Shahrul Anuar Mohd Sah

Diet, growth and movements of juvenile crocodiles Crocodylus porosus Schneider in the Klias River, Sabah, Malaysia

A total of 14 spotlight surveys were carried out from January 1992 to February 1993 along 37 km of the Klias River in north-western Sabah, Malaysia. Surveys were at low tide between 1900 and 0600 h from a survey boat at 15 km h −1 by two observers. A total of 221 sightings were made, which varied between 2 and 29 per survey (mean 15.8). A total of 55 juvenile crocodiles were captured, with 16 recaptures. Calculated density was 0.9–1.8 individuals km −1 , while the estimated crocodile population was 46.1 ± 10.2 (SD) for the survey area. Percentage sightings according to total length were: 42% ≤0.5 m; 40% >0.5-≤1.0 m; 5% > 1.0-≤3.0; and 13% eyes only. Recapture of 16 tagged juveniles suggested that hatchlings ≤0.5 m total length remained within >0.5 km of their release point for at least one month, and juveniles 0.5-≤1.0 m more than one year. Hatchlings had growth rates between 0.01 and 0.08 cm d −1 and 0.3 and 1.5 g d −1 , while larger juveniles grew at least 0.11 cm d −1 and 2.7–2.9 g d −1 . Stomachs of hatchlings and juveniles contained crabs (Ocypodidae), prawns (Atyidae), insects and small fish (Hemiramphidae). Relatively large numbers of juvenile Crocodylus porosus (82.4%) in the Klias River suggests that the area, though under hunting pressure, is desirable as a site for the conservation of C. porosus in the Sabah.

Counting in the dark: Non-intrusive laser scanning for population counting and identifying roosting bats

Population surveys and species recognition for roosting bats are either based on capture, sight or optical-mechanical count methods. However, these methods are intrusive, are tedious and, at best, provide only statistical estimations. Here, we demonstrated the successful use of a terrestrial Light Detection and Ranging (LIDAR) laser scanner for remotely identifying and determining the exact population of roosting bats in caves. LIDAR accurately captured the 3D features of the roosting bats and their spatial distribution patterns in minimal light. The high-resolution model of the cave enabled an exact count of the visibly differentiated Hipposideros larvatus and their roosting pattern within the 3D topology of the cave. We anticipate that the development of LIDAR will open up new research possibilities by allowing researchers to study roosting behaviour within the topographical context of a caves internal surface, thus facilitating rigorous quantitative characterisations of cave roosting behaviour.

A Survey of Acarine Ectoparasites of Bats (Chiroptera) in Malaysia

ABSTRACT A comprehensive 8-yr survey of acarine ectoparasites (ticks and mites) of bats was carried out in 18 localities from 2002 to 2009. Most of the surveys were conducted during 14 national biodiversity scientific expeditions throughout Malaysia. The objective was to identify acarines of known public health importance from bats and thus determine whether there is any potential public health risk in Malaysia. Trapping of bats was conducted using Harp traps and Mist nets. In total, 1,579 individuals comprising of 6 families and 52 species of bats were examined alive. In general, 25.6% of the bats were infested with acarines. Infestation rates of ticks, mesostigmatid mites, and chiggers on bats examined were 0.4, 10.4, and 14.7%, respectively. Their prevalence and mean intensity were tabulated. Genera of ticks extracted were Amblyomma, Dermacentor, Ixodes, and Ornithodoros. Of these genera, only two species can be identified to species level and they are Amblyomma cordiferum and Ixodes simplex. In total, 8 genera and 15 species of mesostigmatid mites were found; the species were Ancystropus eonycteris, Ancystropus zeleborii, Echinonysus nasutus, Laelaps aingworthae, Laelaps nuttalli, Laelaps sanguisugus, Laelaps sculpturatus, Longolaelaps longulus, Longolaelaps whartonii, Meristaspis lateralis, Meristaspis macroglossi, Paraperiglischrus rhinolophinus, Spinturnix acuminatus, Spinturnix americanus, and Spinturnix bakeri. Chiggers on bats were represented by 12 genera and 6 species; the species identified were Gahrliepia fletcheri, Riedlinia lipoxena, Trombigastia cadei, Walchiella impar, Walhiella oudemansi, and Whartonia caobangensis. The study produced an up-to-date list of acarine ectoparasites of bats in Malaysia where a total of 38 genera and 47 species of acarines were listed. Findings of the study demonstrated that 5 genera and 1 species of acarines that may pose potential health risks, can be found on bats.

Foraging Patterns Reveal Niche Separation in Tropical Insectivorous Birds

Abstract. The study examines the uses of attack maneuvers and foraging substrates by ten insectivorous passerine birds to explain how these trophically similar species can coexist in the same habitat, a central question in ecology. Information on the foraging height, attack maneuvers, substrate and foliage density was collected independently for each foraging bird. Sallying was the most frequently used attack maneuver, and leaves were the most frequently used substrate. Statistical analyses showed that the variation in the foraging data was significantly influenced by foraging height, followed by attack maneuver, substrate, and lastly foliage density. The foraging height, the parameters of the attack maneuvers and substrate effectively divided the birds into three foraging guilds: (1) ‘High-sally insectivores’ — birds that foraged in higher strata using sallying tactics, namely Arctic Warbler Phylloscopus borealis, Black-naped Monarch Hypothymis azurea, Asian Paradise-flycatcher Terpsiphone paradisi and Asian Brown Flycatcher Muscicapa dauurica; (2) ‘High-foliage insectivores’ —birds that foraged in higher strata using glean-stretch-hang tactics, namely White-bellied Erpornis Erpornis zantholeuca, Green Iora Aegithina viridissima, and Pin-striped Tit-babbler Macronous gularis; and (3) ‘Understory insectivores’ —birds that foraged in lower strata, namely Abbotts Babbler Malacocincla abbotti, Chestnut-winged Babbler Stachyris erythroptera, and Rufescent Prinia Prinia rufescens. Except for Asian Paradiseflycatcher and Asian Brown Flycatcher, no other two species used similar foraging heights, substrates and attack maneuvers at the same time. However, the use of foliage density differed significantly between these two species. Therefore this parameter should also be taken into consideration in analysis of foraging niche in tropical birds.

Diversity and conservation status of mammals in Wang Kelian State Park, Perlis, Malaysia

A series of surveys in Wang Kelian State Park, Perlis were carried out since 2009 to 2011 to document the diversity of mammals. Two sampling stations; 1) the Wang Burma cave trail and 2) the Orchard leading to Tasik Meranti were sampled for small mammals using mist-nets, harp traps, cage traps and were accounted through direct observation. The highlight of this study includes new geographic records for Rhinolophus chiewkweeae and Rousettus leschenaultii for the state of Perlis. Additionally, there were also 30 new distributional records of mammals in this protected area, increasing the total known mammals of Wang Kelian State Park to 86 species. Although having poorly known mammals such as R. chiewkweeae and Macaca arctoides in this park, the diversity of mammals in Wang Kelian State Park is still underestimated as the species cumulative curve over time has yet to reach a stationary phase. In conclusion more surveys need to be done especially the northern part of the park near the Malaysia-Thailand border and Tasik Meranti in order to look at possible occurrences of threatened mammals highlighted in this study.

Fish checklist of Perak River, Malaysia

Out of the 1000 species of freshwater fish documented in the South-East Asian Tropics, 420 species can be found in Malaysia. Based on experimental gill net studies, Perak River recorded a total of 107 fish species, which comprises of 33 families with Cyprinidae as the dominant family, with 43 species. The fluctuating number of species and species replacement in the upstream direction in this river reflects the orientation of the River Continuum Concept. Gradient changes of salinity, habitat heterogeneity, water velocity and riverbed materials are some of the factors that may contribute to the fluctuation and species replacement.

Effect of differential forest management on land-use change (LUC) in a tropical hill forest of Malaysia

Forest ownership is considered as a vital aspect for sustainable management of forest and its associated biodiversity. The Global Forest Resources Assessment 2015 reported that privately owned forest area are increasing on a global scale, but deforestation was found very active in privately owned hill forest areas of Malaysia. Penang State was purposively chosen as it has been experiencing rapid and radical changes due to urban expansion over the last three decades. In this study, analyses of land-use changes were done by PCI Geomatica using Landsat images from 1991 to 2015, future trends of land-use change were assessed using EXCEL forecast function, and its impact on the surrounding environment were conducted by reviewing already published articles on changing environment of the study area. This study revealed an annual deforestation rate of 1.4% in Penang Island since 1991. Trend analysis forecasted a forest area smaller than the current forest reserves by the year 2039. Impact analysis revealed a rapid biodiversity loss with increasing landslides, mudflows, water pollution, flash flood, and health hazard. An immediate ban over hill-land development is crucial for overall environmental safety.

Assessing Nesting Status of Green Turtles, Chelonia Mydas in Perak, Malaysia

The nesting of green turtle (Chelonia mydas) was monitored from 1998 untill 2013 along the beaches of Pasir Panjang, Segari, Perak. The objective of the study is to assess the nesting status of green turtles in Perak, Peninsular Malaysia in terms of total nests, eggs, survival hatchings, and density of visitors. A total number of green turtle nests found for 16 years were 1,019 nests and varied from 10 to 220 nests per year. Meanwhile, the sum of eggs collected for 16 years were 107,820 eggs, and varied from 553 to 20,881 eggs per year. The temporal pattern of nesting indicates year-round nesting in Perak in most years within the 16 years period. The peak season of nesting was estimated to occur between May and June. Survival hatchlings varied from 23.33% (2,071 hatchlings) to 55.03% (5,018 hatchlings) from 1998 to 2013. The density of visitors was not uniformly distributed among the years, and shows a sign of decline especially from 2006 onwards. This publication provides basic knowledge of green turtle nesting population in Perak, and would be helpful in upgrading the conservation program in Malaysia. In future, we hope 1) for an increase in manpower to obtain accurate nesting records along the nesting beaches during nocturnal survey and, 2) to include the breeding biology data such as nest placement, emergence hour, and morphological characteristics of green turtle.

The rediscovery of Schaefer’s Spine-jawed Snake ( Xenophidion schaeferi Günther & Manthey, 1995) (Serpentes, Xenophidiidae) from Peninsular Malaysia with notes on its variation and the first record of the genus from Sumatra, Indonesia

The family Xenophidiidae is an extremely rare and little-known family of snakes that contains only two species, Xenophidion acanthognathus Günther Manthey and X. schaeferi Günther Manthey that are each known only from their holotypes. We report on the rediscovery of X. schaeferi from two new locations in southern Peninsular Malaysia. The new specimens differ markedly from the holotype of X. schaeferi in colour pattern and are more akin to the patterning of X. acanthognathus from Borneo. However, molecular analyses of one of the new specimens reveal that it only differs from the holotype of X. schaeferi by a minimum sequence divergence of 0.27%. An expanded description of the species based on these specimens is provided and phenotypic variation within the species is discussed. We also report the first record of the genus Xenophidion from West Sumatra, Indonesia. These sensational discoveries continue to underscore the fact that southern Peninsular Malaysia and upland areas of Southeast Asia in general still harbour unrealized herpetological diversity and are still in need of field research-based taxonomic studies.

Prevalence of on-host ticks (Acari: Ixodidae) in small mammals collected from forest near to human vicinity in Selangor, Malaysia

Abstract Ticks are important vectors that transmit a variety of pathogenic microorganisms known to be medically important worldwide. Many vertebrate groups have become host to this organism, and their presence and abundance are an indicator of the condition of both host and its habitat. This study was conducted to determine ticks infestation and its prevalence on small mammals residing in the recreational forests (RF) and semi-urban (SU) residential areas which have encountered Leptospirosis outbreak and cases in Hulu Langat, Selangor Malaysia. Trapping of the small mammals involved deploying two hundred cage traps in a systematic one-hectare plot (100 m × 100 m), as well as along the stream and forest trails at random. Ticks were extracted from the captured individual hosts. Identification of the tick species was performed based on morphological features and molecular approach using 16S rDNA and COI (cytochrome oxidase subunit I) genes. A total of 278 individuals of small mammals belonging to 15 species (13 Rodentia, 1 Scandentia and 1 Insectivora) were captured in the study areas. From these, 34 individuals from eight small mammal species were infested with ticks. The most infested host species was Mullers giant Sunda rat (Sundamys muelleri) with 5.80% (n=16). Ticks prevalence was slightly higher in RF with 6.40% (n=18) compared to SU with 5.80% (n=16). A total of 107 adult ticks (103 female and 4 male) were collected from the infested host. Ixodes granulatus was the most dominant tick species encountered (70.40%, n=85), followed by Dermacentor sp. (18.60%, n=20), while Amblyomma sp. was the least abundant (2%, n=2). This study provides information on tick species present and tick burden on small mammal hosts within the study areas. Our findings suggest that the visitors to the recreational forests and the residents of the semi-urban area were not only exposed to Leptospirosis bacteria but also tick bites and potentially tick-borne disease, therefore, precaution should be taken to avoid contact with small mammal hosts.