Comparative study of vocal communication in two Asian leaf monkeys, Presbytis johnii and Presbytis entellus

This paper presents comparative data on the vocal communication of two Asian leaf monkeys, the Nilgiri langur (Presbytis johnii) and South Indian common langur (Presbytis entellus), based on sound recordings and behavioural observations of free-ranging groups. Spectrographical analyses revealed a repertoire of 18 basic patterns for Nilgiri langurs, and 21 basic patterns for common langurs. The repertoires of the two langur species consist of both discretely structured vocal patterns, in which alterations of the physical parameters are restricted to intra-class variation, and those in which structural variations cause integration between different sections of the repertoire. Qualitative assessments of group scans indicate that in both species vocal behaviour is characterized by pronounced sex-differences in the use of the different elements of the vocal repertoire. Comparison of data available from different populations of P. entellus suggests population-specific modifications on both structural and behavioural levels. Moreover, characteristic elements of the vocal systems of the two Asian species demonstrate striking similarities to those described for the African black-and-white colobus.     

Sociobiology of Hanuman langurs (Presbytis entellus): introduction into the Jodhpur field project

The conceptual development of a longterm project on Hanuman langurs (Presbytis entellus) is described. The joint indo-german project was performed at Jodhpur, India, starting in 1977. Its main aim was to study the interrelations between individual life histories and troop histories. A general overview of the habitat and the langur population is presented.     

Aging and reproductive performance in langur monkeys (Presbytis entellus)

Analysis of data on age and reproductive performance in 16 captive female Hanuman langurs (Presbytis entellus) shows that adult females under the age of 6 years and over the age of 19 years had the lowest rates of reproductive success as measured by the production of viable young that survived beyond 30 days of age. With the possible exception of one female, females over the age of 19 years experienced a variety of idiosyncratic reproductive problems but did not experience a true menopause as defined by total cessation of menstrual cycles. There was no support for the hypothesis that langur monkey females have evolved a lengthy postreproductive period.     

A preliminary investigation of home range use in the Gir Forest langur

Two troops of grey langur monkeys (Presbytis entellus entellus) were observed in the Gir Forest, western India for approximately 220 hours in two of three seasons at very high crude densities ranging from 115–128 langurs per km². Daily activity patterns and home range use are described and a scan-sampling technique of activity distribution employed. Food and predator avoidance are estimated to be major determinants of population density and home range size, structure, and composition.     

Animated documentation of the filaria dance sign (FDS) in bancroftian filariasis

BACKGROUND: Ultrasonography is able to detect adult Wuchereria bancrofti worms in scrotal lymphatic vessels of infected men on account of the characteristic pattern of adult worm movements, known as the filarial dance sign. Furthermore, the technique is able to delineate associated pathology, such as hydrocoele and lymphoedema, which can be diagnosed in early stages. Ultrasonography is also useful in the assessment of macrofilaricidal effects of antifilarial medication.The purpose of this study was to evaluate the usefulness of scrotal ultrasonography, in combination with a new method of digital documentation, in men infected with Wuchereria bancrofti. METHODS: Ultrasonography of the scrotal areas was carried out in 33 male patients from an endemic area in Ghana using a hand-carried ultrasound system and a linear array transducer at 7.5 MHz. Wuchereria bancrofti infection was also assessed by quantification of night blood microfilaraemia and semi-quantitative detection of circulating filarial antigen. Ultrasound findings were documented by print outs and by Digital Video sequences directly exported from the ultrasound machine which were edited in Final Cut Pro 3ledR; and exported, using QuickTimecircledR; Pro, as MPEG-1 video. RESULTS: Worm nests, i.e. dilated lymphatic vessels with the characteristic movement patterns of worms, were found in all patients, and typical examples of larger as well as smaller nests are presented through MPEG-1 video in b- and m-modes as well as Colour Doppler and Pulse Wave Doppler images. CONCLUSION: In this study, the filarial dance sign is being made available on the Internet to readers through MPEG-1 video. This method allows for demonstration of movement patterns rather than static images. In addition, the pathologic ultrasonographic signs of filariasis can be rapidly relayed over great distances and may be helpful to other investigators or clinicians in the diagnosis of patients infected with Wuchereria bancrofti.     

Biosocial functions of grooming behavior among the common Indian langur monkey (Presbytis entellus).

An intensive study of the Indian langur monkey (Presbytis entellus) reveals an interplay between biological and social processes. This study which involved captive animals and over 1,500 observation hours suggests that grooming behavior alone cannot be used to measure status differences between the sexes, nor as a means to understand how pathogens carried by ecto-parasites are controlled. It is shown that the type of grooming exhibited in an interactional setting and the region of the body presented by one animal to another for grooming is often determined by the immediate social events and by the nature of the relationship existing between the participants. For these Colobine langur monkeys grooming behavior not only facilitates integration but it also enables an animal to manipulate a tense situation into a peaceful one. Without reference to many of the other patterns of behavior which only relatively, not absolutely differentiate age and sex classes, grooming behavior cannot be entirely understood.     

Molecular characterization of a truncated antigen (Wb14) of SXP-1 of Wuchereria bancrofti from four endemic regions in India

Wb14 of Wuchereria bancrofti, an orthologue of Brugia malayiSXP-1 and W. bancrofti SXP-1, was amplified from genomic DNA of W. bancrofti microfilaria collected from four distant geographical locations in India viz., Vellore, Bhubaneshwar, Pondicherry and Sevagram. The gene was sub-cloned in a prokaryotic vector pRSET and expressed in Escherichia coli as a truncated protein (∼23 kDa). The nucleotide sequence of the gene is 98% similar to that of WbSXP-1 and is found to be intron-less. However, the analysis and comparison of the derived amino acid sequence with WbSXP-1 showed that Wb14 is truncated at amino acid position 153. The distribution of the two genes in the studied four geographical locations indicated that WbSXP-1 is prevalent only in parasite samples from Sevagram while Wb14 is present in parasites from all the other locations. Only a limited polymorphism was observed in both the genes among the parasites from different geographical locations.     

The process of weaning in hanuman langursPresbytis entellus entellus

Twelve langur infants (seven males and five females) of three focal bisexual unimale troops of Hanuman langurs,Presbytis entellus entellus living near Kailana, Jodhpur, Rajasthan (India) were observed for their weaning behaviour. Weaning starts between 7.0 to 10.0 months of age, average 8.6 months. The process of weaning lasts between 3.2 to 5.6 months, average 4.2 months. A 13-month-old infant is fully weaned. Infants are independent at this age. Male infants are weaned earlier compared to females. Males react to their mothers' rejections more fearlessly and are more vocal compared to females. By and large, infants were found in stress during this period as their mothers are often very harsh, hostile, punitive, and indifferent to their infants. By severing ties with their infants, mothers serve dual purpose of allowing their infants to become independent and may be to become ready to bear offspring.     

Filariasis in Gongola State Nigeria. I: Clinical and parasitological studies in Mutum-Biyu district.

A total of 2552 persons living in 9 villages along the Benue river valley, Mutum-Biyu district of Gongola State, Nigeria were examined between October and December 1989 for filariasis. It is the first time a filariasis survey will be carried out in this State. 276 (10.8%) had Wuchereria bancrofti, 50 (2.0%) had Loa loa, 281 (11.0%) were positive for Mansonella perstans while 12 (0.5%) were positive for Onchocerca volvulus. Villages located near the Benue river had higher prevalence rates than those further away. Dermatitis and hydrocoele were common and clinical manifestations were associated with parasite types. Clinical symptoms without microfilaremia and microfilaremia without clinical symptoms were also observed. The study will fill the gap in our knowledge of filariasis in this part of Nigeria.     

Molecular systematics and conservation of the langurs and leaf monkeys of South Asia

Numerous morphology-based classification schemes have been proposed for langurs and leaf monkeys of South Asia but there is very little agreement between them. An incorrect classification scheme when used as a basis for biogeographic studies can support erroneous hypotheses. Further, lack of taxonomic resolution will also confound conservation efforts, given that conservation biologists use traditional morphology-based-classification schemes to prioritize species for conservation. Here, I have revisited recent molecular phylogenetic studies done on langurs and leaf monkeys of South Asia. Results from these studies are in turn used to derive a rational and scientific basis for prioritizing species for conservation. Molecular data support the classification of langurs of the Indian subcontinent—Hanuman, Nilgiri and purple-faced langurs—in the genus Semnopithecus, whereas Phayre’s leaf monkey along with other Southeast Asian leaf monkeys form another distinct clade (Trachypithecus). The phylogenetic position of capped and golden langurs remains unresolved. Molecular data suggest that they are closely related to each other but this group might have evolved through past hybridization between Semnopithecus and Trachypithecus. Additionally, genetic data also support the splitting of the so-called Hanuman langurs into at least three species. The scores for taxonomic uniqueness of langurs and leaf monkeys of South Asia were revised using this molecular phylogeny-based classification. According to the revised scores, Phayres leaf monkey and golden langur are priority species for conservation followed by capped and Nilgiri langurs.     

A behavior repertoire for the Indian langur monkey (Presbytis entellus)

This behavior repertoire for the Indian langur monkey (Presbytis entellus) is based on observations of free-ranging langurs in north and central India and on an ongoing study of social behavior in colony-living langur monkeys. The purposes of this repertoire are: (1) to allow the investigator to record all social behavior observed, (2) to allow comparison with the results of other observations, and (3) to draw a baseline picture of behavior against which the effects of experimental manipulations may be measured. The behavior units of this repertoire are organized into the categories of general behaviors, infant caretaking, sexual, play, vocalization, agonistic, and grooming. Each unit is defined and examples are given of the contexts in which behaviors are most often used. The repertoire, as designed, is appropriate for use with a focal animal sampling method.     

Impact of untreated bednets on prevalence of Wuchereria bancrofti transmitted by Anopheles farauti in Papua New Guinea

Abstract Despite the growing evidence that insecticide‐treated mosquito nets reduce malaria morbidity and mortality in a variety of epidemiological conditions, their value against lymphatic filariasis infection and disease is yet to be established. The impact of untreated bednets on the prevalence of Wuchereria bancrofti (Cobbold) (Nematoda: Filarioidea) infection and disease was investigated on Bagabag island in Papua New Guinea, where both malaria and filariasis are transmitted by the same vector mosquitoes of the Anopheles punctulatus Dönitz group (Diptera: Culicidae). Community‐wide surveys were conducted recording demographic characteristics including bednet usage. Physical examinations for hydrocoele and lymphoedema were performed and blood samples assessed for filarial and malaria parasites. Mosquitoes were sampled using the all‐night landing catch method and individually dissected to determine W. bancrofti infection and infective rates. Bednet usage among residents was 61% and the mean age of users (25.6 years) was similar to non‐users (22.5 years). Anopheles farauti Laveran was the only species were found to contain filarial larvae: 2.7% infected (all stages), 0.5% infective (L3). The overall W. bancrofti microfilaraemia and antigenaemia rates were 28.5% and 53.1%, respectively. Bednet users had lower prevalence of W. bancrofti microfilaraemia, antigenaemia and hydrocoele rates than non‐users. In comparison, untreated bednets had no effect on the prevalence and intensity of Plasmodium falciparum and P. vivax infections. The impact of bednet usage on rates of microfilaraemia and antigenaemia remained significant even when confounding factors such as age, location and sex were taken into account, suggesting that untreated bednets protect against W. bancrofti infection.     

Dominance,age, and reproductive success in free-ranging female hanuman langurs (Presbytis entellus)

Correlations among female age, dominance, and reproduction were investigated for a 12-year period in free-ranging, provisioned Hanuman langurs (Presbytis entellus), living in one-male groups near Jodhpur in Rajasthan, India. Of 2940 displacement episodes, 27% occurred over natural food, 26% over provisioned food, 8% over grooming, 23% over position and shade, and 16% for other reasons. It was possible to reconstruct a displacement hierarchy that was linear and stable over short periods but fluctuated according to the age composition of the troop, resulting in an age inversed dominance structure. Females occupied top ranks as soon as they experienced menarche (around 2.4 years of age) and gradually declined thereafter, with postmenopausal females (≥30 years) being the lowest ranking individuals. Old females tended to be peripheral, while young females were highly social and active. Fertility peaked at about 7 years and gradually decreased thereafter, but infant mortality was much higher in young females than in old ones. During years when females gave birth, their ranks, especially those of old females, were higher than the average expectation for their age class, which suggests that females compete more vigorously if they have an infant. Reproductive success (i.e., infant survival to ≥2 years) declined significantly from high-over middle-to low-ranking females but did not differ for the three age classes investigated, because the higher fecundity of young females was balanced by better rearing success of older females. These results are discussed in light of the controversy over whether the langur social system is strongly influenced by kin selection (Hrdy and Hrdy, 1976; Dolhinow et al., 1979).     

Trapping, care, and laboratory management of the silvered leaf monkey (Presbytis cristatus)

The silvered leaf monkey (Presbytis cristatus) from South Kalimantan ( Borneo ), Indonesia is a natural host for a variety of filarial nematodes including Brugia malayi and Wuchereria kalimantani . Experimental studies show that it is host for W. bancrofti, a filarial nematode causing elephantiasis in man. Presbytis cristatus is a gregarious primate of primary and secondary forests, roaming in troops of 20-30 members. Primarily a fruit and leaf eater under natural conditions, this monkey can adapt to a laboratory diet of commercial monkey chow supplemented with fruits and vegetables. Troops, led by an alpha male, immediately respond to protect their young during stressful or dangerous situations. Infants are born singly and are bright orange. Transition to the adult grey and black coloration begins three to five months after birth. Silvered leaf monkeys can be readily trapped. Initially they are aggressive and will attack but become tractable several days after capture. Reaching upward is an important feeding behavior of the silvered leaf monkey and they will not feed from the floor of the cage. In the laboratory they are nonaggressive and lend themselves to various procedures such as blood drawing and examination. Silvered leaf monkeys travel well in commercial animal transport cages. In the United Stages they are not an endangered species and can be readily imported. In Indonesia they are not protected by law and can be exported.     

Rotavirus antibodies in hanuman langurs (Presbytis entellus)

Serum samples from wild Hanuman langurs (Presbytis entellus) from Mysore State, India, were compared to samples from a laboratory colony from Davis, Calif., for antibodies to rotavirus, which is an important cause of gastroenteritis in mammals. Animals from the laboratory colony had a higher frequency and higher levels of antibody than wild animals. It is likely that wild populations of langurs have a much lower incidence of rotaviral infection than laboratory populations, which are exposed to both crowded conditions and rotaviruses from other species.     

Feeding and ranging patterns of forest hanuman langurs (Presbytis entellus)

The feeding and ranging patterns of a troop of hanuman langurs (Presbytis entellus, Colobinae) were studied in Kanha Tiger Reserve, central Indian Highlands for 1850 hr (1981–1982), in a mosaic of moist deciduous forest and anthropogenic meadow. The location, size, and species of each tree within the 74.5-ha troop annual range was known and the phenology of all tree species was sampled. According to scan sampling, the troop spent 25.7% of the daytime feeding, with range use concentrated on an island of dry deciduous forest. Whereas adjacent troops occupied only the periphery of the focal troop's range, all-male bands occupied its center, especially during takeover and infanticidal attacks. The troop consumed items from 60 of the 67 species of trees and woody climbers available; mature leaves (34.9% of feeding time), fruits (24.4%), leaf buds (10.6%), flowers and flower buds (9.5%), young leaves (3.6%), insects (3.0%), and gum (1%). The monthly utilization of fruit, open leaf buds, and flower buds is correlated significantly with their abundance, and the troop spent significantly more time feeding and less time moving when consuming mature leaves. Comparison of tree dispersion and langur ranging patterns suggests that the distribution of the most important food trees is a major influence on their range use.     

Localization of Brugia malayi (sub-periodic) adults in different organs of Mastomys coucha and its influence on microfilaraemia and host antibody response

Lymphatic filariasis caused by nematode parasites Wuchereria bancrofti or Brugia malayi is a spectral disease and produces wide range of immune responses and varying levels of microfilaraemia in infected individuals. The relationship between the immune response of host and the developmental stage of the parasite as well as the microfilariae (mf) density and specific location of the adult worms is yet to be understood. As an experimental model, B. malayi adapted in the experimental animal Mastomys coucha has been used widely for various studies in filariasis. The present study was to assess microfilaraemia as well as the humoral immune response of M. coucha during various stages of B. malayi development and their localization in different organs. The result showed that the density of mf in the circulating blood of the experimental animal depended upon the number of female worms as well as the location and co-existence of male and female worms. The mf density in the blood increased with the increase in the number of females. The clearance of inoculated infective stage (L3) or single sex infection or segregation of male and female to different organs of infected host resulted in a microfilaraemic condition. With respect to antibody response, those animals cleared L3 after inoculation and those with adult worm as well as mf showed low antibody levels. But those with developmental fourth stage and/or adult worms without mf showed significantly higher antibody levels.     

The primary structure of langur (Presbytis entellus) pancreatic ribonuclease: adaptive features in digestive enzymes in mammals

The primary structure of pancreatic ribonuclease from langur (Presbytis entellus) has been determined. This sequence differs from that of human pancreatic ribonuclease at 14 (11%) of the amino acid positions. Eight of these 14 differences involve changes of charge, with the langur enzyme having five fewer positive charges than the human enzyme. The difference in charge between human and langur ribonuclease may be an adaptation to the different requirements for a nondigestive and a digestive role, respectively. A number of similarities in expression, gene duplications, and properties between mammalian ribonucleases and lysozymes have been observed, indicating similar adaptations in both enzyme systems.     

Cultural transmission of snake-mobbing in free-ranging Hanuman langurs

A focal troop of free-ranging Hanuman langurs (Presbytis entellus) living in an open scrub forest around Jodhpur was observed mobbing poisonous snakes on two different occasions during field observations of about 4,109 h. These observations of snake-mobbing demonstrate that langurs exhibit a special behaviour against 'potentially dangerous animals' which is similar to the mobbing displays of birds, and of other primates. It is suggested that the adaptive significance of snake-mobbing among langurs lies in the 'cultural transmission' of this information. These observations further support the 'kin-selection' model.     

Identification of a molecular marker for genotyping human lymphatic filarial nematode parasite Wuchereria bancrofti

In India, Mass Drug Administration is on going towards elimination of lymphatic filariasis in many areas, which might lead to intense selection pressure on the parasite populations and their genetic restructuring. This calls for molecular finger printing of Wuchereria bancrofti parasite populations at national level and monitoring genetic changes in the future. For this purpose a reliable, less expensive, rapid, and reproducible molecular tool is necessary, which is not available for W. bancrofti at this time. We identified robust molecular markers based on the comparison of random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) profiles and the genetic data generated from parasite populations collected from areas in Northern (Varanasi, Uttar Pradesh state), Southern (Kozhikode, Kerala State) and Central regions (Jagdalpur, Chattisgarh state) of India, where lymphatic filariasis is endemic for many decades. RAPD profiles for these parasite populations were generated using three different primers and the dendrograms constructed using the profiles were all different. In order to identify appropriate RAPD primer(s), we compared the results of RAPD with the fingerprint profile and genetic data obtained by the more reliable AFLP technique, using the parasite populations from the same areas. RAPD marker (OP8) primer produced phylogenetic data almost similar to that of AFLP analysis. The marker was able to reveal variations between the parasite populations collected from Varanasi, Kozhikode, and Jagdalpur. Most importantly, RAPD primer OP8 produced reproducible results, when tested in three different trials. In view of the limited availability of W. bancrofti parasite DNA, along with a lower cost and ease of performance, RAPD appears to be more suitable compared to AFLP at the present juncture, since complete genome information of this parasite is still not available. Thus, RAPD primer OP8 can be a very useful molecular maker for DNA finger printing of W. bancrofti populations at present.