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

Monday, November 21, 2016

#ElephantTuesdays: Male or female? 🐘

The sexual dimorphism is a condition that some species have when the two sexes show different characteristics. In some animal species, these differences can be very obvious (for example in Mandrills), being manifested by color, size, presence of certain features like breasts, etc.

In the case of African elephants, however, the sexual dimorphism is unfortunately not so clear. Even sometimes for the most trained eyes it can be tough to tell the gender. Even the genitals can be misleading as both penis and vulva hang ventrally. Besides, the male´s testes are located in the abdominal cavity, which makes the assumption even harder.

There are cases when the sex is more than evident: 




but If you don´t get to see an elephant erect, here are some very general tips that will help tell an African elephant´s gender apart.

Overall body shape: Males are more robust and in general bigger than females.

Head: an adult male´s head (forehead) is usually wider than an adult female´s.

Trunk: an adult male´s trunk is pretty thicker/wider than a female´s, especially the base of the trunk.

Tusks: usually longer and thicker in males than in females; a broken tusk might be as well the result of a fight between males.

Breasts: adult females have two breasts between their forelegs: 



As a curiosity: again Can, our African forest elephant in the Abidjan zoo, was thought to be a male for 20 years!!, until we saw her urinating; when males urinate, the penis comes out and then you have a good chance to claim the sex; 

Can urinating:


male urinating: 


 Original video: ACP000ciji

References:
Elephantvoices: https://www.elephantvoices.org/component/content/article/139-elephantvoices/education/807-how-to-sex-african-elephants.html

Monday, November 14, 2016

#ElephantTuesdays: Elephant species 🐘

 Although there used to exist species of elephants on earth, we can unfortunately confirm three occurring currently in Asia and Africa:

Elephas maximus (Asian elephant)
Loxodonta africana (African bush elephant)
           Loxodonta cyclotis (African forest elephant)

Sometimes it might appear easy to distinguish between all three species, or at least between the African and Asian sp., but actually it can be sometimes tricky. If you have a look at the following table, you will notice that in general, African sp. are a bit bigger and heavier than their Asian relatives. But if you are not in Asia or Africa, but in front of an elephant far from their natural habitat (like a zoo) this feature alone can be confusing, as it obviously depends on the individual´s age and physical condition. So one thing that usually helps is the size of their ears, and their head´s shape. In African elephants, their ears reach up over the neck, and the head shape is basically round.

The main morphological differences between the African and Asian elephant species are:


Loxodonta sp.  
Elephas maximus
Weight
4.000-7.000 Kg
3.000-6.000
Height (shoulder height)
3-4 m.
2-3,5 m.
Skin
wrinkled
Relatively smooth
Ears
Bigger
smaller
Tusks
Existing in both sexes
Females have no tusks or only rudimentary
Trunk
2 fingertips/ very wrinkled/more flexible
1 fingertip/less wrinkled/less flexible
Shape of the back
Concave
Convex (sometimes even straight)
Toenails
Forelegs: 4 (sometimes 5)
Hind legs: 3 (sometimes 4)
Forelegs: 5
Hind legs: 4 (sometimes 5)
Belly shape
slopes diagonally downwards towards its hind legs
Round/straight, horizontal
Head shape
round
Two bulges

Interesting as it might be, yet our concern here is not about how to differentiate between African or Asian ele. but how to tell apart the two African species.


Just a short summary of physical African elephant traits:


Loxodonta africana
Loxodonta cyclotis
Weight
4.000 - 7.000 Kg
 2.000 - 4.500 kg
Height (shoulder height)
3-4 m.
2 - 3 m
Skin
wrinkled/ less and shorter hairs
Smoother/long hairs, long eyelashes
Ears
cuts usually are individual; the older they get, the more folded the ear can be

shape of the African continent
cuts usually are individual; the older they get, the more folded the ear can be

 round
Tusks
both sexes

males have stronger ones

usually curved, thicker
both sexes

males have stronger ones

more or less straight downwards, thinner
Trunk
2 finger tip
2 finger tip
Toenails
Forelegs: 4
Hind legs: 3
Forelegs: 5
Hind legs: 4


Asian elephant:



 African bush elephant (Source):


African forest elephant:


Original videos: ACP00022ho, ACP0002cpg

But these are only numbers and approximations, necessary when it comes to taxonomy, but in nature things don´t always work that way; in fact, there´s been controversy between taxonomists when claiming differences between both African species. 

 As a curiosity: years ago, local people and hunters, claimed to exist another species of elephants occurring in Africa, the Pygmy elephant. There was some controversy about this fact, some researchers agreed, some didn´t, and years later those individuals that were seen and thought to be pygmy elephants, happened to be the infants of the African forest species, so the new “discovery” was finally rejected. 

We have been often asked if there is a difference in behavior between all three species, and honestly, we are never really sure what to say. There are plenty of different opinions: some believe that Asian elephants are thought to be more docile than the African species, others don´t; the Africans are thought to be a bit more “dirty” than the Asians (they like to take their own poo and put it on their backs). It is also said that the African forest elephants tend to accumulate food on their backs, while the African bush elephants don´t do it that often… and we have witnessed it: see what the lovely forest elephant Can from the Abidjan zoo likes to do with her food:

Call them what you will, we personally don´t mind if they have big or small ears, thin or thick tusks, if they are clean, dirty, docile or fierce… 
THEY ARE ALL AMAZING AND INTERESTING CREATURES IN ALL THEIR VERSIONS. 

References: 
Kalinga Animal Shelter: http://www.kalinga.eu/page/de/home/index.html 
Upali: http://www.upali.ch/differences_en.html