McMahon-2014-Satellites, the All-.pdf (2.96 MB)
Satellites, the all-seeing eyes in the sky: counting elephant seals from space
journal contributionposted 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 titlePLoS One
Department/SchoolInstitute for Marine and Antarctic Studies
PublisherPublic Library of Science
Place of publicationUnited States of America
Rights statementCopyright 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.