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Published by: IUCN/SSC Reintroduction Specialist Group & Environment Agency-Abu Dhabi

Copyright: © 2018 IUCN, International Union for Conservation of Nature and Natural Resources

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Citation: Soorae, P. S. (ed.) (2018). Global Reintroduction Perspectives: 2018. Case studies from around the globe. IUCN/SSC Reintroduction Specialist Group, Gland, Switzerland and Environment Agency, Abu Dhabi, UAE. xiv + 286pp.

6th Edition

ISBN: 978-2-8317-1901-6 (PDF) 978-2-8317-1902-3 (print edition)

DOI: https://doi.org/10.2305/IUCN.CH.2018.08.en

Cover photo: Clockwise starting from top-left: I. Reticulated python, Singapore © ACRES II. Trout cod, Australia © Gunther Schmida (Murray-Darling Basin Authority) III. Yellow-spotted mountain newt, Iran © M. Sharifi IV. Scimitar-horned oryx, Chad © Justin Chuven V. Oregon silverspot butterfly, USA © U.S. Fish and Wildlife Service VI. Two-colored cymbidium orchid, Singapore © Tim Wing Yam VII. Mauritius fody, Mauritius © Jacques de Spéville

Cover design & layout by: Pritpal S. Soorae, IUCN/SSC Reintroduction Specialist Group

Printed by: Arafah Printing Press LLC, Abu Dhabi, UAE

Download at: www.iucnsscrsg.org www.iucn.org/resources/publications

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Reintroduction of captive-raised Amazonian in

Diogo A. de Souza1,2, Vera M. F. da Silva1,2, Rodrigo S. Amaral2,3, Mumi Kikuchi4, José A. d’Affonseca Neto1,2 & Fernando C. W. Rosas1

1 - Aquatic Mammals Laboratory/INPA. Av. André Araújo, 2936, Aleixo, Manaus/AM - Brazil 69060-000 [email protected]; [email protected]; [email protected] 2 - Friends of Association, AMPA. Rua Jaú, 17, Balbina, Presidente Figueiredo/AM - Brazil 69736-000 [email protected] 3 - Federal Institute of Education, Science and Technology of the Amazonas (IFAM). Av. Cosme Ferreira, 8045, São José Operário, Manaus/AM – Brazil 69086-475 [email protected], [email protected] 4 - Wildlife Research Center of Kyoto University. 2-24 Tanaka-Sekiden-cho, Sakyo-ku, Kyoto - Japan 606-8203 [email protected]

Introduction The Amazonian manatee (Trichechus inunguis) is an exclusively freshwater sirenian endemic to the . It is widely distributed from the main Amazonian rivers of , and to the estuary of the in Brazil (Best, 1984). The is classified as “Vulnerable” by IUCN (Marmontel et al., 2016) and the Brazilian Red Book, and it is listed in Appendix I of CITES. Historical commercial exploitation during recent centuries for oil, hide and meat was the main cause of its dramatic population reduction. Although protected by national laws in all countries of its distribution, T. inunguis hunting still persists for the subsistence of riverine communities and to maintain the illegal trade of its meat. To increase the ecological information available for this species and promote its conservation, since 1974, the Aquatic Mammals Laboratory of the National Institute of Amazonian Research, LMA/INPA, has rescued and rehabilitated orphan Amazonian manatee calves. The success of this rehabilitation program and research resulted in the establishment of a group of that could potentially be returned to the wild, promoting a new step toward the conservation of this species.

Goals Goal 1: To assess the re- adaptation of the captive-raised Amazonian manatees after release in the wild. Goal 2: To monitor the daily and seasonal movements of the released manatees. Amazonian manatee

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Goal 3: To assess the home range and habitat use of the released manatees. Goal 4: To promote environmental education programs in the communities of the project area to increase the engagement of local people in Amazonian manatee conservation activities.

Success Indicators Indicator 1: Survival of the individuals over at least one complete flood pulse of the river. Indicator 2: Movements and exploration of the area by the released manatees and selection of suitable habitats for the species. Indicator 3: Absence or low contact of the released individuals with humans. Indicator 4: Participation and engagement of the local people in the protection and monitoring of the released manatees. Indicator 5: Interaction of the released animals with wild Amazonian manatees.

Project Summary Feasibility: The Amazonian manatee reintroduction program was established in 2008. Release sites were chosen based on the following requirements - appropriate habitats, presence of wild manatees, food availability, an absence or decline in hunting, location within Protected Areas and support of local communities for the protection and post-release monitoring of the animals. Initially, the Cuieiras River (02º41’29.5”S/60º20’51.8”W) in the Puranga-Conquista Sustainable Development Reserve (SDR), Amazonas state, Brazil, was selected as a release site. In this phase, the animals were released directly from captivity into the wild. The individuals showed difficulty adapting, and the translocations were suspended after two releases. A second phase began in 2016 at a new site (Piagaçu-Purus SDR), located in the lower Purus River (04º12’05.7”S, 61º55’48.5”W). To improve the success of the animals after release, we adopted new strategies before the release process, with the animals spending 1 - 4 years in a semi-natural lake for adaptation. In both areas, an education program was also established to create awareness of the project and promote human engagement.

Implementation: Due to illegal hunting and entanglement in fishing nets, orphaned manatee calves from the Amazon rivers in Brazil are rescued by partner organizations, governmental agencies or riverine residents and taken to INPA’s facility. During the rehabilitation process, the animals are kept in fiberglass pools and are fed with an artificial milk formula for approximately two years. Releasing manatees in the Cuieiras River After weaning, they are

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transferred to bigger pools and fed with several natural plants and cultivated vegetables. Animals with the potential to be reintroduced were selected based on their time in captivity, their health conditions and behavior assessments. T. inunguis has high genetic diversity and a panmictic population (Cantanhede et al., 2005); therefore, genetic issues are not exclusionary criteria. The selected animals were transported mostly at night, to avoid the heat, using a covered truck and a regional boat, keeping the animals’ skin wet. Before release, the animals were kept in a floating tank for 1 - 7 days to reduce transportation stress and to test the telemetry equipment. Two release protocols were used: direct release (2008 - 2009) and soft release (2016 - 2017). During the first reintroduction, in the Cuieiras River, four sub-adult manatees were released directly from the pools to the river. We conclude that T. inunguis raised in captivity have very low perception of the seasonal variation in the hydrological cycle and in the search for food. Two animals died approximately 130 days after release. The third individual lost its belt after 165 days, likely due to weight loss. The fourth was recaptured after 120 days with a weight loss of 30% body mass and was returned to captivity for rehabilitation. Thus, the reintroduction protocol was revised, introducing an adaptation phase in a semi-natural area before release.

Since 2011, the selected manatees have been moved to a 13 ha semi-natural facility for the minimum of one year for the gradual adaptation to the environmental conditions (Souza et al., 2012). From 2016 - 2017, nine manatees (5 males & 4 females) were released in the Piagaçu-Purus SDR. One male manatee was released twice, one time in each area. All release processes had the support of the local people helping with the releasing and monitoring procedures.

Post-release monitoring: All reintroduced animals (n=12) were monitored using a radio-telemetry system. A VHF transmitter is attached to a belt and fixed to the caudal peduncle, totaling 900 g in weight. The monitoring was conducted using an aluminum boat and canoe with the manatee's positions determined directly or by triangulation. Additionally, animal-borne digital recorders with an automatic release mechanism were used to record the swimming behavioral and feeding events of the manatees over a short period after release (maximum 14 days) (Kikuchi et al., 2011). The manatees were monitored daily for 75 to 550 days. During the first days after release, the animals remained relatively close to the floating tank, gradually moving greater distances from the release site. Individual differences in movement and space use have been observed. The average displacement of the animals was 3 km/day (min. 0.3 km and max. 37 km per day). The farthest distance recorded from the release site was 100 km. Usually, the manatees were observed in calm water areas with abundant food. Although the animals were raised and kept together for approximately 10 years in captivity, after release, they spent most of their time separately, supporting the information on the solitary behavior of the species.

However, interactions with wild manatees were recorded. Although the signals of transmitters can be lost in some areas, such as flooded forest, radio-telemetry showed a high efficacy rate, totaling more than 2,200 records. Post-release survivorship showed a significant increase after the adoption of the semi-natural captivity stage in the protocol, with a current 100% success rate. One of the

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monitored manatees was recaptured eight months after release, showing increased body size and weight as expected.

Major difficulties faced The high costs of the long-term program to monitor the released animals, including gaining the permits to import the equipment. The long period required for the rehabilitation of the orphan rescued manatees in captivity (5 - 7 years) to achieve the ideal body conditions for release and the cost of maintenance. Logistical difficulties in implementing the semi-captivity facility. Currently, we are using a private area with natural and safe conditions. The inexistence of a standard protocol for the release of Amazonian manatees. We had to learn based on our own actions, defining the best season for release, age of individuals, time in semi-captivity, and how to improve the belt design to avoid injuries. Determining how to evaluate the manatee health conditions and adjust the belts of the released animals; due to the complexity of the habitats plus the cryptic behavior of the species, the observation and recapture of the animals are challenging.

Major lessons learned As the Amazonian manatee is still hunted, one important requirement for the selection of a release site is that the area should be located inside a Protected Area to minimize the risks for the animals.

Local school children greeting the manatees

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Inclusion of former manatee hunters in the monitoring team and involvement of the local people are extremely important for the success of the release program. Environmental education programs are necessary for the protection of the released manatees, highlighting the importance of this species and its habitat in the region. Time spent in the semi-natural captivity area for at least one year is necessary in order to promote the gradual re-adaptation of the manatees and to increase the success of the reintroduction. Reintroduction during the beginning of the rising water of the rivers is recommended to offer greater food availability as well as more time for the adaptation to the seasonal variation in the water level. The VHF belt design for the Amazonian manatee has been widely used in marine sirenians. Until now, there has been no information on the durability of this belt in the Amazon freshwater environment. After examining the conditions of two belts one year after deployment, the need for modifications to minimize injuries to the animals and to improve the monitoring system signals became clear. Antenna - The intensity of the transmitter's signals decreased considerably after six months for 75% of the tracked animals. We noticed that the antenna of the transmitter was broken at its base, and now a modification of the supporting base of the antenna was applied to allow more flexibility and durability. Belts - The metal screws that hold the belt are expected to corrode over time to allow the belt to fall off, preventing injury with the growth of the animal. We found that in freshwater, the corrosion of the belt screws occurs more slowly. To accelerate the corrosion rate, we soaked the steel bolts in vinegar to remove the zinc plating. Our expectation is that the belt can break faster, in less than 18 months. Leather belts are not designed to corrode away but to rip when entangled. For the same reason, we also reduced the leather thickness from 0.4 mm to 0.3 mm.

Success of project

Highly Successful Successful Partially Successful Failure √

Reason(s) for success/failure: Contrary to our early expectations, the inability of the captive-raised Amazonian manatees to understand the seasonal variation in the water level of the rivers suggests a very strong learning component in the species. Therefore, the direct reintroduction of animals from captivity to the wild is not recommended. Constant review of the reintroduction protocol for the species. The inclusion of the semi-natural captivity step shows a 100% success rate for manatee survival in a new environment. Involving former Amazonian manatee hunters with the team considerably improves the monitoring quality due to their great experience in terms of the species ecology and by promoting the empowerment of local people.

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The success of the manatee release program in the Piagaçu-Purus SDR indicates that the environmental characteristics of the region (floodplain and ria lakes) have contributed to the survivorship of the reintroduced animals. The experience and results accumulated up to now are crucial to improve our management techniques (transport, semi-captivity and release) and to propose guidelines for the conservation of this species over the long-term.

References Best, R.C. (1984) The aquatic mammals and reptiles of the Amazon. In: Sioli, H. (Ed.). The Amazon, Limnology and Landscape. Dr. W. Junk Publishers, Dordhecht, The Hague, The Netherlands, 15: 371-412. https:// doi.org/10.1007/978-94-009-6542-3_15

Cantanhede, A.M., da Silva, V.M.F., Farias, I.P., Hrbek, T., Lazzarini, S.M. & Alves-Gomes, J.A. (2005) Phylogeography and population genetics of the endangered Amazonian manatee, Trichechus inunguis Natterer, 1883 (Mammalia, ). Molecular Ecology 14: 401-413. https://doi.org/10.1111/ j.1365-294X.2004.02413.x

Kikuchi, M., da Silva, V.M.F., Rosas, F.C.W., Souza, D. & Miyazaki, N. (2011) The implications of turning behavior performed by Amazonian manatees after release into the wild. Journal of Ethology 30: 187-190. https://doi.org/10.1007/ s10164-011-0290-0

Marmontel, M., de Souza, D. & Kendall, S. (2016) Trichechus inunguis. The IUCN Red List of Threatened Species. Version 2016. Downloaded on 21 July 2017.

Souza, D.A., da Silva, V.M.F., d’Affonseca Neto, J.A., Rosas, F.C.W. & Reis, I.M. (2012) When just return to the wild is not enough: New steps for Reintroduction of Amazonian Manatees in Brazil. Newsletter of the IUCN Sirenia Specialist Group, Sirenews 57: 6-8.

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