Showing posts with label herpetofauna. Show all posts
Showing posts with label herpetofauna. Show all posts

Friday, October 21, 2011

Some Ideas Are Better Than Others


Some ideas are better than others, and establishing a method that allows citizens to report information on the presence of amphibians and reptiles on-line is an excellent one. These types of websites have an obvious value for conservation efforts, but they also increase awarness, educate the public and stimulate interest. The Carolina Herp Atlas (CHA) project developed by the Davidson College Herpetology Laboratory and Davidson College Information Technology Services is aimed at providing detailed data on the distribution of reptiles and amphibians of North and South Carolina. The resulting database can be used by registered users to record personal observations and herp enthusiasts, ametur naturalists, and scientists to study county level distribution maps, photographs, and data on activity periods, habitat relationships, current distributions and other aspects of amphibian and reptile ecology in North and South Carolina. In the 29 month period between 1 March 2007 to 22 September 2009, almost 700 users were registered and received the database received 15,626 amphibian and reptile occurrence records.Distribution data for 32 frog, 51 salamander, 38 snake, 12 lizard, 16 turtle species, and the American Alligator were collected, with  snakes (5,349 records) being the most frequently reported. For conservationsits and scientists obating this data by themselves would be time consuming and expensive. If you have not yet visted this website, take a few minutes to explore it. An on-line article about the site by Price and Dorcas discusses the development and advantages of the database.

Monday, July 11, 2011

The Herpetofauna of Trinidad and Tobago Website

The website Herpetofauna of Trinidad and Tobago and associated blog are now functional. However, the website is a work in progress and needs photos and text. If you can help with that please contact us. JCM

Monday, November 29, 2010

Keeping Some of the Pieces, The Importance of Shade in Cacao Plantations


Cacao and coffee are shade crops that provide habitat for plants and animals dependent upon tropical forest. Unlike corn, they enhance biodiversity in agricultural landscapes locally but they may also have a more global role when they are cultivated in regions of high endemism suffering heavy deforestation. Sulawesi is one of those places that still conceals many undescribed species, but like many other places the forests are being logged and converted into human landscapes. Deforestation and subsequent land-use changes are rampant in the tropics and will eventually force the species that survive the upheaval to use altered habitats such as agro-ecosystems and urban areas that tend to be warmer, drier, brighter and less structurally complex than natural forests.
Southeast Asian amphibians and reptiles are among the most poorly studied and the most threatened vertebrates  (estimated at 30% and 31%, respectively based on IUCN 2008 data). Tropical amphibians and reptiles are highly sensitive to habitat modifications and climate change, making mitigating the effects of land-use change on herpetological diversity in Southeast Asia a conservation priority. Wanger et al. (2010) studied a land-use modification gradient ranging from primary forest, secondary forest, natural-shade cacao agro-forest, planted-shade cacao agro-forest, to open areas in central Sulawesi, Indonesia. They determined species richness, abundance, turnover, and community composition in all habitat types and related these to environmental correlates, including canopy cover and thickness of leaf litter. Human disturbances create environments that favor some species over others. Lizards and snakes for example, thermoregulate by basking in open patches of sun and it may be better to have several (or many) small openings in the canopy than just one large open patch. Therefore, many small openings in the canopy may be a better predictor for species richness and abundance of lizards. Frogs, on the other hand avoid direct exposure to the sun and a closed canopy may be a predictor of their diversity and abundance. Wanger and colleagues used Bayesian model selection to identify the best environmental predictors for amphibian and reptile species richness and abundance, including the lacunarity index (a measure of the degree of gaps) to measure canopy heterogeneity. Their results show that amphibians in Sulawesi were more negatively impacted by land-use changes than reptiles. Amphibian species richness and abundance declined as disturbance increased from pristine forest to open areas, while reptile species richness peaked in natural-shade cacao agro-forest between mildly (secondary forest) and strongly (planted-shade cacao agro-forest) disturbed habitats. Studies done in the Neotropics produced similar responses of amphibians and reptiles to disturbance in humid forests.  Thus conserving species of amphibians and reptiles in tropical environments may be best done long-term by allowing shade trees to rejuvenation on cacao plantations and allowing leaf litter to accumulate.

Literature
Wanger, T. C.,  D. T. Iskandar, I. Motzke, B. W. Brook, N. S. Sodhi, Y. Clough and T. Tscharntke. 2010. Effects of Land-Use Change on Community Composition of Tropical Amphibians and Reptiles in Sulawesi, Indonesia. Conservation Biology 24: 795–802.