1. Proboscidea (animals with trunks/proboscis)

2. History
It is believed that mya, mammals approximately the size of current day pigs, were the roots from which the proboscideans evolved.
Based on both morphological and biochemical evidence, it is agreed that the manatees, dugongs, and hyraxes are the closest living relatives of the today's elephants.

3. History
This mammal order belonging to the Tethytherians evolved in Africa during the Eocene, about 60 mya
Includes over 300 species (some taxonomist count 129) and is the highway for the evolution of the elephants
The oldest proboscidean is Anthracobune, from early or early-middle Eocene (˜50 mya), was found in Africa and Asia, in shore or semi-aquatus shallow environments, but Proboscideans inhabited a wide range (North America, Asia, Europe, and Africa)

4. Evolution
About mya, the ancestors of the modern elephant occupied a variety of extreme environments; from tropical rainforests to deserts in both low and high altitudes.
With the exception of Australia and Antarctica, the proboscideans have over time inhabited every single continent on Earth.
Why did all but two species become extinct?
Inability of the order to evolve to environmental change fast enough

5. Evolution
The mammoth, Asian elephant, and African elephant all originated in Africa. It was only the African elephant that ended up staying and evolving to the animal we know today solely in Africa.
The mammoth became extinct as recently as 5 kya; fossil records indicate that hunting by Man was a factor in eliminating the mammoth, as well as global warming.
The earliest known member of the Proboscidea order are the Moeritheres. They are a pig sized creature that lived in northern Africa between 55 and 60 million years ago. A little later the Palaeomastodons, who existed between 40 to 25 million years ago. branched off and were the first know descendants of the lineage that let to the two present day species of elephants. Interestingly, the mammoth, Asian elephant, and African elephant originated in Africa. It was only the African elephant that ended up staying and evolving to the animal we know today solely in Africa. The mammoth became extinct as recently as 5000 years ago; fossil records indicate that the hunting by Man was a factor in eliminating the mammoth, as well as global warming.

6. Living Species
African elephants (Loxodonta) live in central Africa, from Democratic Republic of the Congo to Mauritania, and are divided into two subspecies (savannah and forest).
Asian elephants (Elephas maximus) inhabit India, Sri Lanka, Myanmar, Indonesia, Thailand, Cambodia, Vietnam, Laos, Malaysia, Nepal, Bangladesh, and southern China, and is divided into four subspecies (Sri Lankan, Indian, Sumatran and Borneo).

7. Physical Characteristics
Height: 5-14 ft at shoulders (males); females of all subspecies are smaller than males.
Length: Up to 30 ft trunk to tail.
Weight: 6,000-15,000 lbs (males).
Lifespan Up to 70 years.
Long, muscular trunk that functions almost as a fifth limb, and males have a pair of huge tusks derived from upper incisors. Their cheek teeth are uniquely adapted to their highly abrasive diet.

8. Habitat Live in tropical and subtropical regions Minimal Needs
Variety of habitats:
Savannas (grassland and woodland)
Rainforests
Mountains
Semi-deserts
Deciduous forests
Within a day's walking distance of water

9. Diet Staples: Grasses, leaves, bamboo, bark, roots.
Elephants are also known to eat crops like banana and sugarcane which are grown by farmers. Adult elephants eat lbs of food per day.
They are capable of pushing down large trees in order to get at their foliage and bark. (The skeleton of elephants is adapted to bear massive weight). Foraging herds can be very destructive of cropland or forest.

10. Reproduction
Mating Season: Mostly during the rainy season Gestation: 22 months Litter size: 1 calf (twins rare)
Calves weigh between lbs at birth
At birth, a calf's trunk has no muscle tone, therefore it will suckle through its mouth. It takes several months for a calf to gain full control of its trunk
Sexual maturity is reached between yrs
Cows typically give birth to 1 calf every 5 years

11. Behavior Typical life span is 60-70yrs
Complex social structure is matriarchal and family is at the core (3-25 members), individuals greet one another by making sounds and touching each other with their trunks They communicate by means of a variety of sounds, some produced vocally and others by tapping or stamping on the ground
Extremely intelligent animals and have memories that span many years
They also display signs of grief, joy, anger and play

12. Climate Change & Other Threats
Habitat loss
Many climate change projections indicate that key portions of elephants’ habitat will become significantly hotter and drier, resulting in poorer foraging conditions and threatening calf survival
Increasing conflict with human populations taking over more and more elephant habitat and poaching for ivory are additional threats
At the turn of the 20th century, there were a few million African elephants and about 100,000 Asian elephants.
Today, there are an estimated 450, ,000 African elephants and between 35, ,000 wild Asian elephants.

13. Case Study: African Elephants Respond to Distant Playbacks of Low Frequency Conspecific Calls (Langbauer,1991)
The purpose of this study was to estimate the distance over which African elephants can perceive the low-frequency calls of conspecifics
58 playback experiments with free-ranging African elephants in Etosha National Park, to estimate the distance over which some of their low-frequency calls are audible to other elephants
Broadcast pre-recorded elephant calls to elephants that were 1.2 and 2.0 km from the loudspeaker, using 5 different stimuli

14. Case Study: African Elephants Respond to Distant Playbacks of Low Frequency Conspecific Calls (Langbauer,1991)
At distances of more than a few meters, many of the low-frequency calls are entirely inaudible to the human ear
These calls appear well suited for transmission over long distances since low-frequency sound propagates more effectively than sound at higher frequencies
Long-distance acoustic communication would help explain some enigmatic aspects of elephant social behavior (coordinated movements of cow-calf groups)

15. Case Study: African Elephants Respond to Distant Playbacks of Low Frequency Conspecific Calls (Langbauer,1991)
For each experiment, the subjects consisted of all elephants present at the waterhole when the playback was broadcast
Classified as being either a 'male' trial or a 'cow-calf group' trial
A full response consisted of the elephant vocalizing, lifting and spreading its ears, remaining motionless in this position, moving the head from side to side and, in the case of males responding to female estrous calls, orienting to and finally walking 1 km or more towards the loudspeaker

16. Case Study: African Elephants Respond to Distant Playbacks of Low Frequency Conspecific Calls (Langbauer,1991)
All the calls used as stimuli elicited responses from the subject elephants
Animals in cow-calf groups tended to give vocal responses more than animals in all-male groups
Male responses tended to persist longer and to involve movement over longer distances than did those of cow-calf groups
Results support the hypothesis that the low-frequency calls of elephants function in communication among elephants over distances of several kilometers

17. Sources