Abundance & distribution in New Caledonia
“Aerial surveys are a cost-effective method for estimating the abundance of wildlife because they cover large areas quickly. Such surveys have been the main method used to estimate the size of the Florida manatee population and dugong populations in Australia for many years (see Heinsohn et al. 1976; Ligon 1976; Irvine and Campbell 1978 for accounts of early surveys). Aerial surveys have been used to estimate abundance in approximately 20 countries for dugongs, and approximately 16 countries for West Indian manatees, plus some coastal populations of West African manatees.” Citation from Marsh, H., T. J. O’Shea, J. E. I. Reynolds. 2011. The ecology and conservation of sirenia: dugongs and manatees. Cambridge University Press.
Aerial surveys were carried out around the mainland of New Caledonia during the winter season in 2003 by Garrigue and co-workers (Garrigue et al., 2008). They estimated the population size to be around 1800 individuals (SD= 332). A subsequent survey was carried out during the warm season in 2008, the population size was estimated to be around 960 individuals (SD= 241). The reasons for such disparity are unknown but cannot rule out a potential decline. Both surveys showed that 84% of the population was located on the west coast and 16% on the northeast coast (Garrigue C. et al, 2008).
Dugong distribution around the mainland of New Caledonia in 2003
Dugong distribution around the mainland of New Caledonia in 2008
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