Metapopulation dynamics and foraging plasticity in a highly vagile seabird, the southern rockhopper penguin

LOIS, NICOLÁS A.; CAMPAGNA, LEONARDO; BALZA, ULISES; POLITO, MICHAEL J.; PÜTZ, KLEMENS; VIANNA, JULIANA A.; MORGENTHALER, ANNICK; FRERE, ESTEBAN; SÁENZ SAMANIEGO, RICARDO; RAYA REY, ANDREA; MAHLER, BETTINA

Ecology and Evolution

John Wiley & Sons

Año: 2020

2045-7758

Population connectivity is driven by individual dispersal potential and modulated bynatal philopatry. In seabirds, high vagility facilitates dispersal yet philopatry is alsocommon, with foraging area overlap often correlated with population connectivity.We assess the interplay between these processes by studying past and current connectivityand foraging niche overlap among southern rockhopper penguin colonies ofthe coast of southern South America using genomic and stable isotope analyses. Wefound two distinct genetic clusters and detected low admixture between northernand southern colonies. Stable isotope analysis indicated niche variability betweencolonies, with Malvinas/Falklands colonies encompassing the species entire isotopicforaging niche, while the remaining colonies had smaller, nonoverlapping niches. Arecently founded colony in continental Patagonia differed in isotopic niche widthand position with Malvinas/Falklands colonies, its genetically identified founderpopulation, suggesting the exploitation of novel foraging areas and/or prey items.Additionally, dispersing individuals found dead across the Patagonian shore in an unusualmortality event were also assigned to the northern cluster, suggesting northernindividuals reach southern localities, but do not breed in these colonies. Facilitated by variability in foraging strategies, and especially during unfavorable conditions, thenumber of dispersing individuals may increase and enhance the probability of foundingnew colonies. Metapopulation demographic dynamics in seabirds should accountfor interannual variability in dispersal behavior and pay special attention to extremeclimatic events, classically related to negative effects on population trends.