How many elephants inhabit the African continent?

 

Gotheim

 

Introducing the African elephant; Loxodonta africana:

 

The African elephant is the largest land living mammal today. It can become nearly 4 meters high, and the male can weigh as much as 7500 kg, the female 3500 kg.

Their average lifespan equals that of humans.

The elephants usually move in herds which consist of females and their young offspring. The herd is lead by the eldest female, the so called matriarch. It has been observed that the herds can consist of as many as 100-200 individuals! (L.Mumbalama, 2000)

Grown bull elephants have usually no social connection to other elephants, except during mating.

Because of their large size the elephant has no natural enemies/ predators except humans. (Some very young or sick elephant infant may sometimes get hunted down and killed by lions or hyenas, but they are usually very well protected by the herd.)

Contrary to the Indian elephant, both the male and female African elephant have tusks, which are valuable items for poachers who make a living out of selling them to the ivory trade market. This above all is recognized as the main reason for decreasing elephant populations during the last centennial.

The population of African elephants are today distributed throughout the continent in 37 different countries, but has the highest density in the southern and eastern parts of Africa.

 

Taxonomy:

 

Kingdom:        Animalia

Phylum:           Chordata

Subphylum:     Vertebrata

Class:              Mammalia

Order:                         Proboscidea

Family:           Elephantidae

Genus:             Loxodonta

Species:          africana africana (the bush elephant) and africana cyclotis (the forest elephant)

 

 

The problem:

 

When it comes to the matter of measuring the continental population size, one should think that the world’s largest land living animal should be easy to track and survey, but this is not the case. At this present time there is going on a debate which compare new and old population estimations. The experts do not seem to agree on which are the more accurate.

In 1999 a report by the IUCN (The World Conservation Union) stated that the population of African elephants was somewhere between (definite) 300.000 and (speculative) 490.000 individuals. (Alex Kirby, BBC News)

Today it is speculated that the number has increased to at most 660.000 individuals. The hypothetical increase of 170.000 beasts along a 4 year period contradicts all earlier trends in African elephant population dynamics, and according to an article by BBC news online environment correspondent Alex Kirby from December 2003, few scientists find this increase realistic.

Some of the facts the scientists have to take into account when considering the new estimates are:

• Hyper aggregation. Due to expanding human populations and decreasing elephant range the elephants tend to migrate to and flock in protected areas, which can give a false impression of increasing numbers. Because it is precisely in these protected areas that most of the population research is made. (Julian Blanc, BBC 2003)
• New counting methods. New and improved counting techniques have shown to give an increase in the population estimations. (I.Douglas-Hamilton, 1986)
• Access to new areas. Several, former restricted, areas due to civil conflicts and political instability are now open for scientists to enter, and thus the new estimates are covering a much larger area than before. (Julian Blanc, BBC 2003)
• Physiological phenomenon. In a paper published in Pachyderm jan-jun-2000, Leonard Mumbalama describes a “baby boom” amongst the herds in the Virunga National Park. He admits he cannot find any immediate explanation to this phenomenon. Even though this observation is restricted to a very small area, it might be that this could be the dawn of a new trend also within several other elephant populations around the continent. (It may sound a bit far fetched, but one should not totally rule out the possibility).

 

 

What are the primary factors which may influence the population size?

 

Based on two reports, “African elephant population study” by I. Douglas-Hamilton published in1987 and “Population and distribution of elephants in the central sector of the Virunga National Park, Eastern DRC” by L. Mumbalama published in 2000, the main factors affecting the population size are:

• Killing of elephants for ivory trade. During the last centennial, the market’s thirst for ivory has expanded rapidly. The largest threat is the dangerous combination of easy money access through elephant poaching and growing poverty amongst an expanding African human population.
• Expansion of human populations. Humans turning woodlands and savannahs over to crop fields are the number one reason for decreasing elephant home range. It is estimated that the African human population has a growth rate of about 3% each year. This does not predict a promising future for the African elephants.
• Political and economical instability. Less governmental control over protected areas and easier access to weapons, in addition to increasing poverty amongst the people, is closely related to the poaching problem and increased ivory trade.
• Food accessibility. Removing the natural vegetation for the agricultural and industrial usage, feed on the nutritional resources of most wild animals as well as the elephant. Weather and long-term climatic changes are also factors to be considered. (Human impact on water distribution and wildlife during dry and wet seasons).

 

 

Methods for counting and estimating:

 

Continental population estimation is based on the sum of the estimations from many individual regional reports. It is perhaps easier to describe it as a pyramid, where at the base of the pyramid you find the estimations from even the smallest “study areas”, whereas at the peak of the pyramid you find the total continental size.

It is in the “study areas” the real job is done. The usual method is to pick a given number of random placed line transects, with given specifics of length and width, within a sampling zone. Information collected from the line transects in the sampling zone is then calculated to make a population estimation for the whole area.

 

The most common:

• Dropping count method (dung pile counting)
• Direct observations (usually through foot or vehicle surveys)

 

Others:

• Carcass counting (registration of poaching trends)
• Interviews with local natives
• Radio marking and tracking (surveying the migration elephants)

 

For the unknown areas, estimations are based on information collected from known areas with similar characteristics like vegetation, soil type and precipitation and so on.

 

 

 

Some final words:

 

I have chosen to summarize some of the arguments for whether the old or new estimations of the African elephant population are the most correct. I feel I have certainly found more arguments supporting the new estimations, even though they are still very much based upon information of theoretical value only.

At present time there is not enough substantial evidence to conclude anything really, except the fact that the number of elephants which inhabit the African continent is still a mystery to be solved in the future.

 

• The current number is correct, due to a physiological phenomenon which has increased the population size.

Referring to the earlier mentioned “baby-boom” one cannot totally rule out the possibility that due to a physiological phenomenon, the African elephant population is currently undergoing growth.

 

• The current number is correct when considering earlier reports as calculations based on restricted information about large inaccessible areas.

One of the main problems when estimating the continental population size is the political disturbance and civil conflicts amongst the African states. Large areas have not been accessible to scientists because of war and random governmental changes. In the last years several countries have “cooled of “and scientists have been allowed to cross the borders and perform research labour in the wild bushes.

 

• The current number is correct due to newly developed more accurate methods of counting and measuring populations, then earlier used.

 

• The current number is wrong because of miscalculations due to misleading impressions.

The shrinking of elephant range due to human expansion and agricultural development can cause the animals to hyper aggregate in protected or safe areas.

 

• Both earlier and newer reports are miscalculations and no one really knows the actual size of the population.

 

 

 

 

 

 

 

Sources:

Population and distribution of elephants in the central sector of the Virunga National Park, eastern DRC by Leonard Mumbalama

www.iucn.org/themes/ssc/afesg/pachy/pdfs/pachy28.pdf

African elephant population study by I.Douglas-Hamilton

www.iucn.org/themes/ssc/afesg/pachy/pdfs/pachy08.pdf

African elephant numbers puzzle by Alex Kirby, BBC

http://newsvote.bbc.co.uk/go/pr/fr/-/hi/sci/tech/3287423.stm

Microsoft encyclopaedia 2003