The most recent IUCN Red List assessment (2008) classified H. alaotrensis as Critically Endangered (CR). Conversion of marsh habitat to rice fields has been the most significant historical threat, to the point where little suitable land remains on which local farmers might cultivate this crop. Hunting for food and capture for pets have also reduced lemur numbers (Petter and Peyriéras, 1970a; Jolly et al., 1984). Various methods of hunting and trapping are employed by local people. Direct pursuit by dogs is the most common, but they may also be captured by using a harpoon, a snare, a stick to knock them out or into the water, by burning their reed bed habitat, or just by chasing them down. Commercial drainage projects are a potential threat. Regular burning to increase cattle pasture, facilitate local fishing, and develop new rice fields in dry years reduces suitable lemur habitat and also promotes the invasion of exotic plant species that may choke the remaining marshes. Population estimates for H. alaotrensis range from 2,500 to 5,000 individuals, representing a decline of approximately 30% in just over a decade (Ralainasolo, 2004; J. Ratsimbazafy, unpubl.). Thanks to efforts of Durrell, a new 42,478-ha protected area was created there in early 2007. This includes both a strict conservation area of 8,000 ha, and an adjacent 5,200-ha core zone of marsh where controlled activities (e.g., fishing) are permitted. In addition, public awareness campaigns continue to focus on the benefits of habitat conservation to the half million or more people who live by the lake. The benefits include erosion control, the biological filtering of agricultural pollutants, and flood prevention. Lac Alaotra is a 722,500-ha Ramsar wetland site, designated in 2003. As of 2010 there was a small, self-sustaining population of around 66 individuals in various European zoos (I. J. Porton, pers. comm.). The captive population was first started by the Jersey Wildlife Preservation Trust (now Durrell) back in 1990, when the first wild animals were obtained, and is an excellent example of the role that captive breeding of an endangered species can play for conservation purposes.