Bushes protect tortoises from lethal overheating in arid areas of Morocco

Abstract

Arid Mediterranean regions that shelter unique biodiversity are threatened by increasing anthropogenic pressures, such as urbanization, overgrazing and climate change. In Morocco, one of the main bush species in arid areas, the jujube (Ziziphus lotus), suffers from officially promoted programmes of removal. The Moorish tortoise (Testudo graeca soussensis) is threatened by such habitat loss. Like most animals, the Moorish tortoise must navigate between microhabitats to find essential feeding resources and thermal refuges. This study combined radio-tracking of free-ranging individuals, microhabitat temperature monitoring and transects in a range of habitats. Tortoises were found to depend on the occurrence of large and relatively abundant bushes to escape lethal overheating. Thus, (1) current official encouragements for the destruction of the jujube bushes should be reappraised; (2) habitat restoration relying on replanting jujube bush should be encouraged; and (3) large-scale monitoring of critical bush densities should be used to better organize conservation plans (protection and/or restoration of areas) for the Moorish tortoise.

Precipitation quantity and timing affect native plant production and growth of a key herbivore, the desert tortoise, in the Mojave Desert

“…Lowered activity can benefit aridadapted species by reducing evaporative water loss and other metabolic expenditures when water is scarce [57,58]. Although species such as the desert tortoise can escape some thermal or metabolic challenges created by water scarcity by retreating into burrows, not all arid tortoise species burrow and many species face substantial challenges in metabolic maintenance as habitat is degraded and temperatures increase [59,60]. Reduced activity in juvenile tortoises in the present study also resulted in fewer foraging and basking behaviors even when green plants were available.…”

Shelter availability, stress level, and digestive performances in the aspic viper

“…The temperature of the shelter and the surface body temperature of the snakes were measured from a distance (20-30cm) using a three-dot infrared laser thermometer (Raytek MX2, Fotronic Corporation, Melrose, MA, USA; measurement diameter 19mm, range -30 to 900°C, precision ±1°C, 250ms per reading; see supplementary material Fig.S1). Surface and internal body temperatures are highly correlated in reptiles (Lagarde et al, 2012). The front of the cages was transparent; hence the observer and the snakes could see each other.…”

“…In most animals, individuals spend a considerable amount of time in refuges, and shelter availability is often essential for the persistence of populations (Wright and Shapiro, 1990;Griffiths, 2001, Souter et al, 2004;Bonnet et al, 2009;Grillet et al, 2010;Lagarde et al, 2012). Shelters provide protection against predators and buffer environmental conditions (Anderson, 1986;Schwarzkopf and Alford, 1996;Sih, 1997;Roper et al, 2001;Berryman and Hawkins, 2006).…”

“…However, previous investigations focused on constraining temperature conditions, i.e. hibernation, aestivation or sun-scorching periods (Seebacher and Alford, 2002;Beck and Jennings, 2003;Lagarde et al, 2002;Lagarde et al, 2012;Cooper and Withers, 2005). Yet many animals intensively use their refuges for reasons other than to escape severe climatic conditions: for instance to sleep, for reproduction or for digestion (Siegel, 2005;Pike et al, 2010;Pike et al, 2011).…”

Home Range of the Spur-Thighed Tortoise, Testudo graeca (Testudines, Testudinidae), in the National Park of El Kala, Algeria

“…2002;Ben Kaddour et al, 2005;Rouag et al, 2007). However, Testudo graeca habitat and activity patterns have been few studied in northern Africa (Lagarde et al, 2008;Lagarde et al, 2012). So, the aim of this work is to study the modes of exploitation of the habitat by the species in a dune maquis in the National Park of El Kala.…”