Linking agricultural practices to lizard trophic behaviour: An ecological approach

Negative effects on the adaptive strategies of the lizards (Eremias argus) under starvation after exposure to Glufosinate-ammonium

Herbicide exposure poses a higher risk to reptiles due to their frequent contact with soil. Besides, food restriction is also a common environmental pressure that can seriously affect the survival of reptiles. The adaptive strategies of reptiles in the face of emerging herbicide pollution and food shortage challenges are not yet known. Therefore, Eremias Argus (a kind of small reptile) was selected as the model to simulate the real scenario of food shortage in lizards, aiming to explore the comprehensive impact of glufosinate-ammonium (GLA: an emerging herbicide) and food restriction on lizards. The results revealed that lizards often regulate their physiological and biochemical activities through body thermal selection and tend to choose lower body temperature, reduce digestibility, and actively participate in fat energy mobilization to avoid oxidative damage in the state of hunger, finally in order to achieve homeostasis. However, herbicide GLA disrupted the lizards' efforts to resist the stress of food shortage and interfered with the normal thermoregulation and energy mobilization strategies of lizards facing starvation. The results of this study would improve our understanding of the impacts of Lizards under extreme stresses, help supplement reptile toxicology data and provide scientific basis for the risk assessment of herbicide GLA.

Could Exposure to Glyphosate Pose a Risk to the Survival of Wild Animals? A Case Study on the Field Lizard Podarcis siculus

Soil contaminants (herbicides, pesticides, and heavy metals) are among the main causes of change in terrestrial ecosystems. These substances lead to a general loss of biodiversity, both of flora and fauna and being able to biomagnify and pass through the food chain, they can endanger the survival of terrestrial vertebrates at the top of this chain. This review analyzes the risks associated with exposure to glyphosate, the active principle of many herbicide products, for the reproductive health of the field lizard (Podarcis siculus) potentially exposed to the substance in its natural habitat; therefore, introducing it as a possible model organism. Data demonstrate that glyphosate is toxic for this animal, affecting the health of the reproductive organs, both in males and females, and of the liver, the main detoxifying organ and closely involved in the female reproductive process. Sharing structural and functional characteristics of these organs with many other vertebrates, the information obtained with this reptile represents a wake-up call to consider when analyzing the cost/benefit ratio of glyphosate-based substances. The data clearly demonstrate that the P. siculus lizard can be considered a good target organism to study the reproductive risk assessment and hazards of exposure to soil contaminants on wild terrestrial vertebrates.

Processes involved in biochemical response to pesticides by lizard Podarcis siculus (Rafinesque-Schmaltz, 1810) – A field study

Although reptiles are non-target organisms of pesticide applications, their ecological niche and trophic role suggest that the use of these compounds in agriculture can have toxicological effects on them. Our recent field study on Italian wall lizard Podarcis siculus in hazelnut orchards evidenced that the use of pesticides-mixtures, consisting of thiophanate-methyl (TM), tebuconazole (TEB), deltamethrin (DM), lambda-cyhalothrin (LCT), besides copper sulphate, induced an increase of the total antioxidant capacity toward hydroxyl radicals and caused DNA damage; however, it did not cause neurotoxicity, and did not induce the glutathione-S-transferases' activities. These results raised some questions which were answered in this study by carrying out analyses on 4 biomarkers and 5 chemical substances in the tissues of non-target organisms coming from treated fields: cytochrome P450, catalase, total glutathione, and malondialdehyde, TM, TEB, DM, LCT and Cu. Our results highlighted a partial accumulation of different chemicals, the involvement of two important mechanisms of defence, and some cellular damages after exposure to the considered pesticides. In details, 1) LCT and DM were not accumulated in lizard muscle, copper remained at basal levels, whereas TM and TEB were uptaken with a partial metabolization of TM; 2) the cytochrome P450 and the catalase were involved in lizard biochemical responses to pesticides-mixtures used for "conventional" farming treatment; 3) "conventional" treatment with pesticides caused damage to lipids, besides DNA, probably related to the excess of hydroxyl radicals.