Namibian Elephant and Giraffe Project
March 2010 Update
Since the start of GPS collaring for this project in September 2002 there have been five separate collaring operations in north-west Namibia. By August 2008 all of the GPS collars fitted between 23rd and 28th October 2007 had failed and no data was available. Only two of the collared elephants were observed continually throughout the rest of the year; the 2009 wet season was one of the highest rainfalls on record, resulting in widespread dispersal of the elephants. It also made observations and field trips difficult between February and May 2009, with many of the ephemeral rivers still flowing during this time.
Behavioural studies continued however, with an observed change in feeding behaviour: from mostly browsing during 'normal' years to mostly grazing during the current year. It is too early to tell whether the increase in the abundance of vegetation will have any effect on the elephants' reproductive potential. However, after two good wet seasons back to back (2008 and 2009), it is expected that there should be an increase in reproduction rate.
Recently the seven years of data were analysed for annual variations in home range. Only five elephants out of the 21 that have been collared were analysed in detail. This was due to the fact that either the collars failed before two consecutive years of data could be gathered or insufficient data was gathered over the time-span of the collar. The home range of the elephants was determined by minimum convex polygon (MCP) analysis.
GPS collaring will take place again as soon as additional funding becomes available.
Wet season 2008 - January to May 2008
The 2008 wet season was one of the wettest on record and there has been some unusual movement. WKM-10 (Western Kunene Male), collared for the fourth time, moved into Etosha National Park which is the first time since the study commenced that he has wandered this far to the east. 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. Unfortunately, his collar, as well as all of the other collars, failed by the end of April.
According to Data Scout (SA) (the collar producer), they received a bad batch of batteries from the manufacturer, which cannot be predicted. They will replace all the collars with new ones and then money will be sought to put the collars on the elephants again. Before their collars failed, data was obtained on WKM-10, WKM-20, EKM-10 and WOM-05 during the wet season.
A table of the movements of the collared elephants during the wet season:
Hot dry season 2007 - September to December 2007
Dry Cold Season Movement of Elephants in North-western Namibia
June to August 2007
Of the four GPS collars that were functional at the start of the cold dry season only two remained so by the end. One of the GPS collared elephants (EKM-03), a young male (20-25 years old), was shot as a problem animal on the 28th July 2007. This elephant has been monitored continuously since 2002 and had one of the largest movements and significantly his home range had not been established. His collar was recovered from the MET office in Outjo. The second GPS collar ceased to provide meaningful data in early June 2007 and belonged to WOM-04. It appears as though WOM-04 has either dropped his collar or is dead. Efforts will be made to collect the collar in the beginning of October 2007. With only two GPS collars functional, there is not a great deal to report, however, it is hoped to re-collar a number of elephants towards the end of October 2007.
2006: Summary of last 12 months of research
Summary
In September 2002, then again in September 2004, eight and five elephants respectively were collared in the Kunene Region. In Phase 1 of the Omusati Elephant study, four elephants were collared in the Region in October 2005. In addition, one further elephant (WKM-14) was collared in February 2006 the western section of the Hoanib River. The total of GPS monitored elephants in the Kunene and Omusati Region is now ten individuals, though difficulties have now been experienced with three of the collars: two had ceased to function by June 2006, while the other collar gives off only a sporadic signal. The movements of all the collared elephants are presented in NEGT's 2006 report; here we present just two examples:
Eastern Kunene Male No.3 (EKM-03)
EKM-03's movement during the cold dry season 2005 was mainly within Hobatere Game Park (HGP), occasionally venturing to areas outside Hobatere Game Reserve (HGR) to the west and south. In the early wet season 2006, EKM-03 went to the east of HGR and entered Etosha National Park (ENP) moving approximately 70km from HGR. He remained in ENP for April and returned to HGR at the end of the wet season. EKM-03's home ranges during the cold dry, hot dry and wet season 2005/06 were 220.8 km2, 443 km2 and 3590km2, respectively. While EKM-03's cold dry and hot dry home ranges were similar to previous years, his wet season movements and home range were completely different from his wet season movements in 2003, 2004 and 2005. It is unknown whether this represents an expansion of range or just a spontaneous movement in response to the exceptional rains. He is a relatively young male (~25 years of age) and he may just be wandering to new areas in a kind of "wanderlust".
Western Omusati Male No.4 (WOM-04)
WOM-04 was collared on the 7th October 2005 at GPS co-ordinates -18.01480°S, 14.38067°E. He is a mature male (approximately 45-50 years of age) and stood 3.45m at the shoulder. His "down time" (amount of time spent on the ground during the collaring process) was 29 minutes. Initially, WOM-04 remained in the area; however, on 4th November 2005 he started moving back to Etosha National Park (ENP) arriving back in the Park 3 days later. WOM-04 spent the rest of the hot dry and most of the wet season in the northern section of ENP. Towards the end of the wet season, WOM-04 left ENP and moved back into the Omusati Region, where he has remained. WOM-04's home ranges during the hot dry and wet seasons 2005/06 were 4364km2 and 4129km2, respectively. It is unknown whether these movements are his normal movements or in response to the above average rains as this was the first year this elephant has been observed during this time period.
Diurnal activity studies
The studies of the diurnal activities of elephants are also an ongoing activity of the researchers. While most of these studies have been concentrated in the Kunene Region, preliminary studies have been undertaken in the Omusati Region.
The seasonal activity of behaviours varies considerably. The most significant shift occurs in the time spent walking and feeding, with a higher percentage of the time spent feeding in the wet and cold season and the amount of time spent resting during the hot dry season; however social activities and water activities decrease during the same period.
The change in percentage time spent in activities is directly linked to the availability of food and water. During this period food is scarce and elephants have to walk significant distances to obtain food and water. From the results it appears as though increasing aridity and temperature result in decreased feeding and social activities, but increased walking, resting and water activities.
Family/Bond Group Studies
There are 38 adult females, sub-adults and juveniles elephants, in seven family units (between three and 10 individuals) in the western section of the research area. It would appear that the traditional herd structure described by previous researchers does not apply in desert-dwelling elephants of north-west Namibia, as there appears to very little social interaction between the various groups.
One of the possible reasons for this diverse nature of the bond groups could be due to the history of the desert-dwelling elephants. Viljoen (1987) reported that the western elephants had been severely depleted by poaching and disturbance during the late 70s and early 80s. Owen-Smith (pers.com.) reported that the Hoarusib elephants, which had numbered approximately 80 individuals in the late 60s, were shot out to three individuals during this poaching event. These three individuals moved south to the Hoanib River and joined up with other remnant herds that had been similarly decimated. This being the case there was no direct or very few family links between any of the other family units in the area. The group associations were more for social interaction and offspring nurturing rather than any direct family relationships.
Omusati Region Research
In addition to the collaring exercise, 3 additional field trips have been undertaken into the Omusati Region to identify and monitor elephants. During each field trip consultations were made with community and conservancy members.
Characteristics and Social Behaviour in the Omusati Region
Studies have commenced in the Omusati, but due to the nature of the environment and the nervousness of the elephant herds' identification and monitoring of the elephant herds has been difficult, with few positive identifications being made.
Human/Elephant Conflict (HEC)
Preliminary consultations with rural farmers have been undertaken; however a more detailed study would be required before any conclusions could be drawn. A suitable person is being sourced at moment but this study is dependent on sufficient funding being available.
Future Research
Kunene Region
Over the next two years research in the Kunene region will be phase down and only elephant movement and population fluctuations will be monitored.
Omusati Region
If additional researchers cannot be found, then research will continue in the following areas:
- GPS monitoring of elephant movements
- Identification and monitoring of individuals
- Consultation with community and conservancy members
If an additional researcher and funding can be obtained, additional research will be conducted on:
- Human/elephant conflict
- Mitigating elephant impact in the region
For the full report, click here.
Update July 06
Effect of artificial water points on the movement and behaviour of desert-dwelling elephants of north-western Namibia
The Project's Elephant Researcher, Dr Keith Leggett, has published a paper on the effect of AWPs in north-western Namibia on the elephant population. Download the full report here.
Abstract:
In November 2002, two artificial water points (AWPs) were drilled in the Hoanib River, north-western Namibia. This arid area (< 100 mm annual rainfall) seasonally supports a relatively large desert-dwelling elephant population.
The range and the distribution of these elephants are determined by the distance that they need to forage from water. Before drilling the AWPs, female family units, hindered by their young, were limited in their movement, needing to stay close to natural permanent water sources. Free-ranging adult male elephants had larger ranges as they were less constrained in their drinking frequencies. However, the drilling of AWPs allowed family units to shift their ranges spatially beyond their normal foraging areas. Free-ranging males did not spatially shift their feeding areas but foraged closer to the AWPs. The seasonal movement of one family unit was disrupted by these AWPs, its members becoming more or less permanent residents along the river. AWPs have also changed the frequency and manner of drinking behaviour in this elephant population.
2005 Progress Report
Dr Keith Leggett
Elephant Researcher
One of the most exciting developments in the last 12 months has been the expansion of the project into the Omusati Region (north of Etosha National Park). This expansion was requested by the Ministry of Environment and Tourism (MET) and will focus on the identification of elephants, seasonal and annual movements and human and elephant conflict in the area. This has greatly increased the area of research and number of elephants to be studied. To facilitate this study, 2 sub-adult and 2 adult elephants were GPS-collared in the region. The collaring was undertaken in collaboration and support of the MET. During the last twelve months the researcher has undertaken research on the social behaviour, movement and diurnal activities of the elephants in the western section of the research area. In the eastern section of the study area, research concentrated on the movement of elephants. The researchers have undertaken 10 field trips and attended 1 community meeting. In addition, the researcher completed his third season of Earthwatch Institute volunteers (5 expeditions).
Movement studies
Movement studies have continued throughout the year. In October 2005, four elephants were GPS-collared in the Omusati region of north-west Namibia. This represents an expansion of the project into a completely new group of elephants in a new geographic region. In total four elephants were collared: two sub-adults and two large adult males. The sub-adult males were still closely associated to their family units. The reason for choosing free-ranging adult males as carriers of the collars was simply that they had proven to have the largest home ranges, and in the case of other Kunene elephants collared they have some of the largest home ranges of any elephant in Africa. All these elephants were collared in the communal areas to the north of Etosha National Park and their movements are unknown.
Movements in the Hot-Dry Season of 2005
(There are three recognisable seasons in the north-west, which are functional, and broadly defined; wet season (January - April), cold-dry season (May - August), and hot-dry season (September - December). However, in practice these seasons are variable.)
The ranges of the four elephants varied tremendously over this period. One elephant - Western Omusati Male No.4 (WOM-04) - moved approximately 150km from his point of collaring back to Etosha National Park. The rest of the newly collared elephants remained in the northern Omusati Region. The range of all eastern Hoanib River GPS-collared elephants was restricted to areas either immediately around or inside Hobatere Game Reserve or Kaross Game Park. In the west research areas, WKM-10 commenced his annual movement from the Hoarusib south the Hoanib River.
The results show that seasonal activity of behaviours varies considerably. The most significant shift occurs in the time spent walking and feeding, with a higher percentage of the time spent feeding in the wet and cold season. The amount of time spent resting during the hot dry season increases; social activities and water activities decrease during the same period. The change in percentage time spent in activities is directly linked to the availability of food and water. During this period food is scarce and elephants have to walk significant distance to obtain sufficient food and water to survive. This results in decreased feeding activity but increased walking activity, also resting time increases with higher temperatures. In response to this, social and water activities decrease during the diurnal hours.
January to May 2007
The 2007 wet season has seen below average rainfalls across the whole of north-west Namibia with little or no rain west of Sesfontein. All GPS-collared elephant (still functioning) home ranges and daily movements have decreased in comparison to all previous wet seasons that have been monitored. Only four collars are still functioning consistently: EKM-03, EKM-06, WKM-10 and WOM-4, while WOM-02 collar functions irregularly (not considered in the following analysis), all other collars have now failed. We are looking at the possibility of replacing at least 4 in the near future (October 2007).
Movements of the Western Omusati Male No.4 (WOM-04 - collar funded by the Trust)
WOM-04 spent the entire wet season 2007 in the northern section of Etosha National Park (he had previously moved into ENP in November 2006). WOM-04's home range during this time was 320 km2. It appears as though WOM-04's movement may not correspond to rainfall and seasonality. His average daily movement during this time was 4.34±3.76 km, with maximum and minimum daily movements of between 0.3 and 21.4 km. Unlike previous years, WOM-04 has not moved back into the Omusati Region at the end of the wet season, preferring to stay in ENP.
January 2007: Overall Summary of the past 12 months
The current project to identify and monitor elephants in the Kunene and Omusati regions of Namibia is an extension of the MET policy related to the consumptive utilisation of resources, and ongoing CBNRM initiatives. In July 2001, at the completion of the Hoanib River Catchment Study, the Namibian Elephant and Giraffe Trust (NEGT) was constituted and research commenced on the Northwest Namibia Desert-Dwelling Elephant and Giraffe Project. The overall aim of NEGT is to provide scientifically gathered data on elephants and other large mammals to local, regional and national decision-makers. The project was initially based in the Kunene Region, but in May 2005, the Ministry of Environment and Tourism (MET) requested that NEGT undertake a detailed study of the elephants in the Omusati Region of Namibia. This project is designed to be a collaborative research effort between NEGT, MET and the Uukwuluudhi Conservancy.
In October 2007, eight elephants were GPS collared in the Western Hoanib River, Hobatere Region and the western Omusati Region. This collaring was paid for by USFWS, International Elephant Foundation and private donors. The GPS collars used were produced by Data Scout (SA). Two of the collars were either removed by the elephants (WOM-6) or failed for unknown reasons very shortly after the collaring (EKM-09). With the exception of the western Hoanib River, elephants' movements during the hot dry season range were restricted to areas around the permanent water sources. The range of all eastern Hoanib River GPS-collared elephants was restricted to areas either immediately around or inside Hobatere Game Reserve or Kaross Game Park. The elephants in the Omustati region had a range restricted to areas around the permanent water sources.
