Juvenile Delinquent Elephants

social order

Social order & dominance hierarchy: provides framework for survival of a group

• Reduces the occurrence of actual fighting and subsequent injury

• Dominance hierarchies: relatively stable in a group once established

• May change over time due to injury or aging of more dominant members or due to new individuals entering a social group

• Cooperation allows individuals of different social ranks to exist in close proximity

elephants

• Largest land mammals

• Largest brain of land mammals, but some whales have larger brains

• Live as long as humans

• Learn quickly and remember for a long time

physical characteristics

• Graviportal (pillarlike legs with thick heavy bones)

• Subungulates (ungulate = having hooves)

• Short nail-like hooves, flattened soles

• The sole of the foot pictured measured 16” by 19”

• The ridges and pads help with traction

female elephants

Female has two breasts with nipples between the front legs

male elephant

Testes are within body cavity, close to the kidneys

elephant trunks

→ The nose or trunk: the olfactory organ of the elephants; associated with the vomeronasal organ (pheromones) located on the palate of the mouth.

→ Two small pits connected by numerous nerve endings which transmit smelling sensation to the brain.

→ When elephants want to detect an odor: they raising and wave their trunk in the air to better inhale the smell.

→ They can find and locate water sources about 50 km away, and can detect the reproductive status of the other elephants from a long distance, especially males detecting female elephants in estrous

elephant teeth

• Highly specialized teeth

• Molars with transverse ridges for grinding: very high crowned

• No canines

• Incisors (upper ones are the tusks)

• Usually 26 teeth:

• the incisors (the tusks)

• 12 deciduous premolars

• 12 molars

• Polyphyodont: cycles of tooth rotation throughout their lives

• Eruption of molars: so only one is in use on each side of jaw at a time

• They begin at the back of the jaw and grow forward

• Six sets of teeth throughout life

tusks

• Tusks appear at birth and grow throughout life

• At age 60 a bull’s tusks may each weigh 132 pounds

• Elephant ivory is a mixture of dentine and calcium salts

• Uses: feeding, display organs, weapons

african elephant

• Larger; head: single dome

• Concave back

• Trunk: two processes (lips)

• Bigger ears

• 21 pairs of ribs

• Both sexes have tusks

• The African Forest: 5 fingernails on its front feet, 4 on the back;

The African Savanna: 4 fingernails on its front feet and 3 on the back

Asian elephants

• Smaller; twin-domed head with an indent in the middle

• Back is rounded

• Trunk has one process

• Smaller ears

• 20 pairs of ribs

• Only males have tusks

• 5 fingernails on its front feet, 4 on the back (rarely 5)

jungle elephants

• Actually called African Forest

• Genetic fingerprinting shows that Africa's Forest and Savannah (African Bush) elephants are as different from one another as lions and tigers, and should be considered as two genetically distinct species (2010)

• Probably separated from African Savannahs about 2.5 million years ago

• Almost no interbreeding between the two populations

• Estimated to be 150,000 in wild

• “Pink ivory” is prized by poachers

• Logging threatens habitat: poachers can access these areas using road networks meant for logging.

• African Forest Elephants are heading for extinction, possibly within the next decade

forest gardener elephants

• Much smaller than African Savannahs

• Males are ~ 8’ tall (13” for Savannahs)

• Rounded ears, narrower face; darker in color, light yellowish or pinkish tinge, and straighter tusks to help the animal move conveniently through the dense undergrowth of its habitat.

• The primary dispersers of seeds for many trees and plant species and therefore they are often referred to as Forest Gardeners

eating habits

The Asian elephant’s diet is made up of a greater proportion of grass and the African’s of leaves

digestion

• 20 to 40 gallons H 2 O per day

• Hindgut fermenters: cecum and large intestine

• Gut microflora aid in digestion of plant material

• Babies do not have microflora (eat dung to help with digestion)

movement

• Radio-tracking in elephants since 1969

• Movement of individuals varies greatly (satellite collar)

• Depends on T°, moisture, breeding season, etc.

• May move an average of 4 to 5 miles per day

• “Streaking” (rapid direct movements) usually takes place at night: stress

• Importance of corridor ecology

social behavior

• Complex social behavior

• Social behavior suggests that elephants possess ability to perceive feelings of other elephants

• Group life: good for defense, instructing young, enhanced mating opportunities

• Matriarchal societies, close family ties

• Closely related adult cows and their immature offspring live together

• Adults: sisters or mothers and daughters

• Typical: 2 or 3 sisters and offspring; one old cow, adult daughters and offspring

• Oldest female leads the group

• Kinship groups or bond groups: 2 to 4 related families that travel together

• As these units increase in size, young adult cows will split from group

• Resource availability

• Adult cows will surround young in times of danger

• Young males leave or are forced out of the family groups

• Adult bulls form small bachelor groups

• Asian bulls are more solitary than Africans

bulls

• “Musth” is a Hindi word meaning “intoxicated”

• Generally bulls come into musth at ∼ 29 years of age

• Musth lasts for 2 or 3 months and seems to coincide with periods of high rainfall

• Bulls seek females during this period

• Quite aggressive

• Likely to fight with other males at this time

• Fights can be monumental because the bulls are so large and their testosterone levels are so high

musth

If a bull elephant goes into musth: a sign that he is healthy

• Typically it lasts between 2-3 months; three stages

– a 3-4 week premusth condition

– a 4-5 week peak musth

– a 4-5 week post-musth condition

• For elephants in captivity, the condition and its duration can vary greatly: deprivation of food and nutrition can cause the elephant to go into musth less frequently and for shorter durations of time

A natural phenomenon in healthy adult bulls, both tuskers and makhnas (tuskless bulls).

• Secretion of a hormone rich substance “temporin” from the temporal gland (on either side of the elephant’s head) and a steady trickle of urine down the back legs

• Musth involves a rise in the reproductive hormones (e.g., testosterone): the animal feels more restless, energetic, aggressive or unpredictable, generally irritable and oversensitive to sounds and movements

signs of musth

• Posture: head unusually high, ears high and spread out

• “Musth rumble” low, pulsating growls: sound like a low-pitched diesel engine

• Great reduction in food intake: burning of fat reserves during this time

do castrated elephants come into musth?

• An elephant that has undergone a vasectomy (laparoscopic vasectomy) would come into musth as the procedure does not affect hormonal changes in the body.

• Castration is extremely difficult in elephants due to the depth of the location of the testicles within the elephant’s body. However, elephants are rarely castrated as this is an extremely complicated process, and illegal elephant owners often breed their elephants in captivity and hence would not benefit from castrating them; castrated elephants do not come into musth

reasons for musth

1. Increased status of bull over non-musth bulls

2. Increased chances of bull in musth finding receptive cows (these bulls travel long distances in search of females)

3. Cows in estrus are quite impressed with bulls in musth

what about the cows?

• Sexual maturity at ∼ 10 years

• In estrus only 2 to 4 days during a 4-month estrus cycle: a cow is only ready to be covered by the bull ∼ 3 to 4 times per year.

• Attract males with a very loud call; she has the final say in whether mating to a particular bull will occur.

• Cows’age, body condition, supply of food and water, other climatic conditions all influence whether she will ovulate or not.

• Gestation period = 630 days (1.7 yrs)

• At birth calf weighs 265 lbs

kruger national park

• South Africa

• Two decades ago: elephant population increased beyond what the environment could support

• Decision was made to cull and transport

• Adults were killed because they were more difficult to transport alive than babies

relocation

• Some of the young elephants orphaned by this culling (less than 10 years of age) were transported to other

national reserves

• Others remained in Kruger NP

• Care was taken to have reasonably sized groups with appropriate numbers of males and females

• The project seemed to work well

• Orphans adjusted well to life in new surroundings and without family members

• Lack of reproduction (because the transplants were young) allowed food supplies to be replenished

problem with relocation

• Within a few years, one of the parks that had accepted older orphans began to have troubles

• Appeared that poachers or disease was responsible for deaths of white rhinos in the park

• 10% of white rhinos were killed before the problem was defined

rhinos

• They are the third largest land mammal, after African and Asian elephants

• Massive head with horns

• Poor vision but good senses of smell and hearing

Baby rhinos have a characteristic pink hue to their hide which disappears with age

problem with relocation → the young bull elephants were rampaging

• There was also destruction of park property, tourist vehicles and attacks on park workers

• Same thing happened at other parks housing the orphans

what was the real cause of this change in social behavior

• The young bulls were entering musth at extremely early ages

• Testosterone levels were elevated

• They acted very much like human street gangs

• Vicious in their attacks: rangers killed some of the obvious elephant group leaders because it was thought that their vicious behaviors could not be changed

• The young bulls killed many rhinos, both white and black

• Rhinos are endangered species that have been carefully protected for many years with extensive efforts to increase numbers

• Within a short time the rhinos were terrified of the elephants

Solution:

→ Adult bull elephants were transported to the parks where the marauding juveniles lived. Within about 8 months time, the presence of the adult bulls suppressed sexual aggression of the younger males by repressing their coming into musth

• The rangers began looking for role models to keep the youngsters from mating at an early age when they could not handle those raging hormones: they decided to bring in some even larger bull elephants.

• The bigger, older elephants established a new hierarchy, in part by sparring with the younger elephants to discourage them from being sexually active → less testosterone

A group of teen-agers who have been acting up who are confronted by their fathers all of a sudden

implication

Evolution for social structure has occurred over a long period of time

• Interference by humans, however well-intentioned, can cause serious problems that are difficult to predict

• We need to be careful

• Social order has extremely important influences on species survival

• "I think everyone needs a role model, and these elephants that left the herd had no role model and no idea of what appropriate elephant behavior was," said Gus van Dyk, Pilanesberg Park's field ecologist

elephants in the lobby

• Mfuwe Lodge in Zambia: built next to a mango tree

• A family of elephants have always visited when the fruit ripens

• Now they wander through the lodge while they are there for the fruit

• A dangerous situation

• Guests are kept away from the elephants but are allowed to take pictures

• The elephants appear placid but..