Tuesday, November 29, 2016

#ElephantTuesdays: Elephant life stages 🐘

If you have small kids, the idea of them someday leaving home is painful and scary in a way. But then when they reach adolescence and start to be irrational and dramatic for apparently no reason, and walk dragging their feet all over your place, the idea of them leaving gets not only reasonable but also urgent J . So, if one thinks of their age when they finally get independent it might appear to be quite late compared to other mammals.

All mammals are dependent on their mothers for a species-specific period of time, ranging from a few weeks to a few years; but have you ever wondered how long do elephant calves stay with their mothers?

The elephant calves have extremely emotional brains and need mom in order to learn how to behave within their own society and to cope with specific situations and stress. They have shown to share emotions and behavior traits with humans, and like humans, the elephant calves stay dependent on their mother (and others in the herd) for survival during quite a long time: after a pregnancy period of about 22 months (my goodness! the longest gestation period in mammals) they start to suckle since they are born until 3.5 – 5 years, and they can even share mom´s milk with a newborn. The elephant calves depend entirely (that is, physically and psychologically) on their mothers for three to five years. However, the bonds between mother and offspring remain strong afterwards, and in the case of mother-daughter they even last a lifetime.

During the infancy, the `mother figure´ is extremely important. The maternal behavior (the care giving behavior given by female mammals) includes: suckling, nurturing, providing shelter, passing on traditions, and protecting from danger among others:

Original video: ACP0002p3f

This video shows a typical `mother behavior´, where the females are protecting the infants from a potential danger (the camera) by pushing them aside with their body and trunk. Like the chimpanzees, allomothers (caring females in the herd other than mothers) can be not only other adult females (frequently called `aunts´), but also young females and the infant´s own siblings. The chance of taking part in an infant´s development period is hugely important to these young future mothers, as they will gather experience for the moment when they have their own offspring. The importance of allomothers is such, that if the biological mother happens to die leaving unweaned offspring, they will do her job (allonurse) by producing milk even if they had no offspring of their own.

This matriarchal system involves not only the obvious maternal responsibilities, but also plays a role in protecting the herd, making daily decisions on movements, feeding and drinking places, etc.

As a curiosity: elephants are thought to be born hairless, but actually they do have most of their `lanugo´ or embryonal hairs on their backs and heads after their birth and keep it for some years:

The adolescence occurs at the age of six to fifteen when they reach sexual maturity. Now is the time when the herds break and form; young bulls gather in bachelor herds and females stay in the matriarchal group.

In the case of adolescent males, this period implies the separation from the matriarchal herd to join other males; youngs gather together and sometimes they join other adult males that can teach them. This phase thus implies male encounters, fights, musth (it usually occurs at the age of 10-12 the first time) and the search for females to mate.
The females, however, stay in their group where they meet their maternal instincts, developing social tasks like caring for the infants.

Finally, the adulthood starts at the age of 15-17, when the families are formed. It´s time to settle their role in the matriarchal system (in the case of females), made up by a head female, mothers, daughters, sisters and aunts. 

Females have a reproductive life very similar to humans, continuing reproducing until midlife and experiencing a post-reproductive phase similar to menopause in women. They give birth to a single calf (twins are very rare) with two to four-year intervals. The moment of the birth is followed by rumbles and trumpets, gland secretions and really high excitement performed by other females of the group.

The African elephants are the land mammals with the longest lifespan under ideal circumstances (not being poached for example): they can reach an age of 60 to 70 years…amazing for wild animals!

According to Weihs (2002), the elephant life stages could be summarized as follows:
LIFE STAGE
YEARS
New-born
0-2
Infant
3-5
Juvenile
6-10
Subadult
11-15
Adult
Over 15


Adult, juvenile and infant
Original video: ACP0002crh

How curious we humans are: we place ourselves right at the top of all living creatures thinking that we are so different from the others; but if we lowered ourselves to come down from our throne and have a closer look at other species like elephants and chimpanzees, we will realize how similar our natures actually are. It´s a good humility exercise.

References:
Dietmar Jarofke (2007): Jarofkes Elefantenkompendium; Haltung, Zucht, Verhalten und Krankheiten der Elefanten.

Weihs; W. (2002): Molar growth and chewing frequencies as age indicators in Asian Elephants.

Fred Kurt, Marion E. GaraΓ― (2007): The Asian Elephant in Captivity. A Field Study.

Elephant Information Repository: http://elephant.elehost.com

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