Using predicted patterns of 3D prey distribution to map king penguin foraging habitat
International audience King penguins (Aptenodytes patagonicus) are an iconic Southern Ocean species, butthe prey distributions that underpin their at-sea foraging tracks and diving behaviourremain unclear. We conducted simultaneous acoustic surveys off South Georgia andtracking of king penguins bree...
Published in: | Frontiers in Marine Science |
---|---|
Main Authors: | , , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2021
|
Subjects: | |
Online Access: | https://hal.science/hal-03460885 https://doi.org/10.3389/fmars.2021.745200 |
Summary: | International audience King penguins (Aptenodytes patagonicus) are an iconic Southern Ocean species, butthe prey distributions that underpin their at-sea foraging tracks and diving behaviourremain unclear. We conducted simultaneous acoustic surveys off South Georgia andtracking of king penguins breeding ashore there in Austral summer 2017 to gain insightinto habitat use and foraging behaviour. Acoustic surveys revealed ubiquitous deepscattering layers (DSLs; acoustically detected layers of fish and other micronekton thatinhabit the mesopelagic zone) at c. 500 m and shallower ephemeral fish schools. Basedon DNA extracted from penguin faecal samples, these schools were likely comprised oflanternfish (an important component of king penguin diets), icefish (Channichthyidaespp.) and painted noties (Lepidonotothen larseni). Penguins did not dive as deepas DSLs, but their prey-encounter depth-distributions, as revealed by biologging,overlapped at fine scale (10s of m) with depths of acoustically detected fish schools.We used neural networks to predict local scale (10 km) fish echo intensity and depthdistribution at penguin dive locations based on environmental correlates, and developedmodels of habitat use. Habitat modelling revealed that king penguins preferentiallyforaged at locations predicted to have shallow and dense (high acoustic energy) fishschools associated with shallow and dense DSLs. These associations could be used topredict the distribution of king penguins from other colonies at South Georgia for whichno tracking data are available, and to identify areas of potential ecological significancewithin the South Georgia and the South Sandwich Islands marine protected area. |
---|