Abstract
In less than one century, the once-abundant Peruvian diving petrel has become the first endangered seabird of the Humboldt Current System (HCS). This small endemic petrel of the South American Pacific coast is now an important indicator of ongoing habitat loss and of the success of local conservation policies in the HCS - an ecoregion designated as a priority for the conservation of global biodiversity. Yet so far, poorly understood life history traits such as philopatry or dispersal ability may strongly influence the species’ response to ecosystem changes, but also our capacity to assess and interpret this response. To address this question, we explore the range-wide population structure of the Peruvian diving petrel, and show that this small seabird exhibits extreme philopatric behavior at the island level. Mitochondrial DNA sequences and genome-wide SNP data reveal significant isolation and low migration at very short distances, and provide strong evidence for questioning the alleged recovery in the Peruvian and Chilean populations of this species. Importantly, the full demographic independence between colonies makes local population rescue through migration unlikely. As a consequence, the Peruvian diving petrel appears to be particularly vulnerable to ongoing anthropogenic pressure. By excluding immigration as a major factor of demographic recovery, our results highlight the unambiguously positive impact of local conservation measures on breeding populations; yet at the same time they also cast doubt on alleged range-wide positive population trends. Overall, the protection of independent breeding colonies, and not only of the species as a whole, remains a major element in the conservation strategy for endemic seabirds. Finally, we underline the importance of considering the philopatric behavior and demographic independence of breeding populations, even at very fine spatial scales, in spatial planning for marine coastal areas.
Highlights
The large-scale oceanographic processes that structure the southern Pacific Ocean fuel the upwelling of nutrient-rich subsurface waters along the West coast of South America[1], resulting in one of the most highly productive oceanic systems on the planet: the Humboldt Current System (HCS)[2,3]
The Peruvian diving petrel (Pelecanoides garnotii), a small seabird endemic to the HCS, is a dramatic example of the way multiple direct and indirect threats may converge on a single species
The Peruvian diving petrel was driven to near-extinction by human-induced threats that included habitat destruction through guano extraction[34,35,36], poaching of adults and egg collection[35], bycatch[35,37], human-introduced predators[15,38] and habitat competitors[39], food competition with fisheries[35,40], light pollution (Sea Shepherd Chile, pers. com.), and the effects of ongoing climate change on the productivity of the HCS3
Summary
The large-scale oceanographic processes that structure the southern Pacific Ocean fuel the upwelling of nutrient-rich subsurface waters along the West coast of South America[1], resulting in one of the most highly productive oceanic systems on the planet: the Humboldt Current System (HCS)[2,3]. The Peruvian diving petrel (Pelecanoides garnotii), a small seabird endemic to the HCS, is a dramatic example of the way multiple direct and indirect threats may converge on a single species. This small insular petrel was once one of the most abundant seabirds of the HCS. A striking example can be found in Isla Chañaral, in northern Chile, where ~100,000 pairs bred in 193838: this population is extinct[15] In contrast to this global decline, marginal range re-expansion and local population growth have been suggested[36]. It may be that the species did not go through a population bottleneck at all, and that its resilience to habitat disruption has been much higher than previously thought
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
