In this piece of path breaking research, the
researchers attempted to estimate the population of emperor penguins (Aptenodytes
fosteri) using a single synoptic survey. They examined the whole
continental coastline of Antarctica using a combination of medium resolution
and Very High Resolution (VHR) satellite imagery to identify emperor penguin
colony locations. Where colonies were identified, VHR imagery was obtained in
the 2009 breeding season. The remotely-sensed images were then analysed using a
supervised classification method to separate penguins from snow, shadow and
guano. Actual counts of penguins from eleven ground truthing sites were used to
convert these classified areas into numbers of penguins using a robust regression
algorithm
Four new colonies were discovered. The location of
three previously suspected sites was confirmed. Total number of emperor penguin
breeding colonies was put at 46. The researchers estimated the breeding
population of emperor penguins at each colony during 2009 and provide a
population estimate of ~238,000 breeding pairs. This is against the last
previously published count of 135,000–175,000 pairs). The researchers say based
on published values of the relationship between breeders and non-breeders, this
translates to a total population of ~595,000 adult birds.
The researchers contend that their work now
provides a comprehensive estimate of the total breeding population that can be
used in future population models and will provide a baseline for long-term
research.
Citation: Fretwell PT,
LaRue MA, Morin P, Kooyman GL, Wienecke B, et al. (2012) An Emperor Penguin
Population Estimate: The First Global, Synoptic Survey of a Species from Space.
PLoS ONE 7(4): e33751. doi:10.1371/journal.pone.0033751
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