Translocation and hand-rearing of the short-tailed albatross Phoebastria albatrus: early indicators of success for species conservation and island restoration

Abstract

Many endemic species, particularly those on remote islands, have been driven to extinction or near extinction by anthropogenic influences. The short-tailed albatross Phoebastria albatrus once numbered in the millions but was thought to be extinct by the mid 20th century. Albatrosses, of the family Diomedeidae, are among the most threatened birds globally as a result of commercial exploitation, introduced predators, and mortality in commercial fisheries. We applied an experimental approach over 5 years to evaluate the translocation and hand-rearing of albatross chicks by comparing growth, physiological health indices, post-fledging survival, and migration patterns with a control group of naturally reared chicks in the source population. Hand-reared chicks had comparable or superior health and similar rates of immediate post-fledging mortality (15%), with mortality strongly female-biased in both groups. Hand-reared birds had longer post-fledging drift periods before attaining sustained flight (also female-biased) but comparable, albeit somewhat wider ranging, migration patterns to naturally reared chicks during their first 6 months at sea. Recruitment to the translocation site of a breeding pair that included a hand-reared bird occurred within 5 years of the first translocation. Success will ultimately depend on continued recruitment and breeding over the coming decades, given delayed breeding in these long-lived species. The results to date, however, have exceeded initial expectations and can inform potential reintroductions of other long-lived, migratory avian species with strong natal philopatry, and reintroductions of native species to former breeding islands.

Ontogenetic changes in at-sea distributions of immature short-tailed albatrosses Phoebastria albatrus

“…Over time they then develop foraging stra tegies that are similar to adults (Riotte-Lambert & Weimerskirch 2013, de Grissac et al 2017. Initial reliance on innate cues could potentially be problematic for species that experienced large population declines and extirpation from breeding colonies (Payne 1977, Hucke-Gaete et al 2004, Le Boeuf et al 2011, especially when conservation actions facilitate reintroduction through translocations (Deguchi et al 2012(Deguchi et al , 2014(Deguchi et al , 2017. In addition, the importance of learning migration behavior and foraging area selection are likely key components of how marine predators will cope with climate-driven changes to ecosystems (Hazen et al 2012a).…”

“…They may also engage in riskier behavior than adults. For many species, survival rates of first-year juveniles are lower than for adults as initial mortality is high (Alderman et al 2010, Deguchi et al 2014, VanderWerf & Young 2016. For long-lived species, such as albatrosses, the immature phase is lengthy (3−12 yr), and these individuals make up a large portion of the population (Porter & Coulson 1987, Crespin et al 2006.…”

“…Torishima is an active volcano and eruptions pose a potential threat to this species (Finkelstein et al 2010). Therefore, in February 2008-2012, a total of 70 one month old short-tailed albatrosses were translocated from Torishima to Mukojima, in the Bonin (Ogasawara) Islands, where they were hand-reared to facilitate reestablishment of a historical colony (Deguchi et al 2012(Deguchi et al , 2014. Though the islands are in relatively close proximity (~350 km), the shift in geographic starting point could influence migratory routes and distributions of chicks fledging from the translocation site on Mukojima.…”

“…High survival suggests efficient foraging strategies or sufficient foraging opportunities during the immature phase. Yet, juvenile short-tailed albatrosses are still the most vulnerable portion of the population to mortality at sea (Suryan et al 2007, Deguchi et al 2014. This can partially be explained by higher fisheries overlap (Suryan et al 2007).…”

Addressing Challenges in the Application of Animal Movement Ecology to Aquatic Conservation and Management

“…Preparing managers for the capabilities of the technology so that they are ready to receive new, potentially transformative, information may be a useful strategy for helping to ensure that data from electronic tagging studies are more likely to be used by managers. There is a growing suite of "success stories" in application of electronic tagging and tracking techniques to management (e.g., Deguchi et al, 2014Deguchi et al, , 2016Crossin et al, accepted) which is promising, but there is also need for additional social science research to better understand (from the perspective of the manager) the relevance of these techniques to contemporary management challenges.…”