The Significance of African Lions for the Financial Viability of Trophy Hunting and the Maintenance of Wild Land

Recent studies indicate that trophy hunting is impacting negatively on some lion populations, notably in Tanzania. In 2004 there was a proposal to list lions on CITES Appendix I and in 2011 animal-welfare groups petitioned the United States government to list lions as endangered under their Endangered Species Act. Such listings would likely curtail the trophy hunting of lions by limiting the import of lion trophies. Concurrent efforts are underway to encourage the European Union to ban lion trophy imports. We assessed the significance of lions to the financial viability of trophy hunting across five countries to help determine the financial impact and advisability of the proposed trade restrictions. Lion hunts attract the highest mean prices (US$24,000–US$71,000) of all trophy species. Lions generate 5–17% of gross trophy hunting income on national levels, the proportional significance highest in Mozambique, Tanzania, and Zambia. If lion hunting was effectively precluded, trophy hunting could potentially become financially unviable across at least 59,538 km2 that could result in a concomitant loss of habitat. However, the loss of lion hunting could have other potentially broader negative impacts including reduction of competitiveness of wildlife-based land uses relative to ecologically unfavourable alternatives. Restrictions on lion hunting may also reduce tolerance for the species among communities where local people benefit from trophy hunting, and may reduce funds available for anti-poaching. If lion off-takes were reduced to recommended maximums (0.5/1000 km2), the loss of viability and reduction in profitability would be much lower than if lion hunting was stopped altogether (7,005 km2). We recommend that interventions focus on reducing off-takes to sustainable levels, implementing age-based regulations and improving governance of trophy hunting. Such measures could ensure sustainability, while retaining incentives for the conservation of lions and their habitat from hunting

Correction: Age estimation of African lions Panthera leo by ratio of tooth areas (PLoS One (2016) 11:4 (e0153648) DOI: 10.1371/journal.pone.0153648)

[This corrects the article DOI: 10.1371/journal.pone.0153648.]

Prediction of the digestibility of the diet of horses: Evaluation of faecal indices

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Age Estimation of African Lions <i>Panthera leo</i> by Ratio of Tooth Areas

<div><p>Improved age estimation of African lions <i>Panthera leo</i> is needed to address a number of pressing conservation issues. Here we present a formula for estimating lion age to within six months of known age based on measuring the extent of pulp closure from X-rays, or Ratio Of tooth AReas (ROAR). Derived from measurements taken from lions aged 3–13 years for which exact ages were known, the formula explains 92% of the total variance. The method of calculating the pulp/tooth area ratio, which has been used extensively in forensic science, is novel in the study of lion aging. As a quantifiable measure, ROAR offers improved lion age estimates for population modeling and investigations of age-related mortality, and may assist national and international wildlife authorities in judging compliance with regulatory measures involving age.</p></div

Plots of Residuals.

<p>Plots of residuals against known ages (left, a) and of known against estimated ages (right, b) using regression model.</p

ANCOVA Analysis.

<p>ANCOVA Analysis.</p

Peri-apical X-ray of African Lion PM².

<p>X-ray showing outline of total tooth and pulp areas for calculating area ratio using Adobe Photoshop after Cameriere et al. (2011) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153648#pone.0153648.ref033" target="_blank">33</a>]. Full details of the outlining and area measuring method are provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153648#pone.0153648.s001" target="_blank">S1 Text</a>.</p

Relationship between Age and ROAR.

<p>Plot of the dataset used in the regression process to estimate age as function of ROAR, along with regression line.</p