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. In 2014, this trend has continued with two poisoning incidents, killing over 100 vultures in total.
Objectives1) Informing conservation:
Significant gaps in the current knowledge base provide the foundation for a detailed assessment of vulture ecology and behaviour as outlined below:
– A study of the ecology, movement patterns, nesting behaviour and resource use.
– A nationwide aerial survey of vulture nests and breeding sites in 2014 and 2015 breeding seasons to determine the current status of vulture populations in Botswana.
– Identification and quantifying of the major threats to vultures in Botswana, including direct and indirect poisoning incidents.
– Assessment of vulture population dynamics to identify priority species and specific areas of concern.
– Determining the full scale of the impact of lead poisoning within vultures in Botswana.
Our results will inform applied conservation actions and identify the most important areas for action, such as:
– A hands-on and proactive approach to respond to significant threats and poisoning incidents across Botswana.
– Advocacy aimed at changing policy for the conservation of vultures in both the short and long-term.
– National and international partnerships with relevant organisations and government departments.
– Working towards the regulation of lead shot in line with countries including Germany and some states in the US.
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.
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.