61 research outputs found
AN OVERVIEW ON THE ECOLOGY OF VARANID LIZARDS
Arida, E. 2008. An overview on the ecology of Varanid lizards. Zoo Indonesia 17(2):67-82. Body size is a morphological character that can be useful to estimate the sizeof home range in varanids. It may also be used to cue for habitat type and mode of lifeof varanid lizards. Nevertheless, although body size may be a good predictor ofhome range size, it may not be useful to infer population density, because nonterritorialitynature of varanid lizards generates home range overlaps. Although nonterritorialitynature may hinder inference of population density, it can signal for highdensity through the signature of aggression. However, the magnitude of density itselfwould not be well quantified. An approach to population density estimation is the useof reproductive biology data. Reproductive biology data of wild varanids can be usedto base a projection on population trends. Despite the notion, data on reproductionfrom wild populations seems to be scarce, especially from some regions in Asia.Regular population monitoring for general census and reproductive status is definitelystill needed to allow for sound estimates of population density and its dynamics
PEMETAAN KONFLIK MANUSIA DENGAN BIAWAK (Varanus salvator) BERBASIS WEB SCRAPING BERITA ONLINE
Latar Belakang: Laju pertumbuhan penduduk bumi yang sangat tinggi dalam beberapa dekade terakhir berimbas terhadap meningkatnya luasan lahan pertanian secara pesat. Salah satu akibat yang muncul dari laju perubahan lahan hutan adalah semakin banyaknya konflik yang muncul antara satwa liar dengan manusia. Meskipun konflik manusia dengan satwa liar juga banyak ditemukan di Indonesia, namun usaha untuk melakukan inventarisasi dan pemantauan jenis-jenis konflik beserta sebarannya masih terbatas. Mamalia dan burung merupakan dua kelompok satwa liar yang telah dikaji secara luas.Metode: Penelitian ini berusaha mengumpulkan data kejadian konflik manusia dengan biawak yang sering muncul di berita-berita daring. Pengumpulan berita dari media online (web scraping) dilakukan secara otomatis dengan menggunakan python package GoogleNews. Berita yang terkumpul dan disimpan dalam format spreadsheet diolah untuk mendapatkan informasi lokasi dan jenis konfliknya.Hasil: 35 kasus konflik biawak pada tahun 2019 dan 66 kasus pada tahun 2020 berhasil dipetakan dan diketahui jenis-jenisnya. Kasus kemunculan biawak di wilayah pemukiman/perkantoran merupakan kasus yang paling banyak diberitakan dimana wilayah Jabodetabek mendominasi pemberitaan konflik manusia dengan biawak.Kesimpulan: Penelitian ini menunjukkan teknik web scraping sangat berguna untuk mengumpulkan berita tentang konflik manusia dengan biawak dalam waktu yang cepat. Berita yang dikumpulkan dapat menunjukkan persebaran dan jenis konflik biawak di Indonesi
Genetic Divergence and Phylogenetic Relationships Among Indonesian Species of Monitor Lizards of the Genus Varanus Based on Cytochrome Oxidase I Sequences
The application of cytochrome oxidase subunit I for genetic divergence and phylogenetic analyses in monitor lizards seems to be limited, despite the practicality and relevance to use the short sequence of this region known as the DNA barcode. Some Indonesian species of monitor lizards are morphologically similar, some of which are legally exported as pet animal commodities and some others being protected by Indonesian national law. Thus, a practical molecular tool that can be useful to help clarify their species identity is essential, especially for closely related species. This study used the DNA barcode to test the application of this mitochondrial DNA region as a molecular tool to identify some species of Indonesian monitor lizards for the first time. Results showed that the Barcodes can facilitate molecular speciesidentification based on their relative amount of genetic divergence and phylogenetic relationships. Closely related species can be distinguished based on the short sequences, as well as a likelihood of species misidentification among samples in this study. Further study should be performed in the future using more species, especially those belong to groups of species complex from the eastern Indonesia and species protected by the Indonesian national law
FIRST REPORT ON THE FEEDING BEHAVIOR OF EARLESS MONITOR, LANTHANOTUS BORNEENSIS AND ITS PREDATION ON RICE FIELD FROG, FEJERVARYA LIMNOCHARIS IN A CAPTIVE ENVIRONMENT
Being endemic to Borneo, the Earless monitor, Lanthanotus borneensis (Steindachner, 1878) is rarely found in its habitats due to its cryptic behavior. We provide care for confiscated animals in the Reptile House of Museum Zoologicum Bogoriense (MZB) in Cibinong, West Java, Indonesia since 2014. Little is known on its natural prey but from scattered descriptive reports. This study is aimed at documenting the feeding behavior of ten captive Earless monitors and events of predation on frogs. We set up two experiments, one with meat of Rice Field Frog, Fejervarya limnocharis, and the other with live frog of the same species. Our recorded observations ran for four weeks for the frog meat feeding experiment and followed by the frog predation experiment. Our results showed that lizards constantly accepted frog meat. Lizards tended to feed before sunset for a short period of time on the muddy soil surface, although a few individuals inconsistently fed under water. The average body mass for these lizards increased by 4.29 g and average SVL by 0.45 cm. We recorded predation on frogs in three out of ten individuals observed during this study. If F. limnocharis is confirmed to occur in the natural habitats of L. borneensis, it is possible that this frog species is among the natural prey for Earless monitors. Further studies on its natural diets should be conducted to gain in-depth knowledge essential for generating effective captive husbandry for this nationally protected species in Indonesia
MATING BEHAVIOR AND BREEDING OF THE BLUE TREE MONITOR, VARANUS MACRAEI IN AN IN-COUNTRY FACILITY IN INDONESIA: A PRELIMINARY NOTE
The Blue tree monitor, Varanus macraei Böhme & Jacobs, 2001 is a tree monitor species favored by reptile keepers. Successful captive breeding was reported from hobbyists and zoos in Europe shortly after its scientific description. Meanwhile, commercial farming to supply international demands has been progressing in Indonesia. However, such successful ex-situ breeding efforts have not yet been documented or published in Indonesia thus far. Therefore, in this, study we describe for the first time the mating behavior and reproduction of a V. macraei couple in an in-country outdoor facility, which is a common husbandry practice for monitor lizard breeders in Indonesia. The male started to approach the female at the beginning of the dry season, in May, with the female showing defensive behavior towards the male, both before mating and after laying eggs, pointing to a seasonal reproductive behavior. Monitor lizards were observed being active during the daytime. Eggs were laid by mid-July 2020. Two of the six eggs laid were revealed to be fertile and hatched after about 23 weeks (5.6 months). The two hatchlings were reared in an indoor enclosure, but only one survived, which showed to be a male
Molecular Sex Determination of Captive Komodo Dragons (Varanus komodoensis) at Gembira Loka Zoo, Surabaya Zoo, and Ragunan Zoo, Indonesia
Captive breeding of endangered species is often difficult, and may be hampered by many factors. Sexual monomorphism, in which males and females are not easily distinguishable, is one such factor and is a common problem in captive breeding of many avian and reptile species. Species-specific nuclear DNA markers, recently developed to identify portions of sex chromosomes, were employed in this study for sex determination of Komodo dragons (Varanus Komodoensis). Each animal was uniquely tagged using a passive integrated micro-transponder (TROVAN 100A type transponders of 13 mm in length and 2 mm in diameter). The sex of a total of 81 individual Komodo dragons (44 samples from Ragunan zoo, 26 samples from Surabaya zoo, and 11 samples from Gembira Loka zoo) were determined using primers Ksex 1for and Ksex 3rev. A series of preliminary PCR amplifications were conducted using DNA from individuals of known sex. During these preliminary tests, researchers varied the annealing temperatures, number of cycles, and concentrations of reagents, in order to identify the best protocol for sex determination using our sample set. We thus developed our own PCR protocol for this study, which resulted in the amplification of band A in females and band C in males. Results from band B, however, turned out to be non-determinative in our study because, for females, band B was not always visible, and for males sometimes a similar, but lighter band was also amplified, making interpretation difficult. In this study, sex determination was based mainly on the difference in size between the female-specific 812 bp fragment and the homologous, longer fragment amplified for males
Population structure, genomic diversity and demographic history of Komodo dragons inferred from whole-genome sequencing
Melanesia holds the world’s most diverse and intact insular amphibian fauna
Identifying hotspots of biological diversity is a key step in conservation prioritisation. Melanesia—centred on the vast island of New Guinea—is increasingly recognised for its exceptionally species-rich and endemic biota. Here we show that Melanesia has the world’s most diverse insular amphibian fauna, with over 7% of recognised global frog species in less than 0.7% of the world’s land area, and over 97% of species endemic. We further estimate that nearly 200 additional candidate species have been discovered but remain unnamed, pointing to a total fauna in excess of 700 species. Nearly 60% of the Melanesian frog fauna is in a lineage of direct-developing microhylids characterised by smaller distributions than co-occurring frog families, suggesting lineage-specific high beta diversity is a key driver of Melanesian anuran megadiversity. A comprehensive conservation status assessment further highlights geographic concentrations of recently described range-restricted threatened taxa that warrant urgent conservation actions. Nonetheless, by world standards, the Melanesian frog fauna is relatively intact, with 6% of assessed species listed as threatened and no documented extinctions; and thus it provides an unparalleled opportunity to understand and conserve a megadiverse and relatively intact insular biota
Exploring the vertebrate fauna of the Bird’s Head Peninsula (Indonesia, West Papua) through DNA barcodes
Biodiversity knowledge is widely heterogeneous across the Earth's biomes. Some areas, due to their remoteness and difficult access, present large taxonomic knowledge gaps. Mostly located in the tropics, these areas have frequently experienced a fast development of anthropogenic activities during the last decades and are therefore of high conservation concerns. The biodiversity hotspots of Southeast Asia exemplify the stakes faced by tropical countries. While the hotspots of Sundaland (Java, Sumatra, Borneo) and Wallacea (Sulawesi, Moluccas) have long attracted the attention of biologists and conservationists alike, extensive parts of the Sahul area, in particular the island of New Guinea, have been much less explored biologically. Here, we describe the results of a DNA-based inventory of aquatic and terrestrial vertebratecommunities, which was the objective of a multidisciplinary expedition to the Bird's Head Peninsula (West Papua, Indonesia) conducted between 17 October and 20 November 2014. This expedition resulted in the assembly of 1005 vertebrate DNA barcodes. Based on the use of multiple species-delimitation methods (GMYC, PTP, RESL, ABGD), 264 molecular operational taxonomic units (MOTUs) were delineated, among which 75 were unidentified and an additional 48 were considered cryptic. This study suggests that the diversity of vertebrates of the Bird's Head is severely underestimated and considerations on the evolutionary origin and taxonomic knowledge of these biotas are discussed.Fieldwork and laboratory activities were supported by the Lengguru 2014 Project (www.lengguru.org), conducted by the French National Research Institute for Sustainable Development (IRD), the Indonesian Institute of Sciences (LIPI) with the Research Centre for Biology (RCB), and the Politeknik KP Sorong, with the help of the Institut Français in Indonesia (IFI) and the French embassy in Jakarta, with corporate sponsorship from COLAS SA Company (Environment Department), Total Foundation, ABS, Wasco, Veolia Eau, SDV-Bolloré,Peer reviewe
Genetic Divergence and Phylogenetic Relationships Among Indonesian Species of Monitor Lizards of the Genus Varanus Based on Cytochrome Oxidase I Sequences
The application of cytochrome oxidase subunit I for genetic divergence and phylogenetic analyses in monitor lizards seems to be limited, despite the practicality and relevance to use the short sequence of this region known as the DNA barcode. Some Indonesian species of monitor lizards are morphologically similar, some of which are legally exported as pet animal commodities and some others being protected by Indonesian national law. Thus, a practical molecular tool that can be useful to help clarify their species identity is essential, especially for closely related species. This study used the DNA barcode to test the application of this mitochondrial DNA region as a molecular tool to identify some species of Indonesian monitor lizards for the first time. Results showed that the Barcodes can facilitate molecular species identification based on their relative amount of genetic divergence and phylogenetic relationships. Closely related species can be distinguished based on the short sequences, as well as a likelihood of species misidentification among samples in this study. Further study should be performed in the future using more species, especially those belong to groups of species complex from the eastern Indonesia and species protected by the Indonesian national law
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