Showing posts with label elephant. Show all posts
Showing posts with label elephant. Show all posts

Tuesday, March 16, 2021

The different African elephant species

 


It has been believed for years that there was only one African elephant species, the savanna elephant (Loxodonta africana), and the small forest elephant was a subspecies. It was only some years ago that the forest elephant (Loxodonta cyclotis) was finally considered as another African elephant species, when research had found that these two elephants are genetically distinct from one another.

I say finally, because by recognizing their status as species and not as subspecies, one can best manage a designed elephant conservation strategy. Forest elephants are ecologically, socially, morphologically and genetically different to savanna elephants, and that´s why a strategy particularly designed is needed. The decline of the forest elephant population represents the decline of an entire endangered species, and not just of a sub-population.

So now we have two recognized African elephant species, the forest and the savanna elephants; but really? Two species? what about the Congo Pygmy elephants, have you ever heard about them?

A bit of history:

the first supposed pygmy elephant was evidenced in a Zoo in Germany (Hamburg Zoo) and then moved to New York, but the authors described it as a very small forest elephant found in Congo and South Western Uganda.

The zoo elephant was a young male called Congo and described by Noack (1906) as Elephas africanus pumilio, later known as Loxodonta pumilio or fransseni. Congo was a small young male with very round ears that reminded a lot of the recently known to science forest elephant (described at the beginning of the 20th century by Matschie, 1900)1. Ever since their discovery, the pygmy elephant status has been debated. Some scientists have supported their existence, most haven´t.

Although the disputed pygmy elephants of the Congo basin are thought to be another separate species by cryptozoologists, it is unanimously believed that those are actually forest elephants.

One explanation to why scientists thought to have found a different species of elephants back in the 20th century could be that they were at that time unfamiliar with the growth patterns and social structure of elephants and thus what they described to be a herd of very small elephants, was actually a herd where the big matriarch had died and thus there remained young females and calves.

There are also voices that claim that this unusually small size of the forest elephants that made the scientists believe in the existence of a third species was due to an early maturity as a result of environmental conditions.

The scientists conclude that the specific taxon Loxodonta pumilio (or Loxodonta fransseni) should be abandoned; so to the question, yes, there are two different African elephant species: savanna and forest elephants.


Congo, a presumed pygmy elephant, now classified as Loxodonta cyclotis (African forest elephant).

 How different are they?

The forest elephants are smaller and thus lighter. Their skin is smoother, with longer hairs (mostly on their trunks) and long eyelashes, that protect their eyes while they walk through the dense forest. Their ears are rounder (cycle=round, otis=ear), the savanna elephant ears have the African continent shape. Like the savanna elephants, both sexes have tusks, but those of the forest species are more or less straight and thinner. The forest elephants have 5 toenails on the front feet and 4 on the hind feet (like the Asian elephants), while the savanna elephants have 4 on the front feet and 3 on the back.

The forest elephants live in smaller family groups (and often more disperse) than savanna elephants and have a different diet, the latter´s consisting basically of grass, whereas the forest elephants eat more browse, tree leaves and fruits.

What´s their geographical range?

As their name suggests, the African forest elephants live in Africa’s forests. While they once inhabited a larger range, they now are confined to the tropical forests of Equatorial West and Central Africa.

The geographical range of the African savanna elephants is wider, but in some areas their distribution overlaps with that of the forest elephants in Central and Eastern Africa. Some scientists talk about “hybrid zones” facilitated by poaching and habitat modifications, and defend the theory that these species can interbreed over more than one generation, which demonstrates that hybrids are fertile2.

Which African elephant species do we see in Chimp&See?

In almost every Chimp&See site where we have found elephants, we have seen forest elephants. But due to that territory overlapping there have been some sites where the elephants weren´t so small anymore. I am referring to Green Snowflake and Restless Star, where both species coexist, whose range overlap and where both species may be inter breeding, and to Soaring Leaf, where we have seen savanna elephants.

Check the Chimp&See Loxodonta africana :

The big Gabela, Green Snowflake (how many front toenails can you count?) 

and compare them to the Chimp&See Loxodonta cyclotis:

Sahndra, Twin Oaks 

Tayo, Twin Oaks

Jino, Green Toadstool 


If you want to see more awesome elephant videos, check our Elephant Discussion Board. Please feel free to post any comment or anything that you want to know about elephants in that board! 

 

Ref:

1.      1. Groves, C. P., & Grubb, P. (2000). Are there Pygmy Elephants?. Elephant, 2(4), 8-10. Doi: 10.22237/elephant/1521732181

       2. Mondol, Samrat & Moltke, Ida & Hart, John & Keigwin, Michael & Brown, Lisa & Stephens, Matthew & Wasser, Samuel. (2015). New evidence for hybrid zones of forest and savanna elephants in Central and West Africa. Molecular ecology. 24. 10.1111/mec.13472

 https://www.iucnredlist.org/

https://www.worldwildlife.org/species/forest-elephant

https://www.bwindiimpenetrablenationalpark.com/see/wildlife/mammals/elephants/

https://animalcorner.org/animals/african-forest-elephant/

Friday, August 3, 2018

Guest Post: The Elephants Lake Project 🐘



As a moderator with Chimpansee, and back to my blog posts about elephants, here´s something that I would love to share with you and that I´m sure you are going to like:

as you already know, we see a lot of African forest elephants at Chimpandsee...such beautiful videos aroused your interest about elephants and we opened a special discussion board about these majestic animals. So elephants are not only part of my daily routine, but I also use some of my spare time to have my nose buried in elephant projects. And this took me to an amazing untiring international organization called “Vier Pfoten” (Four Paws), entirely devoted to animal welfare, and with offices in many countries all over the globe. I would love to take this Chimpandsee guest post to discuss some of the cool conservation work these guys are doing.

This story starts some years ago as a “wonderful dream” of some very brave animal welfare fighters from Vier Pfoten, and it goes like this:

as you all know, elephants have been used as working machines for ages in Asia, with all the suffering that this involves: calves separated from their moms, chained and brutally trained to obey human commands, exhausting working schedules, and elephants psychologically and physically marked for life. The use of hooks to make them obey has been (still is) very much appreciated by the oozies (oozie is the term for Mahout used in Myanmar) working in direct contact with elephants. 

Photo: Ingo Schmidinger. Oozies with their elephants. 
© FOUR PAWS / Jasmine Duthie. Use of hooks. 
                                
But fortunately, these days are over for the timber industry elephants in Myanmar.

Due to new regulations, the use of elephants for working purposes has been banned by law in Myanmar. This means that most of the timber logging elephants in Myanmar (sadly, still 10% of the working elephant population will still be working) that “belong” to the government are now “retired” and need a safe place to finally live in so much deserved peace.

Here´s where Vier Pfoten International comes into play, with the development of an ambitious project coordinated by Ingo Schmidinger ❤, and where I myself have had the tremendous honor to cooperate with; my passion for elephants is not a secret, and such a great news gave me hope again.

© FOUR PAWS / Jasmine Duthie. Fieldwork, VP Team. 
Photo: Yin Min. Fieldwork, Ingo Schmidinger 

So, VP, this international animal welfare organization, has designed a long-term project called Elephants Lake, in order to provide elephants with the appropriate conditions to ensure their welfare…forever. This project consists of 17.000 hectares of land in the Bago Province of Myanmar. According to some research on habitat size and population, this area could house 276-300 elephants.

© FOUR PAWS / Jasmine Duthie. Project´s site. 
© FOUR PAWS / Jasmine Duthie. Project´s site.

The start up of the project will also involve the employment to the local population, an increase of the tourism, and thus a rise of the local economy, by promoting ecotourism with eco-lodges, the commercialization of eco-paper products from elephant dung, honey production and selling from beehive fencing, training anti-poaching patrols, etc.

The first step of this project is the rescued elephant´s rehabilitation at the Elephants Lake. This place will include (in order of appearance) among others:

· An orphanage: where orphans will be taken and introduced to possible allomothers, that will hopefully form matriarch groups.

· A hospital

· And enclosures that provide permanent homes for those elephants that cannot be released, and temporary homes for those that can be released...

…what?? released???

YES, this is the second step and the most exciting part of the project: the possible release of the elephants into the adjacent North Zar Ma Yi Wildlife Sanctuary where they will no longer “belong” to anyone and will live free back in the wild…isn´t it great? The elephants will not only be released from their chains and taken care of, but also will be released from human´s hands (if possible)!

So, the aim of this project is actually to finally let the elephants be elephants.

The project is still toddling and we are in the most difficult part, but even in the most frustrating and tiring moments, we still keep our hearts focused on the vision of the elephants free from chains, hooks and humans…and that gives us the strength and the passion to keep going 😊

Photo: Ingo Schmidinger 


References:

R. Sukumar,  The Asian Elephant: Ecology and Management, Cambridge University Press, 1992

Chaiyarat et al,  Wild Asian elephant Elephas maximus population in Salakpra Wildlife Sanctuary, Thailand, 2015.





Tuesday, September 12, 2017

Elephant communication 🐘




Elephants have complex ways of communicating with each other that involve olfactory, visual, tactile and auditory signals.

They are highly social mammals that live in very complex societies. In this sense, the acoustic communication plays an essential role in locating individuals and maintaining intra- and inter-group cohesion.

The elephant society is a fission-fusion model where individuals aggregate and dissociate based on ecological stressors and other factors such as predator pressures, calf care, and mate selection. As explained in “#ElephantTuesdays: oh mama! a female´s role, the core unit of the elephant social structure is the family unit which consists of an adult female and her offspring. Family units that are found to be highly associated are bond groups. To maintain cohesion and coordination of the family group and association with bond groups, numerous tactile and visual communication cues are used along with a complex system of auditory signals.

Elephants produce a broad range of higher frequency sounds like barks, roars, cries and snorts. But
the most frequently used sounds they produce are the “rumbles”. Rumbles are very low frequency sounds that were originally thought to be originated in the elephant´s stomach (stomach rumbles). These low frequency sounds can reach up to 2 kilometers (Langbauer et al. 1991, McComb et al. 2003) and are used for communication between and within family herds over large distances.

If we compare the range of frequencies used by elephants with those used by humans, we can get an idea of how amazingly low these rumble frequencies can be: a typical human´s voice in speech is about 110 Hz for men, 220 Hz for women and 300 Hz for children, while a typical male rumble is about 12, a female´s rumble is about 13Hz and a calf´s 22Hz.


Original video: ACP000dlbi


It is known that the frequency of the sound is correlated to the level of excitement of the elephant; they produce low frequency sounds when they are in a low level of excitement. These sounds are used to promote group cohesion. In contrast, high frequency sounds are present when the elephants are highly excited.

They are not only great at producing sounds, but also at localizing them: it has been suggested that the larger the space between an elephant´s ears (inter-aural space), the better the ability at localizing sounds, so they extend their ears perpendicularly to their heads in order to localize sounds.

When an elephant rumbles, a replica of the airborne sound is also transmitted through the ground. Seismic communication could supplement airborne communication or be especially beneficial when airborne conditions are not ideal for transmission. (O'Connell-Rodwell, C.E. 2007. Keeping an "ear" to the ground: Seismic communication in elephants. Physiology 22:287-294.).

Elephants also use other senses to communicate, like their vision. Here we talk about visual communication: if you watch an elephant for a long while, you will see a large repertoire of visual signals that they perform to communicate with one another (or with other species) by using their heads, eyes, mouth, ears, trunk, tail, feet and their whole body. So, if you happen to be in front of an elephant and s/he starts run to you, head up high above his/her shoulders, spread ears, you´d better run fast if you have the chance, or start your car and speed up! S/he is telling you that you are not welcomed; it´s a threatening or dominant signal. A subordinate elephant carries his/her head low and his/her ears back. A socially excited elephant rapidly flaps his/her ears, eyes open. A frightened or excited one raises his/her tail and chin, remember?


Original video: ACP0000b7b


You all might remember the blog post about the “elephant trunk”, talking about the elephant´s trunk abilities. They are very tactile animals that touch each other with their entire body to communicate in several contexts like defensive, sexual, playful behaviors etc.

But the trunk is the part of their body with which they more often touch each other to communicate. Remember this video? a beautiful example of tactile communication:


Original videos: ACP000cb8k ACP000cb8l ACP000cb8n



They also use chemical signals to communicate. Trunks up to sniff the air, exploring the ground for urine trails etc., sniffing genitals, mouths, glands or ears of partners…chemical communication gives an efficient long-lasting signal.


Original video: ACP0002p30


Anyone interested in learning more about elephant communication, this is a very interesting visual guide: "What Elephant Calls Mean: A User's Guide" published by National Geographic in 2014

Thanks for reading :-)


References:

Langbauer Jr., W.R. 2000. Elephant Communication
Berg, J.K. 1983. Vocalizations and associated behaviours of the African elephant Loxodonta africana in captivity.
Elephant Voices: https://www.elephantvoices.org/

Tuesday, February 28, 2017

#ElephantTuesdays: ELEFACTS 🐘

This is the last entry of the Elephant Tuesdays blog, and as a kind of farewell, I would like to shortly name some interesting facts about elephants that you might not know. 

Did you know that…?

ELEPHANTS SHOW HANDEDNESS
Elephants are right-trunkers and left-trunkers; they show side preferences when moving their trunks and forefeet for feeding, uprooting and grabbing vegetation (Keerthipriya, P.; Tewari, Rachna; Vidya, T.N. C. Journal of Comparative Psychology, Vol 129(4), Nov 2015, 377-387) 

ELEPHANTS COULD BE TICKLISH
Scientists agree that joy is an emotion that most of the mammals experience. It has been agreed that rats engage in joyful plays like apes, and that they have evolved a gargalesis tickle response. I couldn´t find any scientific written evidence of elephants showing gargalesis, but there are tons of personal experiences among animal keepers and elephant experts that would support it 
ELEPHANTS FIND WAYS TO REDUCE PHYSICAL PAIN
It´s been often witnessed that elephants suffering from physical pain caused by wounds resulting from chains, hooks, amputations, etc. press their forehead against a wall or bite their trunk to reduce pain. 

ELEPHANTS PRODUCE TEARS
In order to draw any scientific conclusion about something, science requires that we be able to measure it. We cannot measure emotions, so although it is a fact that elephants do produce tears, it is not scientifically certain that these tears are the result of an emotional response. 







ELEPHANTS USE THEIR TRUNK AS A SNORKEL
Elephants are known to be excellent swimmers and have been documented to spend hours in deep water swimming with just their trunks above the water line.
It is the only animal that can snorkel at depth. From a physiological point of view, this fact would be impossible, as the resulting pressure differences require special lung structures, and specifically, changes in the pleural membranes and pleural space. An autopsy conducted in 1681 on an elephant revealed that the elephant´s lungs are unusual; they have connective tissue in their pleural space, instead of liquid. As breathing while being underwater must generate enormous pressures to expand their lungs against the water pressure, they need a very strong and thick muscle around their lungs.



ELEPHANTS TAKE SALIVA BATHS
At very high temperatures and with no near water available, elephants will often introduce their trunks inside their mouths to get saliva and spray it on their bodies to get refreshed.

ELEPHANTS ARE CHEMICALLY RELATED TO INSECTS
What does the largest terrestrial mammal have in common with a moth?

They are pheromone fellows; elephants share an attraction to (Z)-7-dodecenylacetate, a female urine pheromone that provokes a high frequency of chemosensory responses in males prior to and during mating, with 140 species of moth (Rasmussen et al., 1996). Such coincidences are a consequence of convergent evolution.



THANKS A MILLION FOR READING !!



References;
National Geographic:
http://news.nationalgeographic.com/news/2002/11/1105_021106_elephantsnorkel.html

National Center for Biotechnology Information (NCBI): 
https://www.ncbi.nlm.nih.gov/pubmed/11909991

Biology, Medicine, and Surgery of Elephants, Murray E., Fowler and Susan K. Mikota (2006)


Pheromones: Convergence and contrasts in insects and vertebrates,Tristram D. Wyatt (in Wyatt, TD (2003) Pheromones and Animal Behaviour: Communication by Smell and Taste. Cambridge University Press, Cambridge)

Von Elefanten und Menschen, Kurt, Fred (2014)

Tuesday, February 21, 2017

#ElephantTuesdays: Sense and sensibility; our big-brained fellows 🐘

The animal psychology defines intelligence as the ability to solve problems, to learn and to deal with new situations, and the size and complexity of the elephant´s brain certainly reflect this fact.

The elephant brain is the largest among terrestrial mammals, and weighs between 4,5 and 6,5 kilograms. The brains of both African and Asian elephants exhibit features comparable to those of some of the cetaceans and the great apes, including humans. 

 Decades of scientific research have been showing that elephants are among the most intelligent and emotionally complex animals.

According to Dr. Jane Goodall, “A tool-using performance in an animal or bird is specified as the use of an external object as a functional extension of mouth or beak, hand or claw, in the attainment of an immediate goal. This goal may be related to the obtaining of food, care of the body, or repulsion of a predator, intruder.”. In this sense, the ability of elephants to manufacture and use tools to solve problems creatively is a good example of intelligence. They use a wide variety of tools both in wild and captive scenarios, for example to reduce ectoparasites, for thermoregulation and to get and manipulate food by using their finger-like tip of their prehensile trunk. 

In the following video, the adult female is removing some ground and taking a sand bath for thermoregulation and/or reducing parasites; according to the tool use definition, it wouldn´t be appropriate to talk about tool use in this particular case as she is not using any external object to achieve her goal, but it is interesting how she uses her right leg as a shovel to fill up her trunk with sand:



original video: ACP000cg74

Like humans, great apes and dolphins, as large-brained species showing a greater developed cerebral cortex, elephants have the amazing capability to learn complicated tasks and retain that information for longer. They have been seen sticking wood pieces between their trunk and a tusk and keeping them for the right moment to be used; this fact reflects the planning skills of intelligent species:


Original video: ACP000cgv8

The empathic behavior in elephants is another sign of intelligence, and can be seen for example in allomothers assisting a female while giving birth by surrounding her and the newborn in a protective and supportive manner. 

Consciousness is one more potential proof of intelligence; apart from humans and apes, dolphins and elephants are also known to possess the capacity to recognize themselves in a mirror (a standard test of self-awareness).

Elephants show social and ecological memory: they recognize a large number of individuals in their own herd or in others. They remember resources such as the location of ephemeral water sources or food available.

Here´s a heart touching tale about elephants remembering their own kind:
Two elephants called Shirley (~53) and Jenny (~30) met in The Elephant Sanctuary in Tennessee after 23 years apart. Their reactions showed obvious signs that they knew each other. Shirley started to display mothering behavior, like protecting Jenny from the sun and harm. They spent the rest of their lives together like mother-daughter. It was then known that Shirley and Jenny had been together in a circus when Jenny was a calf. See what happens when they meet:



References:

Self-recognition in an Asian elephant; Joshua M. Plotnik, Frans B. M. de Waal, Diana Reiss (2006)

https://www.elephantvoices.org/elephant-sense-a-sociality-4/elephants-are-intelligent.html

Biology, Medicine, and Surgery of Elephants, Murray E., Fowler and Susan K. Mikota (2006)

Von Elefanten und Menschen, Kurt, Fred (2014)

Tuesday, February 7, 2017

#ElephantTuesdays: About Emotions 🐘

Elephants are known to have the ability to express emotions. In the same way like humans and chimpanzees do, they can express sadness, empathy, stress, anger, joy, etc. 

Adolescents and juveniles can get easily annoyed or angry with each other. In the clip below, the adolescent in front of the camera gets annoyed by the juvenile approaching from behind, trying to put it away with its trunk from what it was first exploring on the ground, ears flapping. The juvenile leaves bothered with its tail up: so the sequence here would be: adolescent finds something interesting on the ground, juvenile wants to check it too with its trunk but the adolescent gets annoyed by it; juvenile leaves bothered like saying: "ok, it´s all yours!": 


original video: ACP00001vl

We have already talked about their strong social bonds, but have a look at this sequence: there´s a young individual afraid of something in its way and not daring to go through. Tail up, and walking stressed back and forth. The next individual (a juvenile, I would say female) rapidly approaches and touches it with its trunk in a comforting way. The third one does the same thing, trunk touch and approaching to explore the potential danger; it´s a male, excited by the situation with his penis out and flapping ears. Look at the first individual´s reaction when it´s touched by the trunks! it just calms down, accepts to keep walking and follows its `saviors`. Interesting video showing fear, stress and empathy resulting in protection, support and guidance: 

original videos: ACP000cb8k ACP000cb8l ACP000cb8n 

See how they react when they experience a stressful situation (in the case of the video below, the camera is the stressing factor). Tails up, ears flapping. If male, penis out, and if brave enough, ears out and walking in the direction of the potential danger in a threatening way:

original videos: ACP0000b7b , ACP000chqo 

They are as well known to show a special interest when it comes to a relative´s death. 
I´m sure you have heard about the elephant´s graveyard story; it tells that elephants have “graveyards” where they go when they feel that their end is coming closer, and it is certainly a beautiful story to believe in. However, let me just play the “killjoy” here. The reality is that as they get older, they start to lose their molars (remember?) and they need to feed on soft and wet plants that they can easily chew. So they go to the river sides where there are plenty of those plants. They would stay there until they die of starvation and then their bodies flow down the river and end up in a dryer place where the water can´t drag the body anymore. If there were some elephants dying near the same river, the result is a gather place with dead elephant bodies. That´s what local people see, and this fact along with the belief in the elephant´s huge intelligence make this beautiful graveyard story.

It´s been often documented that when an elephant dies, its group (or a different group) stays around the dead body for a while (sometimes even days), just standing and exploring it with their trunks and feet. If you think of the elephant´s need of feeding during many hours a day to get all the nutrients that they need, the fact that they just stay beside a body for hours, "wasting" their precious feeding time, is very surprising. 


Although there are plenty of images showing that they express emotions in front of a relative´s dead body, still there´s little scientific evidence of the reasons why they do it. But they do it… letting aside the scientific explanation, I myself have witnessed awesome scenes. 
Let me tell you a story that I heard about:

Some years ago, in a zoo in Germany, there was a group of female elephants living together for several years. So one day one of those ladies died. In order to avoid a macabre scene for the visitors, the workers in the zoo had to `prepare´ her body inside the elephant house to be transported in a truck out of the zoo. The other three elephants were of course outside during that procedure. The body was then transported in the food truck, and covered with a canvas. They had to drive the food truck with the covered dead elephant body all along the pathway in front of the elephant enclosure where the others stayed. Right when the truck was driving in front of them, all other females went close to the fence and stretched their trunks, sniffing the air. This fact alone was not that special, as they used to do it when the food truck was driving along every day. What was really surprising was that this time they started to trumpet out loud in the direction where their dead group member was being taken.  Amazing, isn´t it?

References:

Save The Elephants: http://www.savetheelephants.org/about-elephants-2-3/elephant-news-post/?detail=rare-video-shows-elephants-mourning-matriarch-s-death

Upali.ch : http://de.upali.ch/zahne-zahnwechsel-stosszahne/

Tuesday, January 24, 2017

#ElephantTuesdays: oh mama! a female´s role 🐘

It is generally known that elephants live in -large- groups, and even that these groups are leaded by a female. But how are they formed? How is the decision made? What are the duties of a leader in the group? There have been several studies on this interesting topic; a very relevant one is known to be the longest continuous elephant research project ever developed, was conducted at Amboseli National Park in Kenya. 

Elephants live in a fission-fusion society, accumulating social and ecological knowledge over decades, and with mother-offspring bond units to clans. These groups gather approximately 8-12 individuals (in the case of African Forest Elephants the groups might be smaller), are formed by related females and leaded by the matriarch, who is typically the eldest and largest female. All members feed, rest, move and interact in a coordinated way and have very close ties.

Family groups are active, as they constantly build up and break down, and therefore it´s usually difficult to distinguish a completely formed group, but generally speaking, four different kinds of units can be distinguished among elephant fission-fusion social structures:

Mother-calf units: both in Asian and African elephant societies, calves lie at the core of the elephant family with the matriarch serving as the head.

Family: within the family group, young females (nulliparous) are engaged as the so-called allomothers. 

 original video: ACP0002hmo

Bond groups: herds can split in related groups, that might at some point gather in closely related families, also called kin groups. Bond group ties are weaker than family ties, but still bond group members assist and defend one another.
Clans, or assemblages of bond groups. Clans are defined as those families and bond groups that share the same dry season home range.

Mother-calf units and families are stable groups, while bond groups and clans are known to be seasonal.

As the eldest female of the group, a matriarchs is a `source of knowledge´ to the others, and in a female-led society, the individual role is the result of age, size, kinship and reproductive condition. The bonds to the matriarch are so strong, that the herd would possibly break after a matriarch´s death.

The matriarch´s tasks are:

·     To lead the group; she will decide when and where to wander, and as a result, what to feed on. She also knows where to go to find the best water sources. However, suggestions are often made by any other member of the group, typically by adults.
·      Protection; she keeps the group away from threats, like human settlements, etc. She will place herself in front of the potential danger, so that she will be attacked first. She will then be protected by the other females of the group, confirming their strong family bonds.
·      She controls the group, noticing where other members are to gather them in case or danger.
·      She educates the group: by teaching the next matriarch.

The female in the group who is a potential matriarch is hard to tell apart; some elephants are natural born leaders, and they start to display their leading abilities at an early age, but sometimes not. As a general rule, a female will succeed in her attempts to be the matriarch if she is confident, well-connected and able to command the respect of others. And all these qualities must be proven all over the years, until the members of the herd are able to recognize her as their leader. So the wise matriarch will be a combination of both natural leadership qualities (“personality”) and long experience; thus, she needs to be genetically and socially well connected to all the members of the group.  

And what about the males? What is the male role in an elephant society? In former elephant posts we discussed about the different life stages of the elephants. When adolescence occurs (at the age of 6 – 15), males leave the matriarchal herd to join other males. Independent males are seen in small male groups, and will go from one family to the next during sexually active periods. The males can build strong bonds, but still not so strong like families.
Young males often gather in unstable bachelor groups (all-male groups), sometimes associated with an adult male. Solo males have already reached the adult age:

original video: ACP000c165 

* In the video below, could you tell who the matriarch is?



References:

Murray E. Fowler, Susan K. Mikota (2006): Biology, Medicine, and Surgery of Elephants

Elefanten in Zoo und Circus, European Elephant Group (EEG), Das Elefanten-Magazin, January 2015.

Elephant Voices: https://www.elephantvoices.org/


*answer here

Tuesday, January 17, 2017

#ElephantTuesdays: the elephant´s vision 🐘

The elephant´s eyes are quite small If one compares them with their body dimensions. Their sense of vision is moderate, as they lean more on their olfactory and auditory senses instead.

The eyes of an elephant are located on the sides of the head and therefore provide better peripheral vision, rather than binocular vision. 



Elephants (and especially African Forest elephants) have long eyelashes to protect them from the blowing sand, dirt, debris and the dense vegetation:

original video: ACP0002hmp

In addition to the upper and lower eyelids, and like many other animals, all elephants species have a third eyelid (the so-called nictitating membrane, from latin nictare, to blink) which moves horizontally across the eye, and which works for moisten and protection when bathing or dusting.

Some elephants develop a white ring that encircles the iris as they mature. This ring is similar to an age-ring that may develop in humans (as they age) called arcus lipoides, and does not affect vision.

Elephants are dichromatic; they have two kinds of color-sensors in their retina, one type of cones for *reds and another for greens. That means that they are "color-blind" when you compare them to humans (we are trichromatic: we have three kinds of cones: red, green and blue).

What is also interesting is that they are one of the animals that exhibit arrhythmic vision, that is, their vision changes within the daytime. At night, their eyes are most sensitive to violet light so they can see pretty well under the smallest amount of daylight when the prevailing color of the atmosphere is in the violet range. They have pretty sensitive rods as well (the higher density of rods in the retina, the more sensitive to light one can be), so elephants do a good job when it comes to night vision compared to humans.

The eyesight of the elephants is thought to reach a range of about 46 m. However, this can vary and be much shorter, probably because elephants use their vision sense less than their olfactory and auditory senses. When they focus on their vision, however, they show to react to the smallest ear movement of another elephant placed up to 50 m. in the distance. 


The elephant eyes are amazingly beautiful, and like humans, they can show different colors; the four most common eye colors are dark brown, light brown, honey and gray, but there are more tones like: blue-gray, gold, brown tones, green and yellow, and even the right and left eye of one elephant can be differently colored.




As a curiosity: There have been documented occurrences of elephant herds being led by a blind member, fulfilling amazingly its role as the herd leader.


*Some authors claim that elephants possess cones for reds and blues (deuteranopia) instead of reds and greens : Von Elefanten und Menschen, Fred Kurt (2014).





References:

Murray E. Fowler, Susan K. Mikota (2006): Biology, Medicine, and Surgery of Elephants

Fred Kurt (2014): Von Elefanten und Menschen.

Seaworld Parks & Entertainment: https://seaworld.org/en/Animal-Info/Animal-InfoBooks/Elephants/Senses