Bioacoustic Study of Insectivorous Bats

The microbat has developed advanced echolocating ability compared to the megabats or old-world fruit bats that relies mainly on vision and olfaction for food hunting. The microbats orient and capture their prey by means of echolocation that involves ultrasonic calls >20kHz, in which a frequency beyond the range of human hearing. Their morphological features and echolocation calls are designed in correlate with their adaptability with the environment especially with their superiority maneuver, detection and localize targeted object in cluttered environment. In Borneo, there are a total of 100 bats’ species with 85 species from Sarawak (15 Megabats and 70 echolocating microbats). The use of ultrasonic detectors in monitoring echolocation calls by using bat detectors has surged the researchers’ interest to study on bats and their habitat relationship as well as addressing questions concerning their activity patterns despite the limitations in this method. Present study intends to build a call library comprising of different species call frequencies as well as bat activity patterns in Kubah National Park via acoustic measures. To date, higher elevations recorded the highest activity that is determined by the number of passes but lower by species richness as compared to the lower elevation. Acoustic monitoring provides additional data of bat species that occur at each elevation that were not caught during trapping. These data will be highly useful in studying effect of landscape changes in the future

Multi-Locus Sequence Analysis Indicates Potential Cryptic Speciation in the Chigger Mite <i>Neoschoengastia gallinarum</i> (Hatori, 1920) Parasitising Birds in Asia.

Neoschoengastia gallinarum is widely distributed in Asia, preferentially parasitising birds, and heavy infestations have clinical impacts on domestic fowl. In common with other trombiculid mites, the genetic diversity and potential variation in host preferences or pathology induced by N. gallinarum are poorly understood. This study aimed to unravel the geographical variation and population structure of N. gallinarum collected from galliform birds in Peninsular Malaysia and Thailand by inference from concatenated mitochondrial-encoded cytochrome c oxidase subunit I (COI), and nuclear-encoded internal transcribed spacer 2 (ITS2) and 18S ribosomal DNA gene sequences, including a comparison with previously published data from southeastern China. Our multi-locus sequence analysis revealed three monophyletic clades comprising (A) specimens from Peninsular Malaysia, (B) the samples from Thailand together with a minority of Chinese sequences, and (C) the majority of sequences from China. Similarly, most species delimitation approaches divided the specimens into three operational taxonomic units. Analysis of molecular variance revealed 96.41% genetic divergence between Malaysian and Thai populations, further supported by the absence of gene flow (Nm = 0.01). In conclusion, despite the two countries sharing a land border, populations of N. gallinarum from Peninsular Malaysia and Thailand appear to be genetically segregated and may represent distinct cryptic species

On the taxonomy of chigger mites (Acariformes: Trombiculidae) parasitizing birds in Thailand and Malaysia, with the description of a new species

Chigger mites were collected from 65 bird species in different regions of Thailand and Malaysia. In total, 21 species were recorded. The previously unknown fauna of chiggers parasitizing shorebirds of Thailand included one new species, Neacariscus (Whartonacarus) andamanensis n. sp. as well as Neacariscus (Neacariscus) pluvius (Wharton, 1945) previously recorded only in Oceania; Neacariscus (Whartonacarus) shiraii (Sasa, Kano and Obata, 1952) (known from Oceania and Japan); and Neacariscus (Whartonacarus) sulae (Oudemans, 1910) and Schoengastia archaea (Taufflieb, 1960), both described from West Africa. Toritrombicula kirhocephales Goff, 1982 described from Papua New Guinea was for the first time recorded in Asia (Thailand). Neoschoengastia gallinarum (Hatori, 1920) and Helenicula comata (Womersley, 1952) were for the first time recorded in Thailand. Ascoschoengastia lorius (Gunther, 1939) was for the first time recorded in Malaysia. Finally, Ericotrombidium cosmetopode (Vercammen-Grandjean and Langston, 1971) described from free larvae, was for the first time recorded on a host (bird Pellorneum ruficeps Swainson); and Leptotrombidium miculum (Traub and Audy, 1954) was for the first time recorded on a bird host. New host species were recorded for a large part of the collected chigger species.</jats:p

Survey on the small mammals in Sg. Kangkawat research station Imbak canyon conservation areas

Sg. Kangkawat Research Station is a newly established research station in the Imbak Canyon Conservation Area, Sabah which encompasses both primary and secondary forest areas. Limited data is available on the small mammal diversity for this particular area. Therefore, a survey-based study on small mammal diversity was carried out between the 29th September – 8th October 2018 along the established trails within the vicinity areas of this research station. Small mammal trapping was done using traps (mist nets, harp traps, cage traps and pitfall traps) employed randomly along the Nepenthes trail, the Kawang trail, the South Rim trail and the Pelajau trail. This study documented a total of 32 small mammal species i.e. represented by 26 species (15 spp. of new records for ICCA ) of volant small mammals (Chiroptera) and 6 species of non-volant small mammals (Rodentia, Scadentia, Insectivora, Carnivora). The total number of specimens recorded was 108. A new distribution record on the Free-tailed Bat, Chaerephon cf. johorensis, was documented for Sabah and Borneo during this study

Population Genetic and Ecological Studies of the Bornean Endemic Cox’s Leaf-nosed Bat (Hipposideridae: Hipposideros coxi) in Sarawak

The endangered Cox’s Leaf-nosed bat, Hipposideros coxi, is known as a rare Bornean endemic species which are currently known as geographically disjunct population that are distributed in Northern region and Southwest region in Sarawak, Borneo. This study looked into the i) ecology, echolocation, physiology and dietary preferences together with ii) population genetic; gene flow and genetic structure of H. coxi in Sarawak. Little is known about the population size, abundance and trend of this endemic species; therefore, the ecological survey was conducted to study their distribution and ecological behaviour in six areas across Sarawak. Roost survey revealed an approximate of 34 individuals from three caves (Bako National Park, Gunung Mulu NP, and Wind Cave Nature Reserve). Their roost exhibit microclimate variation that influenced greatly by the number of individuals at the roosting sites, where H. coxi roost with more individuals showed higher temperature. Echolocation analysis revealed a marked difference of 5 kHz in peak frequency between the Northern region population (50.0 ± 0.18 kHz) and Southwestern region populations (45.3 ± 0.56 kHz). This variation further correlates with their morphological features, where the higher call frequency from Northern region having lighter body mass (8.75 ± 0.96 g) compared to Southwest population that exhibit lower call frequency but larger body mass (9.4 ± 0.44 g). The activity pattern recorded from three caves revealed that their emergence variation was influenced by the timing of sunsets and sunrise. Hipposideros coxi population from Northern region emerge earlier before sunsets, whereas, the population from Southwest region emerge approximately 5 to 10 minutes pass the sunsets. Analysis of diet preferences identified seven insects’ orders (Coleoptera, Lepidoptera, Hemiptera, Diptera, Hymenoptera, Trichoptera and Odonata) from the stomach content indicating that H. coxi is a generalist feeder. The gene flow and genetic structure based on 25 samples of H. coxi populations in Sarawak were revealed using concatenated mitochondrial DNA Cytochrome-b and partial D-loop gene. Phylogenetic analyses resulted in two major splits according to the sites that fall into two geographic groups (Northern regional group - Gunung Mulu NP; Southwestern regional group - Bako NP, Mount Penrissen, Tanjung Datu, Wind Cave NR) The Northern population shows a genetic divergence of 4.2% from the Southwestern population (indicating a conspecific species group). Time scale divergence analyses showed the diversification of H. coxi lineage in Borneo occur ~9.02 Mya. The diversification within Southwestern region took place during Pleistocene epoch. The repeated glacial cycle may have formed the geographical barriers among population. Thus, resulted in fragmented population and cut off the gene flow among H. coxi population within Sarawak, Borneo. The absence of gene flow contributed to a pronounced genetic structure within the population indicating this species is reproductively isolated. Partitioning of genetic diversity using AMOVA revealed a major genetic differentiation among and within the populations. Finally, the population level genetic analysis divulged a multimodal distribution curve. Thus, suggest that the population have been affected by bottleneck event which was supported by positive neutrality test of Tajima’s D (2.09). Bayesian Skyline Plot analyses further supported the population expansion hypothesis. To conclude, this study revealed that there may be multiple other sites occupied by H. coxi that yet to be discovered. Microclimate data presented in this study are crucial in identifying the hotspot for this species occurrences. All this information on this endangered bat would be fundamental insights to conserve and manage this species form further declining. Keywords: Divergence, echolocation, molecular marker, microclimate, roost ecolog

Survey on the Small Mammals in Sg. Kangkawat Research Station Imbak Canyon Conservation Areas

Sg. Kangkawat Research Station is a newly established research station in the Imbak Canyon Conservation Area, Sabah which encompasses both primary and secondary forest areas. Limited data is available on the small mammal diversity for this particular area. Therefore, a survey-based study on small mammal diversity was carried out between the 29th September – 8th October 2018 along the established trails within the vicinity areas of this research station. Small mammal trapping was done using traps (mist nets, harp traps, cage traps and pitfall traps) employed randomly along the Nepenthes trail, the Kawang trail, the South Rim trail and the Pelajau trail. This study documented a total of 32 small mammal species i.e. represented by 26 species (15 spp. of new records for ICCA ) of volant small mammals (Chiroptera) and 6 species of non-volant small mammals (Rodentia, Scadentia, Insectivora, Carnivora). The total number of specimens recorded was 108. A new distribution record on the Free-tailed Bat, Chaerephon cf. johorensis, was documented for Sabah and Borneo during this study