Eighteen years of Antillean manatee Trichechus manatus manatus releases in Brazil: lessons learnt I RAN C AMPELLO N ORMANDE ,F ABIA D E O LIVEIRA L UNA A NA C LÁUDIA M ENDES M ALHADO ,J OÃO C ARLOS G OMES B ORGES P ITÁGORAS C ARLOS V IANA J UNIOR ,F ERNANDA L ÖFFER N IEMEYER A TTADEMO and R ICHARD J. L ADLE Abstract The Antillean manatee Trichechus manatus manatus was once widespread from the south-eastern coast of Brazil to Central America and the Caribbean. In Brazil habitat destruction and overhunting severely reduced and fragmented the wild population, restricting extant sub- populations to the north and north-east coast. In response to these threats an ambitious government-led programme was initiated in 1994, with the aim of rehabilitating orphaned manatee calves and releasing them into the southernmost subpopulation. The programme is unique within Brazil, and has invested unprecedented resources in post-release monitoring. So far 30 manatees have been released at three sites, with a high rate of success (. 75%). Time in captivity appears to be a key variable determining post-release success: too long or too short a time in captivity decreasing the probability of survival. We describe the main features of this long-term programme and identify six key lessons learnt: (1) close monitoring, health assessments and rescues can significantly increase the success of releases, (2) combining different monitoring techniques results in high-quality data and reduces tracking costs, (3) long-term studies are needed to effectively evaluate the results, (4) re- leasing manatees at c. 5 years of age can increase chances of success, (5) soft-release is important to aid acclimatization, and (6) the programme has been effective in raising awareness among the general public, supporting education and fund-raising. Keywords Brazil, management, manatee, rehabilitation and release, Sirenia, soft-release, translocation, Trichechus manatus This paper contains supplementary material that can be found online at http://journals.cambridge.org Introduction H abitat destruction, persecution and environmental change have dramatically reduced the distribution and abundance of many large mammal species. Many of the rarest species now only exist in small, highly disjunct popu- lations with a high risk of extinction as a result of the com- bined effects of inbreeding depression, loss of genetic diversity and environmental and demographic stochasticity (Lande, 1988; Stacey & Taper, 1992; Frankham, 1995; Hedrick & Kalinowski, 2000). These problems can be partially miti- gated by facilitating movement between remaining sub- populations through corridors and other linkages between critical habitats (Bennett, 2003) or by translocation of indi- viduals (Griffith et al., 1989; Fischer & Lindenmayer, 2000; Seddon et al., 2007; Ewen et al., 2012). Sometimes populations have become so fragmented that translocation (‘the intentional release of animals in the wild in an attempt to establish, re-establish or augment a popu- lation’; Griffith et al., 1989) is the only available conservation option, despite the high costs and considerable technical difficulties involved. Sutherland et al. (2009) recently iden- tified the question ‘what is the relative effectiveness of differ- ent methods for facilitating movement of a species among disjunct patches of its habitat?’ as one of 100 important questions in global conservation. Answering this question is not simple but is becoming increasingly urgent as anthropo- genic climate change makes the possibility of wide-scale translocations (e.g. assisted dispersal) more likely (e.g. McLachlan et al., 2007). The Antillean manatee Trichechus manatus manatus in Brazil provides a good example of the challenges of trans- locating large mammals. Before European colonization manatees were widespread along the coast of Brazil as far as the southern state of Espírito Santo. However, they have IRAN CAMPELLO NORMANDE* (Corresponding author), FABIA DE OLIVEIRA LUNA, PITÁGORAS CARLOS VIANA JUNIOR and FERNANDA LÖFFER NIEMEYER ATTADEMO† National Research Centre for the Conservation of Aquatic Mammals, Chico Mendes Institute for Biodiversity Conservation, Estrada do Forte Orange, s/n, Itamaracá, Pernambuco 53900-000, Brazil E-mail iran.normande@icmbio.gov.br ANA CLÁUDIA MENDES MALHADO and RICHARD J. LADLE‡ Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Alagoas, Brazil JOÃO CARLOS GOMES BORGES Aquatic Mammals Foundation, Recife, Brazil *Also at: Institute of Biological and Health Sciences, Federal University of Alagoas, Maceió, Alagoas, Brazil † Also at: Veterinary Medicine Department, Federal Rural University of Pernambuco, Recife, Pernambuco, Brazil ‡ Also at: School of Geography and the Environment, Oxford University, South Parks Road, Oxford, UK Received 21 December 2012. Revision requested 21 March 2013. Accepted 11 June 2013. First published online 19 August 2014. Oryx, 2015, 49(2), 338–344 © 2014 Fauna & Flora International doi:10.1017/S0030605313000896 https://doi.org/10.1017/S0030605313000896 Published online by Cambridge University Press