IntroductionDespite the fact that vulture populations are rapidly decreasing, relatively little is known about the species found in the Kalahari region of Botswana. The aim of this project is to ensure that vulture populations remain viable in both Botswana, and the rest of southern Africa, due to their transboundary movements. By strengthening community and transboundary conservation efforts, the project aims to contribute towards the applied conservation of vultures in southern Africa.
Researcher: Dr Glyn MaudeRegion: Botswana
BackgroundVulture populations are decreasing globally at an alarming rate. In Botswana, two species of vulture were classified by the IUCN in 2014 as Endangered and three more as Vulnerable. However, there are still significant knowledge gaps in terms of the population sizes, movement patterns and reproductive successes of vultures across the Kalahari region.
Prior to this study, there was no data available on the size of the lappet-faced vulture population in Botswana or their ranging patterns, and only preliminary data exists that suggests there is a low breeding success rate. Limited ecological research has been conducted on white-headed and hooded vultures, and therefore our knowledge of many key areas of vulture behaviour and ecology in Botswana is highly limited.
In addition, blood lead levels in vultures have not been tested in Botswana, nor have the impacts of high levels been quantified. Lead poisoning in birds is a cumulative multi-systemic disease, affecting the liver, kidney, heart, and gastrointestinal, hematopoietic, reproductive and nervous systems. Of 239 individual vultures tested to date, 21.3% display elevated blood lead levels leading to lead poisoning. These results suggest that lead toxicity represents a previously unappreciated, but significant source of mortality in vultures.
Vultures are significantly affected by poisoning both directly by poachers and indirectly by farmers targeting carnivores. Incidents of vulture deaths following poisoning are widely documented, but little is known about the long-term impact on vulture populations. In 2013, more than 1 000 vultures, predominantly white-backed vultures, were killed in known poisoning incidents in the Zambezi Region (former Caprivi Strip) and northern Botswana. This trend has continued over the past five years.
The overall objective is to promote and conduct local and transboundary vulture conservation actions that will result in the vulture population of Botswana and southern Africa remaining viable. In addition, using community engagement efforts, we aim to persuade communities not to use poisons in a way that will harm vultures or other wildlife.
1) Informing conservation:
Over the past two years, the project’s efforts have provided important information to organisations that will aid with efforts towards the conservation of vultures and other wildlife species. These organisations included departments within the Botswana Government (Department of Wildlife and National Parks, Botswana Defence Force, anti-poaching units and the police), Birdlife Botswana, Birdlife International, Endangered Wildlife Trust EWT, African Lion Working Group, Poison Working Group, Vulture Working Group and others.
Our objectives in the next two years are to:
- Evolve our study of the ecology, movement patterns, nesting behaviour and resource use of hooded vultures, white-headed, cape and white-backed vultures.
- To continue with aerial surveys of vulture nests and breeding sites in order to determine the current status of vulture populations in Botswana.
- To continue to identify the major threats and solutions to these threats to vultures in Botswana.
- Support one Master’s study on vultures with a student from Botswana.
The project has shown that lead poisoning is a threat to vulture populations and is engaging other groups and bodies in order to advocate for joint actions to deal with the issue. One discussion is the source of the lead as, although there is strong evidence that spent ammunition is a significant contributor, there is a need to determine what other sources of lead there may be, and eliminate these from the diet of vultures. High levels of lead have been found in waterholes provided for wildlife with protected areas of Botswana.
The conservation aims are summarised below:
- When waterholes provided for wildlife have very high levels of heavy metals in them, to advocate for the water to be “purified” or the waterhole closed down.
- To educate ammunition users to choose to use lead free ammunition as viable and effective alternatives exist specifically cooper bullets.
- To continue to work with the DWNP and BDF to visit known vulture poison sites to assist with “clean ups”.
- To continue to organise and facilitate “poison training” workshops in Maun and surrounding areas in collaboration with “poison expert” Tim Snow.
- To continue to advocate for the banning of the use in Botswana of extremely harmful pesticides and the tighter regulation of other pesticides that can be used as poisons.
- To continue with community engagement on the issue of the use of poisons with meetings with village chiefs and community members at the village kgotla.
- Advocacy aimed at changing policy for the conservation of vultures in both the short and long term.
- Work with the EWT to facilitate efforts to do a provisional assessment of the design of power lines in Botswana in regards to the electrocution of raptors.
3) Community education:
Vultures contribute significantly to ecosystems, yet they are often a target for persecution and are widely misunderstood. A captive lappet-faced culture, previously injured and unable to fly, will act as a culture ambassador to help communicate our message, allowing people to see a vulture up close and learn about their unique features and adaptations. In particular:
- Improve understanding of vultures, their importance and unique adaptations to their roles and niche within the ecosystem, using a vulture ambassador.
- Work within local communities with all ages to promote vulture conservation, highlight the importance of vultures to ecosystems, debunk widely-held myths and promote positive culture linkages with raptors and vultures.
- Work with farmers as a target group to address relevant issues.
- A canon and net method will continue to be used for the targeted capture of cultures. Captured vultures will have blood samples taken and analysed for lead content levels. All cultures will be fitted with patagial wing tags (i.e., fitted between the wing and body) for post-release identification and mark-recapture analysis.
- Aerial surveys will be carried out over protected areas and historical breeding areas in Botswana using either a gyrocopter or small fixed wing aircraft. All active and old nest sites will be surveyed at the beginning and end of the breeding season to determine breeding success rates. GIS analysis will examine habitat characteristics and anthropogenic influences on nest location and nesting success.
- GPS data provided by transmitters fitted to vultures will be monitored to identify possible poisoning incidents. All reported incidences of mortality and poisoning will be thoroughly investigated and documented following national protocol.
Community education and awareness:
Activities will be conducted in targeted locations both around the primary office base in northern Botswana and nationwide. Activities will focus on reaching farmers and children and include education and practical activities. The focus will be on the importance of vultures in the Kalahari ecosystem together with vulture ecology, behaviour and conservation as well as awareness of the impact of poisoning.
The Raptors Botswana team has made great progress on many fronts in our mission to learn more about vultures and ensure their future conservation in Botswana. Here we report on some highlights of our activities.
Breeding ecology of Cape vultures in the Tswapong Hills
In 2017 Tsaone Goikantswemang started to monitor two Cape vulture colonies in the Tswapong Hills. All the trips made were successful, and on every visit all the nests were photographed and documented. During the fieldwork, hundreds of nests were identified and monitored from the nest stage to egg, chick and fledged chick stage. Tsaone and our team have done really well on these trips, as to view all the nesting sites involved lots of walking in extreme heat and difficult conditions. The preliminary results show that the Bonwalenong breeding site had the largest number of breeding pairs at 215. This may be due to the site having two cliff faces which the Cape vultures use for breeding. Manong Yeng breeding site has only one cliff, but still had 84 vulture pairs that attempted to breed. Tsaone presented her initial findings at the wildlife symposium in Maun in February 2018.
Breeding patterns of white-backed vultures and raptors in Linyanti and Khwai
Following the early- and mid-season surveys, conducted in June and August, respectively, we conducted a third late-season nest survey around Linyanti on 26-27 September 2017 and in Khwai just afterwards. The aerial survey was piloted by Brian Bridges in a two-seater gyrocopter with Raptors Botswana team members as observers. Valuable logistical support and assistance was provided by Wilderness Safaris and Wild Act for these surveys. The aim was to determine the nesting numbers and locations of all raptors species seen in the wider Linyanti and Khwai regions of the Okavango Delta.
The surveys repeated those of 2006/7 and determined the breeding success of 2017/8. Leungo Leepile has now, as part of his Master’s study, compared the wealth of information gathered over the different time periods to look at the status of breeding white-backed vultures today in the two regions. His results showed a 53.5% decrease in nesting pair numbers, from just below 100 pairs in 2006/7 to 46 in 2017/8, with a greater decline in Linyanti than in Khwai. In both areas breeding success was also significantly lower in 2017 than it was ten years ago, dropping from 62% to 36%. There is great concern that if recent poisoning rates continue, this population has a high probability of extinction in the next five to 13 years.
There are presently 11 satellite transmitters on four vulture species (two hooded, one Cape, one white-headed and seven lappet-faced) which continue to give us valuable information. The hooded vultures continue to range in northern Botswana with the occasional trip into Namibia, Zambia and Zimbabwe. The white-headed vulture appears to determinedly remain almost entirely within the boundaries of the Central Kalahari Game Reserve, which is fascinating. The Cape vultures still often move into South Africa, going as far south as Kimberley and Bloemfontein. However they still tend to range around the eastern border of Botswana and remain in relatively close proximity to their main breeding areas. The lappet-faced vultures are by far the most adventurous and cover vast distances, travelling into South Africa, Namibia and Zimbabwe.
Lappet-Faced Vulture Study
Rebecca Garbett has led this study as part of her PhD, and is busy analysing the movement data collected over a number of years. The most striking results have been the differences in home range sizes between breeding and non-breeding birds, which were found to be statistically different within the breeding season, but not outside of the breeding season. The incredibly large areas that lappet-faced vultures range over, and the numerous geographical and political boundaries they cross, pose a great conservation challenge.
Rebecca is currently investigating habitat selection in relation to the use of protected areas across southern Africa. From an initial look at the number of GPS fixes of tracked birds in the protected areas of Botswana, it seems that breeding birds are utilising these areas more than non-breeding birds, particularly so within the breeding season. These results are already identifying the necessity of different conservation strategies for breeding and non-breeding populations where lappet-faced vultures are concerned.
Community Engagement Team Activities
Our conservation education team continues to promote awareness in communities around Botswana about the importance of vultures, and the impact on these and other species of direct and indirect poisoning. So far our team has visited more than 15 communities to raise this issue, and recently expanded the kgotla sessions to communities such as Beetsha, Gonutsoga Kuke and D’kar.
During the last quarter of the year, the educational team organised an international vulture awareness day with the community of Disaneng ward in Maun. The day was well attended by community leaders, students and regular community members and was enjoyed by all.
Our engagement team has also been working with children at schools (primary and junior) and colleges in the communities of Maun, Ghanzi, Motopi, Makalambedi and others. This work is done in part with the Environmental Education or Wildlife Clubs in the schools. Activities conducted with children have included games that incorporate learning about vulture nesting behaviours, ecology and the threats to vultures.
None of our work would be possible without significant resources and support from a wide range of people and organisations, too numerous to mention all here. Our sincere thanks go to the Wilderness Wildlife Trust and Wilderness Safaris for their continued support.
The results of the aerial survey carried out in June 2017 can be read here: Progress report – Aerial Surveys 2017
In the last five years in Botswana there have been high numbers of vultures killed by poachers and farmers through the use of poisons. Of the 26 vultures onto which we deployed transmitters onto in the last four years, nine have died and almost all of these have been due to poisoning episodes.
With poaching on the increase in Botswana the numbers of vultures poisoned in the last five years in Botswana has increased by as much as 400% with in some cases between 400 and 1 000 vultures being killed in a single poison episode.
Others threats that exist, some of which our work has uncovered, include ingestion of lead by vultures, low nesting success, habitat loss and destruction, human disturbances, electrocution and collision by power lines. In 2017 we had two of our wing-tagged vultures killed by collision (white-backed) or electrocution (lappet-faced). We suspect many more tagged and untagged vultures have died in this manner with their deaths remaining unnoticed. In 2017, we are working with Endangered Wildlife Trust (EWT) to conduct an initial assessment of the power lines in Botswana to determine if their designs are high risk to raptors for electrocution and collision.
In the past, every year has had cases where vultures with transmitters have been poisoned along with a minimum of between 6 and over 300 other vultures. We are facilitating and funding EWT staff to come to Botswana and view existing power lines across sections of the country. An initial assessment of the threat of electrocution and collisions of raptors by these power lines will complete by July of 2017. Further actions will then be decided upon depending on the results of this initial assessment.
We have produced two published papers relating to vultures, many reports that have been widely spread, a vast amount of educational material including many hundreds of posters, calendars, arm bracelets, badges, T-shirts, hats and leaflets. Along with partners, we have built a vulture restaurant and education centre in Ghanzi.
Annual Report February 2016
The overall aim of this project is to ensure that vulture populations remain viable in Botswana and thus southern Africa in general, due to transboundary movements of vultures by strengthening community and transboundary conservation efforts.
Poisoning events claim countless numbers of vultures across southern Africa; ivory poaching has now been directly linked as a key source of these. In 2015, six African vulture species were up-listed by IUCN to either Endangered or Critically Endangered. All vultures in Botswana now fall into these two categories.
Ongoing research has found that elevated blood lead levels (BLLs) in vultures pose a potentially significant threat to populations. Out of 600 vultures captured and tested to date, representing populations from across Botswana, 31% have elevated lead levels. The highest average BLLs were associated with hunting farms and, in addition, 40% of birds had high BLLs within the hunting season whilst 24% had elevated BLLs out of hunting season. These findings support the hypothesis that spent lead ammunition in carcasses is likely the main source of lead for vultures. However, other potential sources of lead such as water, forage and soil are being investigated.
Lappet-faced vulture breeding success rates in 2015 were 31% (5 out of 16 nests), marginally higher than 2014 but significantly below those that have been found in other parts of Africa (40-50%).
Throughout 2015 more than 15 000 km of raptor road surveys were conducted across northern Botswana, with 2 471 recorded raptor observations of 28 different species. This study will be compared with research conducted in the 1990s to identify population trends of raptors over the last 20 years.
More than 1 500 participants were involved in raptor conservation education during 2015 whilst it is hoped that the vulture conservation message was communicated to many more. The recent opening of a vulture restaurant in Ghanzi promises to be a very valuable tool for vulture conservation education for all ages.
Nesting surveys continued throughout the vulture breeding season, with a particular focus on the eight lappet-faced vultures fitted with transmitters. Out of the eight birds being monitored, four are nesting in Botswana, while one appears to be nesting in the Karas region of Namibia this year.
The project is also monitoring a number of nests occupied by vultures with no tagging devices; these were located by aerial surveys carried out in June. The majority of these are in the Makgadikgadi Pans – a breeding stronghold for these birds. A number of nests currently contain either an egg or a chick. Further monitoring will continue throughout the breeding season.
Unfortunately, one of the white-backed vultures that had been fitted with a transmitter in early 2014 died in July. The bird was in Namibia at the time of death and the carcass and transmitter were retrieved by colleagues based in Windhoek. It appears that the death of this vulture may have been due to the ingestion of a carcass contaminated with non-steroidal anti-inflammatory medication from a Namibian feedlot. This is an example of the possible presence of these damaging medications in the southern African veterinary system, which could be catastrophic to vulture populations, as has been witnessed in the Indian vulture crisis.
Community education activities have continued in Maun and Ghanzi. The 5th of September was International Vulture Awareness Day and Raptors Botswana was invited to the opening of the Chris L. Woolcott Vulture Restaurant in Ghanzi where the team provided a full day of educational activities. The restaurant marks the first official “lead-free, clean meat” restaurant for vultures in Botswana.
The project continues to work towards securing a “vulture ambassador,” which will constitute a significant addition to its conservation education activities by helping to dispel many of the myths that surround vultures and enabling people to see these birds close up. Official permission has been obtained from the Botswana Department of Wildlife and National Parks to house the bird in Maun by the end of the year.
In early April, a Raptors Botswana educational workshop was held in Maun in conjunction with a junior rugby tournament where the Raptors Botswana team conducted educational activities for over 120 children between the ages of 9 and 14.
A vulture capture event was conducted during May in the Makgadikgadi Pans to enable the testing of blood lead levels in vultures across Botswana. Movement data from vultures fitted with transmitters have provided surprising information. Recently, we noted the most northerly movement of a lappet-faced vulture to the north of Zimbabwe and across into Zambia, some 600 km from where the bird was originally tagged in the Makgadikgadi Pans.
At the beginning of the breeding season in June, aerial surveys were carried out over the Makgadikgadi Pans across the northern part of the Central Kalahari Game Reserve. These surveys identified nine active lappet-faced vulture nests, which is considerably fewer than last year. Active nests will be monitored throughout the breeding season to gather information on breeding success rates and the factors which may affect nesting failures.
Unfortunately, vultures in Botswana continue to be threatened and within the Chobe enclave in northern Botswana, 40 vultures were poisoned in May. The site was identified, documented and cleaned up by a local NGO with the assistance of the Botswana Defence Force.
In May, Raptors Botswana was invited to present its research findings, specifically the impact of lead on vulture populations, to the Botswana Wildlife Producers Association AGM – an ideal forum to address the possible effects of lead ammunition on vultures. Raptors Botswana also attended a vulture awareness day in Victoria Falls, Zimbabwe in late June.
A Cape vulture at Khama Rhino Sanctuary and two lappet-faced vultures in Francistown have been fitted with transmitters. These are the first transmitters to be deployed in the area, and will enable the project’s researchers to better monitor this subpopulation in eastern Botswana.