Translocation as a tool for conservation of the Hawaiian monk seal

• Published in: Biological conservation 2011-11, Vol.144 (11), p.2692-2701
• Main Authors: Baker, J.D., Becker, B.L., Wurth, T.A., Johanos, T.C., Littnan, C.L., Henderson, J.R.
• Format: Article
• Language: English
• Subjects: Adults; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Conservation; Conservation, protection and management of environment and wildlife; Dispersal; Foraging habitats; Fundamental and applied biological sciences. Psychology; General aspects; Hawaiian monk seal; Islands; Males; Marine; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Position (location); Relocation; Seals; Survival; Translocation
• ISSN: 0006-3207; 1873-2917
• DOI: 10.1016/j.biocon.2011.07.030

► Risk of mortality during capture and transport of monk seals is very low. ► Translocated seal survival was indistinguishable from native seals at release sites. ► Weaned monk seal pups appear most amenable to translocation. ► Older monk seals disperse sooner and further after release than do weaned pups. ► In most cases, the stated goals of Hawaiian monk seal translocations were achieved. The deteriorating demographic status of the endangered Hawaiian monk seal has motivated renewed and expanded proposals for conservation action, including translocation of seals to improve survival. Over the past three decades, numerous monk seal translocations have been conducted with a variety of objectives, including mitigating shark predation and conspecific male aggression, reducing human–seal interactions, and taking advantage of favorable foraging habitats to improve survival. Here, we analyze our cumulative experience with translocation of Hawaiian monk seals. We found a strong correlation between the time seals remained in the vicinity of the release site and their age. Recently weaned pups (with little or no at-sea foraging experience) exhibited high fidelity to release sites commensurate with that shown by untranslocated pups to their birth location. In contrast, juvenile and adult seals tended to stray from their release locations farther and sooner. Nevertheless, when 21 adult male seals were moved more than 1000 km from Laysan Island in the Northwestern Hawaiian Islands (NWHI), to the main Hawaiian Islands (MHI), they subsequently dispersed among the MHI; however, only one was observed to return to the NWHI. Translocated seals appeared to survive at rates comparable to seals native to the release site. Outcomes suggest that in most cases the intended objectives of translocations were achieved. Except for one notable case, translocations within the MHI to arrest human–seal interactions were mostly unsuccessful. These findings will be essential for informing successful large-scale translocation plans in the future.