Leggett Annual Report 2008

4. Results

4.1. Eastern Kunene Elephants

Eastern Kunene Male (EKM) -07

This is the first time that this elephant has been collared.  EKM-07 is a mature male.

After collaring, EKM-07 spent his time in and around the southern border of Hobatere

Game Reserve.  His daily movement and home range during the hot dry season were

relatively small (see Table 1 for details).  This compressed home range during the hot

dry season around known water points and safe from disturbance is typical of

elephants in this area.

Eastern Kunene Male (EKM) -08

Until his collar failed in late November, EKM-08 spent his hot dry season in and

around Hobatere Game Reserve. His home range and daily movements were

relatively small (see Table 1 for details).  Unfortunately, his collar failed before any

wet season data could be obtained.

Eastern Kunene Male (EKM) -09

This was the first time that this elephant has been collared. Unfortunately, EKM-09’s

collar failed soon after fitting, so very few data points were obtained for this elephant.

Eastern Kunene Male (EKM) -10

This is the first time that this elephant has been collared.  EKM-10 remained within

the borders of Hobatere Game Reserve during the 2007 hot dry season.   Only erratic

readings were recorded from EKM-10’s collar during the 2008 wet season.  However,

they placed this elephant in the areas to the west of Hobatere Game Reserve.   As very

little data were obtained from this collar it was difficult to draw any conclusions.  The

home range data for EKM-10 during the hot dry and wet seasons are shown in Table

4.2.  Western Kunene Elephants

Western Kunene Male (WKM) – 10

WKM-10 was collared for the fourth time.  He still has the largest home range of any

of the collared elephants in northern Namibia and one of the largest home ranges ever

recorded for African elephants.   WKM-10 spent the hot dry season in the Hoanib

River.  He moved to the eastern section of the research area in early February 2008.

He stayed in this area until early March 2008 before moving briefly further east into

Etosha National Park.  Unfortunately, his collar failed at this time.  He was observed

to have returned to the western Hoanib River early in August 2008.  His daily

movements and home ranges during the hot dry and wet seasons are shown in Table

Western Kunene Male (WKM) – 20

WKM-20 was a young male and this is the first time that this elephant has been

collared. Shortly after collaring, WKM-20 moved to the south of the Hoanib River

and spent his time there.  In February 2008, WKM-20 moved from the hills in the

south of the Hoanib River catchment to the east, joining WKM-10 in the area to the

east of Hobatere Game Reserve.  He remained here until early April 2008, when his

collar failed.  He was observed to have returned to the western Hoanib River in

October 2008.  His daily movements and home range during the hot dry and wet

seasons are shown in Table 1.

4.3. Western Omusati Elephants

Western Omusati Male (WOM) – 05

This is the first time that this elephant has been collared.  WOM-05 stayed in the area

where he was collared for the entire hot dry season, with small daily movements and

home range.   During   the wet season, before WOM-05’s collar failed, he spent his time

in the areas north of where he was collared.  His range was larger than during the hot

dry season, but still quite restricted.  Details of his home range and daily movements

during both the hot dry and wet seasons are shown in Table 1.

Western Omusati Male (WOM) – 06

This is the first time that this elephant has been collared.  Unfortunately, WOM-6

broke his collar within a month of its being fitted.  His daily movements and home

range were fairly large before the collared failed (see Table 1 for details).

Table 1: Movement and home range data for GPS collared elephants during the

hot dry season 2007 and the wet season 2008.

N.a. – not analysed due to failure of the collars

The variance on average daily movement is high.  This is due to several factors, not

least is of which is that, due to the erratic nature of the collars, none of the data sets

are complete.  In addition, on the basis of hourly movement data obtained for

elephants in north-western Namibia in the past, it appears that elephants walk

excessively one day then spend the next few days resting (each individual has his own

pattern), leading to large differences in daily distances walked.  This data has been

submitted for publication and copy of the paper will be supplied in later reports.

These hot dry and wet season data (where obtained) compare favourably to previously

gathered data on GPS collared elephants in northwest Namibia (see Table 2 for details

on previously collared elephants). Table 2 also shows the age, sex, number of data

points, period of study and home range (determined by MCP analysis) of GPS

collared elephants in the Kunene and Omusati Regions of northwest Namibia.

Table 2: Summary of current and previously GPS collared elephants in northwest Namibia .

4.4.  Behavioural Studies

4.4.1. Carry out identification, social and behavioural studies on resident elephants.

Research Question:

The annual variations in water availability and ambient temperatures are significant in

an arid area (Jacobson et al., 1995; Leggett et al., 2001).  This study examines the

behaviour of elephants in response to variations in environmental conditions.  By

definition this study needs to be undertaken over a longer time scale to encompass the

wider variation in climatic conditions that occurs in an arid region.

Method:

Elephants were individually identified using a combination of photographs and

identification sheets.  The photographic techniques used were similar to techniques

already described by Douglas-Hamilton and Douglas-Hamilton (1975), Moss (1982)

and Sukumar (1989).  Photographs were taken from the front, left and right side of

each individual.  In addition, field identification sheets were kept for each individual

elephant.  When an unknown elephant was characterised, it was given a unique

nomenclature and, during all subsequent observations, its nomenclature, current

elephant-elephant associations and activity were recorded.  The exception to this was

if an elephant broke a tusk or if any additional holes or tears in the ears were noted.

In this event, the relevant identification sheets were updated and the changes added to

the database.

Three different types of activity studies were undertaken and compared. All methods

used either point sample techniques or focal sample techniques over specified time

intervals. When studying elephant groups, a point sample technique similar to that

described by Barnes (1982) and Kalemera (1987) was used.  All individual activity

within the group was recorded at 2-minute intervals for up to 3 hours. This 2-minute

scan study obtained data only on feeding, water, resting, social and walking activities

for multiple individuals.  The second method used a focal sample technique, where

known individuals were observed for a minimum of 30 minutes to a maximum of 3

hours, data being recorded at 5-minute intervals (Kabigumila, 1993; Lee, 1996).

Detailed information on each individual was recorded on a check sheet similar to that

described by Lee (1996), and activities were defined in a manner similar to that

described by Guy (1976). These were categorised under 5 main headings and

subdivided as follows:

(1) Feeding:

(a) Grazing

(b) Browsing

(c) Debarking of trees

(2) Activities associated with water:

(a) Drinking (Water Activities)

(b) Wallowing

(c) Dust bathing

(3) Resting

(a) Standing or sleeping in shade

(b) Standing or sleeping in the open or sun

(4) Social activities:

Activities include: playing, fighting, communication, aggression, nursing and courtship

(5) Walking

The third method also employed a focal sample technique similar to that described by

Guy (1976). The technique focused on an individual, with data recorded continuously

for between 60 minutes and 5 hours, using the same activity categories as described

for the 5-minute focal animal study.  A change in behaviour was defined as any

activity undertaken for longer than 1 minute.  For example, if an elephant was

walking and stopped to feed for less than a minute, then walked on, the activity would

be regarded as “walking” and not “walking/feeding”.

Throughout the study, an effort was made to collect data on all age groups.  For the

purposes of this study, age groups were defined as follows: juveniles, being those

young elephants that had not yet been weaned (0-5 years), sub-adults (5-10 years

female, or until they have their own offspring, 5-14 years male, or until they leave the

family unit), and adults (>10 years female; >14 years male).  During each field trip,

attempts were made to collect data on all age groups for every hour between 0700 and

1900. However, due to seasonal light availability, this was not possible in all morning

and evening time slots.

The first elephant encountered by the researcher at the start of a research day was

observed and activities recorded.  To avoid biasing the study to those individuals that

were easily found, if the first individual encountered had been observed in the

previous day, observations were not undertaken and another elephant was sought

instead.  Most elephants were initially encountered either in the riverbeds or on the

river plains, then followed and observed.  Although this infers a bias towards

individuals that reside or traverse these areas, elephants in this area spend about 85%

of their time in these habitats.  When undertaking 2-minute scan or 5-minute focal

animal studies, it was possible to observe up to four different individuals or groups in

a day, depending on accessibility.  However, the number of studies that could be

undertaken was reduced when longer-term studies were conducted. There was

generally a lack of data collected during the wet season as it was difficult to get into

the field during this period due to rainfall and flooding in the rivers.

Results:

Identification and social studies are ongoing.  As calves are born or any new elephants

appear in the research area, they are identified, photographed and catalogued.

Seasonal activity budget studies are currently in process and only preliminary analysis

has been conducted.  These studies also included behavioural and social interactions

as well as current herd associations.  Results from the 2008 season are presented in

Table 3.

Table 3: Summary of diurnal activity (as percentage of time) from data obtained during the 2008 research season

As can be seen from the results, observed activity during the 2008 season has varied

significantly from previous years.  During the 2008 wet season, approximately

350mm of rain was recorded at Sesfontein (long-term average – 87.9mm) and

approximately the same amount was recorded in Purros (no annual average available,

but the town is in the 50mm isohyet).  This was reflected in the amount of available

grazing and browsing, which was much greater than in previous years.  Grazing was

by the far the dominant feeding activity during the later part of the wet season

whereas, in all previous years, browsing has been the dominant feeding activity.

4.4.2  The Dung Study

Research question:

From data obtained during the activity studies it became apparent that elephants in the

arid area of western Namibia defecated less than any other group of elephants in

Africa (Table 4).  A detailed series of studies examining the frequency, seed

composition and potential distribution, weight and the percentage of moisture in the

dung was undertaken.

Table 4: Comparison between defecation rates of elephants in three African countries

Method:

When a known individual was observed to defecate, the time, number of boluses and

the total weight (using a digital 5000g scale) of the defecation event were recorded.

In addition, one bolus was retained from each defecation event to determine the

percentage of moisture in the bolus.  This study was undertaken to determine whether

the percentage of moisture in the dung of desert-dwelling elephants varied

significantly from elephants in higher rainfall areas of Africa. The bolus was weighed

when first collected (within 15 minutes and 2 hours of the defecation event,

depending on accessibility) and then stored in a net bag to allow airflow and prevent

seed germination. The weight was then recorded at 24, 48 and 72 hour, and one month

intervals. In practice, measurements were taken at 24 hour intervals and the bolus then

left to air dry in the atmosphere for one month when it was re-weighed.

A second bolus was retained from each defecation event for seed analysis.  This study

was undertaken to look at the dispersal of  Acacia erioloba  and  Faidherbia albida

seeds in the dung.  Once a bolus had been collected, it was dissected and the seeds

were extracted and washed.  Only whole seeds were then used for further analysis;

partially crushed seeds and seeds that contained weevil holes were discarded on the

grounds that they would never germinate.  All seeds found in the dung were taken to

the National Herbarium in Windhoek for identification. The vast majority (99%) of

seeds found in the dung were either  A. erioloba  or  F. albida  seeds.

As the seeds in an elephant’s stomach absorb moisture and swell to as much as twice

their normal size, in order to establish the correct weight of the seeds at the time of

consumption, dry seeds collected from  A. erioloba  pods were weighed. 1000 seeds

were weighed 3 times and divided to get the mean weight of one seed, which was

determined to be 0.26g.  A similar exercise was undertaken with  F. albida  and the

seed weight was determined to be 0.25g.

Results:

A summary of results obtained for the last three years of the project are shown in

Table 3.

Table 3: Summary of dung results 2004-2008.

In 2008, defecations consisted of an average of 4.73 boluses, which was higher than

the average observed during the years 2004-2007.  The average weight of one bolus

(usually recorded after 15 minutes – 2 hours of defecation) was 1322 g and the

average total defecation was 6257 g.  This undoubtedly reflects the availability

vegetation that was observed during this year.

Only two seed species (Acacia. erioloba and Faidherbia albida) were observed   in the

dung. There were a large number of seeds observed in the dung during the wet and

early cold dry seasons, but, as the hot dry season developed, there was a noticeable

decline in the number of  A. erioloba  and an increase in the  F. Albida seeds. The

average number of seeds found in each bolus was 120 (0 – 230), which was lower

than the average number of seeds found n previous years.  This was probably due to

the lower rainfall of the 2006-2007 wet season rather than the higher rainfall observed

during 2007-2008 wet season.

The 2008 dung analysis revealed that an average of 16.8% of moisture in the elephant

dung was lost in the initial 24 hours after collection, which was similar to that

recorded in previous years.  However, the moisture then decreased by a further 11.8%

over the next 24-hour period (this was exceptionally high in comparison to previous

years). There was a further 42.3% reduction to a dry weight measured after one

month.

4.5. Document the demographic structure of elephant herds, including herd

sizes, recruitment rates, age/sex ratios and mortality factors in the

western Kunene, eastern Kunene, and Omusati Regions.

Research Question:

The desert-dwelling elephant’s reproductive rate is probably one of the lowest of any

elephant population.  This study was undertaken to assess birth rates, mortality and

the ratio of males to females in the elephant population of northwest Namibia.

Methods:

The family units and free roaming males of the research area were studied by direct

observation and data recorded over the 10 years of study.

Results:

The reproduction rate of the desert-dwelling elephants varies considerably and is

dependent on environmental conditions.  Viljoen (1988) determined that the

reproduction rate of elephants in the arid western areas of Namibia was 1.9%, while in

the eastern section of the research area, it was 2.8%.  Viljoen’s study was conducted

in 1981-83, a period of high stress for the elephants.  Not only was there a civil war

but there was also an arid climatic cycle that was affecting elephants’ behaviour.

During the NEGT study period, 14 calves have been born (reproduction rate of

~2.5%) in the arid western areas. These reproduction rates are low compared to those

in elephant populations in higher rainfall areas of Namibia, with reproduction rates of

up to 3.3% in the eastern section of the research area (Leggett, unpublished)  and

Etosha National Park (Lindeque, 1991).  The reason for the low reproduction rates in

the western region is probably due to the effect of the arid environment and the lack

of nutritious vegetation on the females’ ability to conceive.

Data on herd structure and demographics has been continually collected during the

research.  The current age class distributions are shown schematically in Figures 9 and

10.

Figure 10: Age class distribution of male desert-dwelling elephants

Figure 11: Age class distribution of female desert-dwelling elephants

Age class definitions (after Moss 1996):

0A     0-4.9 years

0B     5-9.9 years

1A    10-14.9 years

1B    15-19.9 years

2      20-24.9 years

3      25-34.9 years

4      35-49.9 years

5      50+

The data reflect the history of these elephants with few adult males above 35 years as

these would have been killed during the poaching events of the late 1970s and early

1980s. by contrast there are a large percentage of female elephants in this age class.

There are currently few male and female elephants in the 1B, 2 and 3 age groups and

the reason for this is uncertain. These years correspond to the late 1980’s and early

1990’s, while poaching had decreased during this period, there were several dry

season back to back, possibly reducing the breeding rate of these elephants.  Since this

time the elephants have been reproducing at a rate of about 2.8%.  The relative

abundance of young males is interesting and could point to preferential selection for

males under “normal” rainfall condition and periods of low stress.

Recent Mortalities

2006/2007 was a relatively low rainfall year, with no rainfall recorded west of

Sesfontein.  Interestingly, only 2 mortalities (one adult female (20-24 years of age)

and one juvenile (2 years of age) were recorded during the 2006/2007 drought period.

Neither of these two deaths could be directly attributed to the drought itself.  The

adult female was shot by a local Ovahimba herdsman who claimed that the female

attacked him.  This is possible as the female had a young calf (the other mortality) and

she may have been protecting the calf.  The calf was still suckling at the time and

lasted only 3 more months in the care of her grandmother.  Malnutrition was thought

to be responsible for the calf’s death.   It is possible that the drought was not over a

significantly long enough period to affect mortality.  The 2007/2008 wet season was

an above average rainfall year and no deaths were recorded during this year.

In the 10 years of the study, 4 calves (2 males and 2 females), 2 sub-adults (2 males),

and 4 adults (2 females and 2 males) have died.   Of these, one adult female and one

sub-adult male were shot either on problem animal control or by local herdsmen.

4.6. Provide appropriate elephant data and training to the MET, conservancy

organisations and selected stakeholders to facilitate appropriate

monitoring, management plans and decision-making within known

elephant ranges.

Several meetings have been undertaken with MET officials both in Outjo and

Windhoek concerning elephants and elephant-related activities.  One community

meeting was undertaken with members of the Sesfontein Conservancy.  It has been

agreed to undertake a series of training seminars with local conservancy members.

The venue and timing of these training seminars has yet to be determined.  After

several unsuccessful approaches to conservancies, an alternative way of training

conservancy game guides has been developed with the Namibian Academy for

Tourism and Hospitality (NATH).  Two courses will be offered through NATH in

2009.  Initially, the course will be offered to tour guides already employed by safari

companies; at a later time, conservancy game guides will be offered the same course.

The course will be made up of theoretical and practical courses in the following

topics:

Theoretical course (3 x 4 hour lectures)

(a)  Origin and classification

(b)  Anatomy and physiology

(c)  Ecology

(d)  Behaviour

(e)  Social structure

(f)  Historical distribution and abundance

(g)  Present day distribution and abundance in Namibia

Practical Course (4 days in the field)

(a)  How to track elephants

(b)  How to behave around elephants

(c)  How to deal with aggressive elephants

(d)  Individual characteristics and identification

(e)  How to avoid elephant problems while camping

(f)  How to get the most out of the elephant experience

5.0 References

Barnes, R. F. W. 1982. Elephant feeding behaviour in Ruaha National Park, Tanzania.

African Journal of Ecology  20:123-136.

Douglas-Hamilton, I. and Douglas-Hamilton, O. 1975.  Among the Elephants .  Collins

and Harvill Press, London. UK.

Guy, P.R. 1976. Diurnal activity patterns of elephants in the Sengwa Region,

Rhodesia.  East African Wildlife Journal  14:285-295.

Jacobson, P.J., Jacobson, K.M., Seely, M.K. 1995.  Ephemeral Rivers and Their

Catchments: Sustaining People and Development in Western Namibia.  Desert

Research Foundation of Namibia, Windhoek.

Kabigumila, J. 1993. Diurnal activity of elephants in the Ngorongoro Crater,

Tanzania.  African Journal of Ecology  31:75-80.

Kalemera, M.C. 1987. Dry season diurnal activity of elephants in Lake Manyara

National Park, Tanzania.  African Journal of Ecology  25:255-263.

Lee, P.C., 1996. Studying the behaviour of elephants, In: Kangwana, K (Ed.),

Studying Elephants . African Wildlife Foundation, Kenya, pp 98-119.

Leggett, K.E.A., Fennessy, J.T., Schneider, S. 2001.  Rainfall, water sources and

water use in the Hoanib River catchment, Northwest Namibia.  DRFN Occasional

Paper, 15, 37-75. Desert Research Foundation of Namibia, Windhoek.

Lindeque, M. 1991. Age structure of the elephant population in Etosha National Park,

Namibia. Madoqua 18: 27-32.

Moss, C.J. 1982.  Portraits in the Wild: Behavior Studies of Eastern African

Mammals .  University of Chicago Press, Chicago.

Moss, C.J. 1996. Getting to know a population, In: Kangwana, K (Ed.),  Studying

Elephants . African Wildlife Foundation, Kenya, pp 58-74.

Sukumar, R. 1989.  The Asian Elephant: Ecology and Management .  Cambridge

University Press, Cambridge, UK.

Viljoen, P.J. 1988.  The ecology of the desert-dwelling elephants Loxodonta africana

(Blumenbach, 1797)    of western Damaraland and Kaokoland .    PhD. Thesis,

University of Pretoria, Pretoria, South Africa.