Are geckos useful bioindicators of air pollution?

Metal contents in house geckos (Squamata: Gekkonidae) from industrial and urban areas of southern Tamaulipas, Mexico and western Andalucía, Spain, may reflect airborne metal pollution

House geckos share living quarters with humans in the tropical and subtropical regions inhabited by these reptiles. Gecko behavior, biological traits, continuous exposure to suspended particulate matter 0 µm in diameter (PM₁₀) and dust, as well as status as exotic species, motivated the choice of these species to examine environmental exposure to ambient air pollutants, in particular metals, and subsequent accumulation in these organisms. One part of the study was conducted in Tamaulipas (Mexico) where Hemydactylus frenatus is abundant in urban and industrial environments, the other part was conducted in Andalucia (Spain) where Tarentola mauritanica is found in similar environments. Adult geckos were collected on buildings in locations affected by various air pollution sources. For both species, higher metal contents were observed in whole-body (including digestive tracts) analysis and were markedly different between collection sites. Contents in tails, digestive tracts, and carcasses without digestive tracts were not correlated. Based on contamination factor values, bioaccumulation in H. frenatus tissues occurred for 12 of the 15 metals analyzed. Data suggest that H. frenatus might serve as a biomonitor for Cu, Ni, Pb, Cr, Li, and V, whereas T. mauritanica might be a biomonitor for Cu, Ni, Pb, and Cr. To our knowledge, metal contents for H. frenatus are reported here for the first time. House gecko data could be integrated into a highly representative monitoring system and health risk assessments related to air quality in residential areas.

Shooting skinks for good: Producing a movie improves attitudes towards a threatened species

The interaction between the Anthroposphere and the Biosphere has resulted in increasingly rapid biodiversity loss. This negative interaction is influenced by attitudes (feelings, actions, and perceptions) of humans towards certain species. Despite the importance of reptiles in food chains and ecosystem services, they are often negatively perceived, resulting in fear and persecution. In this scenario, Education for Sustainable Development (ESD) may contribute for students to develop positive attitudes towards nature and, in particular, towards reptile conservation. Some studies showed that watching wildlife movies improves attitudes of people towards wildlife. However, few information is available on the impact of engaging people in movie production in their attitudes on biodiversity. Here we present an exploratory case study and describe a project-based learning activity (PBL) implemented with Cabo Verdean high-school students and planned to improve their perceptions, feelings and actions towards reptiles in general, and the threatened endemic species C. vaillanti in particular. We asked students to write a script, shoot and produce a short film that could improve the attitudes of their community towards this endemic species. This movie was then presented to the community in a public event and subjected to a content analysis. To evaluate the impact of the activity on students, they were asked to fill in two questionnaires, before and after the activity. Our results showed significant increase of positive feelings of students about the reptiles, and increased perception of their importance, and of positive actions towards C. vaillanti from pre to post test. The movie content analyses and interviews showed that students learned about species biology, threats and reasons for its conservation, of which endemicity was the most frequently cited. Our findings support the value of engaging the public in PBL for EDS and the positive impacts of this engagement in public attitudes towards species conservation.

Phylogenetic analyses of distantly related clades of bent-toed geckos (genus Cyrtodactylus) reveal an unprecedented amount of cryptic diversity in northern and western Thailand

Cyrtodactylus species are the most diverse of the geckos and are widely distributed in Southeast Asia, including Thailand. However, their patterns of distribution, especially in northern and western parts of Thailand, remain unknown because few Cyrtodactylus species in these regions have been described. Thus, a data set of mitochondrial NADH dehydrogenase 2 (ND2) gene and flanking tRNAs from Cyrtodactylus found in northern and western Thailand, including contiguous areas, was assembled to elucidate phylogenetic relationships and identify the distribution patterns of these geckos. The results showed four well-supported clades, a northwestern clade (A), a northern clade (B), a western clade (C), and a special clade characterized by specific morphological features (D). Clades A-C were grouped with strong support by the geography of their localities from northern Thailand (Mae Hong Son and Chiang Mai Provinces) along the Tenasserim mountain ranges to Phang-Nga Province, Thailand. Clade D is a distinct clade of Cyrtodactylus species characterized by a tuberculate and prehensile tail and distributed widely in mainland Southeast Asia. Overall, the results suggest a pattern of geographic separation and distribution of Cyrtodactylus in northern and western Thailand. Additionally, this study provides evidence of a hidden biodiversity of Cyrtodactylus in these regions.

'Biohyets': a method for displaying the extent and severity of environmental impacts

Bioindicators are often more sensitive indicators of both biodiversity and environmental change than abiotic pollution parameters. The responses of selected plants and animals to anthropogenic insults can be used to assess environmental responses at a variety of spatial and temporal scales. This study maps the response of key reptile, mammal, bird and plant species to airborne contaminants around a large mine and mineral processing operation at Olympic Dam in arid Australia. The responses of different bioindicators should ideally be integrated in order to comprehend overall trends in biological integrity adjacent to pollution sources. Assimilation of different bioindicator responses allows greater precision and geographic coverage of the monitored region and reduces potential distortion from unrelated biological or monitoring responses of individual indicator groups. A single, integrated measure of ecosystem health that overlays the responses of otherwise incompatible datasets, is also of more value to industrial operators and environmental regulators than several disparate responses. Biohyets, which are the contours of bioindicator index values derived from multiple biotic measurements, are here used to map variability in ecosystem health and to identify regions, response variables and disturbance parameters for more rigorous analysis.