Tantalus Monkeys Research Articles

Patterns of crop-raiding by wild and domestic animals near Gashaka Gumti National Park, Nigeria

This paper examines crop damage by mammals and the farmers' experiences of crop losses around Gashaka village on the south-western border of Gashaka Gumti National Park, Nigeria. Data were collected via a weekly count of damaged maize crops in 23 fields in the wet season and 30 in the dry season. We examined: (i) seasonal frequency and extent of damage, (ii) losses experienced relative to expected gains, and (iii) aspects of fields in relation to their susceptibility to raiding. Cows caused the greatest amount of damage during the year. Tantalus monkeys were the wild species that caused the most damage. The experience of individual farmers varied from no damage to complete loss of an entire season's crop. Currently the only apparent certainty in predicting losses for farmers was that those farmers with fields closer to wildlife refuges are more likely to experience greater losses. The importance of domestic animal crop damage should not be underestimated in its impact on farmers' livelihoods. Management of crop-raiding in general requires an integrated approach taking domestic animals into account. Pro-active guarding is suggested as having potential to reduce crop losses in Gashaka.

Further investigation of simian immunodeficiency virus Vif function in human cells.

Primate lentivirus Vif proteins function by suppressing the antiviral activity of the cell-encoded apolipoprotein B mRNA-editing enzyme-catalytic polypeptide-like (APOBEC) proteins APOBEC3G and APOBEC3F. It has been hypothesized that species-specific susceptibilities of APOBEC proteins to Vif proteins may help govern the transmission of primate lentiviruses to new host species. Consistent with this view and with previous results, we report that the Vif proteins of several diverse simian immunodeficiency viruses (SIVs) that are not known to infect humans are not effective inhibitors of human APOBEC3G or APOBEC3F when assessed in transient-transfection experiments. Unexpectedly, this lack of SIV Vif function did not prevent the replication of two vif-deficient SIVs (SIVtan and SIVmnd1; isolated from tantalus monkeys and mandrills, respectively) in a human T-cell line, HUT78, that expresses both APOBEC 3G and APOBEC3F, a finding which demonstrates that some SIVs are partially resistant to the antiretroviral effects of these enzymes irrespective of Vif function. Additional virus replication studies also revealed that the Vif protein of SIVtan is, in fact, active in human T cells, as it substantially enhanced the replication of its cognate virus and human immunodeficiency virus type 1. In sum, we now consider it improbable that species-specific restrictions to SIV Vif function can explain the lack of human infection with certain SIVs. Instead, our data reveal that the species-specific modulation of Vif function is more complex than previously envisioned and that additional (as-yet-unidentified) viral or host factors may be involved in regulating this dynamic interaction between host and pathogen.

SIVagm: genetic and biological features associated with replication.

African green monkeys (AGMs) belong to a superspecies that include the following four species: vervet (Chlorocebus pygerythrus), grivet (C. aethiops), sabaeus (C. sabaeus) and tantalus monkeys (C. tantalus). Each species carries a distinct SIVagm subtype, named SIVagm.ver, SIVagm.gri, SIVagm.sab and SIVagm.tan but remain clinically asymtomatic throughout their life. SIVagm needs the CD4 molecule and a chemokine-receptor, usually CCR5, Bonzo and/or Bob, for cell entry. Molecular and functional analyses of AGM CD4 and CCR5 revealed evidence of a true co-evolution between SIVagm and their natural hosts. The V3 loop of the SIVagm external glycoprotein is relatively conserved compared to that of HIV-1, but equally a determinant for coreceptor usage. SIVagm are able to replicate in stimulated peripheral blood mononuclear cells (PBMC) and macrophages. Efficient replication of SIVagm in vitro is associated with a cytopathic effect. SIVagm regulatory proteins show low amino acid identities with that of HIV-1, but many functions are conserved. The Tat protein of SIVagm is a transactivator of SIVagm LTR, albeit to a relatively lesser extent than Tat of HIV-1. Vif of SIVagm increases virus infectivity in AGM PBMC, demonstrating that SIVagm Vif is a positive regulator of virion infectivity. Vpr of SIVagm shares with HIV-1 Vpr its ability to transactivate the viral LTR, causes cell cycle arrest in AGM cells and facilitates nuclear import of pre-integration complexes and infection of non-dividing cells. AGM Vpr has been reported to also induce apoptosis, but the pathways involved in the mechanisms leading to apoptosis seem to be divergent compared to HIV-1 Vpr. SIVagm.ver3delta nef shows limited replicative capacity in vitro and in vivo, which suggests that Nef of SIVagm provides activation signals to the cells that facilitate SIV replication. The levels of plasma viral RNA in naturally infected AGMs are in a wide range (<10(3) to >6.10(6) RNA copies/ml), with many animals displaying steady-state levels of >10(6) RNA copies/ml levels, which in humans are associated with progression towards AIDS. Viral load per se therefore is not directly linked with pathogenicity. SIVagm-infections differ, however, from pathogenic HIV/SIVmac infections by a low viral load in peripheral lymph nodes. These relatively low localized tissue viral load levels are associated with lack of signs of detectable immunopathology. More detailed studies on the precise immunological environment during natural SIV infections, especially during primary infection, and on the interactions between SIVagm and host-specific cellular proteins are needed to better understand the mechanisms by which these naturally SIV infected nonhuman primate species are protected against progression towards AIDS.

Foraging energetics in patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus): Implications for reproductive seasonality

The patas monkeys (Erythrocebus patas) in Kala Maloue, Cameroon, have their birth season in the mid-dry season, whereas closely related, sympatric tantalus monkeys (Cercopithecus aethiops tantalus) have their birth season in the wet season. To evaluate the optimality of a species-specific birth season, I estimated the daily intake of available energy and gross protein, and energy expenditure for one individual of each sex of each species between respective birth and mating seasons. The monkeys obtained a larger amount of available energy and gross protein in the birth season than in the mating season. No significant seasonal differences in energy expenditure between the birth and mating season were found. Thus, the birth season appears to be timed to the season when the monkeys can obtain more surplus energy and protein. Interspecific differences in the optimality of birth season were attributed to widely exploitative foraging, supported by the patas’ high locomotive ability, which may enable them to obtain more energy from seeds of Acacia seyal and gums of A. sieberiana, and more protein from grasshoppers and seeds of A. seyal in the mid-dry season than the tantalus monkeys. A review of preceding studies suggests that the availability of seeds of Acacia fruiting during the dry season may exert the dominant influence on timing of birth not only in patas but also in savanna monkeys (Cercopithecus aethiops), which include the tantalus monkeys. Am. J. Primatol. 52:169–185, 2000. © 2000 Wiley-Liss, Inc.

Seasonal, sex, and interspecific differences in activity time budgets and diets of patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus), living sympatrically in northern Cameroon

I examined seasonal, sex, and interspecific differences in activity time budgest and diets of patas (Erythrocebus patas) and sympatric tantalus monkeys (Cercopithecus aethiops tantalus) on the basis of 5-day data sets collected in three and two different seasons, respectively, by the method of focal animal sampling. The seasons included species-specific mating and birth seasons. As compared with not only the birth season but also conspecific females, both patas resident male and tantalus male spent less time feeding and more time resting, day and night, in their respective mating seasons. Given that day-resting time includes time for vigilance for non-resident males and receptive females, this may reflect that males should minimize time spent feeding to allow maximum participation in other fitness-increasing activities such as mating-relating activities asSchoener (1971) predicted. In both species, the males consumed fruits containing less protein but more calories and showed a high feeding rate to compensate for the shorter time spent feeding in the mating season. In contrast, females consumed protein-rich food types (i.e. animals, protein-rich seeds, leaves, and flowers) in the birth season to meet the high demand for protein due to pregnancy and lactation. Given that the season for males was considered to be not a calendar but a reproductive “season” (i.e. mating or birth season), both sexes of patas spent more time moving and less time day- and night-resting than did the tantalus counterparts irrespective of the “season”. Patas subsisted on fruits, gums, and supplementarily lipid-rich seeds as an energy source and animal matters and protein-rich seeds as a protein source. In contrast, tantalus subsisted on fruits and lipid-rich seeds as energy and flowers and leaves as protein.

Foraging energetics in patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus): implications for reproductive seasonality.

The patas monkeys (Erythrocebus patas) in Kala Maloue, Cameroon, have their birth season in the mid-dry season, whereas closely related, sympatric tantalus monkeys (Cercopithecus aethiops tantalus) have their birth season in the wet season. To evaluate the optimality of a species-specific birth season, I estimated the daily intake of available energy and gross protein, and energy expenditure for one individual of each sex of each species between respective birth and mating seasons. The monkeys obtained a larger amount of available energy and gross protein in the birth season than in the mating season. No significant seasonal differences in energy expenditure between the birth and mating season were found. Thus, the birth season appears to be timed to the season when the monkeys can obtain more surplus energy and protein. Interspecific differences in the optimality of birth season were attributed to widely exploitative foraging, supported by the patas' high locomotive ability, which may enable them to obtain more energy from seeds of Acacia seyal and gums of A. sieberiana, and more protein from grasshoppers and seeds of A. seyal in the mid-dry season than the tantalus monkeys. A review of preceding studies suggests that the availability of seeds of Acacia fruiting during the dry season may exert the dominant influence on timing of birth not only in patas but also in savanna monkeys (Cercopithecus aethiops), which include the tantalus monkeys.

Differential habitat utilization by patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus) living sympatrically in northern Cameroon.

In order to obtain reliable evidence for differences in habitat preferences between two closely related savanna-dwelling primate species, namely, patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus), I collected data on vegetation and patterns of range use concurrently at a single study site, Kala Maloue, Cameroon, in a similar manner for a group of each species. Kala Maloue consisted of 64% grassland mostly dominated by Gramineae spp. and the rest was woodland. Tantalus monkeys showed preference for woodland, especially gallery forest, much more than did the patas irrespective of the season. Moreover, patas preferentially established their home range in grassland in the wet season. Interspecific and seasonal differences in habitat preferences could be interpreted on the basis of interspecific and seasonal differences in preferences for main food. In dry season, tantalus utilized water-containing areas at a frequency closely in proportion to the availability of such areas while the patas utilized water-containing areas more frequently than expected. This is because tantalus established a smaller home range along the river where water was never completely depleted throughout the dry season. Both the patas and the tantalus preferred woodland to grassland as sleeping sites possibly owing to predation avoidance. Both the daily travel distance per group weight and the home range size per group weight were greater for patas than for tantalus partly because of higher preference for grassland with low habitat quality in the case of patas. It is suggested, however, that high locomotive ability enabled patas to effectively utilize small and widely dispersed items of food such as grasshoppers and to explore areas with high availability of food and water and with preferable sleeping sites.

A Full-Length and Replication-Competent Proviral Clone of SIVAGMfrom Tantalus Monkeys

African green monkeys (AGM) are classified into four distinct species (commonly termed vervet, grivet, sabaeus, and tantalus monkeys), all of which are known to be infected with simian immunodeficiency virus (SIVAGM) in the wild. Sequence analysis of partialgagandenvregions has indicated that each of the four species harbors a phylogenetically distinct SIVAGMsubtype. This species-specific diversity suggests that African green monkeys have been infected with SIVAGMfor an extended period of time, possibly even before their speciation from a common ancestor. However, our understanding of the evolutionary history of this group of viruses is still incomplete, in part because sequence information for most isolates is limited to small subgenomic regions. There are only six SIVAGMproviruses which have been sequenced in their entirety, and these represent only three of the four SIVAGMlineages (i.e., SIVAGMgri, SIVAGMver, and SIVAGMsab). In this paper, we have generated the first full-length proviral clone for SIVAGMinfecting tantalus monkeys (SIVAGMtan). Lambda phage techniques were employed to clone this provirus (TAN) as a single genomic unit from productively infected Molt 4 (clone 8) cells, and sequence analysis confirmed the integrity of all major open reading frames, exceptvprwhich contained an in-frame stop codon. The proviral clone was also biologically active since transfection yielded replication-competent virions. Amino acid sequence comparisons of all major viral proteins indicated that TAN was roughly equidistant from previously characterized sabaeus, grivet, and vervet strains, thus confirming that it represents a fourth independent SIVAGMlineage. Given the need for well-characterized reference reagents, this full-length tantalus provirus should facilitate future studies of SIVAGMmolecular biology and evolution.

Identification of a New Subgroup of SIVagm in Tantalus Monkeys

Simian immunodeficiency viruses from African green monkeys (SIVagm) can be classified into three subgroups based upon the species from which they were isolated. The most extensively studied subgroup are composed of SIVagm isolated from vervet monkeys ( Cercopithicus pygerythrus). Fewer isolates have been characterized from either grivets ( Cercopithicus aethiops) or green monkeys ( Cercopithicus sabeus). An additional distinct species of African green monkeys, tantalus monkeys ( Cercopithicus tantalus), has not been characterized in terms of SIV infection. A high seroprevalence of SIV-specific antibodies was identified in sera collected from Ugandan tantalus monkeys, SIV was isolated from PBMC (SIVagm/tan), the gag region amplified by polymerase chain reaction, cloned, and sequenced. Based upon gag , SIVagm/tan isolates cluster genetically with other previously recognized SIVagm strains. However, SIVagm from tantalus monkeys forms a distinct genetic subgroup. These data confirm earlier observations of species specific subtypes of SIVagm viruses and support the hypothesis that these viruses may have coevolved with their host during geographic dispersion throughout Africa.

Simian immunodeficiency viruses from central and western Africa: evidence for a new species-specific lentivirus in tantalus monkeys

Although up to 50% of African green monkeys (AGMs) are infected by simian immunodeficiency viruses (SIV) in their natural habitat, they remain asymptomatic carriers of these lentiviruses. They provide an attractive model to study not only the origin but also the link among genetic variation, host-virus adaptation, and pathogenicity of primate lentiviruses. SIVagm have been isolated from three species of AGM: the vervet (Cercopithecus pygerythrus), the grivet (Cercopithecus aethiops), and the sabaeus (Cercopithecus sabaeus) monkey. We studied four new SIVagm isolates from a fourth AGM species, the tantalus monkey (Cercopithecus tantalus), caught in the Central African Republic, and four new isolates from feral sabaeus monkeys from Senegal. Antigenic properties and partial env sequences were used to evaluate the diversity among these isolates. Alignment of env sequences in SIVagm isolated from tantalus and sabaeus monkeys permitted detailed mapping of the variable and conserved domains in the external glycoprotein. Genetic distances indicated that SIVagm isolates from tantalus monkeys are the most divergent among SIVagm in feral AGMs in Africa. The fact that AGMs are infected by four distinct lentiviruses, each specific for a single AGM species, supports the hypothesis of a coevolution of these viruses and their natural hosts and suggests that SIV transmission is a rare event among separated AGM species in the wild.

Sequence and Phylogenetic Analyses of a New STLV-I from a Naturally Infected Tantalus Monkey from Central Africa

Simian T-cell leukemia virus (STLV-I) is an oncovirus highly related to human T-cell leukemia virus type I (HTLV-I). To further examine the extent of variability, dissemination patterns, phylogeny, and evolution of these viruses, we analyzed a new STLV-I variant from a naturally infected Cereopithecus aethiops var. tantalus from the Central African Republic. Sequence analyses of its LTR, gag, pol, env, and pX (Orf II) genes indicated that this isolate, STLV-I (Tan 90), is 6% divergent from the prototype HTLV-I (ATK) and is the most divergent African STLV-I characterized to date. Our phylogenetic data indicate that southeast Asian and African STLV-I and HTLV-I strains segregated from each other thousands of years ago and that Japanese HTLV-I strains represent a relatively recent introduction of African or New World isolates. The data also indicate that interspecies transmission occurred several times on different continents over prolonged periods of time.

Activity budget and diet of patas monkeys in Kala Maloue National Park, Cameroon: A preliminary report

A preliminary study was carried out on the feeding ecology of patas monkeys in the rainy season in Cameroon. Their daily activity rhythm revealed two active peaks. The proportion of time spent on feeding with respect to waking time was 30%. Patas monkeys largely depended on the flowers and buds of herbaceous plants and the larvae of insects for their diet as they ranged widely. Patas monkeys spent more time in feeding and travelled for a longer distance per day than the sympatric primate species, the tantalus monkey. It is considered that these findings reflected the large amount of food requirement due to the large body size, as well as the low density and high degree of dispersal of their food.

Variable Territoriality among Tantalus Monkeys in Cameroon

The socio-ecology of representative groups of tantalus monkeys (Cercopithecus aethiops tantalus) was observed during 1974–1975 in three habitats in Cameroon. Observations took place during the wet and dry seasons in sahelian savannah, guinea savannah and farmed forest. In the sahel, large groups did not appear to defend territories. In the other two habitats, smaller groups did so. The different patterns of territoriality and group size appeared to be the result of differences in food supply and predation pressures.

Invasion of the Forest By an African Savannah Monkey: Behavioural Adaptations

AbstractTantalus monkeys, a race of the savannah species Cercopithecus aethiops, have invaded the cultivated forest of Bakossi in south-west Cameroon during the last seventy years and become important agricultural pests. The cultivated forest is a new habitat to which they are well adapted by virtue of their eclectic diet, their habit of foraging away from tall trees, their semi-terrestriality, their flexible group size and their cryptic nature. The indigenous related species of the rainforest are less able to exploit the changed habitat, probably because they are insufficiently terrestrial or cryptic and they typically forage among the trees that provide their refuge. As a result of their conflict with the farmers whose crops they raid, the forest tantalus monkeys contrast with conspecifics in the savannah by their less predictable ranging patterns, their quieter call repertoire, a striking and consistent male pattern of vigilance behaviour and their habit of hiding from dogs rather than giving the loud alarm calls that are invariably given where canids are not associated with man.

The diet and feeding behaviour of Cercopithecus aethiops tantalus.

The feeding behaviour of representative groups of tantalus monkeys (Cercopithecus aethiops tantalus) was observed during 1974-1975 in three habitats in Cameroon. Observations took place during the wet and dry seasons in sahelian savannah, guinea savannah and farmed forest. The tantalus monkeys were similar to other races of C.aethiops that have been studied in that they were omnivorous and lacked any narrow specialisations of either diet or feeding techniques. The dietary range was similar in all three habitats, although considerable seasonal variation occurred. About one third of all feeding took place on the ground.

Comparative Susceptibility of Kidney Cells from Different Monkey Species to Enteric Viruses (Poliomyelitis, Coxsackie, and Echo Groups)

Summary Kidney tissue cultures of 13 species of monkeys and 4 species of baboons were tested for comparative susceptibility to the enteric viruses belonging to the poliomyelitis, Coxsackie and echo groups. Cells from sooty mangabey (Cercocebus fuliginosus), white-crowned mangabey (Cercocebus torquatus lunulatus), and diana (Cercopithecus diana roloway) monkeys from Africa, and cynomolgus (Macaca cynomolgus) monkeys from Singapore and the Philippine Islands, closely resembled the cells of rhesus monkeys (Macaca mulatta) from India in their high susceptibilities to the viruses tested. Cells from the African red grass monkey (Erythrocebus patas) were found to be twice as susceptible as rhesus cells to polioviruses, and about equally susceptible to echo types 7, 8, and 12, and Coxsackie group B viruses. However, patas cells were resistant to plaque production when exposed to Coxsackie A9, and echo virus types 1, 3, 4, 6′, 9, and 14. Similar results were obtained with African white-nosed (Cercopithecus nictitans buttikoferi), mona (Cercopithecus mona campbelli) and mustache (Cercopithecus cephus) monkeys. African green (Cercopithecus aethiops sabaeus) and tantalus (Cercopithecus aethiops tantalus) monkeys yielded cells highly susceptible to all three groups of viruses tested, showing even greater susceptibility than rhesus cultures to the echo viruses. Four species of baboon (Papio papio, P. cynocephalus, P. doguera, and Mandrillus leucophaeus) yielded kidney cultures almost equal to rhesus cultures in susceptibility to poliovirus. Coxsackie virus A9 and echo virus type 1 were not cytopathogenic in yellow baboon (P. cynocephalus) cultures, while drill baboon (M. leucophaeus) cells proved highly susceptible to echo viruses. Poliovirus plaques were produced in the lemur, Perodicticus potto. The suggestion is made that cells of differing susceptibilities might offer advantages for isolations of enteric viruses from clinical specimens; they might be used as differential media are in the isolation of enteric bacterial colonies. Because of the greater susceptibility of patas cells over those of rhesus or cynomolgus, they also offer an advantage for the detection of small amounts of poliovirus.