Multiple co-occurring bioeconomic drivers of overexploitation can accelerate rare species extinction risk

Research output: Contribution to journalArticlepeer-review

Abstract

The unsustainable harvest of species for the global wildlife trade is a major cause of vertebrate extinction. Through the anthropogenic Allee effect (AAE), overexploitation to extinction can occur when a species' rarity drives up its market price, enabling profitable harvest of all remaining individuals. Even in the absence of rarity value, however, the harvest of other species can subsidize the overexploitation of a rare species to the point of extinction, a phenomenon termed opportunistic exploitation. These two pathways to extinction have been considered independently, but many traded species experience them simultaneously. In this study, we develop a simple model that incorporates these mechanisms simultaneously and demonstrate that including multiple harvest strategies with market-based feedbacks fundamentally alters rare species extinction risk and the rate at which overexploitation occurs. As a pertinent case study, we consider the harvest of ground pangolins Smutsia temminckii. Our results show that pangolin extinction was generally associated with high rarity value, the use of multiple harvest strategies and the simultaneous harvest of a common species that has a fast life history. Pangolin population depletion and short-term extinction risk were greatest when harvesters used a combination of pursuit and opportunistic (i.e. multi-species) harvest strategies. Policy implications. Our results suggest that feedbacks between multiple financial incentives to overharvest can exacerbate the risk of extinction of rare species. As a result, continuing to address AAE and opportunistic exploitation as separate extinction pathways may insufficiently capture extinction risk for many exploited species. Criteria for assessing extinction risk or harvest sustainability of exploited species should incorporate multiple drivers of harvest pressure, with an expanded focus on including species with high rarity value that are exploited in multi-species harvest regimes.

Original languageEnglish (US)
Pages (from-to)754-763
Number of pages10
JournalJournal of Applied Ecology
Volume60
Issue number5
DOIs
StatePublished - May 2023
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Ecology

Keywords

  • Smutsia temminckii
  • anthropogenic Allee effect
  • harvest model
  • opportunistic exploitation
  • overexploitation
  • pangolin
  • rarity value
  • wildlife trade

Fingerprint

Dive into the research topics of 'Multiple co-occurring bioeconomic drivers of overexploitation can accelerate rare species extinction risk'. Together they form a unique fingerprint.

Cite this