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Satellites, the all-seeing eyes in the sky: counting elephant seals from space

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posted on 2023-05-18, 01:42 authored by Clive McMahonClive McMahon, Howe, H, van den Hoff, J, Alderman, R, Brolsma, H, Mark HindellMark Hindell
Regular censuses are fundamental for the management of animal populations but, are logistically challenging for species living in remote regions. The advent of readily accessible, high resolution satellite images of earth mean that it is possible to resolve relatively small (0.6 m) objects, sufficient to discern large animals. To illustrate how these advances can be used to count animals in remote regions, individual elephant seals (Mirounga leonina) were counted using satellite imagery. We used an image taken on 10/10/2011 to count elephant seals (n = 17906306 (95%CL)) on the isthmus of Macquarie Island, an estimate which overlapped with concurrent ground counts (n = 1991). The number of individuals per harem estimated using the two approaches were highly correlated, with a slope close to one and the estimated intercept also encompassing zero. This proof of concept opens the way for satellites to be used as a standard censusing technique for inaccessible and cryptically coloured species. Quantifying the population trends of higher order predators provides an especially informative and tractable indicator of ecosystem health.


Publication title

PLoS One



Article number









Institute for Marine and Antarctic Studies


Public Library of Science

Place of publication

United States of America

Rights statement

Copyright 2014 the Authors-This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Repository Status

  • Open

Socio-economic Objectives

Assessment and management of coastal and estuarine ecosystems

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