Latent extinction risk

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In conservation biology, latent extinction risk is a statistical model used to assess a species' chance of survival or extinction. Latent risk can also help determine the potential of how a species could become threatened.

Latent risk can most easily be described as the difference, or discrepancy, between the current observed extinction risk of a species and the theoretical extinction risk of a species predicted by its biological or life history characteristics.[1]

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[edit] Calculating latent extinction risk

Because latent risk is the discrepancy between observed and predicted risks, the values of both of these are required (See population modeling and population dynamics). Once these values are known, the latent extinction risk can be calculated as Observed Risk - Predicted Risk = Latent Extinction Risk.

When the latent extinction risk is a positive value, it indicates that a species has not yet encountered deleterious effects due to human induced impacts such as habitat degradation even though their biology (i.e. low rates of reproduction) would suggest a high threat.

Negative values indicate that current anthropogenic changes influence the extinction risk of a species more than the study of the species' biology would indicate. This is often because a species has been exposed to extreme endangering processes. Species with severely low negative values are usually listed as an endangered species and have associated recovery and conservation plans.[1]

[edit] Limits to latent extinction risk

One of the issues associated with latent extinction risk is its difficulty to calculate based on the limited availability of values for predicted extinction risk. Most taxa do not have sufficient information of their biology and life histories to actually calculate the estimated risk value or create a model to determine a projected extinction risk. This modeling, however, can be created in most mammals, which usually have well documented life histories and biological characteristics that can clearly influence the resilience or resistance of a species.

[edit] How latent risk influences conservation

Latent risk can help determine which ecological systems should be given attention in conservation strategies. Areas with high positive latent risk have a greater chance of being threatened when humans begin to interfere. These are areas or ecosystems in which human interference would be potentially disastrous as many species would become threatened or extinct. Species within these areas have higher sensitivity to future human impact.

Conservation planning could anticipate future population declines and aid in their prevention. For this reason, hotspots, which are areas of highest latent extinction risk, would be good conservation priorities.[2] Because it is much more cost-effective to use preventative tactics than to restore a damaged area, the latent risk hotspots are worthwhile and wise investments of capital assigned to conservation. Ultimately, it is much simpler to try to prevent species decline than to try to battle the eminent risk of extinction of a species already facing repercussions of human impact and latent risk calculations are strong tools to determine the allocation of preventative conservation funding.

[edit] Current hotspots

Among the highest in latent risk, regions of the North American tundra and many islands are current hotspots of threatened species. Islands, particularly of the Caribbean and both the South Pacific and Indian Oceans, have a higher risk because of high levels of speciation, endemism and a greater number of species with small habitat ranges. Arctic North America, conversely, has many large-bodied mammals, particularly carnivorous mammals, with slow life histories and thus slow reproductive rates.

Urban sprawl is the leading cause of the loss of biological diversity in the United States[3] and severely threatens other areas of the world. In island regions, development is especially dangerous because of higher effects on endemic species with small ranges. Sprawl also threatens all areas of high latent extinction risk because hotspots are usually relatively undisturbed regions with highly sensitive species. Other biological and life history attributes which make a species more susceptible to extinction are high habitat specificity, diet, fecundity, metabolic requirements, longevity, and phylogeny.[4][5]

[edit] References

  1. ^ a b Cardillo, M.; Mace, G. M.; Gittleman, J. L. & Purvis, A. (2006), “Latent extinction risk and the future battlegrounds of mammal conservation”, Proceedings of the National Academy of Sciences of the United States of America 103 (11): 4157-4161, DOI 10.1073/pnas.0510541103 .
  2. ^ Brooks, T. M.; Mittermeier, R. A.; de Fonseca, G. A. B.; Gerlach, J.; Hoffman, M.; Lamoreux, J. F.; Mittermeier, C. G.; Pilgrim, J. D.; et al. (2006), “Global Biodiversity Conservation Priorities”, Science 313 (5793): 58-61, DOI 10.1126/science.1127609 .
  3. ^ Baldwin, R. F.; Ray, J. C.; Trombulak, S. C. & Woolmer, G. (2006), “Relationship between spatial distribution of urban sprawl and species imperilment: response to Brown and Laband”, Conservation Biology 21 (2): 546-548, DOI 10.1111/j.1523-1739.2007.00664.x .
  4. ^ Cardillo, M.; Mace, G. M.; Jones, K. E.; Bielby, J.; Bininda-Emonds, O. R. P.; Sechrest, W.; Orme, C. D. L. & Purvis, A. (2005), “Multiple causes of high extinction risk in large mammal species”, Science 309 (5738): 1239-1241, DOI 10.1126/science.1116030 .
  5. ^ McKenzie, N. L.; Burbidge, A. A.; Baynes, A.; Brereton, R. N.; Dickman, C. R.; Gordon, G.; Gibson, L. A.; Menkhorst, P. W.; et al. (2007), “Analysis of factors implicated in the recent decline of Australia's mammal fauna”, Journal of Biogeography 34 (4): 597-611, DOI 10.1111/j.1365-2699.2006.01639.x .