Inter-annual consistency in the phenology and trophic niche of the Southern Rockhopper penguins from Isla de los Estados, Tierra del Fuego, Argentina

DODINO, SAMANTA; TOM HART; RICCIALDELLI, LUCIANA; IGNACIO JUAREZ MARINEZ; ALICE EDNEY; PÜTZ, KLEMENS; POLITO, MICHAEL J.; RAYA REY, ANDREA

Viña del Mar

Congreso; 11th International Penguin Congress; 2023

Phenological and trophic niche consistency are known to impact the ability of speciesto respond to climate change. Understanding these ecological variables is key toassessing the potential adaptability of endangered species like the SouthernRockhopper Penguin (Eudyptes chrysocome). To study their phenology and colonyattendance we deployed time-lapse cameras from 2013 to 2017at Isla de los Estados(Argentina) and processed the images using the citizen science project PenguinWatch. We also collected adult feather samples to study their pre-moult foragingniche and trophic position (TP) using stable carbon (δ13C) and nitrogen (δ15N) isotopeanalysis. To estimated their TP, we used previous information of baseline’s stableisotope values of the food web around the colony. We found phenological consistencybetween years with little variation in arrival (~October 1th) and departure dates(~March 30th) for the breeding season as well as in departure (~February 1th) andarrival (~February 20th) for the pre-moult trip. Nonetheless, we found significantdifferences in δ13C and δ15N values between years, with 2014 and 2017 having thelowest values for both isotopes for the pre-moult period. Regarding TP, we found nodifferences between years. Results indicate that Rockhoppers are consistent in theirphenology and their TP across years, with differences in isotope composition possiblyrelated to variation in foraging areas. This data provides key information forevaluating their adaptive capabilities, resilience and their risk of phenologicalmismatch, all important in order to assess their vulnerability to future environmentalchanges.