Mediterranean hatchling lizards grow faster at higher altitude: a reciprocal transplant experiment

Abstract

Summary 1.In reptiles, growth is subject to proximate environmental influences, such as food availability and temperature, that may be crucial during the early stages of postnatal development. Mediterranean regions, with their severe summer drought, offer an excellent opportunity to examine the effects of environmental variations in precipitation and productivity on the timing of reproduction and growth rates of lizards. 2. In this study, we compared the incubation time, size at hatching, growth rates and changes in juvenile body condition of two nearby populations of the lizard Psammodromus algirus separated by 600-700 m altitude in central Spain. We combined a reciprocal incubation experiment at 27 and 30 ° C with a reciprocal transplant experiment to distinguish between environmental and population-specific sources of geographical variation. 3. At both temperatures, eggs from the high-elevation site hatched sooner. Several important phenotypic traits of juveniles were primarily determined by the growing environment: the high-elevation site provided more food and allowed hatchlings to grow faster and reach larger size. 4. Environmental effects overrode familial ones, as shown by the larger growth rate of half-sibs released at the high-elevation site. However, both the size and the growth rate of juveniles were also influenced by their mother's site of origin, which means that population differences may reflect a genetic differentiation and/or different maternal effects. 5. Low precipitation and associated food scarcity were seemingly the main factors constraining the growth rates of juveniles at the lowland site.

European rabbits as ecosystem engineers: warrens increase lizard density and diversity

“…In dehesas, open pastures often harbour the highest prey abundances (Martín and Salvador 1995), whilst in disturbed and intensively grazed areas such as rabbit warrens one may expect to find lower abundances (Kruess and Tscharntke 2002). However, mean arthropod abundances in this study (0.96 ± 0.12 arthropods per minute of search) were within the range recorded by Iraeta et al (2006) at a ''better'' (1.71 ± 0.23) versus a ''worse'' (0.62 ± 0.23) site for P. algirus. Data are comparable because these authors used the same insect census technique as in the present study.…”

Exploring plastic and genetic responses to temperature variation using copper butterflies

“…Fischer & Fiedler 2002b, Fischer et al 2004. Thus the lack of differentiation found here highlights the notion that associations between body size and environmental (temperature) variation are more complex than previously thought, and may range from positive to negative , Blanckenhorn & Demont 2004, Iraeta et al 2006, Cvetkoviç et al 2009). Such diverging patterns presumably result from interactions between temperature, generation time, voltinism and season length, all of which affect insect body size (Blanckenhorn 1997, Chown & Gaston 1999.…”

“…This is counterintuitive, as life-history theory generally predicts higher intrinsic growth rates at higher altitudes (or, more generally, in cooler environments), in order to compensate for seasonal time constraints and the overall lower temperatures (Abrams et al 1996, Bubliy & Loeschcke 2005, Iraeta et al 2006. The reason for the deviation from the expected pattern in the case of L. tityrus is a change in voltinism: while high-altitude populations are monovoltine, low-altitude ones are bivoltine (Tolman & Lewington 1998).…”

Latent effects of egg incubation temperature on growth in the lizard Anolis carolinensis

“…In many oviparous reptiles, incubation temperature has been shown to affect hatchling size and body proportions (Shine et al, '97;reviewed in Birchard, 2004;Deeming, 2004), growth rates (Van Damme et al, '92;Alberts et al, '97;Deeming, 2004), locomotor performance (Vanhooydonck et al, 2001;BlouinDemers et al, 2004;Deeming, 2004), and behaviors including thermoregulation (Burger, '98;Downes and Shine, '99;Flatt et al, 2001;Deeming, 2004). Although reaction norms may differ dramatically between populations (Niewiarowski and Roosenburg, '93;Iraeta et al, 2006), many studies of temperature-induced plasticity in reptiles focus on one population (reviewed in Deeming, 2004;however, see O'Steen, '98;Buckley et al, 2007). The current study examined temperature-induced plasticity in development and growth rates in several populations of the lizard Anolis carolinensis with similar life histories, but varying thermal environments.…”