Nora R. Ibargüengoytía

INSTITUTO DE BIODIVERSIDAD Y MEDIO AMBIENTE - UNIVERSIDAD DEL COMAHUE · LABORATORIO DE ECOFISIOLOGÍA E HISTORIA DE VIDA DE REPTILES

Explanations for differences in thermal biology within and between species of lizards employ concepts of phylogenetic inertia and plasticity. We compared the thermal biology of three liolaemid species in the Andean highlands in Argentina: two allopatric congeners (Phymaturus williamsi and P. aguanegra) each in syntopy with Liolaemus parvus. We pred...

Aim: Squamate fitness is affected by body temperature, which in turn is influenced by environmental temperatures and, in many species, by exposure to solar radiation. The biophysical drivers of body temperature have been widely studied, but we lack an integrative synthesis of actual body temperatures experienced in the field, and their relationship...

Ecophysiological plasticity determines, to a great extent, the geographic distribution and the vulnerability of ectotherms to climate change. We studied the relationship between locomotor performance and temperature of Liolaemus elongatus lizards in three populations in northern Patagonia, Argentina, differing in thermal characteristics. We related...

In temperate, polar and montane environments, ectotherms must find ways to endure throughout the coldest months of the year. Lizards search for microsites where temperatures remain warm or alter their biochemical balance to tolerate freezing or avoid it by supercooling. We evaluated the cold hardiness and potential winter refuges of two populations...

The rising temperature predicted is of main concern for ectotherms because its direct impact on their behavior and physiology. Since physiological performance mediates a species’ resilience to warming exposure, physiological plasticity could greatly reduce the susceptibility to climate change. We studied the degree to which Diplolaemus leopardinus’...

Barry Sinervo passed away on 15 March 2021 in Santa Cruz after battling cancer for six years. Barry was working until the very last day when he finished his last manuscript with his closest friend and collaborator Donald Miles. The herpetological community has lost an influential biologist who contributed with major works on evolutionary biology ,...

Given the rapid loss of biodiversity as consequence of climate change, greater knowledge of ecophysiological and natural history traits are crucial to determine which environmental factors induce stress and drive the decline of threatened species. Liolaemus montanezi (Liolaemidae), a xeric-adapted lizard occurring only in a small geographic range i...

Basking and retreat sites constitute a key resource in the habitat of any ectotherm. Identifying the elements that are used and modelling the microhabitat selection of species is crucial for assessing the impact of anthropogenic disturbances at the population level and, therefore, focusing on conservation efforts. We investigated how structural att...

Body temperature has relevant effects on the immune response. Here, we characterized the thermal biology and health condition of the viviparous lizard Liolaemus kingii from Patagonia (Argentina), by studying fild body temperatures, presence of injuries or ectoparasites, body condition (BC), and individual immune response capacity with the phytohema...

The diversity of habitats generated by the Andes uplift resulted a mosaic of heterogeneous environments in South America for species to evolve a variety of ecological and physiological specializations. Species in the lizard family Liolaemidae occupy a myriad of habitats in the Andes. Here we analyze the tempo and mode of evolution in the thermal bi...

The reproductive cycle of Galapagos giant tortoises has primarily been studied in captive individuals via noninvasive methodologies, including hormonal studies, radiographs, and ultrasound. During the annual reproductive cycle, mating peaks occur during the hot season months (December–June), followed by nesting during the cool season (June–December...

Lizard activity and endurance of cold climate is regulated by several factors such as evolutionary potential, acclimatization capacity, physiological tolerance, and locomotion among thermally advantageous microenvironments. Liolaemus lineomaculatus, a lizard inhabiting a wide range of cold environments in Patagonia, provides an excellent model to t...

Understanding how human beings perceive and interact with the local herpetofauna is fundamental for its conservation. In this chapter, we propose looking forward to the local ecological knowledge (LEK) of the Patagonian lizards, especially the “matuasto”. The preliminary analysis of ethnohistorical sources points out the relevant role of “matuastos...

In this chapter, we provide a detailed and integrated review of the reproductive biology and life-history traits related to reproduction of lizards that inhabit the cold and harsh environments of Patagonia, Argentina. Lizards of the genera Liolaemus, Phymaturus, and Homonota have shown distinctive life-history traits, such as the retention of eggs...

The extent of stress caused by acute and chronic environmental disturbances depends on the adaptive ability of organisms to behaviorally and physiologically adjust to change and on the timing and magnitude of the disturbances. This resilience is a result of numerous exposures to perturbations throughout the evolution of the species. In Patagonia, v...

Behavioral and physiological traits of ectotherms are especially sensitive to fluctuations of environmental temperature. In particular, niche‐specialist lizards are dependent on their physiological plasticity to adjust to changing environmental conditions. Lizards of the genus Phymaturus are viviparous, mainly herbivorous, and inhabit only rock pro...

In ectotherms, the likelihood of surviving an infection is determined by the efficiency of thermoregulation, the availability of a variety of thermal microenvironments, the individual's health status, and the virulence of the infective agent. Physiological and behavioral demands related to an efficient immune response entail a series of costs that...

In ectotherms, temperature exerts a strong influence on the performance of physiological and ecological traits. One approach to understand the impact of rising temperatures on animals and their ability to cope with climate change is to quantify variation in thermal-sensitive traits. Here, we examined the thermal biology, the temperature dependence...

The immune state is an essential component of survival as it directly influences physiological performance and health status. Variation in the leukocyte profile, a significantly increase in body temperature, and a detriment of the eco-physiological performance are among the possible consequences of an unhealthy state. In this study we analyse and d...

Temperature has a significant influence on physiology, ecology, and life history of ectotherms. Despite environmental fluctuations, lizards have developed behavioral mechanisms to maintain a relatively constant body temperature. These behaviors are particularly important for lizards living at high elevations like the high mountain lizard Phymaturus...

In environments where the temperature periodically drops below zero, it is remarkable that some lizards can survive. Behaviorally, lizards can find microsites for overwintering where temperatures do not drop as much as the air temperature. Physiologically, they can alter their biochemical balance to tolerate freezing or avoid it by supercooling. We...

In ectotherms, environmental temperature exerts a strong influence on multiple phenotypic aspects such as locomotion, metabolic rate/ energy balance, reproduction and growth. In particular, thermal sensitivity of metabolism is especially interesting due to its ecological relevance and direct effects on fitness. The aim of this work was to evaluate...

The effect of temperature on the distributions of ectothermic vertebrates is well documented. Despite the increase of 6°C expected in the next 60 years in South America, numerous vertebrates are still considered as “Least Concern” species by the IUCN due to their large distribution, insufficient widespread threats, and insignificant population decl...

Herein we studied the reproductive biology of a viviparous lizard (Mabuya dorsivittata) from the Wet Chaco region (northeastern Argentina) and compared the results with other populations from the Espinal (central Argentina) and the Atlantic Forest (southeastern Brazil), and with other Neotropical species of Mabuya to better understand the possible...

Climatic envelope models have predicted the extinction of populations, but few studies have provided accounts of responses of individual species to climate change. Herein, we report on the geographical and temporal variation of growth rates, age at sexual maturity and longevity of two populations of a South American lizard, Tropidurus torquatus. Th...

The lizard genus Phymaturus comprises two reciprocally monophyletic clades: Phymaturus palluma and Phymaturus patagonicus. Species belonging to the P. patagonicus clade occur in extra-Andean Patagonia, and some of them remain with unresolved phylogenetic relationships after studies based on morphological and nuclear and mitochondrial DNA (mtDNA) ev...

Ectotherms are especially vulnerable to climate change due to their dependence on environmental thermal conditions to obtain adequate body temperatures for physiological performance. An approach to predict the impact of global warming in ectotherms is quantifying their locomotor sensitivities to temperature across the thermal performance curves (TP...

Longevity and age at maturity are key life-history traits, directly linked to fitness attributes such as survival and reproductive output. It has been proposed that these traits are strongly influenced by environmental factors, such as temperature, seasonality, and precipitations, which determine the existence of a continuum of life-histories that...

Algunos reptiles desarrollan fiebre como respuesta inmunitaria innata para mejorar la capacidad del sistema inmune y combatir una infección, aunque esta pueda resultar en detrimento de las reservas energéticas debido al gasto metabólico. Los individuos infectados que presentan bajas reservas energéticas tienden a reducir su temperatura corporal (hi...

The lizard genus Phymaturus comprises two reciprocally monophyletic clades: Phymaturus palluma and Phymaturus patagonicus. Species belonging to the P. patagonicus clade occur in extra-Andean Patagonia, and some of them remain with unresolved phylogenetic relationships after studies based on morphological and nuclear and mitochondrial DNA (mtDNA) ev...

In the highlands of the Andes, lizards must balance precisely the allocation of energy for growth and reproduction to ensure their survival. We studied the individuals’ age, growth rates, age at sexual maturity, and maximum life span of the viviparous lizard Phymaturus antofagastensis, endemic of cold and harsh environments at high altitudes in the...

Integrative behavioral studies show that the interplay between individual physiology and social behavior influences the ecology of the species, ultimately affecting individual fitness. Particularly in lizards, color polymorphism is associated with differential behaviors and reproductive strategies, which are evident in mature males during the matin...

Climatic and ecological conditions can determine the existence and degree of parental care. In species that live in cold-temperate environments and exhibit high reproductive effort it is expected that parental care would have greater selective value. In this study, we aimed to detect maternal behavioural responses to predation threats in the lizard...

Two hypotheses have prevailed to explain the evolution of viviparity in reptiles: the first proposed that viviparity evolved in response to cold-climates because the possibility of pregnant females to thermoregulate at higher temperatures than embryos could experience in a nest in nature. The second hypothesis posits that the advantage of viviparit...

An increase in temperatures and frequency of drought events are predicted in the High Andes due to climate change. Species could respond with changes in its range, abundance and phenology. Here, we used a species distribution model to assess and predict the vulnerability to climate change of the endemic lizard Phymaturus palluma of the Andes. The m...

The best predictors of reproductive patterns are commonly associated with climate factors, but evolutionary history also plays an important role. The semifossorial and viviparous lizard Ophiodes intermedius from the Wet Chaco region of Argentina showed an annual cycle with asynchrony between males and females and an unusual pattern for subtropical...

Climate change and rising global temperatures pose a serious threat to biodiversity. We assessed the vulnerability to global warming of four genera of iguanian lizards whose distributions include a broad range of environments from the Peninsula of Yucatán to southern Patagonia. Original data on body temperatures (Tb), operative temperatures (Te, ‘n...

Reproductive and life history patterns in reptiles are tightly related to the environmental conditions, so male reproductive cycles have been historically characterized as continuous, for tropical lizards, or seasonal, for temperate lizards. However, males of Liolaemus and Phymaturus lizards (Liolaemidae), from cold-temperate climates of high altit...

Studies on reproductive modes, size at maturity, clutch size and clutch frequency have contributed greatly to our understanding of life history variation among lizard populations, and thereby, to implement conservation strategies. Herein, we studied the reproductive biology of the vulnerable tegu lizard Kentropyx viridistriga from Corrientes, north...

The vulnerability of populations and species to global warming depends not only on the environmental temperatures, but also on the behavioral and physiological abilities to respond to these changes. In this sense, the knowledge of an organism’s sensitivity to temperature variation is essential to predict potential responses to climate warming. In p...

The Puyehue-Cordón Caulle eruption of 4 June 2011 dispersed about 100 million tonnes of pyroclastic materials resulting in ash accumulations of 30 cm depth on the Patagonian steppe, an area occupied by several lizard species. Herein we analysed, by experimental trials, the effects of ash and slope on running performance of two endemic and vulnerabl...

Recently, Sinervo et al. (2010, Science, 328: 894–899) reported declines of lizard biodiversity due to local warming trends and altered thermal niches. Herein, we applied the Sinervo et al. (2010) physiological model to predict the local extinction risk of three species of lizard from Patagonia. Whereas the previous model used a single equation (fo...

For ectotherms like lizards, temperature plays a key role in shaping life history traits such as age and size at sexual maturity, longevity and growth. In cold, temperate habitats like Patagonia, balancing the energy expended to growth and reproduction is vital for persistence. In the present study, age and growth of the lizard Phymaturus spectabil...

Individuals devote energy intake to growth, maintenance and reproduction, so knowing the way in which they allocate this energy between competing demands is essential to understand their relationship with the environment. Phymaturus lizards, viviparous and mostly herbivorous, inhabit cold environments of the Andes highlands of Argentina and Chile,...

Lizards that live in the harsh climate of the Argentinean Patagonia (40°–53° S) are active for a period restricted to spring and summer when vitellogenesis, pregnancy and birth take place. Herein, we present data on the female reproductive cycle, body size at sexual maturity, litter size and fat-body cycle of one of the world's southernmost reptile...

For ectotherms, like lizards, the temperature plays a key role in shaping life history traits such as age and size at sexual maturity, longevity and growth rates. In cold temperate habitats, like Patagonia, lizards must present a very precise balance of the energy expended to growth and reproduction in order to persist in these harsh environments....

Herein, we describe the reproductive biology of Phymaturus spectabilis, a lizard species that inhabits rocky outcrops in cold and arid environments of the Patagonian steppe of Argentina. We studied male and female reproductive cycles, mean annual reproductive output, allometric changes during ontogeny, and sexual dimorphism, mainly with a non-invas...

Puyehue is a largely basaltic stratovolcano located in the southern volcanic zone of the Andes, with an irregular inter-occurrence intervals of eruption that affects the ecology of the native communities. The latest Puyehue eruption occurred in June 2011and dispersed about 100 M tons of pyroclastic materials to the Patagonia steppe of Argentina, du...

Herein we describe the reproductive biology of a population of the Amazon Lava Lizard (Tropidurus torquatus (Wied-Neuwied, 1820)) from Corrientes, northeastern Argentina (Wet Chaco). We describe the male and female reproductive cycles, minimum body size for adults, reproductive output, mean relative clutch mass, fat body cycles, and sexual dimorphi...

The genus Phymaturus, entirely viviparous and mostly herbivorous, inhabits the cold and harsh environments of the Andean highlands of Argentina and Chile, and the Patagonian steppe of Argentina. Phymaturus punae is a vulnerable lizard endemic to the Biosphere Reserve San Guillermo (National Park and Provincial Reserve) in San Juan (Argentina) that...

The locomotor performance of lizards depends on their morphological and physiological adaptations to the habitat. However, when the habitat changes dramatically, for example, by a volcanic eruption, the performance of lizards may be affected. We registered the vegetation cover, the surface covered by ash, the presence of crevices suitable for Phyma...

We used skeletochronology to assess the age structure, body size and sexual maturity in two populations of Liolaemus pictus argentinus from San Carlos de Bariloche, Argentina. The species occupies a wide altitudinal range within the Patagonian Lake District which enabled us to choose populations from two climatic extremes: 771 m a.s.l. and 1615-176...

Luego de la elaboración de la primera lista roja de la herpetofauna de la República Argentina, realizada en el año 2000, son numerosos los cambios y estudios efectuados en los diferentesgrupos de saurios de la Argentina. Si bien hay avances realizados en todas las ramas de la biología relacionadas a las lagartijas, los progresos taxonómicos y ecoló...

When an animal in the laboratory experiences a change in temperature, physiological processes are affected but they stabilize under the new temperature condition over a few weeks by a process of phenotypic plasticity called acclimation, but whether an organism can acclimate or not depends on the trait and the taxon. Liolaemus sarmientoi is one of t...

Recent studies predict that several lineages of tropical animals are at particular risk given current estimates of global climate change. Yet, much uncertainty exists on the effects of climate shifts in ectothermic species from cool temperate regions such as Patagonia. In this study, we focus on the impact of environmental temperature on growth, ag...

The trends of body temperatures in the field (Tb) and preferred body temperatures in the laboratory (Tpref) of the genus Liolaemus relative to reproductive mode, air temperature (Tair), precipitation, latitude, and elevation were studied using phylogenetic comparative analysis. Results were discussed in the framework of the evolution of thermal phy...

A new Phymaturus species called Phymaturus sinervoi, is described in the present study. The new species is a member of the "Phymaturus patagonicus" group from Patagonia. It lives at about 1100 m of altitude in a volcanic rocky habitat near to Cari Laufquen plateau, in the southern-central steppe of Rio Negro Province, Argentina. The new species and...

Phymaturus zapalensis inhabits harsh thermal environments in the steppe of Patagonia, Argentina, characterized by climate conditions that impose constraints on reproduction, providing an appealing model to study the role of steroid hormones in the regulation of seasonal reproductive events. Males of P. zapalensis exhibited a postnuptial spermatogen...

We determined the thermal biology of the oviparous Liolaemus boulengeri and the viviparous Liolaemus lineomaculatus populations localised at high and low latitude sites in Patagonia, Argentina. We present data of body temperatures in the field (Tb) and preferred temperature in the laboratory (Tpref), micro-environmental and operative temperatures a...

We studied the relationship between locomotor performance and temperature in Liolaemus pictus argentinus, from the Andean–Patagonian forest, Argentina. We determined the running speed in long and sprint runs at four different body temperatures, the panting threshold, and minimum critical temperature. The results are discussed in relation to body te...

Locomotor activity performance of reptiles is largely temperature dependent and, in harsh environments with short activity periods during the day and throughout the year, plays a vital role in the fitness of the species. This particular study focuses on the performance and the thermal sensitivity for running, at different body temperatures, of the...