Environmental drivers of growth rates in Guadarrama wall lizards: a reciprocal transplant experiment

Abstract

Growth rates have complex sources and may determine adult body size in organisms with indeterminate growth. Thus, the interpretation of interpopulation differences in body size along geographical gradients requires the examination of growth and to distinguish between the proximal and ultimate causes of it. Several studies support a link between growth rates and habitat production via climatic effects. Environmental constraints, such as food abundance, may be correlated with climatic conditions and could, in turn, limit growth rate because of limited energy availability. We performed a reciprocal transplant experiment to disentangle the effects of environmental and genetic factors on body size interpopulational divergence in the lizard Podarcis guadarramae along a 500-m elevation gradient with contrasting environmental conditions. Our results showed that the growing environment determined growth rates of juvenile lizards, independently of the population of origin. Hatchlings experiencing the high-altitude growing environment, which had colder and more humid climatic conditions, grew faster than those growing in the low-altitude environment. However, mother's site of origin did not affect growth. We conclude that the drivers of growth rate differences in P. guadarramae lizards are probably related to between-sites differences in water and food availability.

Countergradient Variation in Reptiles: Thermal Sensitivity of Developmental and Metabolic Rates Across Locally Adapted Populations

“…Adaptation of developmental physiological rates is an important, yet underutilized avenue of research for understanding population persistence under changing and novel environments. Countergradient variation for traits expressed later in the life history have been well documented in reptiles, including growth (Sears and Angilletta, 2003;Uller and Olsson, 2003;Li et al, 2011;Snover et al, 2015;Ortega et al, 2017), body size (Oufiero et al, 2011;Iraeta et al, 2013), scale size (Oufiero et al, 2011), preferred body temperature (Hodgson and Schwanz, 2019), nest date (Knapp et al, 2006;Edge et al, 2017), reproductive output (Knapp et al, 2006;Li et al, 2011;Fetters and McGlothlin, 2017), critical thermal limits and water loss (Kolbe et al, 2014) and locomotor performance (Niewiarowski, 2001;McElroy, 2014). It is possible that CnGV for traits observed later in life are also a consequence of developmental environment, such as food availability, temperature and stress (DuRant et al, 2013;Noble et al, 2018).…”

Age structure of a lizard along an elevational gradient reveals nonlinear lifespan patterns with altitude

“…2006 ; Ortega et al. 2015 , 2017 ). However, in spite of the harmful environmental conditions and the long activity time ( Zamora-Camacho et al.…”

Environmental suitability models predict population density, performance and body condition for microendemic salamanders

“…Alternative pathways that can explain the relationship between environmental suitability and local species abundance involve the variation of available resources. For instance, climatic or environmental variations can influence food availability, with cascading effects on the growth rate and fitness of individuals 19 – 21 . Such a relationship can be particularly important for animals with highly specialized diet.…”