Abdul Hamid Ahmad | Universiti Malaysia Sabah (original) (raw)

Papers by Abdul Hamid Ahmad

Zootaxa, 2013

Twenty-two species of the genus Myrmarachne are reported from Borneo in the present study. Among ... more Twenty-two species of the genus Myrmarachne are reported from Borneo in the present study. Among those, eight are new to science, M.

PLOS ONE

Great argus pheasants are known for their elaborate visual mating displays, but relatively little... more Great argus pheasants are known for their elaborate visual mating displays, but relatively little is known about their general ecology. The use of passive acoustic monitoring—which relies on long-term autonomous recorders—can provide insight into the behavior of visually cryptic, yet vocal species such as the great argus. Here we report the results of an analysis of vocal behavior of the Bornean great argus (Argusianus argus grayi) in Sabah, Malaysia, using data collected with 11 autonomous recording units. Great argus regularly emitted two call types, the long call and the short call, and we found that although both call types were emitted throughout the day, the short calls were more likely to occur during the morning hours (06:00–12:00LT). Great argus were less likely to call if there was rain, irrespective of the time of day. A substantial portion of calls at our site (~20%) were emitted between the hours of 18:00–06:00LT. We found that for nighttime calls, calling activity incr...

Primates in Flooded Habitats

Royal Society Open Science

Evidence for compression, or minimization of code length, has been found across biological system... more Evidence for compression, or minimization of code length, has been found across biological systems from genomes to human language and music. Two linguistic laws—Menzerath's Law (which states that longer sequences consist of shorter constituents) and Zipf's Law of abbreviation (a negative relationship between signal length and frequency of use)—are predictions of compression. It has been proposed that compression is a universal in animal communication, but there have been mixed results, particularly in reference to Zipf's Law of abbreviation. Like songbirds, male gibbons ( Hylobates muelleri ) engage in long solo bouts with unique combinations of notes which combine into phrases. We found strong support for Menzerath's Law as the longer a phrase, the shorter the notes. To identify phrase types, we used state-of-the-art affinity propagation clustering, and were able to predict phrase types using support vector machines with a mean accuracy of 74%. Based on unsupervised...

Environmental Engineering and Management Journal

Rats (Rattus spp.) can cause substantial economic loss to oil palm (Elaeis quineensis Jacq.) plan... more Rats (Rattus spp.) can cause substantial economic loss to oil palm (Elaeis quineensis Jacq.) plantations. Spatial occurrence of rat in oil palm plantation has not been adequately dealt. We evaluated the rat occurrence at an oil palm plantation in Sabah, Malaysia using habitat factors from GIS and GeoEye data. Among the regression models examined, binomial logistic regression model best predicted the rat occurrence. Overall accuracy of the occurrence prediction calculated from an independent dataset was nearly 80%. The results allow us to identify factors of rat occurrence and recommend necessary control measures to the plantation management.

Scientific Reports

Early morning calling occurs across diverse taxa, which may be related to optimal conditions for ... more Early morning calling occurs across diverse taxa, which may be related to optimal conditions for sound transmission. There exists substantial inter- and intra-specific variation in calling time which is influenced by intrinsic, social and/or environmental factors. Here, we investigate environmental predictors of calling in gibbons. We hypothesized that male solos— which occur earlier and tend to be longer than duets—would be more influenced by environmental variables, if earlier, longer calling bouts are energetically costly, and therefore limited by overnight energy expenditure. Our top model for male solo events included amount of rain in the previous 24 hours, and explained 30% of the variance, whereas the top model for duet events (which included presence and amount of rainfall) explained only 5% of the variance. Rain the previous night led to a later start time of male solos (~30 minutes), but our top model for duet start time did not include any reliable predictors. Male solo ...

Journal of Advanced Agricultural Technologies

The antioxidant activity of Clarias gariepinus and Clarias sp.1 epidermal mucus were determined. ... more The antioxidant activity of Clarias gariepinus and Clarias sp.1 epidermal mucus were determined. Aqueous extracts of C.sp1 contained relatively higher levels of protein concentration [602.04mg g-1 fresh weight] than other extracts while the organic extracts (aqueous phase) of C.sp1 gave higher levels of protein concentration (43.50mg g-1 fresh weight) than dichloromethane phase for both species. The chemical composition analysis revealed the values of moisture, ash, crude protein, fat and carbohydrate contents present in both species. The DPPH scavenging effect of all extracts and standards on the DPPH radical decreased in order of: ascorbic acid > BHT > dichoromethane phase extract of C. gariepinus > aqueous phase of C. gariepinus > acidic extract of C.sp1 > acidic extract of C. gariepinus > dichloromethane phase extract of C.sp1 > aqueous phase extract of C.sp1 > aqueous extract of C. gariepinus > aqueous extract of C.sp1 at the concentration of 100ug/ml, respectively. Reducing power activities in all extracts increased with increasing concentration except for acidic extract of C. gariepinus which decreased at concentration of 100ug/ml. The Ferric Reducing Antioxidant Power (FRAP) also increased as the concentration increased for all extracts. However, all extracts showed lower scavenging activity, reducing power and FRAP activities than BHT and ascorbic acid at the same concentrations. This preliminary information suggest that mucus from these fish species may be a source of novel antioxidant agents for fish and human health related applicants.

Tropical Conservation Science

Knowledge of fundamental aspects of ecology such as species richness and distribution, and the fa... more Knowledge of fundamental aspects of ecology such as species richness and distribution, and the factors affecting them, is increasingly used to identify priority areas for conservation and to effectively manage threatened species.We investigated the species richness and distribution pattern of nonhuman primate communities inhabiting 10 sampling sites in four different habitat classes corresponding to increasing habitat disturbance level, that is, old growth forest, twice logged forest, repeatedly logged forest, and oil palm plantation, in and around Kalabakan Forest Reserve, in central Sabah, Malaysian Borneo. By using direct and indirect survey methods, we confirmed the existence of 9 out of the total 10 primate species, found in Sabah, within the surveyed areas. Based on the monthly number of primate species detected, our results indicated a general trend of decreasing primate species richness with increasing habitat disturbance level. However, the response within the disturbed forest sites showed some variations with some sites in repeatedly logged forest displaying comparable primate species number to that of the undisturbed forest sites.We also found that within the forest habitats, tree density is a good predictor of the richness of the primate community with a positive effect. Hence, tree density may be a key indicator for evaluating primate communities in forest habitats. Overall, the results of our study suggest that although not equivalent to areas of undisturbed forest, degraded forestsincluding those that have been repeatedly logged-are still valuable for primate conservation. In contrast, oil palm plantations have mainly negative effects on the primate community

Canyon Conservation Area in 2010. Yayasan Sabah, a statutory body of the Sabah state government, ... more Canyon Conservation Area in 2010. Yayasan Sabah, a statutory body of the Sabah state government, manages the area for conservation, research, training, education and nature recreation. Around this research station are various habitats over 300−1,400 m: primary lowland and upper mixed dipterocarp forest (300−900 m), lower montane forest (900−1,200 m) and rocky ultrabasic lower montane forest (1,200−1,400 m; J. Kulip, Universiti Malaysia Sabah, in litt. 2011). Hunting pressure around the station is low, although outsiders sometimes seek an aromatic wood, Gaharu Aquilaria malaccensis, in the area. Materials and methods Camera-trapping was carried out by the Institute for Tropical Biology and Conservation of Universiti Malaysia Sabah and Yayasan Sabah over 14−19 June 2011, around the Gunung Kuli Research Station. Fifteen camera-traps, comprising nine digital cameras (eight Capture, Cuddeback, CA, U.S.A.; one Field-Note Duo, Marif, Yamaguchi, Japan) and six analogue cameras (FieldNote II, Marif, Yamaguchi, Japan) were set along the Ridge Trail. This trail follows the main ridge west of the Gunung Kuli Research Station, looping approximately 10 km through steep slopes; it is around 1 m wide and does not break the canopy. During this survey, 4-8 people used this trail, but usually few people pass the trail. The camera-traps were placed around 30 cm above the ground and at every 150 m along the Ridge Trail itself in an otherwise undisturbed forest, covering elevations between 300 and 600 m (Table 1).

CATnews is the newsletter of the Cat Specialist Group, a component of the Species Survival Commis... more CATnews is the newsletter of the Cat Specialist Group, a component of the Species Survival Commission SSC of the International Union for Conservation of Nature (IUCN). It is published twice a year, and is available to members and the Friends of the Cat Group.

Journal of Mammalogy, 2016

We compared feeding behavior of frugivorous civets with those of other sympatric frugivores in a ... more We compared feeding behavior of frugivorous civets with those of other sympatric frugivores in a Bornean rainforest. For each frugivore residing in 3 different species of fig trees (Ficus variegata , F. fistulosa , and F. benjamina), we recorded temporal visitation patterns, visitation length, and time spent searching for fruit spanning 1,758h

... In: Padoc, C. and NL Peluso (Eds.). ... 1793) Appias pandione (Geyer, 1832) Appias paulina (C... more ... In: Padoc, C. and NL Peluso (Eds.). ... 1793) Appias pandione (Geyer, 1832) Appias paulina (Cramer, [1777]) Cepora iudith (Fabricius, 1787) Cepora pactolicus Butler, 1865* Delias hyparete (Linnaeus, 1758) Hebomoia glaucippe (Linnaeus, 1758) Leptosia nina (Fabricius, 1793) ...

Mammalia, 2016

We investigated fruit selection of a radio-collared female binturong (

ABSTRACT The genus Sundamys comprises the species Sundamys muelleri, Müller&quot;s rat, w... more ABSTRACT The genus Sundamys comprises the species Sundamys muelleri, Müller&quot;s rat, which is widespread in the Sundaic biogeographical subregion, and three other taxa, the mountain giant rats of Borneo S. infraluteus, Java S. maxi and Sumatra S. atchinensis. Nine additional specimens of the Borneo Mountain giant rat are reported, and one field record, adding new locations to the known range of the species in the Crocker Range, notably the vicinity of Gn. Alab, and Gn. Lumaku, Sabah, and at Pa Raye, Kalimantan Utara. Measurements of the specimens, and the first from Gn. Mulu, Sarawak, are tabulated with previously published data. Trapping results indicate that this rat is confined to an altitudinal range, 900 – 2350 m, broadly corresponding with the limits of Lower Montane Forest, especially Oak-Laurel forests, and that it occurs both in pristine habitat and in disturbed forests. The topography of the uplands of northern Borneo provides connections between all locations except Mulu, which is surrounded by lowlands. A review of palaeoecological interpretations indicates that favourable habitat for this rat was more extensive in north-western Borneo in the terminal Pleistocene, but may have been more reduced than at present during warm episodes of the Holocene. Consideration of palaeo-environments in the Sundaic subregion suggests that there may have been no genetic contact between mountain giant rats of Sumatra and Borneo during the Quaternary. Although molecular evidence is lacking, it is reasonable to treat Sundamys infraluteus, S. atchinenesis and Sundamys maxi as distinct species, arising independently by vicariant evolution from a Pliocene ancestry.

Mitochondrial DNA, Jul 15, 2015

Here we report the complete mitochondrial genome of the Bornean banteng Bos javanicus lowi (Cetar... more Here we report the complete mitochondrial genome of the Bornean banteng Bos javanicus lowi (Cetartiodactyla, Bovidae), which was determined using next-generation sequencing. The mitochondrial genome is 16,344 bp in length containing 13 protein-coding genes, 21 tRNAs and 2 rRNAs. It shows the typical pattern of bovine mitochondrial arrangement. Phylogenetic tree analysis of complete mtDNA sequences showed that Bornean banteng is more closely related to gaur than to other banteng subspecies. Divergence dating indicated that Bornean banteng and gaur diverged from their common ancestor approximately 5.03 million years ago. These results suggest that Bornean banteng might be a distinct species in need of conservation.

Intestinal parasitosis is still an important public health problem. The aim of this study was to ... more Intestinal parasitosis is still an important public health problem. The aim of this study was to determine the prevalence of gastrointestinal protozoan parasites (GIP) in schoolchilden and its association with socio-economic and environmental factors. A series of sample collections for stool was carried out in Sekolah Kebangsaan Inanam II, Kota Kinabalu, Sabah. Samples from 100 schoolchildren were examined by direct smear and formol-ether concentration techniques. The modified Kato-Katz technique was performed to estimate the parasitic burden, expressed in the number of protozoa per gram of stool. The proportion of overall infected samples was 31%. When ranked by proportion, parasite loads were found as follows: Entamoeba histolytica (83.87%), Giardia lamblia (35.48%), Entamoeba coli (22.58%), Entamoeba hartmanni (25.81%), Iodamoeba butschlii (19.35%) and Endolimax nana (6.45%). Both single and double infections in the study had equal percentages (35.48%), followed triple infection ...

Jurnal Teknologi, 2015

Animal species identification based on their sound has received attentions from researchers. This... more Animal species identification based on their sound has received attentions from researchers. This is to establish fast and efficient identification method. Identification of frogs have been one of the examples where research activities have shown some progress. Mel Frequency Cepstrum Coefficient (MFCC) and Linear Predictive Coding (LPC), coupled with k-th Nearest Neighbor (k-NN) or Support Vector Machines (SVM) have been the favorate approachs used by researchers. Quite recently, a new classification and identification method of sound using entropy-based approach for species identification of Australian frogs was proposed. Shannon, Rènyi and Tsallis entropy were used as features of extraction for the purpose of pattern recognition. Result shows that the full entropy-based animal sound identification system has successfully identified most of the frog species used in this study. The overall classification accuracy is as high as 91% with two failures from nine samples at 70% and 40%, ...

This is an article published in the Debate Forum in the Journal of Indonesian Natural History. It... more This is an article published in the Debate Forum in the Journal of Indonesian Natural History. It reviews the available information on the fate of the Sumatran rhino on Malaysia and how the species reached the current state i.e. very close to extinction. This forum stresses the importance of the Allee effects, which most likely had operated within the populations of the species in Malaysia within the last 50 years. The effects could insidiously push a species to extinction before meaningful intervention could be taken.