When to stop managing or surveying cryptic threatened species Kelly Mitchell

Levels of Endangerment

Cryptic Species

Errors Managers Can Make They stopped managing for something that still needs assistance They may be managing for something that is already gone

Jerdon’s Courser South Island Takahe Mahogany Glider

Maximized long-term benefit The Ultimate Goal Find the optimal allocation of resources to actions that maximizes the net expected long- term benefit Resources Actions Maximized long-term benefit

It’s A Trade-off Surveying Managing Nothing

Objectives of the paper 1)Introduce Partially Observable Marchov Decision Process (POMDP) 2)Use POMDP as a tool to generate rules of thumb for optimal allocation of conservation efforts

Species of interest

Background 400-500 remaining Critically endangered

Current Management Anti-poaching efforts Surveying

Management 1 of the 4 core areas 50% intensity needed $18,744/year for management

Surveying and Total Budget 10% must be surveyed $10,870/year =$30,000

What are tigers worth? $175,134/year Determine which value system to use Donations (9) Willingness to pay (265) Ecotourism value

Chance of extinction and survey success Managed vs Not Managed Detectability When Surveyed vs Not 5.8% 10% 78% 1%

Questions 1)What is the optimal strategy? 2) When is it best to invest in management? 3) When should there be surveys? 4) When should we give up?

Results Read blue line backwards. During the years of managing and surrendering as time passes our belief in its existence declines rapidly

Tm Ts V>Cm Tm&Ts V<Cm Tm Ts What is optimal? 175,134 30,000 Always optimal to manage first If the value of the animal is greater than the cost you spend more time working with it. 175,134 30,000

When to stop surveying or managing The smaller the value compared to cost the more time is invested in management When an asymptote is reached it is no longer optimal to survey Green: Tiger Blue: generic highly threatened animal When an symtope is reached it is no longer optimal A) managing B)surveying

When detection is a problem Managing Surveying The more valuable and difficult to detect a species is, the longer is the time of management before surveying

General Rules of Thumb Managing first is always more optimal than surveying The duration of management depends on our belief in the species existence, its value, and the urgency of its status At a critical probability of extinction economic value has less effect At some point it may be most optimal to surrender efforts

Questions?