adult males. Males leave their natal herd at this age, but females remain with their female relatives throughout their lives.
- Litter size: Usually one calf; rarely twins (structure of uterus allows births several weeks apart)
- Weight: 75-115kg (165-254 lbs)
- Height: 75-100 cm (2.5-3.5 ft)
- Calves are very hairy compared to adults. Hairier than African elephant calves.
Infant (< 1 year old):
- Can stand on feet shortly after birth
- Follow the mother in her daily routines within a few days
- During first three months develop motor skills
- Females attracted to young calves
- Females are attracted to young calves; often minister to their needs so mothers can spend more time feeding and resting, which are important for lactation
- Age of weaning 18 months to 3 years or longer;
- May be forced to wean when younger sibling is born.
- Around age of weaning, differences in sexes begin to appear
- Females strengthen bonds with family
- Males become more independent, leaving family for longer periods to feed, explore or play
- Initial period of rapid growth slows at about 5 years; decline in growth rate is greater for fe-males than for males
- Females care for young of both sexes during 10-15 years of development until sexual maturity.
- Can be difficult to distinguish from juveniles
- No fixed age of puberty; may depend on available nutrition
- Males often seen away from herds
- Age of sexual maturity varies depending on nutrition
- Bulls 14-15 (as early as 9) years
- Cows minimum age to breeding 14-15 years; usuall 18-20
- Females have square backs
- Males continue to grow at continuous slow rate. Female growth plateaus between 15 and 30 years
Lifespan/Longevity: The lifespan of Asian elephants is about 70 years.