Sakaerat Biosphere Reserve Research Articles

A new species of karst-dwelling bent-toed gecko of the Cyrtodactylusintermedius group (Squamata, Gekkonidae) from eastern Thailand and the phylogenetic placement of C.intermedius.

A new karst-dwelling bent-toed gecko of the Cyrtodactylusintermedius group is described from Khlong Hat District, Sa Kaeo Province, eastern Thailand, based on an integrative taxonomic analysis of genetic data and morphological characteristics. Phylogenetic analyses using the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene revealed that topotypes of C.intermedius were sister to a clade containing C.kulenensis from Cambodia, an unnamed lineage from Sakaerat Biosphere Reserve in Nakhon Ratchasima Province, Thailand, and the Khlong Hat lineage described here as Cyrtodactyluskhlonghatensis sp. nov. Multivariate analyses of morphometric and meristic characters showed that C.khlonghatensis sp. nov. is morphologically distinct from all other species in the group by having the combination of SVL 76.5-82.8 mm in adult males and 88.5 mm in an adult female; eight supralabial and nine infralabial scales; 30-32 paravertebral tubercles; 20 or 21 longitudinal rows of dorsal tubercles; 43 or 44 ventral scales; seven or eight expanded subdigital lamellae on the 4th toe; 12 unmodified subdigital lamellae on the 4th toe; 19 or 20 total subdigital lamellae on the 4th toe; 31 or 32 total number of enlarged femoral scales; enlarged femoral and precloacal scales continuous; 6-8 pore-bearing precloacal scales in males; three or four rows of enlarged post-precloacal scales; 1-3 postcloacal tubercles; proximal femoral scales less than one-half the size of distal femoral scales; absence of interdigital pocketing between digits of forefeet and hindfeet; and posterior border of the nuchal loop rounded. Uncorrected pairwise genetic divergences (p-distances) between the new species and other species of the intermedius group ranged from 4.73-22.55%. The discovery of this new species exclusively in isolated karst formations from the Thai-Cambodia border suggests that there may be further undiscovered Cyrtodactylus in unexplored karst landscapes along the border of eastern Thailand and western Cambodia.

The dynamics of deciduous dipterocarp forest in relation to climate variability in the Sakaerat Biosphere Reserve, Northeastern Thailand

Abstract. Yatar C, Thinkampheang S, Sungkaew S, Wachrinrat C, Asanok L, Kamyo T, Hermhuk S, Kachina P, Thongsawi J, Phumphuang W, Yarnvudhi A, Waengsothorn S, Cheysawat S, Marod D. 2024. The dynamics of deciduous dipterocarp forest in relation to climate variability in the Sakaerat Biosphere Reserve, Northeastern Thailand. Biodiversitas 25: 3088-3098. Climate change is a major environmental problem influencing forest dynamics. To clarify tropical seasonal forest dynamics under climate change, we conducted long-term monitoring of all trees with Diameter at Breast Height (DBH) ?4.5 cm within a 1-ha permanent plot established in 2004 in a deciduous dipterocarp forest in the Sakaerat Biosphere Reserve (SBR), Northeastern Thailand. Surveys of all trees within the plot with DBH ?2 cm were conducted in 2008, 2015, and 2019. Climate data were obtained from the SBR climate station during 2004-2019 and used to extract dates with drought and wet conditions. Forest dynamics varied among species and periods, with stem density exhibiting a decreasing trend. Despite prolonged drought conditions from 2004 to 2009, which usually leads to increased mortality rates, the recruitment rate was 7-fold higher than the mortality rate at a site protected from fire during 2004-2008, and most of the recruited species were pioneer species, shrubs, and small trees. A contrasting trend was observed during 2015-2019, with a mortality rate almost 10-fold higher than the recruitment rate, indicating a significant ecological disturbance, likely to have been driven by a severe El Niño event during 2015-2016. Thus, climate induced disturbances (i.e., drought and fire) appear to have inhibited tree regeneration in the deciduous dipterocarp forest, particularly when they occurred in combination and for specific timing and intensity levels. Addressing the challenges posed by drought and fire to tree regeneration requires holistic management approaches that consider both ecological and climatic factors. Monitoring and adaptive management are also essential to mitigate the impact of future disturbances and support the long-term viability of forest ecosystems.

Environmental factors differentially influence species distributions across tree size classes in a dry evergreen forest in Sakaerat Biosphere Reserve, northeastern Thailand

ABSTRACT Plant communities in tropical forests are influenced by multiple environmental variables. For trees, soil and topographic characteristics are key factors that impact the establishment of many species. In this study, the impacts of soil properties and topography on forest structure, species composition, α- and β-diversity, and tree species distribution across size classes were investigated in a dry evergreen forest (DEF) in the Sakaerat Biosphere Reserve, northeastern Thailand. Within a 16 ha permanent plot, all trees with a diameter at breast height (DBH) ≥ 1 cm were recorded. Tree species distributions mostly respected gradients of plot elevation and soil nutrient, including available P; these variables were strongly associated for most size classes. Structural attributes (basal area and tree density) of trees with a DBH of 5–10 cm were highly sensitive to these variables. For trees with a DBH of 2–5 cm, α-diversity was negatively associated with available P while β-diversity was associated with topography and available P. These findings demonstrate the strong influence of topographic and edaphic variables in shaping the DEF. Sensitivity to these variables, particularly elevation and increases in available P, increased with increasing tree size among size classes, as small trees were less sensitive than were larger trees. Our study provides an example of how different environments affect many of the features of tropical forest structure, such as tree size class and species composition.

Finding the green in differently disturbed forests under different weather conditions: detection and occupancy of the green pit viper <em>Trimeresurus (Cryptelytrops) macrops</em> at the Sakaerat Biosphere Reserve, Thailand

The response of venomous snakes to anthropogenic landscape disturbance remains scarcely studied in tropical regions. Green pit vipers are among the most diverse venomous snakes in the Southeast Asian tropics and bite the highest number of people of any group of venomous snakes where they are found, yet conservation and snakebite management efforts have been hindered by limited prior studies of these organisms in both natural and anthropogenically disturbed landscapes. Subsequently, we sought to address key knowledge gaps regarding the persistence and response of green pit vipers to anthropogenic disturbance. Utilizing repeated field surveys coupled with remote sensing landscape feature data, we fit single-season Bayesian occupancy models to investigate the potential influences of weather variables on detection and various landscape features on the persistence of the big-eyed pit viper (Trimeresurus (Cryptelytrops) macrops). Temperature and humidity marginally positively influenced detection. The probability of T. macrops occupancy increased with increasing distance to buildings and houses, roads, water, and increased canopy height and elevation but decreased with increasing distance to the core zone of the reserve, natural forest, and if a site was a plantation. Our findings suggest that anthropogenic landscape disturbance influences the presence of T. macrops within a biosphere reserve in Thailand, contrary to the general perception that the species is resilient to land-use change. We strongly suggest further study of the green pit viper response to human disturbance, which would significantly benefit conservation and snakebite management plans for these diverse organisms.

Ground-dwelling ant diversity in forests and agricultural land use at Sakaerat Biosphere Reserve, Thailand

Abstract. Khongthawie S, Hasin S, Ponpinij S, Pinkaew N. 2023. Ground-dwelling ant diversity in forests and agricultural land use at Sakaerat Biosphere Reserve, Thailand. Biodiversitas 24: 5937-5946. Ants play essential roles in terrestrial ecosystems, for example, soil engineers, seed dispersers, biological control agents, and indicators to monitor environmental stress and disturbance. This research aimed to study the diversity and community composition of ground-dwelling ants at Sakaerat Biosphere Reserve and its surrounding areas. Pitfall traps collected ground-dwelling ants from three habitat types: agricultural areas, dry dipterocarp forests, and dry evergreen forests; the environmental factor in this work was soil temperature. The results revealed that 109 ant species in 40 genera belonging to 8 subfamilies. Notably, the dry dipterocarp forest exhibited the highest ant diversity with 71 species, followed by the dry evergreen forest and agricultural area with 62 and 54 species, respectively. Overall, the present study reveals that soil temperature and vegetation significantly influenced ant species composition; ant species being more likely to be found in forests than in agricultural areas, and species classified as uncommon groups based on occurrence were the largest group in every study site. Besides, the information on ant species obtained from this work had the potential to be used as bioindicator species for ecosystem management and human impacts on forests.

Legacy effects of canopy gaps on liana abundance 25 years later in a seasonal tropical evergreen forest in northeastern Thailand

AbstractLianas require host trees to reach and stay in the forest canopy, but as seedlings and juveniles, they benefit from canopy gaps created by treefalls. Here, we evaluated the relative importance of these two aspects, that is, the availability of potential hosts vs. the legacy effect of past treefall gaps, on the local abundance of liana stems in a seasonal tropical evergreen forest in the Sakaerat Biosphere Reserve in northeastern Thailand. Within a 2.5‐ha plot for forest dynamics monitoring, canopy height was measured in 1993 and 2018 at 5‐m intervals to distinguish areas of mature (canopy height ≥ 20 m), building (10–20 m), and gap phases (< 10 m). In 2017–2018, we surveyed all liana stems ≥ 1 cm in diameter at breast height within 50 subplots (10 m × 10 m each) and recorded their diameter and the diameter of the host tree. Of a total of 445 liana individuals, 242 could be identified at least to the family level, while the others had clear morphological traits of climbing mechanisms. The number of liana stems was higher in areas that had been at the building/gap phase than those at the mature phase in 1993. When this 25‐year‐old legacy of past gap locations was considered, there was a positive association of local abundance between lianas and trees in areas at the mature phase in 2018. In conclusion, liana abundance reflected a long‐term legacy of past treefall gaps more than 25 years earlier in this seasonal evergreen forest.

Seeing wildlife behavior in a new way: Novel utilization of computer vision for focal reptile videography behavior study

AbstractTechnology has the potential to assist and directly address ecological topics. Our study compared efficiency and efficacy of foreground‐detection computer vision and manual review methods for understanding behavior, natural history, and ecology of green pit vipers. Between 2015 and 2020 at the Sakaerat Biosphere Reserve in Thailand, 18,871 scans (pictures and timelapse recordings) and 1,507 minutes of continuous videos were recorded for 6 adult female, big‐eyed pit vipers (Trimeresurus macrops). MotionMeerkat, an open source computer vision tool for finding ecological events in long video, appeared to be less efficient and overestimated presence of behaviors. Our study suggested that foreground‐detection computer vision methods, exemplified by the program MotionMeerkat, can be free and open‐source as well as easy to learn and use, but may not be as time efficient or fully address the complexity of ecological topics compared to review of images by human observers.

Elusive species and where to find them: assessment of survey protocols for primates habitat selection

Context With the ongoing biodiversity crisis and the continued loss of species, it becomes crucial to find practical solutions to monitor threatened animal populations for wildlife conservation and management. However, in practice, monitoring is especially challenging for elusive, rare, and wide-ranging species, where estimating abundance is often expensive and time-consuming. Alternatively, estimating occupancy (i.e. detection/non-detection data) may be less resource-intensive, while still providing useful information for monitoring population trends. Aims We aimed to describe a new field method, the random walk grid survey, to conduct a habitat selection study on elusive diurnal forest-dwelling primates. We explored how to improve occupancy estimates when detection probability is low and determined the minimal effort needed for reasonable estimates on the species habitat selection by using site-occupancy models. Methods We collected data to assess the northern pigtailed macaques’ (Macaca leonina) occupancy and detection probability using a random walk survey of degraded forest fragments in Sakaerat Biosphere Reserve in Northeast Thailand. We ran simulations to identify what is required for minimum survey efforts to obtain reasonable estimates of occupancy and detection probability on small or relatively large spatial scales, covering a small primate community in Southeast Asia. Key results Simulations showed that the probability of detecting macaques increased dramatically with an increased survey effort. However, compared with similar line-transect survey methods, the random walk grid survey was less time-consuming. Additionally, the occupancy and habitat selection estimates were similar to our knowledge of macaque distribution within the study area. Conclusions Our findings suggest that the new random walk grid survey method is effective to assess the elusive northern pigtailed macaques’ occupancy, and to provide reliable data on habitat selection where there is low macaque abundance and detection probability in a degraded forest fragment. Implications Our survey protocol could be used as a starting point to target high location occupancy to start habituation processes, but also for further intensive studies on primate behaviour and habitat use of primate communities. Finally, combining the random walk grid survey with automated recording devices (e.g. camera traps or passive acoustic surveys) could help improve occupancy and detection probability estimates for long-term monitoring programs and over large spatial scales.

Space use and activity of Boiga cyanea – A major songbird nest predator in a seasonal tropical forest in Thailand

Predator-prey interactions are fundamental drivers of population dynamics. Studying both predator and prey species simultaneously yields particularly useful insights into these complex interactions. Despite being significant, widespread avian nest predators, Southeast Asian snakes are rarely simultaneously studied in relation to avian prey. The Green Cat Snake Boiga cyanea is a primary nest predator, estimated to be responsible for 17–33% of forest songbird nest depredations in Northeast Thailand. We explored both diurnal and nocturnal movements of 14 (5 male, 9 female) adult B. cyanea with radio-telemetry for an average of 68 ± 16 days per individual, between 21 October 2017 and 8 June 2019 in the dry evergreen forest of the Sakaerat Biosphere Reserve (SBR). We quantified horizontal movements (m) and area of space use (ha) and activity through motion variance (Ϭ m 2 ) during the study period using dynamic Brownian Bridge Movement Models (dBBMMs) and reported our findings within the context of a simultaneously run avian nest monitoring study initiated in 2013 within the same forest. On average, adult B. cyanea moved 56.4 ± 10.4 m/day and used areas of 9.4 ± 3.4 ha, while their activity averaged 2.8 ± 0.8 Ϭ m 2 . Males moved 51.4 m/day farther than females, and in general, adult B. cyanea moved 50.3 m/day farther during the avian nesting season than the avian non-nesting season. We refrain from inferring statistical differences with the dBBMM outputs between sexes and seasons within our sample because of the unequal samples and sampling effort during the study period. Only two individuals (one male and one female) were sufficiently radio-tracked across both seasons (the avian nesting and non-nesting seasons), and these two displayed a clear increase in their respective movements, space use and activity during the avian nesting season. This could suggest that movements, space use and activity likely differ between the avian nesting and non-nesting seasons for male and female B. cyanea , however it is only two individuals. All individuals were exclusively nocturnal, moving throughout the night, and often descending from higher diurnal refugia (> 2 m) to forage closer to the ground after sunset. Our openly available data may yield further insight when combined with other major avian nest predator species like the congeneric invasive Brown Tree Snake Boiga irregularis on the island of Guam.

Nonchalant neighbors: Space use and overlap of the critically endangered Elongated Tortoise

AbstractTo prevent population extirpations, we need to understand a species’ requirements, especially for critically endangered species inhabiting biodiversity hotspots. Studying animal movement provides necessary insights and gauges protected area effectiveness. Southeast Asian protected areas are becoming isolated, stressing the need for maintaining population viability. We used radio‐telemetry with the critically endangered Elongated Tortoise (Indotestudo elongata) to assess: movements, space use, and conspecific overlap in a small protected area—Sakaerat Biosphere Reserve, Thailand. Movements were weakly seasonal, higher in hot and wet seasons than the dry season, and annual space use varied (4.24–55.57 ha), with conspecifics frequently overlapping. Conspecific comparisons revealed males (n = 5) moved similarly to females (n = 12) but used larger areas. Despite more instances of conspecific attraction over avoidance (20:8), avoidance/attraction behavior appeared disconnected from individual size; therefore, interaction patterns may result from resources locations (mates or food) rather than competition (i.e., no evidence of smaller individuals avoiding larger individuals). Female–female attraction suggests no resource exclusion tactics at our temporal resolution. Male–female attraction may indicate seasonal reproductive movements, but we could not detect significant interactive effects linking conspecific attraction or step length to breeding activity. Our observations of annual space use and overlap present critical components when designing robust population assessments underlining any successfulI.elongataconservation effort. In the context of previous work connecting space overlap with population viability, our results suggest the biosphere population ofI.elongatato be reproductive, with enough resources to be viable, emphasizing the importance of relatively small protected natural areas.

Native Burmese pythons exhibit site fidelity and preference for aquatic habitats in an agricultural mosaic

Animal movement and resource use are tightly linked. Investigating these links to understand how animals use space and select habitats is especially relevant in areas affected by habitat fragmentation and agricultural conversion. We set out to explore the space use and habitat selection of Burmese pythons (Python bivittatus) in a heterogenous, agricultural landscape within the Sakaerat Biosphere Reserve, northeast Thailand. We used VHF telemetry to record the daily locations of seven Burmese pythons and created dynamic Brownian Bridge Movement Models to produce occurrence distributions and model movement extent and temporal patterns. To explore relationships between movement and habitat selection we used integrated step selection functions at both the individual and population level. Burmese pythons had a mean 99% occurrence distribution contour of 98.97 ha (range 9.05–285.56 ha). Furthermore, our results indicated that Burmese pythons had low mean individual motion variance, indicating infrequent moves and long periods at a single location. In general, Burmese pythons restricted movement and selected aquatic habitats but did not avoid potentially dangerous land use types like human settlements. Although our sample is small, we suggest that Burmese pythons are capitalizing on human disturbed landscapes.

Seasonal changes in spatial variation of soil respiration in dry evergreen forest, Sakaerat Biosphere Reserve, Thailand

Seasonal changes in spatial variation of soil respiration in dry evergreen forest, Sakaerat Biosphere Reserve, Thailand

Can post-capture photographic identification as a wildlife marking technique be undermined by observer error? A case study using King Cobras in northeast Thailand.

Identifying individuals with natural markings is increasing in popularity to non-invasively support population studies. However, applying natural variation among individuals requires careful evaluation among target species, snakes for example have little validation of such methods. Here we introduce a mark-free identification method for King Cobras (Ophiophagus hannah) from the Sakaerat Biosphere Reserve, in northeast Thailand using both subcaudal scale pholidosis (scale arrangement and number) and unique ventral body markings to distinguish individuals. This project aims to evaluate the impact of observer error on individual identification. Observers of varying expertise, will distinguish between King Cobra individuals using identifying photographs from a previous study. We will ask randomly assigned observers to distinguish individuals via: 1) subcaudal pholidosis, 2) ventral body markings, and 3) combination of both measures. Using Bayesian logistic regression, we will assess the probability observers correctly distinguish individuals. Based on exploratory observations, we hypothesise that there will be a high probability of correct identifications using subcaudal pholidosis and ventral body markings. We aim to stimulate other studies implementing identification techniques for scrutinous assessment of such methods, in order to avoid subsequent errors during long-term population studies.

When Northern Pigtailed Macaques (Macaca leonina) Cannot Select for Ideal Sleeping Sites in a Degraded Habitat

Primates must select sleeping sites carefully to maximize fitness. In habitats with diminished quality and availability of resources, sleeping site selection becomes an even more crucial aspect of primate survival. We investigated sleeping site selection patterns in northern pigtailed macaques (Macaca leonina) living in a degraded habitat by testing the hypotheses of random selection, predation avoidance, and food proximity. We followed a group of northern pigtailed macaques in Sakaerat Biosphere Reserve, northeastern Thailand, over 14 months between February 2017 and October 2018. We identified 107 total sleeping sites and analyzed the forest structure at 50 sleeping sites and 50 randomly selected available sites. While the rate of reuse was low and random (N = 15), with sleeping sites characterized by a low availability of large and tall trees, the selection pattern was not random, with sleeping sites occurring more often in familiar areas (i.e., high site fidelity), and those with a greater number of stems and a higher canopy. These sleeping site characteristics were likely selected to decrease detection by predators and facilitate macaque escape in case of attack, supporting the predator avoidance hypothesis. However, food proximity also played a key role in sleeping site selection in this degraded habitat. Macaques often slept within, or close to, their first/last feeding site and selected their sleeping sites following food distribution, presumably to maximize energy intake. Our results present a new impact of habitat degradation on sleeping site selection in large primate groups: the use of a high number sleeping sites in order to cope with low availability and scattered distribution of fruit resources.

Northern pigtailed macaques rely on old growth plantations to offset low fruit availability in a degraded forest fragment.

Space-use and foraging strategies are important facets to consider in regard to the ecology and conservation of primates. For this study, we documented movement, ranging, and foraging patterns of northern pigtailed macaques (Macaca leonina) for 14 months in a degraded habitat with old growth Acacia and Eucalyptus plantations at the Sakaerat Biosphere Reserve in northeastern Thailand. We used hidden Markov models and characteristic hull polygons to analyze these patterns in regard to fruit availability. Macaques' home range (HR) was 599 ha and spanned through a natural dry-evergreen forest (DEF), and plantation forest. Our results showed that active foraging increased with higher fruit availability in DEF. Macaques changed to a less continuous behavioral state during periods of lower fruit availability in DEF, repeatedly moving from foraging to transiting behavior, while extending their HR further into plantation forest and surrounding edge areas. Concomitantly, macaques shifted their diet from fleshy to dry fruit such as the introduced Acacia species. Our results showed that the diet and movement ecology adaptations of northern pigtailed macaques were largely dependent on availability of native fruits, and reflected a "high-cost, high-yield" foraging strategy when fresh food was scarce and dry fruit was available in plantation forest. Conversely, wild-feeding northern pigtailed macaque populations inhabiting pristine habitat approached a "low-cost, low-yield" foraging strategy. Our results outline the effects of habitat degradation on foraging strategies and show how a flexible species can cope with its nutritional requirements.

Species richness and abundance of monogonont rotifers in relation to environmental factors in the UNESCO Sakaerat Biosphere Reserve, Thailand

The UNESCO Sakaerat Biosphere Reserve plays an important role in nature conservation and environmental protection. Previous focus on terrestrial habitats and neglect of aquatic ecosystems has resulted in an incomplete picture of biodiversity of the area. Based on the first investigation of planktonic diversity, rotifers were collected seasonally at five localities from September 2013 to May 2014 using a Schindler-Patalas plankton trap and a plankton net. Fifteen families, 25 genera and 71 species of rotifers were identified. The most diverse families were Lecanidae, Brachionidae, Lepadellidae, and Trichocercidae, accounting for 80% of the total species count. The maximum species richness was reported at the reservoir, with 57 species (80% of the total), while the minimum species richness (34) was observed at the ponds. The rainy season had the highest density, followed by winter and summer, with 149.15 N/l from an intermittent stream, and 95.43 and 50.68 N/l from a pond, respectively. Most of the sampling sites at the three seasonal occasions were dominated by a planktonic species Polyarthra vulgaris. The results indicate that the seasonal variation of the rotifer assemblage is related to the seasonal variation of physicochemical parameters.

Foraging strategies underlying bird egg predation by macaques: A study using artificial nests.

Bird egg predation is widespread in non-human primates. Although nest predation is often described as opportunistic, little is known about foraging strategies and nest detection in primates. Since it is the prevalent cause of nest failure in the tropics, birds select nest sites within specific microhabitats and use different nest types to increase nesting success. Identifying the nests targeted by the northern pigtailed macaques (Macaca leonina), an omnivorous cercopithecine species, and known nest predator, will shine light on nest foraging strategies in primates. The aim of this research was to reveal if nest predation is a selective or opportunistic feeding behavior. We studied, using artificial nests and camera traps, the influence of nest type (open-cup vs. cavity), microhabitat (i.e., understory density, canopy cover, canopy height, ground cover, and presence vs. absence of thorns and lianas), and nest height, on nest predation by a troop of northern pigtailed macaques in the Sakaerat Biosphere Reserve (Thailand), a degraded environment. In our study, macaque predation on artificial nests was high; out of the 200 nests that were set up, 112 were plundered by macaques. Although predation rates decreased with nest height, nest type, and microhabitat had no significant effect on predation by macaques. Nest detectability and accessibility did not affect predation rates. Macaques actively searched for nests in different microhabitats, suggesting that nest predation by this primate might be considered a selective feeding behavior in this degraded habitat. Consequently, nest predation by this primate might have important conservation implications on the population dynamics of forest-dwelling bird species. Behavior observation methods, such as instantaneous scan sampling, may underestimate nest predation by primates, a furtive and cryptic behavior.

Seasonal and Land Use Effects on Amphibian Abundance and Species Richness in the Sakaerat Biosphere Reserve, Thailand

Habitat destruction and degradation in the tropics have led to a dramatic increase in altered habitats. Understanding the impacts of these disturbed areas on biodiversity will be critical to future conservation efforts. Despite heavy deforestation, Southeast Asia is underrepresented in studies investigating faunal communities in human-modified landscapes. This project assessed the herpetofaunal community in dry dipterocarp forest, secondary disturbed forest, and Eucalyptus plantations in the Sakaerat Biosphere Reserve. In May, June, and September of 2015, we surveyed using 10 passive trapping arrays. Both the Eucalyptus plantations and secondary disturbed forest habitats (224 and 141 individuals, respectively) had higher amphibian abundance than the dry dipterocarp forest (57 individuals), but we observed significant seasonal variation in amphibian abundance. During the wetter month of September, we recorded higher numbers of amphibian individuals and species. In particular, we noted that distance to a streambed influenced amphibian abundance during the rainy season. The three most abundant species in May and June were Microhyla fissipes, Fejervarya limnocharis, and Microhyla pulchra. In September, the three most abundant species were Microhyla fissipes, Glyphoglossus molossus, and Kaloula mediolineata.Our findings suggest that seasonal resources should be considered when conducting monitoring programs and making conservation decisions for amphibians.

Spatial ecology of a small arboreal ambush predator, Trimeresurus macrops Kramer, 1977, in Northeast Thailand

Abstract The Big-Eyed Green Pit Viper (Trimeresurus macrops; Kramer, 1977) is a venomous snake species endemic to Southeast Asia. Although we have some knowledge of the systematics and toxicology of T. macrops, little is known about the spatial ecology of this species. From May 2013 to February 2014, we used radio-telemetry to determine home-range sizes of 13 adult female T. macrops inhabiting the Sakaerat Biosphere Reserve in Northeast Thailand. We found that individual home ranges for T. macrops averaged 0.175 ha, with activity areas ranging from 0.112-0.303 ha and core areas ranging from 0.023-0.052 ha. There was little overlap between conspecific tracked females, especially for the most used areas of their home ranges. We find that T. macrops ambushes more in higher humidity and expresses very little diurnal activity. They use the groundstory for ambushing, then retreat over small distances to higher refuge during the day. Future studies should focus on prey abundance, habitat selection, and survival rates.

Centipede, Scolopendra dawydoffi (Chilopoda: Scolopendridae), predation on an egg-laying snake, Sibynophis triangularis (Squamata: Colubridae), in Thailand

While typically insectivorous, large centipedes are known to attack and eat vertebrates. Though opportunistic, this behavior might be relatively frequent. Predation of centipedes on snakes is rarely observed. We report an incident, witnessed at the Sakaerat Biosphere Reserve, Thailand, involving the predation of a scolopendrid centipede, Scolopendra dawydoffi, on a female colubrid snake, Sibynophis triangularis. This is the first known case of a centipede predating on a vertebrate that that was laying eggs.