Porcine zona pellucida vaccine immunocontraception of African elephant (Loxodonta africana) cows : a review of 22 years of research

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.http://www.abcjournal.orgam2018Production Animal Studie

Non-lethal elephant-population-control methods: summary of the first ESAG workshop

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 (PZP) vaccine, vasectomy, and Gonadotropin Releasing Hormone (GnRH) 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

Immunocontraception of the female African savanna elephant (Loxodonta africana) in South Africa : from pipe dream to policy

Globally, African savanna elephants have been assessed as ‘endangered’. Consequently, additional threats and losses due to human–elephant conflict (HEC) could further exacerbate the species’ decline. In stark contrast, South Africa’s elephant populations are mostly confined within fenced-in reserves that impede natural processes such as migration. As ecosystem engineers, elephant population growth herein should be limited. Within South Africa, elephant management has evolved as differing wildlife philosophies from utilitarian conservation (‘nature for man’) to biocentric preservation (‘nature for nature’) and a combination thereof, have been practiced. Traditionally, both HEC and population control have been largely synonymous with lethal control, i.e. culling. However, with the increase of public or expert input to Policy, lethal control is not favoured by the public. As an alternative, immunocontraception of female African savanna elephants through non-invasive, native porcine zona pellucida (pZP) vaccinations has been employed successfully and is currently adopted in 43 elephant reserves across South Africa. Current legislation now recommends culling as the last population management resort. Newly promulgated legislation calls for wellbeing and welfare to be carefully measured in all biodiversity management decisions taken to minimise threats to biodiversity. As a keystone species, elephant is a direct driver of biodiversity change. Accordingly, and in light of these developments, all population management options, including immunocontraception, must be fully considered in South Africa’s largest national park, the Kruger.https://www.publish.csiro.au/wrhj2024Production Animal StudiesSDG-03:Good heatlh and well-beingSDG-15:Life on lan

Regulation of a small, discrete African elephant population through immunocontraception in the Makalali Conservancy, Limpopo, South Africa

Populations of the African elephant, Loxodonta africana, are growing rapidly in southern Africa, to the extent that population control has become essential. The management option of translocation is no longer realistically available, whilst culling has become ethically unacceptable, especially to the general public. Previous immunocontraception trials on elephants with Porcine Zona Pellucida (PZP) vaccine demonstrated that it is safe, effective, reversible, remotely deliverable, and has had no evident adverse side effects. We demonstrate effective contraceptive management of a discrete, small population of free-roaming elephants in the Makalali Conservancy, Limpopo province, South Africa. Complete reproductive control has been demonstrated in all 18 original targeted females, who have by now passed the population's average intercalving interval of 56 months without giving birth. A zero population growth rate has been maintained within this target group since August 2002. On the basis of this small sample over a short period, immunocontraception should be considered a viable means of population management as an alternative to long-term culling strategies in small populations.The Humane Society of the United States (HSUS), the National Research Foundation and Amarula.http://www.sajs.co.zahj2024Centre for Veterinary Wildlife StudiesSDG-03:Good heatlh and well-beingSDG-15:Life on lan

Lack of spatial and behavioral responses to immunocontraception application in African elephants (Loxodonta Africana)

Opinions are divided as to whether human intervention to control elephant (Loxodonta africana) population growth is desirable, partly because of elephant welfare concerns. Female contraception through immunization with porcine zona pellucida (PZP) proteins is viable. The effects of sustained use and application of the PZP vaccine on elephant behavioral and spatial responses were examined by evaluating herd ranging, fission–fusion dynamics, association patterns, and reproductive and sexual behaviors. Minimal change was anticipated as a result of long calf dependence on and association with cows, a reduced but not indefinite 0% growth rate and the known mechanism of action of PZP vaccines, and minimal expected change in resource requirements necessitating behavioral or spatial use adaptations. Although behavioral effects identified in previous hormonal contraceptive trials were evident, it was demonstrated that immunocontraception caused no prolonged behavioral, social, or spatial changes over the 11-yr study period. Individually identified elephants were monitored from 1999 to 2011. Minimal, short-term social disruption, with temporary changes to the herds’ core ranges, was observed during the annual treatment events, particularly in the first three treatment years, when vaccinations were conducted exclusively from the ground. Thereafter, when vaccinations were conducted aerially, minor disruptions were confined to the morning of administration only. Despite sustained treatments resulting in demographic changes of fewer calves being born, treatments did not alter spatial range use, and no adverse interherd–intraherd relations were observed. Similarly, resource requirements did not change as calving still occurred, although in fewer numbers. It was concluded that PZP immunocontraception has no detectable behavioral or social consequences in elephants over the course of 11 yr, providing a convincing argument for the use of sustained immunocontraception in the medium to long term as an important tool for elephant management. Behavioral consequences of alternative management approaches should all receive similar scrutiny to enable managers to make informed decisions when weighing management interventions.The Humane Society International. Ms. Delsink received a National Research Foundation Bursary through National Research Foundation Grants (reference numbers: 205623 and FA2006032300024) to Robert Slotow.http://zoowildlifejournal.com/am201

Porcine zona pellucida vaccine immunocontraception of African elephant (Loxodonta africana) cows: A review of 22 years of research

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

Movement patterns of two reintegrated African elephant (Loxodonta africana) herds: transitioning from captivity to free-living

With the escalating challenges in captive elephant management, the study of elephant reintegration emerges as a pivotal area of research, primarily addressing the enhancement of animal welfare. The term ‘reintegration’ refers to the process of rehabilitating captive elephants to a natural system, allowing them to roam freely without intensive human intervention. There is a relative paucity of research addressing the behavioural adaptations post-reintegration, despite reintegration of over 20 elephants across various fenced reserves in South Africa. Our study centres on two distinct herds of reintegrated African elephants, monitoring their movement patterns in two South African reserves over a 57-month period post-release. The primary goal of the study was to establish whether the flexibility and adaptability of movement behaviour of reintegrated elephants can be considered as one of the indicators of determining the success of such an operation. The second aim of our study was to investigate if the reintegrated elephants demonstrated an adaptability to their environment through their hourly, daily, and seasonal ranging patterns after a period of free roaming that exceeded 4 years. Our findings indicated that reintegrated elephants, much like their wild counterparts (movement based on literature), displayed notable seasonal and diurnal variations in key movement parameters, such as utilisation distribution areas and reserve utilization. These patterns changed over time, reflecting an adaptive shift in movement patterns after several years of free roaming. Notably, the trajectory of changes in movement parameters varied between herds, indicating unique adaptation responses, likely resulting from differences in the reintegration process (familiarity of reserve, season of release, presence of wild elephants). Although our study is constrained by the limited number of reintegrated herds available for analysis, it underscores the potential of captive elephants to successfully adapt to a free-living environment, emphasising the promising implications of reintegration initiatives

Prey selection by a reintroduced lion population in the Greater Makalali Conservancy, South Africa

Lion prey selection was studied on the Greater Makalali Conservancy (140 km2), Limpopo Province, South Africa, in order to assist with management strategies. Monitoring was carried out between February 1998 and December 2001. Lion killed 15 species, with warthog, blue wildebeest, Burchell’s zebra, kudu and waterbuck constituting approximately 75% of their diet. Between 2.2% and 3.1% of the  available prey biomass was killed yearly, while each female equivalent unit (FEQ) killed between 3 kg and 3.2 kg daily. Lion predation was greater for warthog,  wildebeest and waterbuck and less for impala than expected. When male lion were present, a greater number of warthog and giraffe were killed, while number of females had a significant effect on medium sized prey species and total prey species killed. Significantly more warthog, wildebeest and kudu were killed in winter than summer. More prey than expected was killed in open habitats and less than expected in thickets. Managers of small,  enclosed reserves need to constantly monitor prey populations, especially medium sized prey and may be able to reduce  predation on large prey species by manipulating male lion numbers. Reserves also need to contain adequate open habitats for lion to make use of these areas for hunting.Key words: Panthera leo, predation, management strategies, biomass, female equivalent unit

Population demography and spatial ecology of a reintroduced lion population in the Greater Makalali Conservancy, South Africa

Many recently established small game reserves in southern Africa have introduced lion, and have had to actively manage their populations as the lion are in relatively small

LACK OF SPATIAL AND BEHAVIORAL RESPONSES TO IMMUNOCONTRACEPTION APPLICATION IN AFRICAN ELEPHANTS ( LOXODONTA AFRICANA

Opinions are divided as to whether human intervention to control elephant (Loxodonta africana) population growth is desirable, partly because of elephant welfare concerns. Female contraception through immunization with porcine zona pellucida (PZP) proteins is viable. The effects of sustained use and application of the PZP vaccine on elephant behavioral and spatial responses were examined by evaluating herd ranging, fission–fusion dynamics, association patterns, and reproductive and sexual behaviors. Minimal change was anticipated as a result of long calf dependence on and association with cows, a reduced but not indefinite 0% growth rate and the known mechanism of action of PZP vaccines, and minimal expected change in resource requirements necessitating behavioral or spatial use adaptations. Although behavioral effects identified in previous hormonal contraceptive trials were evident, it was demonstrated that immunocontraception caused no prolonged behavioral, social, or spatial changes over the 11-yr study period. Individually identified elephants were monitored from 1999 to 2011. Minimal, short-term social disruption, with temporary changes to the herds’ core ranges, was observed during the annual treatment events, particularly in the first three treatment years, when vaccinations were conducted exclusively from the ground. Thereafter, when vaccinations were conducted aerially, minor disruptions were confined to the morning of administration only. Despite sustained treatments resulting in demographic changes of fewer calves being born, treatments did not alter spatial range use, and no adverse interherd–intraherd relations were observed. Similarly, resource requirements did not change as calving still occurred, although in fewer numbers. It was concluded that PZP immunocontraception has no detectable behavioral or social consequences in elephants over the course of 11 yr, providing a convincing argument for the use of sustained immunocontraception in the medium to long term as an important tool for elephant management. Behavioral consequences of alternative management approaches should all receive similar scrutiny to enable managers to make informed decisions when weighing management interventions.The Humane Society International. Ms. Delsink received a National Research Foundation Bursary through National Research Foundation Grants (reference numbers: 205623 and FA2006032300024) to Robert Slotow.http://zoowildlifejournal.com/am201