Population density of the spur-thighed tortoise Testudo graeca declines after fire in north-western Africa

PLoS One. 2019 Aug 16;14(8):e0220969. doi: 10.1371/journal.pone.0220969. eCollection 2019.

Abstract

Fire is a key ecological process in several biomes worldwide. Over recent decades, human activities (e.g. rural abandonment, monoculture plantations) and global warming are magnifying the risk of fire, with changes in fire intensity and frequency. Here, we offer the first study that examines the impact of fire on the spur-thighed tortoise Testudo graeca living in a native cork oak forest and pine plantation in north-western Africa. A total of 44 transects (22 burnt and 22 unburnt) were sampled at 8 sites affected by fires of natural cork oak forest and pine plantation with 8 surveys per site in 2015-2017 (264 hours of sampling effort). Tortoise densities were estimated with line-transect distance sampling. The detection probability of tortoises was higher in burnt (0.915) than unburnt (0.474) transects. The density of tortoises was negatively associated with elevation and declined with fire by c. 50% in both forest types. The negative response of T. graeca to fire should be considered in conservation planning of this species in north-western Africa in a future scenario of changes in fire regime.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Africa, Northern
  • Africa, Western
  • Animals
  • Conservation of Natural Resources*
  • Ecological Parameter Monitoring / statistics & numerical data
  • Ecological Parameter Monitoring / trends*
  • Fires*
  • Forests*
  • Pinus
  • Population Density
  • Quercus
  • Turtles*

Grants and funding

BC, SF, and XS received a grant coded (2015-1) from Instituto de Estudios Ceutíes (https://www.ieceuties.org) to cover part of the fieldwork. The work of EG and RCRC was supported by the Spanish Ministry of Economy, Industry and Competitiveness and European Regional Development Fund (Project CGL2015- 64144; MINECO/FEDER). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. There was no additional external funding received for this study.