Python brongersmai

Abstract: The anthropogenic introduction of alien species is one of the main causes of biota homogenization worldwide. Part of these introductions provokes biological invasions, which cause serious ecological and economic impacts from local to global scales. In order to prevent this and give proper management to exotic species, it is necessary to use predictive tools to prioritize sites with a higher probability of their establishment, thus preventing impacts in local ecosystems and communities. Here, we used ecological niche and interaction models to estimate the invasive potential of four species of exotic snakes identified as high risk and currently sold as pets in Mexico (Python brongersmai, P. molurus, P. regius, and Malayopython reticulatus), and simulate their impact as top predators (according to the average length of the prey that each snake species consumes) of species of native terrestrial vertebrates to this country. Results indicate that all four exotic snake species could generate severe impact on the community of native vertebrates within the country, while P. molurus could get to cause the largest impact given that it would get to interact and potentially consume a greater number of species. The organisms that would be mostly preyed by these snakes would be birds, followed by mammals, reptiles and finally amphibians. This pattern results from a combination of factors including prey body size preferences for predation in the exotic snakes’ native ranges, and the amplitude of the potential distribution areas and the number of species from each vertebrate group in Mexico. This paper shows the utility of combining methodological approaches for risk prevention and risk analysis for invasive alien species.

Abstract: Context Each year, millions of reptile skins are commercially exported from Southeast Asia for exotic leathers. Quotas are commonly used to regulate this trade, but quotas are sometimes exceeded and do little to ensure harvest sustainability. Aims To explore the relationship between the size of live pythons and their skins, and to assess whether skin measurements can be used to enforce the application of limits on the size of harvested snakes. Methods We measured the body size of three heavily harvested python species (Malayopython reticulatus, Python breitensteini and Python brongersmai) in Indonesia and Malaysia and examined the relationship with skin length, skin width, the size of the ventral scale and its adjacent dorsal scale. Key results Measurements of 2261 pythons showed strong relationships between the size of live pythons and measurements made on their skins. Skins can be stretched 30% longer than the body length of snakes from which they came and inter-facility and country differences in stretching technique result in different relationships between the sizes of live snakes and the measurements made on their skins. Male and female Malayopython reticulatus differed in their skin dimensions relative to the size of the live snake, but these differences were minor. Conclusions Despite variations in stretching techniques, in functional terms, this variation is minor (maximum 3.5% relative to each mean measurement) and does not limit application of skin sizes for regulating trade within an acceptable level of error. However, differences in the stretched length of Indonesian and Malaysian skins were much greater (5.9% of the mean length of skins), and, thus, each country should apply its own limits and predictive tools. Implications The strong relationship between the skin size and the size of the live snake offers great potential for regulating trade by using skin-size limits. Inspection of the size of skins can be used to enforce harvest-size limits and focus harvesting away from sexes and life stages most critical for population persistence. This management tool has numerous advantages over current regulatory practices (quotas) and should be considered for management of trade in Asian reptile skins.

Abstract: Blood python (Python brongersmai Stull, 1938) is one of heavily exploited wildlife in Indonesia. The high demands on its skin trade have made its harvesting regulated under quota-based setting by the government to prevent over-harvesting. To gain understanding on the sustainability of P. brongersmai in the wild, biological characters of wild-caught specimens were studied. Samples were collected from two slaughterhouses from Rantau Prapat and Langkat. Parameters measured were morphological (Snout-vent length (SVL), body mass, abdomen width) and anatomical characters (Fat classes). Total samples of P. brongersmai in this research were 541 with 269 male and 272 female snakes. Female snakes had the highest proportion of individuals with the best quality of abdominal fat reserves (Class 3). Linear models are built and tested for its significance in relation between fat classes as anatomical characters and morphological characters. All tested morphological characters were significant in female snakes. By using linear equation models, we generate size limit to prioritize harvesting in the future. We suggest the use of SVL and stomach width ranging between 139,7 – 141,5 cm and 24,72 – 25,71 cm respectively to achieve sustainability of P. brongersmai in the wild.