Assessing the extent and impacts of linear infrastructure on Sri Lanka's natural and protected areas: Implications for future development planning.

Linear infrastructure (LI) has varying effects on landscapes depending on different ecosystems' sensitivity and threat levels. Economically developing tropical countries are particularly at risk from LI. Therefore, understanding a country's current LI network and planning future developments to avoid further fragmentation and disturbance is crucial. This study aimed to assess the extent of Sri Lanka's LI network (i.e., roads, railroads, and powerlines), given that it is both a biodiversity hotspot and an economically developing country in the tropics. First, we calculated the average normalized difference vegetation index (NDVI) and normalized difference built-up index (NDBI) indices and examined their spatial autocorrelation per divisional secretariat division. Then a multivariate cluster analysis was used to determine clusters of natural and protected areas that may receive similar impacts from different LI and their combinations. Results indicated that roads are the most widespread LI type in Sri Lanka, followed by powerlines and railroads. Over 80% of Sri Lanka's total land area falls within 1 km of either a national or a provincial/local road. Areas with high NDVI were primarily manmade habitats, with less than 20% contribution from protected areas. Over 50% of the total protected area of Sri Lanka is being impacted by all three types of LI. Powerlines were the most common LI type in protected areas in proportion to their total network lengths. To minimize environmental impact while achieving development goals, future LI development activities should use a landscape approach to identify development needs and strategies informed by these findings.

Attitudes towards the Potential Use of Aversive Geofencing Devices to Manage Wild Elephant Movement.

Aversive geofencing devices (AGDs) or animal-borne satellite-linked shock collars might become a useful tool to mitigate human-elephant conflict (HEC). AGDs have the potential to condition problem elephants to avoid human-dominated landscapes by associating mild electric shocks with preceding audio warnings given as they approach virtual boundaries. We assessed the opinions of different stakeholders (experts, farmers, and others who have and have not experienced HEC; n = 611) on the potential use of AGDs on Asian elephants. Most respondents expressed positive opinions on the potential effectiveness of AGDs in managing elephant movement (62.2%). About 62.8% respondents also provided positive responses for the acceptability of AGDs if pilot studies with captive elephants have been successful in managing their movements. Some respondents perceived AGDs to be unacceptable because they are unethical or harmful and would be unsuccessful given wild elephants may respond differently to AGDs than captive elephants. Respondents identified acceptability, support and awareness of stakeholders, safety and wellbeing of elephants, logistical difficulties, durability and reliable functionality of AGDs, and uncertainties in elephants' responses to AGDs as potential challenges for implementing AGDs. These issues need attention when developing AGDs to increase support from stakeholders and to effectively reduce HEC incidents in the future.

Strategies of protected area use by Asian elephants in relation to motivational state and social affiliations.

Animals' space requirements may vary according to life-history and social considerations. We observed 516 wild adult Asian elephants from both sexes, over 9 years, to investigate how life-history traits and social behavior influence protected-area (PA) use at Udawalawe National Park, Sri Lanka. Male PA-use, quantified in terms of average between-sightings-interval (BSI), was significantly influenced by the interaction of age class and motivational state (i.e. reproduction vs. foraging). Musth lengthened with age, with a median of 24.5 days for ages 21-30, 32.5 days for ages 31-40, and 45 days for those > 40. A minority (11%) used it exclusively during musth, while others used it exclusively for foraging (44%) or both (45%). Males using it in both states and older musth-only males were more likely to be seen across years. There were 16 social communities containing between 2-22 adult females. Females' BSI was significantly influenced by social ties, but this relationship was weak, because members of social communities do not necessarily disperse together, resulting in high individual variation in space-use. Inter-annual variability in sightings among individuals of both sexes indicates that around ¾ of the population is likely non-residential across years, challenging the prevailing fortress-conservation paradigm of wildlife management.

Skull of the Asian (Paradoxurus Hermaphroditus) and the golden (Paradoxurus Zeylonensis) palm civet: Geometric morphometric analysis using palate, tooth and frontal landmarks.

This study aims to determine the differences in skull between Asian and golden palm civets by geometric morphometric method. The landmarks were marked on these photographs, and principal component, classical cluster and canonical variance analyses were performed. The method of geometric morphometry of the skull is a powerful tool used to differentiate the species. Fourteen and 20 homologous landmarks were marked using tpsutil and tpsdig2 programs on the frontal and palatinal directional photographs, respectively. As a result of the study, the first principal component (PC1) accounted for 33.586% on the frontal view, 41.602% on the palatinal view of the total shape differences, respectively. Distinctive differences on the frontal and palatinal view were observed in the caudal, rostrolateral and the last molars and the caudal palatine, respectively.

Characterization of Daboia russelii and Naja naja venom neutralizing ability of an undocumented indigenous medication in Sri Lanka.

BACKGROUND: Indigenous medicinal practice in Sri Lanka talks about powerful compounds extracted from native plants for treating venomous snake bites which are hardly documented in literature but are used by the indigenous doctors for thousand years. OBJECTIVE: We screened the neutralizing ability of a herbal preparation practiced in indigenous medicine of Sri Lanka, consisting of Sansevieria cylindrica, Jatropha podagrica and Citrus aurantiifolia, for its ability to neutralize venom toxins of Naja naja (Common Cobra) and Daboia russelii (Russell's viper). MATERIALS AND METHODS: The venom toxicity was evaluated using a 5-day old chicken embryo model observing the pathophysiology and the mortality for six hours, in the presence or absence of the herbal preparation. The known toxin families to exist in snake venom, such as Phospholipase A2, Snake venom Metalloprotease, were evaluated to understand the mechanism of venom neutralizing ability of the herbal preparation. RESULTS: The LD50 of D. russelii venom, as measured using the 5-day old chicken embryo model, was 4.8 ± 0.865 ug (R2 = 84.8%, P = 0.079). The pre-incubation of venom with the herbal preparation increased the LD50 of D. russelii venom to 17.64 ± 1.35 µg (R2 = 81.0%, P = 0.100), showing a clear neutralizing action of D. russelii venom toxicity by the herbal medicine. Whereas the pre-incubation of venom with the 1× venom neutralizing dose of commercially available polyvalent anti-venom serum shifted the LD50 venom only up to 5.5 ± 1.35 µg (R2 = 98.8%, P = 0.069). In the presence of the herbal preparation, Phospholipase A2 activity of D. russelii venom was significantly reduced from 9.2 × 10-3 mM min-1 to 8.0 × 10-3 mM min-1 and that of N. naja from 2.92 × 10-2 mM min-1 to 0.188 × 10-2 mM min-1. Further, the pre-incubation of N. naja venom with the herbal preparation significantly reduced its Metalloprotease activity from 0.069 units min-1 to 0.019 units min-1. CONCLUSION: The herbal preparation shows a clear neutralizing action against the toxicities of D. russelii and N. naja venoms demonstrating the potential to be used as a plant based antidote for snake envenomation.

Demographic variables for wild Asian elephants using longitudinal observations.

Detailed demographic data on wild Asian elephants have been difficult to collect due to habitat characteristics of much of the species' remaining range. Such data, however, are critical for understanding and modeling population processes in this endangered species. We present data from six years of an ongoing study of Asian elephants (Elephas maximus) in Uda Walawe National Park, Sri Lanka. This relatively undisturbed population numbering over one thousand elephants is individually monitored, providing cohort-based information on mortality and reproduction. Reproduction was seasonal, such that most births occurred during the long inter-monsoon dry season and peaked in May. During the study, the average age at first reproduction was 13.4 years and the 50(th) percentile inter-birth interval was approximately 6 years. Birth sex ratios did not deviate significantly from parity. Fecundity was relatively stable throughout the observed reproductive life of an individual (ages 11-60), averaging between 0.13-0.17 female offspring per individual per year. Mortalities and injuries based on carcasses and disappearances showed that males were significantly more likely than females to be killed or injured through anthropogenic activity. Overall, however, most observed injuries did not appear to be fatal. This population exhibits higher fecundity and density relative to published estimates on other Asian elephant populations, possibly enhanced by present range constriction. Understanding the factors responsible for these demographic dynamics can shed insight on the future needs of this elephant population, with probable parallels to other populations in similar settings.