Captivity and habituation to humans raise curiosity in vervet monkeys

The cognitive mechanisms causing intraspecific behavioural differences between wild and captive animals remain poorly understood. Although diminished neophobia, resulting from a safer environment and more “free” time, has been proposed to underlie these differences among settings, less is known about how captivity influences exploration tendency. Here, we refer to the combination of reduced neophobia and increased interest in exploring novelty as “curiosity”, which we systematically compared across seven groups of captive and wild vervet monkeys (Chlorocebus pygerythrus) by exposing them to a test battery of eight novel stimuli. In the wild sample, we included both monkeys habituated to human presence and unhabituated individuals filmed using motion-triggered cameras. Results revealed clear differences in number of approaches to novel stimuli among captive, wild-habituated and wild-unhabituated monkeys. As foraging pressure and predation risks are assumed to be equal for all wild monkeys, our results do not support a relationship between curiosity and safety or free time. Instead, we propose “the habituation hypothesis” as an explanation of why well-habituated and captive monkeys both approached and explored novelty more than unhabituated individuals. We conclude that varying levels of human and/or human artefact habituation, rather than the risks present in natural environments, better explain variation in curiosity in our sample of vervet monkeys.

Fevers and the social costs of acute infection in wild vervet monkeys

Fevers are considered an adaptive response by the host to infection. For gregarious animals, however, fever and the associated sickness behaviors may signal a temporary loss of capacity, offering other group members competitive opportunities. We implanted wild vervet monkeys (Chlorocebus pygerythrus) with miniature data loggers to obtain continuous measurements of core body temperature. We detected 128 fevers in 43 monkeys, totaling 776 fever-days over a 6-year period. Fevers were characterized by a persistent elevation in mean and minimum 24-h body temperature of at least 0.5 °C. Corresponding behavioral data indicated that febrile monkeys spent more time resting and less time feeding, consistent with the known sickness behaviors of lethargy and anorexia, respectively. We found no evidence that fevers influenced the time individuals spent socializing with conspecifics, suggesting social transmission of infection within a group is likely. Notably, febrile monkeys were targeted with twice as much aggression from their conspecifics and were six times more likely to become injured compared to afebrile monkeys. Our results suggest that sickness behavior, together with its agonistic consequences, can carry meaningful costs for highly gregarious mammals. The degree to which social factors modulate the welfare of infected animals is an important aspect to consider when attempting to understand the ecological implications of disease.

On the problem of craniological differentiation in two species of the green monkeys: Chlorocebus pygerythrus and C. aethiops (Cercopithecidae, Primates)

The problem of taxonomic differentiation in the order Primates is one of the important problems of evolutionary anthropology and primatology. The systematics of primates reflects their evolutionary relationships and allows to reconstruct the possible ways of formation of particular groups. Clarification of primate taxonomy involves a wide range of data, primarily from the field of morphology. Among the morphological features that distinguish particular taxa, the special role belongs to the system of craniological characters, which allow diagnosing the skulls in museum collections or fossil materials. The article is devoted to craniological identification of two species of the genus Chlorocebus: Chlorocebus pygerythrus (vervets) and Chlorocebus aethiops (grivets).

Nasal Carriage of Methicillin-Resistant Staphylococcus aureus Among Sympatric Free-ranging Domestic Pigs and Wild Chlorocebus Pygerythrus in a Rural African Setting

Background Methicillin Resistant Staphylococcus aureus (MRSA) nasal carriage in domestic pigs and vervet monkeys is a risk factor for subsequent severe infections in domestic pigs and for dissemination to the human population. This study assessed nasal carriage of MRSA in domestic pigs and sympatric vervet monkeys in a rural African village during an outbreak of a virus hemorrhagic fever suspected to be contracted from wild primates. This study was conducted during the 2012 Ebola outbreak to determine nasal carriage of MRSA in free-ranging domestic pigs and sympatric freely roaming vervet monkeys using conventional methods. Staphylococcus aureus (S. aureus) isolated from the anterior nares were tested for susceptibility to commonly used antibiotics and conventional PCR was used to confirm methicillin resistance. Results MRSA was significantly more in wild vervet monkeys compared to free ranging domestic pigs (p=0.003875). Overall, there was a high level of resistance to tetracycline [90% (63/70) in pigs and 67% (10/15) in vervet monkeys], trimethoprim/sulphamethoxazole [90% (63/70) in pigs and 67% (10/15) in vervet monkeys], and penicillin [83% (58/70) in pigs and 67% (10/15) in vervet monkeys]. Conclusion The nasal carriage of drug resistant S. aureus in freely roaming domestic and wild animals presents a risk for widespread environmental spread of antimicrobial resistance thus presenting a risk for treatment failure in domestic animals, wild animals, and humans.

Sick and Tired: Polyparasitism, Food Stress and Sickness Behaviour in a Gregarious Mammal

Although sickness behaviour in response to non-lethal parasites has been documented in wild animals, it remains unclear how social and environmental stress might also shape an animal’s behavioural response to parasitism, nor do we know whether simultaneous infection with more than one parasite changes the way animals respond. Here, we combine physiological, environmental, behavioural and parasite measures to investigate behavioural responses to infection in wild vervet monkeys (Chlorocebus pygerythrus) living in a semi-arid region of South Africa. We quantified both activity budget and behavioural predictability to investigate the occurrence of sickness behaviour and infection with two non-lethal gastrointestinal parasite genera. Higher parasite load was linked to an increase in the time spent resting. However, the nature of the relationship with other behaviours was contingent on both the parasite genus in question, and how parasite species interacted, highlighting the importance of considering co-infection. Overall, food availability was the dominant predictor of behavioural change suggesting that, for monkeys living in a more extreme environment, coping with ecological stress may override the ability to modulate behaviour in response to other physiological stressors. Our findings provide insight into how animals living in harsh environments find ways to cope with parasite infection, avoidance, and transmission.

Social contact behaviors are associated with infection status for Trichuris sp. in wild vervet monkeys (Chlorocebus pygerythrus)

Social grooming in the animal kingdom is common and serves several functions, from removing ectoparasites to maintaining social bonds between conspecifics. We examined whether time spent grooming with others in a highly social mammal species was associated with infection status for gastrointestinal parasites. Of six parasites detected, one (Trichuris sp.) was associated with social grooming behaviors, but more specifically with direct physical contact with others. Individuals infected with Trichuris sp. spent significantly less time grooming conspecifics than those not infected, and time in direct contact with others was the major predictor of infection status. One model correctly predicted infection status for Trichuris sp. with a reliability of 95.17% overall when the variables used were time spent in direct contact and time spent grooming others. This decrease in time spent grooming and interacting with others is likely a sickness behavior displayed by individuals with less energy or motivation for non-essential behaviors. This study emphasizes the possible links between host behavior and parasitic infections and highlights the need for an understanding of a study population’s parasitic infections when attempting to interpret animal behavior.

Molecular detection of Anaplasma phagocytophilum DNA in Olive Baboons and Vervet monkeys in Kenya

BackgroundNonhuman primates (NHPs) occupy an important place in zoonotic spill-overs, serving as either reservoirs or amplifiers of multiple neglected tropical diseases including tick-borne infections. Anaplasmosis is caused by obligate intracellular bacteria of the family Anaplasmatacae. They are transmitted by Ixodid tick species and have a wide host range including wild animals, domestic animals and humans. The aim of this study was to establish the presence of Anaplasma phagocytophilum in Olive baboons and Vervet monkeys in Laikipia County, Kenya.ResultsA total of 164 whole blood samples, collected by USAID Predict II project from Laikipia County, 17 Kenya, were included in the study. These comprised of 146 samples from Olive baboons (Papio anubis) and 18 from Vervet monkeys (Chlorocebus pygerythrus) respectively from Mpala Research Center and Ol jogi Conservancy in Laikipia County. Using conventional Polymerase Chain Reaction (PCR), positive results for A. phagocytophilum in 26 Olive baboons and 4 Vervet monkeys were detected with primer sets EHR16SD/R. However, low sensitivity was observed with the p44 gene. The amplification of DNA template with the primer set p44 (p3709 5/ p4257 23 5) using nested PCR could not be obtained. Our results revealed the presence of A. phagocytophilum in Olive baboons and Vervet monkeys. This study found an overall prevalence of 18.3% for Anaplasma phagocytophilum. A distinct genotype of A. phagocytophilum was detected that was different from the others in the gene bank database.ConclusionThis study provides valuable information on the presence of A. phagocytophilum bacteria in Olive baboons and Vervet monkeys in Kenya. It indicates a need for future research to establish the public health implications of zoonotic A. phagocytophilum isolates and the role of nonhuman primates as reservoirs.