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Uncertainty in Population Estimates for Endangered Animals and Improving the Recovery Process.

Haines AM, Zak M, Hammond K, Scott JM, Goble DD, Rachlow JL - Animals (Basel) (2013)

Bottom Line: United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery.Also, bird and mammal recovery plans reported more estimates of population size and uncertainty compared to reptiles and amphibians.We suggest the use of calculating minimum detectable differences to improve confidence when delisting endangered animals and we identified incentives for individuals to get involved in recovery planning to improve access to quantitative data.

View Article: PubMed Central - PubMed

Affiliation: Applied Conservation Lab, Department of Biology, Millersville University, Millersville, PA 17551, USA. Aaron.Haines@millersville.edu.

ABSTRACT
United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery. The objective of our study was to evaluate whether recovery plans provide uncertainty (e.g., variance) with estimates of population size. We reviewed all finalized recovery plans for listed terrestrial vertebrate species to record the following data: (1) if a current population size was given, (2) if a measure of uncertainty or variance was associated with current estimates of population size and (3) if population size was stipulated for recovery. We found that 59% of completed recovery plans specified a current population size, 14.5% specified a variance for the current population size estimate and 43% specified population size as a recovery criterion. More recent recovery plans reported more estimates of current population size, uncertainty and population size as a recovery criterion. Also, bird and mammal recovery plans reported more estimates of population size and uncertainty compared to reptiles and amphibians. We suggest the use of calculating minimum detectable differences to improve confidence when delisting endangered animals and we identified incentives for individuals to get involved in recovery planning to improve access to quantitative data.

No MeSH data available.


Comparison in the percentage of terrestrial vertebrate recovery plans that provide a current population and provide an estimate of uncertainty (e.g., variance) for the current population size estimate by animal Class taxa.
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animals-03-00745-f002: Comparison in the percentage of terrestrial vertebrate recovery plans that provide a current population and provide an estimate of uncertainty (e.g., variance) for the current population size estimate by animal Class taxa.

Mentions: The percentage of recovery plans that provide a current population size did not differ significantly by decade (χ2 = 2.10, p-value = 0.55), but the percentage of recovery plans that provided uncertainty or an estimate of variance for the current population size did (χ2 = 16.04, p-value = 0.001) with the 2000s and 2010s reporting more variance (Figure 1). The percentage of recovery plans that provide a current population size was significantly different between terrestrial vertebrate Classes (χ2 = 9.57, p-value = 0.02), and the percentage of recovery plans that provided uncertainty or an estimate of variance for the current population size also differed between animal Classes (χ2 = 37.80, p-value < 0.01) (Figure 2). More recovery plans for the taxa Class Aves and Mammalia reported more estimates of current population size and variance for population size in comparison to Reptilia and Amphibia (Figure 2).


Uncertainty in Population Estimates for Endangered Animals and Improving the Recovery Process.

Haines AM, Zak M, Hammond K, Scott JM, Goble DD, Rachlow JL - Animals (Basel) (2013)

Comparison in the percentage of terrestrial vertebrate recovery plans that provide a current population and provide an estimate of uncertainty (e.g., variance) for the current population size estimate by animal Class taxa.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494452&req=5

animals-03-00745-f002: Comparison in the percentage of terrestrial vertebrate recovery plans that provide a current population and provide an estimate of uncertainty (e.g., variance) for the current population size estimate by animal Class taxa.
Mentions: The percentage of recovery plans that provide a current population size did not differ significantly by decade (χ2 = 2.10, p-value = 0.55), but the percentage of recovery plans that provided uncertainty or an estimate of variance for the current population size did (χ2 = 16.04, p-value = 0.001) with the 2000s and 2010s reporting more variance (Figure 1). The percentage of recovery plans that provide a current population size was significantly different between terrestrial vertebrate Classes (χ2 = 9.57, p-value = 0.02), and the percentage of recovery plans that provided uncertainty or an estimate of variance for the current population size also differed between animal Classes (χ2 = 37.80, p-value < 0.01) (Figure 2). More recovery plans for the taxa Class Aves and Mammalia reported more estimates of current population size and variance for population size in comparison to Reptilia and Amphibia (Figure 2).

Bottom Line: United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery.Also, bird and mammal recovery plans reported more estimates of population size and uncertainty compared to reptiles and amphibians.We suggest the use of calculating minimum detectable differences to improve confidence when delisting endangered animals and we identified incentives for individuals to get involved in recovery planning to improve access to quantitative data.

View Article: PubMed Central - PubMed

Affiliation: Applied Conservation Lab, Department of Biology, Millersville University, Millersville, PA 17551, USA. Aaron.Haines@millersville.edu.

ABSTRACT
United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery. The objective of our study was to evaluate whether recovery plans provide uncertainty (e.g., variance) with estimates of population size. We reviewed all finalized recovery plans for listed terrestrial vertebrate species to record the following data: (1) if a current population size was given, (2) if a measure of uncertainty or variance was associated with current estimates of population size and (3) if population size was stipulated for recovery. We found that 59% of completed recovery plans specified a current population size, 14.5% specified a variance for the current population size estimate and 43% specified population size as a recovery criterion. More recent recovery plans reported more estimates of current population size, uncertainty and population size as a recovery criterion. Also, bird and mammal recovery plans reported more estimates of population size and uncertainty compared to reptiles and amphibians. We suggest the use of calculating minimum detectable differences to improve confidence when delisting endangered animals and we identified incentives for individuals to get involved in recovery planning to improve access to quantitative data.

No MeSH data available.