The Sumatran rhinoceros (Dicerorhinus sumatrensis) is on the verge of extinction in Malaysia. At the Sumatran rhinoceros Conservation Centre in Sungai Dusun, the reproductive behaviour of two female and two male rhinoceroses were studied for 8-10 months during attempts to breed them in captivity. Due to the paucity of scientific information on the reproductive biology of the Sumatran rhinoceros, this study was conducted to obtain information on the reproductive behaviour of this species. The male rhino was introduced to a female rhino in the morning for 1-2 h daily in order to observe for behavioural oestrus. Observations were made on the signs of oestrus and mating behaviour. Oestrus was determined by receptivity towards the male and lasted about 24 h. Common signs of oestrus were an increase in frequency of urine spraying, tail raising or swinging, anogenital and other contacts. Although the males exhibited mounting, the inability of the male to achieve intromission was poor. The study demonstrated that the pattern of courtship and copulation of the captive Sumatran rhinos were comparable with those of other rhino species, reported previously by other scientists and flehmen reflex was also exhibited by the male Sumatran rhinos. In a captive breeding programme, it is recommended that only an oestral female is introduced into a male enclosure due to the male solitary behaviour and to avoid serious injuries inflicted onto the females.
Matched MeSH terms: Behavior, Animal*; Sexual Behavior, Animal
There are many products claiming to be an electronic solution towards repelling mosquitoes. Several reviews were published in debunking these claims. However, there is a lack of a systematic study on effects of electromagnetic (EM) or more specifically, radio frequency (RF) waves against mosquitoes due to the conclusions made in those years. Therefore, we attempt to establish a fundamental study on female Aedes Aegypti (Linnaeus) mosquitoes by quantifying the collective behavior of the mosquitoes against a continuous stream of low-powered RF signals via a broadband horn antenna using image processing methods. By examining the average lateral and vertical positions of the mosquitoes versus frequency and time, the data shows negligible consistency in the reactions of the mosquitoes toward the different frequencies ranging from 10 to 20,000.00 MHz, with a step of 10 MHz. This was done by examining 33 hours of spatiotemporal data, which was divided into three sessions. All three sessions showed totally different convolutions in the positions in arbitrary units based on the raster scan of the image processing output. Several frequencies apparently showed up to 0.2-70% shift in both lateral and vertical components along the spectrum, without repeatability for all three sessions. This study contributes to the following: A pilot study for establishing the collective effects of RF against mosquitoes, open-source use, and finally a low-cost and easily adaptable platform for the study of EM effects against any insects.
Undertaking behavior is a significant adaptation to social life in enclosed nests. Workers are known to remove dead colony members from the nest. Such behavior prevents the spread of pathogens that may be detrimental to a colony. To date, little is known about the ethological aspects of how termites deal with carcasses.
Presbytis chrysomelas chrysomelas endemic only in Sarawak and Kalimantan was categorized by IUCN as a critically endangered primate that require special attention from research and conservation perspectives. A qualitative study on ranging patterns of P. c. chrysomelas was conducted in the Samunsam Wildlife Sanctuary, Sarawak. The study was conducted over a period of 13 months from December 2004 to December 2005 with 213 days of observation. Behavioural observation covered 17 groups with special emphasis on two main groups and 1 subadult group. Scanning and focal sampling were employed as the observation methods. Results indicated that P. c. chrysomelas had vertical, straight horizontal, and cross-horizontal types of movement patterns. P. c. chrysomelas was recorded to have a short movement distance (31.8-54.3 m). Distribution, abundance types, and food resources might be the factors that shaped the patterns of movement and distance in P. c. chrysomelas.
From May 2005-2006, selections of river crossing locations and sleeping sites used by a one-male group (BE-Group) of proboscis monkeys (Nasalis larvatus) were investigated along the Menanggul River, tributary of the Kinabatangan River, Sabah, Malaysia. The frequency of river crossings for focal monkeys in the BE-Group was significantly higher at locations with narrow branch-to-bank distances. Branch-to-bank distances were defined as the distances between the longest tree branches extending over the river and the bank of river on each side. This was measured in areas crossed by the monkeys. The focal monkeys used locations with a higher probability of successful river crossings that did not require jumping into the water and swimming across than those that did. The frequency of sleeping site usage by the BE-Group was positively correlated with the frequency of using river crossing locations by the focal monkeys. Previous reports on predation of proboscis monkeys indicate that clouded leopards (Neofelis diardi) and crocodilians (Tomistoma schlegeli and Crocodylus porosus) may be the major terrestrial and aquatic predators of these monkeys. The selection of river crossing locations by proboscis monkeys may be influenced both by the threat of these predators and the location of suitable and protected sleeping sites. Finally, sleeping sites locations that offer arboreal escape routes may protect proboscis monkeys from leopard attack.
The efficiency of a metaheuristic algorithm for global optimization is based on its ability to search and find the global optimum. However, a good search often requires to be balanced between exploration and exploitation of the search space. In this paper, a new metaheuristic algorithm called Ringed Seal Search (RSS) is introduced. It is inspired by the natural behavior of the seal pup. This algorithm mimics the seal pup movement behavior and its ability to search and choose the best lair to escape predators. The scenario starts once the seal mother gives birth to a new pup in a birthing lair that is constructed for this purpose. The seal pup strategy consists of searching and selecting the best lair by performing a random walk to find a new lair. Affected by the sensitive nature of seals against external noise emitted by predators, the random walk of the seal pup takes two different search states, normal state and urgent state. In the normal state, the pup performs an intensive search between closely adjacent lairs; this movement is modeled via a Brownian walk. In an urgent state, the pup leaves the proximity area and performs an extensive search to find a new lair from sparse targets; this movement is modeled via a Levy walk. The switch between these two states is realized by the random noise emitted by predators. The algorithm keeps switching between normal and urgent states until the global optimum is reached. Tests and validations were performed using fifteen benchmark test functions to compare the performance of RSS with other baseline algorithms. The results show that RSS is more efficient than Genetic Algorithm, Particles Swarm Optimization and Cuckoo Search in terms of convergence rate to the global optimum. The RSS shows an improvement in terms of balance between exploration (extensive) and exploitation (intensive) of the search space. The RSS can efficiently mimic seal pups behavior to find best lair and provide a new algorithm to be used in global optimization problems.
Mark-release-recapture experiments were undertaken in January 1989, in Pos Betau, Pahang, Malaysia, with the malaria vector Anopheles maculatus. On two consecutive nights, 121 and 175 blood-fed mosquitos were released. A mean recapture rate of 11.5% and survival rates of 0.699-0.705 with an estimated oviposition cycle period of 2.35 days were obtained from the releases. About 68% of all recaptures were taken within a distance of 0.5 km from their release points and the longest detected flight was 1.6 km. No heterogeneity was found between indoor and outdoor biters of An. maculatus.
Data are presented from a long-term study of banded langurs in three contrasting rain forest habitats in Peninsular Malaysia. Results from different sites and months are used to correlate ranging patterns with food availability and other environmental variables. Day range lengths are correlated with availability of preferred foods; the degree of territoriality is related to the distribution and size of food sources and length of time for which any one of these produces favoured food items.
In order to control any pest it is essential to study the life cycle, biology and bionomics of the target pest under control. With this respect, we have studied the flight range of the house fly Musca domestica (L.). The flight range of the house fly from two sites i.e, the poultry farm and a stable farm has been studied. The flight range study was conducted using a mark release technique. The approach we used in this study was that the flies collected from the respective farms were marked and released at different distances from the farms. The flies were then re-captured from the poultry farm and the stable farm. Studies conducted elsewhere use the technique of releasing the insect species at one spot and recapturing the insect species with the help of baited traps placed at various locations from the release point. The advantage of the approach used in this study was that the flight range as well as the homing effect was determined. From this study, the flight range of house flies released at the poultry farm was 7 km whereas flight range for flies release from stable farm was 5 km. The recovery rate of house flies at the poultry and stable farm was 0.05% and 0.016%, In this study, marked specimens has been detected up to 8 days in field conditions indicating that under field condition the life expectancy could be in the range of 1-2 weeks.
Laboratory rearing systems are useful models for studying Rhinotermitid behavior. Information on the biology of fungus-growing termites, however, is limited because of the difficulty of rearing colonies in the laboratory settings. The physical structure of termite nests makes it impossible to photograph or to observe colonies in the field. In this study, an artificial rearing system for field-collected colonies of the fungus-growing termite Odontotermes formosanus (Shiraki) was developed to facilitate observation in the laboratory. We recorded colony activity within the artificial rearing system and documented a variety of social behaviors that occurred throughout the food processing of the colony. This complex miniature ecosystem was cooperatively organized via division of labor in the foraging and processing of plant materials, and the observed patterns largely resembled the caste and age-based principles present in Macrotermes colonies. This work extends our insights into polyethism in the subfamily Macrotermitinae.
To propose proper conservation measures and to elucidate coexistence mechanisms of sympatric carnivore species, we assessed temporal activity patterns of the sympatric carnivore species using 37,379 photos collected for more than 3 years at three study sites in Borneo. We categorized activity patterns of nine carnivore species (one bear, three civets, two felids, one skunk, one mustelid, one linsang) by calculating the photo-capturing proportions at each time period (day, night, twilight). We then evaluated temporal activity overlaps by calculating the overlap coefficients. We identified six nocturnal (three civets, one felid, one skunk, one linsang), two diurnal (one felid, one mustelid), and one cathemeral (bear) species. Temporal activity overlaps were high among the nocturnal species. The two felid species possessing morphological and ecological similarities exhibited clear temporal niche segregation, but the three civet species with similar morphology and ecology did not. Broad dietary breadth may compensate for the high temporal niche overlaps among the nocturnal species. Despite the high species richness of Bornean carnivores, almost half are threatened with extinction. By comparing individual radio-tracking and our data, we propose that a long-term study of at least 2 or 3 years is necessary to understand animals' temporal activity patterns, especially for sun bears and civets, by camera-trapping and to establish effective protection measures.
Effective communication requires animal signals to be readily detected by receivers in the environments in which they are typically given. Certain light conditions enhance the visibility of colour signals and these conditions can vary depending on the orientation of the sun and the position of the signaller. We tested whether Draco sumatranus gliding lizards modified their position relative to the sun to enhance the conspicuousness of their throat-fan (dewlap) during social display to conspecifics. The dewlap was translucent, and we found that lizards were significantly more likely to orient themselves perpendicular to the sun when displaying. This increases the dewlap's radiance, and likely, its conspicuousness, by increasing the amount of light transmitted through the ornament. This is a rare example of a behavioural adaptation for enhancing the visibility of an ornament to distant receivers.
In general, African catfish shows higher survival rates in the dark conditions than in the light conditions. In this study, larval behavior of African catfish was observed under 0, 0.01, 0.1, 1, 10, and 100 lx using a CCD camera to investigate the reason why African catfish larvae show higher survival rates in dark conditions. The larvae showed significantly higher swimming activity under 0, 0.01, and 0.1 lx than that under 10 and 100 lx. The larvae also showed significantly increased aggressive behavior under 10 and 100 lx; the swimming larvae attacked resting individuals more frequently under 10 and 100 lx than under 0, 0.01, and 0.1 lx. The aggressive behavior and sharp teeth of the attacking larvae appeared to induce skin surface lesions on injured larvae. Chemical substances were then generated from the injured skin surface, and these chemical stimuli triggered cannibalistic behavior in other fish near the injured fish. The results of this study demonstrate that the higher survival rates of African catfish larvae under dark conditions are a result of inactivity and subsequent increase in chemical releasing stimuli concentrations around inactive individuals that triggers feeding behavior in nearby active catfish. Therefore, we recommend larval rearing of African catfish in dark or dim conditions, as it improves catfish survival rates.
Misotermes mindeni Disney and Neoh is a solitary endoparasitoid of Macrotermes gilvus (Hagen) (Termitidae: Macrotermitinae), exclusively parasitizing the head of major soldiers. In this study, behavioral and morphological changes in the parasitized termite host were evaluated. We also observed the larval parasitoid emerging from the host. We found that parasitism mainly occurred in termite mounds overgrown with grass and mounds that had been broken up previously for other experiments. The parasitized soldiers showed a significantly lower level of interspecific aggressiveness compared with healthy soldiers (P < 0.05). Parasitized soldiers also changed in habitat preference to one isolated chamber of the nest. This might be an adaptive strategy that facilitates parasitoid dispersal, provides protection to parasitoids, and reduces the risk of parasitism to host colony. An abnormally rounded head capsule and remarkably short mandibles are characteristics of a parasitized soldier. The older larval fly stages were found only in major soldiers. We suggest that parasitization may first start in fourth or even earlier larval termite instars. The fly larva develops in the termite soldier's head capsule and pupates inside the host's body.
Flight activities of two sympatric termite species, Macrotermes gilvus (Hagen) and Macrotermes carbonarius (Hagen), were studied in Penang Island, Malaysia. Herein, we present the first documentation of chronological reproductive isolation of M. gilvus and M. carbonarius. Flights of M. gilvus were recorded over a remarkably long 7-mo period from March to September, whereas swarming of M. carbonarius took place from November to January. Swarming events of M. gilvus and M. carbonarius occurred under atmospheric pressures of 1,005-1,011 and 1,006-1,010 hPa, respectively. Most flights of M. gilvus occurred on days with rain, whereas M. carbonarius avoided rain. Flight activity of M. gilvus was correlated significantly with atmospheric pressure and rainfall. The threshold temperature and relative humidity of M. gilvus flights were between 23 and 26 degrees C and 83 and 98% RH, respectively; M. carbonarius swarmed between 25 and 30 degrees C and 72 and 83% RH, respectively. The flight activity of M. gilvus concentrated in the warmer and humid months with a monthly total rainfall of 228 mm. Both species swarmed at distinct times of day during the limited field observations: Flights of M. gilvus began between 0300 and 0430 hours (light intensity <1 Lx), and flights of M. carbonarius lasted for only 4-10 min between 1900 and 1910 hours (at dusk; light intensity: 20-200 Lx). Windless conditions were preferred for the flights of both species.