Looking for new emperor penguin colonies? Filling the gaps

André Ancel,Robin Cristofari,Phil N Trathan,Caroline Gilbert,Peter T Fretwell,Michaël Beaulieu

doi:10.1016/j.gecco.2017.01.003

Abstract

Detecting and predicting how populations respond to environmental variability are crucial challenges for their conservation. Knowledge about the abundance and distribution of the emperor penguin is far from complete despite recent information from satellites. When exploring the locations where emperor penguins breed, it is apparent that their distribution is circumpolar, but with a few gaps between known colonies. The purpose of this paper is therefore to identify those remaining areas where emperor penguins might possibly breed. Using the locations of emperor penguin breeding colonies, we calculated the separation distance between each pair of geographically adjacent colonies. Based on mean separation distances between colonies following a circumpolar distribution, and known foraging ranges, we suggest that there may yet be six undiscovered breeding locations with half of these in Eastern and the remainder in Western Antarctica. Productivity in these regions suggests that food resources are likely to sustain emperor penguin populations.Our analysis highlights a fundamental requirement, that in order to predict how species might respond to regional climate change, we must better understand their biogeography and the factors that lead to their occupation of particular sites. Regarding emperor penguins, remote sensing should target the identified gaps apparently devoid of penguins in order to update the total number of colonies, to re-evaluate both the regional and global population of emperor penguins, and to gain a better understanding of their biogeography.

Highlights

The climate of our planet is undergoing regional and global changes, which are driving shifts in the distribution and phenology of many plants and animals (Hansen et al, 2013)
The impact of climate changes is more visible in coralline ecosystems, where small variation in temperature can lead to the massive bleaching of coral reefs (Hoegh-Guldberg et al, 2007)
Using the remotely sensed locations of 46 emperor penguin breeding colonies determined by their guano stains on sea ice (Fretwell et al, 2012), combined with two colony locations close to the Mertz Glacier (Ancel et al, 2014) and four colony positions on ice-shelves (Fretwell et al, 2014) together with others (Wienecke, 2012; LaRue et al, 2015), we calculated the loxodromic separation distance, that is the shortest distance between two points on the surface of a sphere, between each pair of geographically adjacent colonies

Summary

Introduction

The climate of our planet is undergoing regional and global changes, which are driving shifts in the distribution and phenology of many plants and animals (Hansen et al, 2013). The impact of climate changes is more visible in coralline ecosystems, where small variation in temperature can lead to the massive bleaching of coral reefs (Hoegh-Guldberg et al, 2007). Ancel et al / Global Ecology and Conservation 9 (2017) 171–179 small variation in temperature and sea ice cover can alter seabird populations (Croxall et al, 2002; Jenouvrier et al, 2012; Lynch and LaRue, 2014; Lyver et al, 2014). These regions provide examples that may foreshadow future events elsewhere on the planet

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