Scielo RSS <![CDATA[Bothalia - African Biodiversity & Conservation ]]> vol. 48 num. 2 lang. en <![CDATA[SciELO Logo]]> <![CDATA[<b>Changes in African Elephant (<i>Loxodonta africana</i>) faecal steroid concentrations post-defaecation</b>]]> BACKGROUND: Faecal hormone metabolite measurement is a widely used tool for monitoring reproductive function and response to stressors in wildlife. Despite many advantages of this technique, the delay between defaecation, sample collection and processing may influence steroid concentrations, as faecal bacterial enzymes can alter steroid composition post-defaecation. OBJECTIVES: This study investigated changes in faecal glucocorticoid (fGCM), androgen (fAM) and progestagen (fPM) metabolite concentrations in faeces of a male and female African elephant (Loxodonta africana) post-defaecation and the influence of different faeces-drying regimes. METHOD: Subsamples of fresh faeces were frozen after being dried in direct sun or shade for 6, 20, 24, 48 and 72 h and 7 and 34 days. A subset of samples for each sex was immediately frozen as controls. Faecal hormone metabolite concentrations were determined using enzyme immunoassays established for fGCM, fAM and fPM monitoring in male and female African elephants. RESULTS: Hormone metabolite concentrations of all three steroid classes were stable at first, but changed distinctively after 20 h post-defaecation, with fGCM concentrations decreasing over time and fPM and fAM concentrations steadily increasing. In freeze-dried faeces fGCM concentrations were significantly higher than respective concentrations in sun-dried material, which were in turn significantly higher than fGCM concentrations in shade-dried material. In contrast, fAM concentrations were significantly higher in sun- and shade-dried faeces compared to freeze-dried faeces. Higher fPM concentrations were also found in air-dried samples compared to lyophilised faeces, but the effect was only significant for sun-dried material. CONCLUSION: The revealed time restriction for collecting faecal material for hormone monitoring from elephants in the wild should be taken into account to assure reliable and comparable results. However, if logistics allow a timely collection, non-invasive hormone measurement remains a powerful and reliable approach to provide information about an elephant's endocrine status. <![CDATA[<b>Who owns and is responsible for the elephant in the room? Management plans for free-roaming elephant in South Africa</b>]]> In 2008, South Africa adopted its 'National Norms and Standards for the Management of Elephants in South Africa'. Concern has subsequently been raised as to whether these norms and standards apply to free-ranging elephant on land, which had not been enclosed with a fence with the express purpose of containing these animals and other game on the property. The application of these norms and standards pivots on whether the owner(s) of the property have taken possession of these animals in accordance with common law applicable to game, or have given effect to the provisions of the Game Theft Act. To address this concern, this article briefly explores the evolution of South African regulatory jurisprudence applicable to game, including elephant, and analyses the norms and standards in relation to international and national legislation and common law applying to elephants. The norms and standards are not applicable to unowned, free-roaming elephant. These norms and standards, therefore, do not fulfil their primary objective of uniform management of elephant across South Africa. This limitation of the norms and standards, therefore, needs to be considered when they are revised. <![CDATA[<b>Vulnerability of vulture populations to elephant impacts in KwaZulu-Natal</b>]]> Elephant were previously widespread in savanna and coastal systems of KwaZulu-Natal (KZN), but were virtually extirpated by 1870. Over time, elephant have been reintroduced into their former range in KZN, but always onto small fenced systems (mean size 191.3 km² ± 87.8 km², median size 107.0 km², range 14 km² - 900 km²). These populations have increased rapidly (8.4% per annum), and although a number of populations are now being managed using contraception, the majority of the populations (66.7%, 14 out of 21) are stocked above the 'preferred density' as defined in their approved management plans, while others will soon exceed the preferred density. Vulture populations in KZN are small, declining and already at risk of extinction. In KZN, 94.2% of tree-nesting vulture nests occur in areas with elephant; this could increase to 99.5% in the near future if proposed land-use change takes place. Anthropogenic impacts in the broader landscape mean that there are limited opportunities for vultures to nest elsewhere, and we hypothesise that loss of suitable nesting habitat in existing areas, including through impact of elephant on large trees, could result in declines and even extirpation of these species as breeding residents. Given the demonstrated and potential impacts of elephants on large trees necessary for vulture nesting, it is essential that the role of protected areas and extensive wildlife systems for vultures be adequately taken into account when managing elephant populations. It is important that a precautionary and adaptive management approach is taken regarding management of elephant in areas important for vultures, at least until the ecological interactions between vultures, vegetation, elephant and other drivers are better understood, and until the willingness and ability to manage elephant numbers and impact according to the elephant management plans are demonstrated. <![CDATA[<b>Non-lethal elephant population control methods: Summary of the first workshop of the Elephant Specialist Advisory Group of South Africa</b>]]> Management interventions are necessary to control elephant numbers within fenced wildlife reserves in South Africa. Use of non-lethal control methods is increasing, but information about their suitability and effects are not widely available. Three such methods are currently available: immunocontraception with porcine zona pellucida vaccine, vasectomy and gonadotropin-releasing hormone vaccine. Here we consolidate what we know about these methods, using published sources and material shared at a workshop held in South Africa in 2016, in order to provide up-to-date information for future policy decisions concerning the use of these methods in South Africa and elsewhere. <![CDATA[<b>Use of anti-gonadotropin-releasing hormone vaccines in African elephants (<i>Loxodonta africana</i>): A review</b>]]> BACKGROUND: Androgen-related aggressive behaviour and musth cause serious problems in captive African elephant bulls and often lead to human and animal injuries, and damage to property. OBJECTIVES: To review the work carried out with anti-gonadotropin-releasing hormone (GnRH) vaccines to control androgen-related behaviour and fertility in captive and free-ranging elephant bulls and the induction of anoestrus in elephant cows. METHOD: In the first study, an anti-GnRH vaccine from Pepscan was tested in six bulls (four captive and two free-ranging). Once the vaccine Improvac® became available, the effect on behaviour, the reproductive organs and semen quality was tested. Improvac® was also used to attempt induction of anoestrus in elephant cows. RESULTS: The first study proved that aggressive behaviours are significantly associated with increased faecal androgen concentrations. Musth (n = 1) and aggressive behaviour (n = 2) were down regulated and correlated with a decline in faecal androgen concentrations. Aggression and musth could be controlled with Improvac® (600 µg), but were more consistent when the dose was increased to 1000 µg administered every five to six months. The same dose down regulated testicular function and bulls (n = 17) were rendered infertile within 12 months after commencement of treatment. Initial attempts to induce anoestrous with 600 µg in free-ranging elephant cows gave inconclusive results, but 1000 µg in captive cows delivered five-monthly was successful. CONCLUSION: The treatment of elephant bulls with Improvac® resulted in the successful down-regulation of androgen-related behaviour and sperm production in captive and wild elephant bulls of various ages (≤ 34 years). Preliminary studies to induce anoestrus in cows with Improvac® appear to be successful. <![CDATA[<b>Porcine zona pellucida vaccine immunocontraception of African elephant (<i>Loxodonta africana</i>) cows: A review of 22 years of research</b>]]> BACKGROUND: The native porcine zona pellucida (pZP) vaccine has been successfully used for immunocontraception of wild horses, white-tailed deer and approximately 90 zoo species for more than 25 years. OBJECTIVES: To provide proof of concept and test contraceptive efficacy of pZP in African elephants. Once completed, test the population and behavioural effects on cows in the Greater Makalali Private Game Reserve (GMPGR). Following the GMPGR, test efficacy, population effects, safety and reversibility in 25 reserves with populations ranging from 9 to 700 elephants. METHOD: Histological sections were reacted with anti-pZP antibodies to provide proof of concept. From 1996 to 2000, 21 and 10 cows were treated with pZP vaccine in the Kruger National Park (KNP) and monitored for pregnancy. Population effects of pZP with Freund's adjuvants (three vaccinations in Year 1 with one annual booster) were studied on 18 cows in the GMPGR. Another six game reserves with a total of 90 cows were added to the project. The project was then expanded to include another 18 reserves. RESULTS: Binding of anti-pZP antibodies to elephant zona proteins was demonstrated in vitro. The KNP provided efficacy results of 56% and 80%, respectively. The contraceptive efficacy in the GMPGR and additional six reserves was 100% following calving of pregnant cows. Safety and lack of impact on social behaviour were demonstrated. In larger populations, efficacy was > 95%. CONCLUSION: Contraceptive efficacy and safety of pZP vaccine could be demonstrated in small to large populations. The methodology is now being implemented in approximately 800 cows on 26 reserves across South Arica. <![CDATA[<b>Vasectomies of male African elephants as a population management tool: A case study</b>]]> Elephant populations in South Africa are largely confined to fenced reserves and therefore require continued management to prevent high elephant densities that may cause habitat degradation. Growing human populations surrounding these reserves limit the possibility for wildlife range expansion, adding socio-economic considerations to the growing list of challenges reserve managers must contend with. Often, reserves have therefore opted to manage elephant population growth using various contraceptive methods to reduce birth rates, with lethal control acting as a last resort. Reserve owners at the Pongola Game Reserve South in northern KwaZulu-Natal opted to vasectomise the oldest male elephants to limit elephant population growth. Besides the reduction in birth rates, vasectomies were anticipated to have minimal impacts on behaviour. This study aimed to examine behavioural implications of treatment by monitoring musth, dominance and social behaviours of vasectomised males. Physical and behavioural observations of vasectomised males were recorded using instantaneous scan sampling and continuous focal samples of study individuals between 2011 and 2016. These data were also collected for non-treated adolescent males, with which to substantiate potential impacts of vasectomies. This case study has revealed that the behaviour of the vasectomised males was not influenced by vasectomies: musth was displayed as anticipated in the oldest males; a linear dominance hierarchy was maintained, headed by the oldest individual, and association patterns with female groups remained intact. Further, the younger non-treated males fell in line with the overall dominance hierarchy. This unique post-treatment study supports the use of vasectomies as a relatively cost-effective (one-off treatment), low-risk and successful tool for the management of elephant population growth, and an option which is preferable to both lethal control and hormonal contraceptives. Further research to establish the impacts of vasectomies on female behaviour and population dynamics is recommended.