This discussion was first published on Dec 1 2010 as part of the 2010-2011 Red List update, but remains open for comment to enable reassessment in 2013.
In 2004, Laysan Duck Anas laysanensis was uplisted to Critically Endangered under criterion B1a+c(iv) because new information suggested that its population was undergoing extreme fluctuations within its extremely small range on just one island.
However, in 2004 and 2005, 42 individuals were translocated to the two islands of Midway Atoll National Wildlife Refuge; the birds bred successfully in their first year (Reynolds and Klaviter 2006) and the founder population has since increased in size, to an estimated 350 individuals in 2010 (M. Reynolds in litt. 2010), despite being hit by an outbreak of avian botulism in 2008, which killed up to 40-50% of that population (M. Reynolds in litt. 2008). The latest estimate for Laysan put the population there at 503-682 mature individuals (Reynolds and Citta 2007). By the 2011 Red List update, the population will be estimated to have been increasing for at least five years without the occurrence of extreme fluctuations (i.e. a rapid tenfold increase or decrease).
Thus it is proposed that this species be downlisted to Vulnerable under criterion D2, as although the species is thought to be increasing, it occupies an AOO of less than 20 km2 and fewer than six locations, and the potential effects of human activities or stochastic events mean it is capable of becoming Critically Endangered or even Extinct in a very short time period. Comments on this proposal would be welcome.
Reynolds, M. H. and Citta, J. J. (2007) Postfledging survival of Laysan Ducks. J. Wildl. Manage. 71: 383-388
Reynolds M. and Klavitter J. (2006) Translocation of wild Laysan duck Anas laysanensis to establish a population at Midway Atoll National Wildlife Refuge, United States and US Pacific Possession. Conservation Evidence 3: 6-8
The following letter was received from Michelle Reynolds on 27 February 2011 in reaction to the above topic: Anas laysanensis Reynolds Feb11
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