Disease Risk and Conservation Implications of Orangutan Translocations

Abstract

Critically Endangered orangutans are translocated in several situations: reintroduced into historic range where no wild populations exist, released to reinforce existing wild populations, and wild-to-wild translocated to remove individuals from potentially risky situations. Translocated orangutans exposed to human diseases, including Coronavirus Disease 2019 (COVID-19), pose risks to wild and previously released conspecifics. Wildlife disease risk experts recommended halting great ape translocations during the COVID-19 pandemic to minimize risk of disease transmission to wild populations. We collected data on orangutan releases and associated disease risk management in Indonesia during the COVID-19 pandemic, and developed a problem description for orangutan disease and conservation risks. We identified that at least 15 rehabilitated ex-captive and 27 wild captured orangutans were released during the study period. Identified disease risks included several wild-to-wild translocated orangutans in direct contact or proximity to humans without protective equipment, and formerly captive rehabilitated orangutans that have had long periods of contact and potential exposure to human diseases. While translocation practitioners typically employ mitigation measures to decrease disease transmission likelihood, these measures cannot eliminate all risk, and are not consistently applied. COVID-19 and other diseases of human origin can be transmitted to orangutans, which could have catastrophic impacts on wild orangutans, other susceptible fauna, and humans should disease transmission occur. We recommend stakeholders conduct a Disease Risk Analysis for orangutan translocation, and improve pathogen surveillance and mitigation measures to decrease the likelihood of potential outbreaks. We also suggest refocusing conservation efforts on alternatives to wild-to-wild translocation including mitigating human-orangutan interactions, enforcing laws and protecting orangutan habitats to conserve orangutans in situ.

Keywords: COVID-19; conservation; disease; orangutan; reinforcement; reintroduction; translocation.

Figure 1

Orangutan translocations in Indonesia since 2015. Annual rates are estimated from Sherman, Ancrenaz and Meijaard (4), available rescue center annual reports and news blogs, KSDAE news blog and unpublished data. Release rates shown may be lower than actual releases, as some rescue centers did not have publicly available data for all years.

Figure 2

PPE use and human proximity in wild-to-wild orangutan translocations during COVID-19 pandemic. Pictures showing examples of mixed use of PPE and human proximity to orangutans during captures and releases of wild orangutans between March 15, 2020 and March 14, 2021. The orangutans are in the blue sling and the orange and black net, respectively. Identifiable human features and organizational logos are obscured to protect anonymity. Image credits from left to right: BBKSDA Sumatera Utara via KSDAE Top News blog http://ksdae.menlhk.go.id/assets/uploads/ou_sipirok2.JPG (70); BKSDA Kalimantan Tengah via Facebook https://www.facebook.com/BKSDAKalimantanTengah/posts/1365289040500502 (69).

Figure 3

PPE use and human proximity in wild-to-wild orangutan translocations prior to COVID-19 pandemic. Pictures showing examples of mixed use of PPE and human proximity to orangutans during capture and releases of wild orangutans prior to March 15, 2020. The orangutan in the top photo is in the orange and black net. Identifiable human features and organizational logos are obscured to protect anonymity. Image credits from top to bottom: BKSDA Aceh via KSDAE Top News blog http://ksdae.menlhk.go.id/assets/news/Translokasi_ortu1.jpeg (78); BKSDA Kalimantan Tengah via KSDAE Top News blog http://ksdae.menlhk.go.id/assets/news/gambb.jpg (80).

Figure 4

Qualitative risk matrix for orangutan translocation using COVID-19 example. OU = orangutans; GA = great apes. Colored cells inside double lines denote overall qualitative rank. Consequence definitions are presented in the two cells beneath each category name, with species and ecosystems in the top cell and health and biosecurity in the cell below. Likelihood category definitions are presented in the two cells to the right of each category name, for species and ecosystems and then for health and biosecurity from left to right. Cells relevant to OU translocation scenarios have a thick border and list factors considered in risk ranking.

Figure 5

Orangutan conservation complexity. Cells in far left column are activities and policies affecting orangutans. Central section cells describe positive and negative factors that affect orangutan conservation outcomes. The second column from the right shows the interim goals of activities and policies. Key threats that activities and policies aim to address are in the far right column. Arrows indicate relationships between cells.