Effects of dehorning on population productivity in four Namibia sub-populations of black rhinoceros (Diceros bicornis bicornis)

The black rhinoceros (rhino) (Diceros bicornis) is critically endangered, with poaching being one of several threats to the species’ survival. Many reserves across several countries, including Namibia, South Africa, and Zimbabwe, now dehorn their rhinos in an attempt to reduce poaching. Historical data collected by the Namibian Ministry of Environment, Forestry, and Tourism and Save the Rhino Trust were used to investigate whether dehorning has an effect on age at first reproduction (AFR), inter-calving interval (ICI), birth sex ratios, calf survival, cause of death, and lifespan. These were assessed in four Namibian sub-populations (hereafter referred to as ‘populations’) of black rhino (denoted A, B, C, and D) which have undergone varying levels of dehorning. No significant difference was found in any of the variables between dehorned and horned individuals. Population was a significant predictor of AFR (LRT = 7.433, p = 0.024) and ICI (LRT = 13.281, p = 0.004), although pairwise comparisons only found populations A and B to be significantly different (AFR: z = −2.736, p = 0.017, ICI: z = −3.705, p = 0.001). Additionally, a significantly higher number of males than females were born in population D (p = 0.021, CI = 0.544, 0.960). The main cause of death across all individuals was poaching, although there was no significant difference in the proportion of rhinos poached between dehorned and horned individuals (X(2) = 0.638, p = 0.424, n = 265). No evidence was found to suggest that dehorning has any effect on AFR, ICI, birth sex ratios, calf survival, or lifespan in the black rhino, which is reassuring in the continued use of dehorning as an anti-poaching technique in this species

Leopard Panthera pardus camera trap surveys in the arid environments of northern Namibia

In Namibia, leopards (Panthera pardus) are widely distributed, used commercially as trophy animals and are often persecuted for perceived or real predation on livestock and valuable game species outside protected areas. Therefore, leopard populations living in protected areas might be important source populations and for maintaining connectivity. Little data on their population sizes and densities are available from the northern part of the country, particularly from protected areas. Here, we estimated leopard densities using a spatial capture–recapture approach in northern Namibia: (i) the Khaudum National Park (KNP) in north-east Namibia with an annual average rainfall of 450 mm and (ii) the Lower Hoanib River (LHR) in north-west Namibia with an annual average rainfall of 25 mm. With an effort of 2430 and 2074 camera trap nights in the KNP and LHR, respectively, 11 adult female and six adult male leopards were identified in the KNP, whilst only one adult female leopard was detected once in the LHR. For the KNP, a maximum likelihood approach (using the package SECR) revealed a density estimate of 2.74 leopards/100 km2, whereas a Bayesian approach (using the package SPACECAP) revealed a density estimate of 1.83 leopards/100 km2. For the LHR, no density estimate could be determined and it is suggested that the leopard density in such an arid environment is low. These are the first leopard density estimates based on camera trap surveys provided for these protected areas and thus of importance for further monitoring programs to understand leopard population dynamics. We discuss our findings with current habitat changes and conservation measures in both study areas.Open Access funding enabled and organized by Projekt DEAL. The publication of this article was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – project number 491292795. This study was funded by the Ministry of Environment, Forestry and Tourism (MEFT) in Namibia, WWF Germany and the Messerli Foundation in Switzerland. Sarah Edwards received a post-doctoral bursary from the University of Pretoria, South Africa.https://link.springer.com/journal/42991hj2023Centre for Wildlife Managemen

Leopard Panthera pardus camera trap surveys in the arid environments of northern Namibia

In Namibia, leopards (Panthera pardus) are widely distributed, used commercially as trophy animals and are often persecuted for perceived or real predation on livestock and valuable game species outside protected areas. Therefore, leopard populations living in protected areas might be important source populations and for maintaining connectivity. Little data on their population sizes and densities are available from the northern part of the country, particularly from protected areas. Here, we estimated leopard densities using a spatial capture–recapture approach in northern Namibia: (i) the Khaudum National Park (KNP) in north-east Namibia with an annual average rainfall of 450 mm and (ii) the Lower Hoanib River (LHR) in north-west Namibia with an annual average rainfall of 25 mm. With an effort of 2430 and 2074 camera trap nights in the KNP and LHR, respectively, 11 adult female and six adult male leopards were identified in the KNP, whilst only one adult female leopard was detected once in the LHR. For the KNP, a maximum likelihood approach (using the package SECR) revealed a density estimate of 2.74 leopards/100 km2, whereas a Bayesian approach (using the package SPACECAP) revealed a density estimate of 1.83 leopards/100 km2. For the LHR, no density estimate could be determined and it is suggested that the leopard density in such an arid environment is low. These are the first leopard density estimates based on camera trap surveys provided for these protected areas and thus of importance for further monitoring programs to understand leopard population dynamics. We discuss our findings with current habitat changes and conservation measures in both study areas

High species diversity of Echinococcus spp. in wild mammals of Namibia

An opportunistic survey for Echinococcus spp. in wild mammals was conducted in seven distinct study areas throughout Namibia, representing all major ecosystems, between 2012 and 2021. In total, 184 individually attributable faeces and 40 intestines were collected from eight species of carnivores, and 300 carcasses or organs of thirteen species of ungulates were examined for Echinococcus cysts. Nested PCR and sequencing of the mitochondrial nad1 gene led to the identification of five species of the Echinococcus granulosus sensu lato complex. Echinococcus canadensis G6/7 was found throughout Namibia at low frequency in lions, cheetahs, African wild dogs, black-backed jackals and oryx antelopes. Echinococcus equinus was present only in northern Namibia, locally at high frequency in lions, black-backed jackals and plains zebras. Echinococcus felidis was found only in one small area in the north-east of Namibia, but with high frequency in lions and warthogs. Echinococcus granulosus sensu stricto was identified only in two African wild dogs in the north-east of Namibia, and Echinococcus ortleppi occurred in central and southern Namibia in black-backed jackals and oryx antelopes. The development of fertile cysts indicated active intermediate host roles of oryx antelopes for E. canadensis and E. ortleppi, of warthogs for E. felidis, and of plains zebras for E. equinus. Our data support earlier hypotheses of exclusive or predominant wildlife life-cycles for E. felidis involving lions and warthogs, and – in Namibia – for E. equinus involving lions and/or black-backed jackals and plains zebras. Our data further support an interlink of wild and domestic transmission for E. ortleppi. A possible involvement of livestock and domestic dogs in transmission of E. canadensis G6/7 and E. granulosus s.s., the two parasite species with highest zoonotic potential, is uncertain for Namibia and needs further investigation

Impeding the rhinoceros surge of slaughter in southern Africa with DNA genetic forensic matching

The recent surge in illegal slaughter of African rhinoceros species has invigorated conservation and law enforcement resolve to intercept and prosecute poachers to the level of life-altering sentences in hopes of stemming the practice, which today is both deftly organized and highly profitable. More than 7000 African black and white rhinoceros (Diceros bicornis and Ceratotherium simum) have been killed through poaching in the past decade across Africa with South Africa suffering the highest losses. In southern Africa wildlife rangers, law enforcement officials and genome scientists have mounted a DNA individual identification protocol based upon composite short tandem repeat- STR (also called microsatellite; N=23) genotyping of rhinoceros to tie confiscated evidence convincingly to specific poaching incidents for presentation in criminal prosecutions. This completion of the “ circle of evidence” suitable for prosecution involved two critical developments: 1.) population genetic structure of White and Black Rhinoceros species, subspecies and structured populations; and 2.) match probability statistics for separate panmictic rhinoceros populations required to assess the chance of a random match within the studied population. An extensive database named RhODIS® (Rhino DNA Index System) modeled after CODIS, the US FBI criminal DNA database, accessed 20,000 rhinoceros specimens , DNA profiles and demographic information. RhODIS® data includes \u3e 5800 forensic case samples for which links were made between recovered horns, evidence tissue and specific rhinoceros carcasses in \u3e120 cases. In recent cases forensic genetic individualization allowed life alterring punishments upon conviction, establishing legal precedents for prosecuting traficers of rhino horns suitable for other endangered species traffic . The judicial prosecution, conviction and sentencing of suspects in southern Africa, whereby confiscated rhinoceros horns matched a specific crime scene carcass with a robust “match probability”, affirm the utility of the RhODIS® approach in actual criminal prosecutions of the perpetrators of illegal rhinoceros trade and are changing the legal culture of anti- poaching enforcement

Robust Forensic Matching of Confiscated Horns to Individual poached African rhinoceros

Black and white rhinoceros (Diceros bicornis and Ceratotherium simum) are iconic African species that are classified by the International Union for the Conservation of Nature (IUCN) as Critically Endangered and Near Threatened (http://www.iucnredlist.org/), respectively. At the end of the 19th century, Southern white rhinoceros (Ceratotherium simum simum) numbers had declined to fewer than 50 animals in the Hluhluwe-iMfolozi region of the KwaZulu-Natal (KZN) province of South Africa, mainly due to uncontrolled hunting. Efforts by the Natal Parks Board facilitated an increase in population to over 20,000 in 2015 through aggressive conservation management. Black rhinoceros (Diceros bicornis) populations declined from several hundred thousand in the early 19th century to ∼65,000 in 1970 and to ∼2,400 by 1995 with subsequent genetic reduction, also due to hunting, land clearances and later poaching. In South Africa, rhinoceros poaching incidents have increased from 13 in 2007 to 1,215 in 2014. This has occurred despite strict trade bans on rhinoceros products and strict enforcement in recent years