The Conservation Status of Gibbons in Vietnam - Gibbon Research ...

The Conservation Status of Gibbons in VietnamDate of most recent survey:This refers only to biodiversity surveys likely to report gibbons, e.g. an amphibian-focussed surveymight not record gibbons if they are present, but a general mammal survey would be expectedto.Date of most recent confirmed record:Gibbon records are considered confirmed only if there is direct evidence (a specimen, sighting orvocalization heard) obtained by a reliable observer with associated reliable location data. It isconsidered provisional if the only evidence is from a specimen, sighting or vocalization reportedsecond-hand.Minimum population:For each site, the gibbon population is given as the minimum number of groups which wereconfirmed from the site at the time of the most recent report, or where relevant and possible, acombined number from multiple reports. This does not necessarily represent the full populationof the site. Gibbon groups rather than individuals are the preferred unit for presenting the size ofthe population. The number of groups is more likely to be recorded during a survey than thenumber of individuals, due to the practical ease of recording vocalisations compared to directsightings. Where a number of individuals at a site has been recorded, that data is also presented.ix