Disease Risk and Conservation Implications of Orangutan Translocations

Outcomes of orangutan wild-to-wild translocations reveal conservation and welfare risks

Wild orangutans (Pongo spp.) are captured and moved (wild-to-wild translocated) primarily to prevent crop foraging or out of concern for orangutans' survival in fragmented habitat. Little is known about wild-to-wild translocation frequency, circumstances, and possible species conservation and individual welfare outcomes. We investigated orangutan wild-to-wild translocations in Indonesia from 2005 to 2022 using primarily data from public sources and consultation with practitioners. At least 988 wild orangutans were captured for translocation during the study period, including many reproductively valuable resident females and adult males removed from unprotected fragmented forests and forest patches. Data on health condition (n = 808) indicated 81.7% were reported as healthy at time of capture. Information on post-capture disposition (n = 268) showed that only 23% were translocated immediately. Mean estimated killing combined with reported translocation removals was calculated to affect 3.3% of orangutans in Kalimantan, and 11.6% in Sumatra, both higher than the threshold of mortality from human actions expected to drive populations to extinction. Negative impacts are likely compounded where multiple individuals are translocated from the same area, and for the Tapanuli orangutan (P. tapanuliensis), which has the smallest population and range of all orangutan species. Data on reasons for capture (n = 743) indicated most translocations (69%) were conducted to address crop foraging and orangutan presence in or around croplands and plantations. Forest cover analysis around 104 orangutan capture sites with high resolution spatial information indicated that deforestation levels in the year preceding capture were not significantly associated with likelihood of captures for translocation. To improve conservation outcomes, wild-to-wild translocations should be used only in exceptional circumstances. Most orangutans should instead be monitored and protected in situ by addressing conflicts and maintaining the forests, including forest fragments, they are using. When translocation is necessary, post-release survival and potential conservation impacts must be monitored.

Fragmented forest affects the southern black-horned capuchin (Sapajus nigritus cucullatus) in the Argentinean Atlantic Forest

The southern black-horned capuchin, Sapajus nigritus cucullatus, is considered Near Threatened on the IUCN Red List and Vulnerable in Argentina. The species is mainly threatened by habitat loss and fragmentation. The aim of this study was to compare range size, group size, and density in S. n. cucullatus groups between areas of continuous and fragmented habitat in the Atlantic Forest in Argentina. The study was carried out in two areas in northern Misiones province, one continuous and one anthropogenic fragment. Fieldwork was carried out for 5 days each month from November 2019 to March 2020 and from November 2020 to March 2021. SARS-CoV-2 restrictions meant we could not survey in the intervening period. Group counts were made on existing trails and subsequent group follows. We georeferenced encounters and follows to estimate home range sizes. We calculated density based on home range modeling using 100% minimum convex polygons (MCP), and compared these using generalized linear models (GLM). Smaller groups and lower density of S. n. cucullatus were found in continuous forest, with group sizes between 12 and 23 individuals, and density of 0.14 ind/ha, whereas in the fragmented forest, group sizes were between 32 and 36, with density of 0.62 ind/ha (n = 107; zero-inflated negative binomial regression [ZINB], p < 0.05). The higher density in forest fragments may be due to reduced dispersal ability. This work highlights data on species plasticity that could contribute to the development of conservation management strategies for S. n. cucullatus and its habitat.

Viruses in sanctuary chimpanzees across Africa

Infectious disease is a major concern for both wild and captive primate populations. Primate sanctuaries in Africa provide critical protection to thousands of wild-born, orphan primates confiscated from the bushmeat and pet trades. However, uncertainty about the infectious agents these individuals potentially harbor has important implications for their individual care and long-term conservation strategies. We used metagenomic next-generation sequencing to identify viruses in blood samples from chimpanzees (Pan troglodytes) in three sanctuaries in West, Central, and East Africa. Our goal was to evaluate whether viruses of human origin or other "atypical" or unknown viruses might infect these chimpanzees. We identified viruses from eight families: Anelloviridae, Flaviviridae, Genomoviridae, Hepadnaviridae, Parvoviridae, Picobirnaviridae, Picornaviridae, and Rhabdoviridae. The majority (15/26) of viruses identified were members of the family Anelloviridae and represent the genera Alphatorquevirus (torque teno viruses) and Betatorquevirus (torque teno mini viruses), which are common in chimpanzees and apathogenic. Of the remaining 11 viruses, 9 were typical constituents of the chimpanzee virome that have been identified in previous studies and are also thought to be apathogenic. One virus, a novel tibrovirus (Rhabdoviridae: Tibrovirus) is related to Bas-Congo virus, which was originally thought to be a human pathogen but is currently thought to be apathogenic, incidental, and vector-borne. The only virus associated with disease was rhinovirus C (Picornaviridae: Enterovirus) infecting one chimpanzee subsequent to an outbreak of respiratory illness at that sanctuary. Our results suggest that the blood-borne virome of African sanctuary chimpanzees does not differ appreciably from that of their wild counterparts, and that persistent infection with exogenous viruses may be less common than often assumed.

Novel viral and microbial species in a translocated Toutouwai (Petroica longipes) population from Aotearoa/New Zealand

BACKGROUND

Translocation is a common tool in wildlife management and its implementation has resulted in many conservation successes. During translocations, any associated infectious agents are moved with their wildlife hosts. Accordingly, translocations can present a risk of infectious disease emergence, although they also provide an opportunity to restore natural infectious communities ('infectome') and mitigate the long-term risks of reduced natural resistance.

METHODS

We used metatranscriptomic sequencing to characterise the cloacal infectome of 41 toutouwai (North Island robin, Petroica longipes) that were translocated to establish a new population within the North Island of New Zealand. We also screened for pathogenic bacteria, fungi and parasites.

RESULTS

Although we did not detect any known avian diseases, which is a positive outcome for the translocated toutouwai population, we identified a number of novel viruses of interest, including a novel avian hepatovirus, as well as a divergent calici-like virus and four hepe-like viruses of which the host species is unknown. We also revealed a novel spirochete bacterium and a coccidian eukaryotic parasite.

CONCLUSIONS

The presumably non-pathogenic viruses and microbial species identified here support the idea that most microorganisms likely do not cause disease in their hosts, and that translocations could serve to help restore and maintain native infectious communities. We advise greater surveillance of infectious communities of both native and non-native wildlife before and after translocations to better understand the impact, positive or negative, that such movements may have on both host and infectome ecology.

Human-Borne Pathogens: Are They Threatening Wild Great Ape Populations?

Climate change and anthropic activities are the two main factors explaining wild great ape habitat reduction and population decline. The extent to which human-borne infectious diseases are contributing to this trend is still poorly understood. This is due to insufficient or fragmented knowledge on the abundance and distribution of current wild great ape populations, the difficulty obtaining optimal biological samples for diagnostic testing, and the scarcity of pathogen typing data of sufficient quality. This review summarises current information on the most clinically relevant pathogens of viral, bacterial, parasitic, and fungal nature for which transmission from humans to wild great apes is suspected. After appraising the robustness of available epidemiological and/or molecular typing evidence, we attempt to categorise each pathogen according to its likelihood of truly being of human origin. We further discuss those agents for which anthroponotic transmission is more likely. These include two viral (Human Metapneumovirus and Respiratory Syncytial Virus), one bacterial (diarrhoeagenic Escherichia coli), and two parasitic (Cryptosporidium spp. and Giardia duodenalis) pathogens. Finally, we identify the main drawbacks impairing research on anthroponotic pathogen transmission in wild great apes and propose research lines that may contribute to bridging current knowledge gaps.

Metatranscriptomic Comparison of Viromes in Endemic and Introduced Passerines in New Zealand

New Zealand/Aotearoa has many endemic passerine birds vulnerable to emerging infectious diseases. Yet little is known about viruses in passerines, and in some countries, including New Zealand, the virome of wild passerines has been only scarcely researched. Using metatranscriptomic sequencing we characterised the virome of New Zealand endemic and introduced species of passerine. Accordingly, we identified 34 possible avian viruses from cloacal swabs of 12 endemic and introduced bird species not showing signs of disease. These included a novel siadenovirus, iltovirus, and avastrovirus in the Eurasian blackbird (Turdus merula, an introduced species), song thrush (Turdus philomelos, introduced) and silvereye/tauhou (Zosterops lateralis, introduced), respectively. This is the first time novel viruses from these genera have been identified in New Zealand, likely reflecting prior undersampling. It also represents the first identification of an iltovirus and siadenovirus in blackbirds and thrushes globally. These three viruses were only found in introduced species and may pose a risk to endemic species if they were to jump species boundaries, particularly the iltoviruses and siadenoviruses that have a prior history of disease associations. Further virus study and surveillance are needed in New Zealand avifauna, particularly in Turdus populations and endemic species.