Sykes Monkeys Research Articles

Perception of chirps by Sykes's monkeys (Cercopithecus albogularis) and humans (Homo sapiens).

Four Sykes's monkeys (Cercopithecus albogularis) and 4 humans (Homo sapiens) discriminated among 12 chirps presented in a repeating background paradigm. The test stimuli consisted of sets of 4 chirps recorded from Sykes's monkeys, red-tailed monkeys (C. ascanius), and small East African birds. Reaction times were submitted to a multidimensional scaling analysis. All monkey listeners perceived the bird chirps as similar to each other and distinct from the monkey calls, whereas 3 of the 4 human listeners had difficulty distinguishing the bird chirps from the monkey calls. Both human and monkey subjects tended to perceive Sykes's and red-tailed monkey calls as very similar to one another, but the degree of perceived similarity was greatest for the monkey listeners. The data suggest that the perceptual map of these calls is influenced by their biological significance in nature.

Isolation of Leishmania major from a Naturally Infected Vervet Monkey (Cercopithecus aethiops) Caught in Kiambu District, Kenya

demic in several parts of Kenya. The current general situation and epidemiology of these 2 diseases suggest zoonoses and the existence of animal reservoirs. Different species of rodents are involved as reservoirs of L. major in different parts of the Old World. Through most of its distribution, gerbils, Tetera spp., are the principal reservoir hosts, and other rodents in Israel, Senegal, Ethiopia, and Saudi Arabia have also been implicated (Gunders et al., 1968, Transactions of the Royal Society of Tropical Medicine and Hygiene 62: 465; Ranque et al., 1974, Bulletin de la Societe de Pathologie Exotique 67: 167174; Elbihari et al., 1984, Annals of Tropical Medicine and Parasitology 78: 543-545). Occasionally, dogs have been found to be infected with L. major, which has recently been isolated in Egypt (Schnur et al., 1985, Transactions of the Royal Society of Tropical Medicine and Hygiene 79: 134-135) and Saudi Arabia (Peters et al., 1985, Transactions of the Royal Society of Tropical Medicine and Hygiene 79: 831-839). The presence of Leishmania major in Baringo District was reported in gerbils, Tetera nigricauda, and ground squirrels, Xerus rutilus, by Heisch (1963, East African Medical Journal 40: 359362), and in addition, Beach et al. (1984, Transactions of the Royal Society of Tropical Medicine and Hygiene 78: 747-751) isolated a strain of L. major from Phlebotomus dubosqi in the same region. Recent studies have also shown that several other species of rodents harbour natural infections of L. major and human cases have also been reported in Baringo District (Githure et al., 1986, Annals of Tropical Medicine and Parasitology 80: 501-507; Muigai et al., 1987, Transactions of the Royal Society of Tropical Medicine and Hygiene [in press]). Old World nonhuman primates, such as Sykes monkeys, vervet monkeys, and baboons, have been shown to be susceptible to experimental infection with L. donovani (Githure et al., 1986, Transactions of the Royal Society of Tropical Medicine and Hygiene 80: 575-576). Recent experiments show that Old World monkeys are also susceptible to experimental infection with L. major. Our study was therefore designed to determine whether or not monkeys caught in the wild harbour any leishmanial parasites. Three species of Old World primates were trapped using locally made traps and brought to the Institute of Primate Research, Karen, where they were quarantined before introducing them into the colony. The 40 study animals included 30 vervet monkeys (Cercopithecus aethiops), 5 Sykes monkeys (Cercopithecus mitis), and 5 baboons (Papio cynocephalus). Of these 40 animals, 28 vervet monkeys came from Thika in the Kiambu District. The rest came from Kibwezi

Leishmania major: The suitability of east african nonhuman primates as animal models for cutaneous leishmaniasis

The susceptibility of four species of East African nonhuman primates to experimental infection with Leishmania major was investigated. Four Syke's monkeys ( Cercopithecus mitis), two vervet monkeys ( Cercopithecus aethiops), two baboons ( Papio cynocephalus), and two brown bushbabies ( Galago garnettii) were each inoculated intradermally on the left eyelid, left ear, and nose with 0.1 ml of medium containing 1 × 10 7 promastigotes of a characterized L. major strain. All the nonhuman primates except the bushbabies developed erythema and conspicuous nodules on the eyelids and ears by 3 weeks PI. The nodules increased rapidly in size and ulceration was evident on the eyelids and ears by 49 days PI in the vervets, Syke's, and baboons. The aspirates were positive in culture or smears at 35, 49, 63, and 77 days PI. No parasites were observed in cultures or smears at 92, 105, 128, 147, and 161 days PI. The lesions in these animals began resolving by 84 days PI and were completely healed by 112 days PI. The exception was one baboon in which lesion healing did not start until around 147 days and was completely healed by 182 days PI. Cultures from the liver failed to demonstrate visceralization of the parasite in any of the animals throughout the 68 weeks of the experiment. Challenge with the same strain of L. major 6 months PI, corresponding to about 3 months after self cure, failed to produce infection in any of these experimental hosts. All the nonhuman primates except the bushbaby when challenged with the same strain of L. major at 12 months PI developed lesions and were positive for parasites at 14 and 28 days PI. Positive cultures were obtained from the eyelid and ear of one vervet up to 42 days PI. However, the lesion sizes in all these animals were smaller than in the initial infection and did not ulcerate. The nodules disappeared within 6 to 8 weeks as compared to 16 weeks in the initial infection. The histopathological appearance of the lesions varied from diffuse infiltration of plasma cells and lymphocytes which increased progressively to granulomata with epitheloid cells. This study shows that the vervets, Syke's, and the baboons are equally susceptible to L. major infection, while bushbabies are refractory. The vervets, Syke's, and baboons demonstrate a self-healing phenomenon within about 3 months which is comparable to that observed in humans infected with L. major. These three species of nonhuman primates are therefore considered as suitable models for drug or vaccine trials against human zoonotic cutaneous leishmaniasis.

The suitability of East African primates as animal models of visceral leishmaniasis

The susceptibility of four East African primate species to experimental infection with Leishmania donovani was investigated. Vervet monkeys ( Cercopithecus aethiops), Sykes monkeys ( C. mitis) and baboons ( Papio cynocephalus) all supported low grade infections for periods ranging between four and eight months and subsequently showed evidence of self-cure. Greater bushbabies ( Galago crassicaudatus) remained completely refractory throughout the course of the experiment. The significance of hepatic histiocytic nodules in the infected primates, similar to those observed in asymptomatic human visceral leishmaniasis, and the susceptibility of Old World primates to experimental infection are discussed.

A comparative study of basal metabolism and thermoregulation in a folivorous ( Colobus guereza) and an omnivorous ( Cercopithecus mitis) primate species

1. 1. Abdominal temperatures ( T ab) and oxygen consumption (V̇O 2) were measured in two males each of colobus and Sykes monkeys. 2. 2. T ab in both species had the same range (36–38.5°C), but there were marked differences in the daily rhythms. 3. 3. Low ambient temperatures ( T a) had little effect on T ab; at T a = 33.5–35.5° C, however, T ab rose quickly to above 40°C. 4. 4. The thermoneutral zone (TNZ) extended from about 5 to 28°C in both species. 5. 5. In the colobus monkeys the basal metabolic rate (BMR) was considerably lower than in the Sykes monkeys: 85% vs 113% of the value predicted from body mass.

Brief report: Normal hematology values of Sykes monkeys (Cercopithecus mitis albogularis).

Hematologic values are presented for the Sykes monkey (Cercopithecus mitis albogularis). The values are, in general, similar to published findings for other primate species. Elevated hemoglobin, possibly caused by high altitude, was noted. Significant differences of several values between males and females are discussed.

Colonic electrolyte flux and gut composition as seen in four species of sub-human primates

1. 1. Studies compare the composition of gastrointestinal contents and transmucosal electrolyte flux in four species of subhuman primates. 2. 2. The bushbaby, an insectivore, had significantly drier stomach contents, potassium and chloride concentration than the baboon, vervet or sykes monkey. 3. 3. While the caecum of all primates appeared to be the major site of microbial fermentation, the sykes monkey, a herbivore, indicated the highest level of stomach fermentative activity. 4. 4. Transmucosal electrolyte flux occurred primarily within the proximal colon of the baboon, vervet and sykes monkey. 5. 5. Volatile fatty acids were absorbed from the proximal colon of these animals.

Organic acid production and digesta movement in the gastrointestinal tract of the baboon and sykes monkey

1. 1. Studies compare the sites of organic acid production and patterns of digesta movement in herbivorous and omnivorous sub-human primates. The results of this study indicate that digestive functions of the herbivorous Sykes monkey and omnivorous baboon are very similar. 2. 2. While not being the principal site of digesta retention, the stomach was shown to retain particulate matter longer than fluids and to selectively retain the larger particles for a longer period of time. 3. 3. Retention of both fluid and particulate matter was observed in the baboon's caecum and colon. Colonic mixing of many meals was evident and required 3–5 days for the complete evacuation of digesta markers. 4. 4. A substantial degree of microbial fermentation and organic acid production was observed in the hindgut of both species of primate and demonstrated no distinct advantage for the more herbivorous species.

Territories and movements of sykes monkeys (Cercopithecus mitis kolbi neuman) in Kenya.

The movement pattern and territories of troops of sykes monkeys is compared in two areas in relation to plantations of exotic softwood. Monkey troops showed similar patterns of movement which was governed by the availability of food resources. Sykes monkeys are territorial in behaviour. The sizes of the territories vary from 13.2 to 16.0 ha. The possible explanations of the factors that led other troops to do damage to forests of exotic trees is discussed.

The annual reproductive cycle of an African monkey (Cercopithecus mitis kolbi Neuman).

Reproductive activities in the sykes monkey are seasonal and associated with changes in the amount of rainfall. Conceptions and births were confined to discrete dry periods of the year while pregnancy and lactation proceeded when rainfall was high. 54.5% of the population was breeding.

Reticulum cell sarcoma in a Sykes monkey (Cercopithecus albogularis).

The gross and microscopic characteristics are described of a reticulum cell sarcoma found in a Sykes monkey during the course of 112 postmortem examinations of monkeys.

The blood factors I and i in primates including man, and in lower species.

AbstractHuman‐type blood factors I and i have been investigated in several primate species including man, and in other mammals. The anti‐I tests were performed with the original antiserum which led to the discovery of blood factor I. The anti‐i serum used was obtained from a patient with severe idiopathic hemolytic anemia. Both antisera were similar in serological reactivity, except for their difference of specificity. Human adults, in general, have blood factor I but lack factor i; those very rare adults of type i who lack factor I have the factor i instead. In newborn human infants the factor I is still undeveloped and blood factor i is present in its place.In all other species only juvenile and adult animals have so far been tested. Chimpanzees lack blood factor I but have the factor i, which could be interpreted as phylogeny paralleling ontogeny; however, gibbons lack both factors I and i while orangutan has an intermediate position. All Catarrhini tested, namely, yellow baboons, geladas, patas, mangabeys, macaques, African green, talapoin and Sykes monkeys lack blood factor I but have the factor i. Among Platyrrhini the results are less uniform: Capuchins have very strong blood factor I and a weak factor i, while squirrel and spider monkeys have factor i and little or no factor I. On the other hand, marmosets have both factors I and i well developed. Only two single prosimians were tested: slow loris had factor i but no factor I, while potto lacked both factors I and i.Among non‐primate animals, sheep, goat, deer, cat and South American agoutilack both factors I and i; dog and rat lack factor I but have a weak factor i, while rabbit has a very strong factor I but lacks the factor i.Bearing in mind the relatively small number of animals tested within each species, the present study indicates a heterophile behavior of the blood factors I and i in mammals, in that their distribution cuts across taxonomic lines.