The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform
Naofumi Nakagawa - One of the best experts on this subject based on the ideXlab platform.
-
despotic wild patas monkeys Erythrocebus patas in kala maloue cameroon
American Journal of Primatology, 2008Co-Authors: Naofumi NakagawaAbstract:The socio-ecological model predicts that the quality, distribution, and patch size of food resources determines the dominance hierarchy of female monkeys based on the type of food competition they experience. Comparative studies of closely related species have evaluated the socio-ecological model and confirmed its validity. For example, female patas monkeys in Laikipia, Kenya, form a nonlinear and unstable dominance hierarchy (i.e., egalitarian), whereas females of sympatric, closely related savannah monkeys form a linear and stable dominance hierarchy (i.e., despotic), in accordance with the model's predictions of the characteristics of food resources. I compared agonistic interactions involving food between patas monkeys (Erythrocebus patas) and sympatric savannah monkeys (Cercopithecus aethiops) in Kala Maloue, Cameroon. I found linear dominance hierarchies not only in savannah monkeys, but also in patas monkeys in Kala Maloue. The rates of agonistic interactions during feeding between patas monkeys were equivalent to those between savannah monkeys in Kala Maloue; further, these rates were significantly higher than those of both Laikipia patas and savannah monkeys. The results imply that patas monkeys in Kala Maloue are not egalitarian, but are despotic, similar to savannah monkeys. Disparity in the dominance hierarchies of patas monkeys between Kala Maloue and Laikipia were attributable to the differences in the characteristics of food resources. Although patas monkeys in Laikipia subsist on small and dispersed food resources within a high-density area, those in Kala Maloue subsisted on food resources that were clumped in intermediate-sized patches within a low-density area. This study shows that the socio-ecological model is applicable not only for interspecific comparisons but also for intraspecific comparisons. Am. J. Primatol. 70:238–246, 2008. © 2007 Wiley-Liss, Inc.
-
difference in food selection between patas monkeys Erythrocebus patas and tantalus monkeys cercopithecus aethiops tantalus in kala maloue national park cameroon in relation to nutrient content
Primates, 2003Co-Authors: Naofumi NakagawaAbstract:Phytochemical or nutrient analyses of primate diets have revealed clues to their food selection in a single species. On the other hand, few interspecific comparisons of phytochemical or nutrient composition of primate diets have been made, although diets are considered to differ in phytochemical or nutrient content from primate species to species, since different species have different body weights and different morphological and physiological characteristics. I compared the nutrient content of diet between patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus) living sympatrically in Cameroon. patas subsisted on a smaller number of food items, most of which were also tantalus food items. Then, I compared the protein–fiber ratio and the available energy content of the food items eaten by patas (patas foods) with those items eaten only by tantalus (tantalus foods). Both variables were higher in patas than tantalus foods, although there was no significant difference in available energy of plant foods. Next, when I performed discriminant analysis for patas foods and tantalus foods, employing the above two variables, a discriminant function with positive coefficients for both variables was obtained. The mean discriminant-function score of patas foods was higher than that of tantalus foods. Despite being somewhat larger in weight, patas selectively fed on a smaller number of foods of higher quality than did tantalus. I discuss why the results are inconsistent with a well known body weight–diet relationship (Jarman–Bell principle). Energy-efficient locomotion enables patas to exploit not only small dispersed food items of high quality but also areas where high-quality foods are distributed in clumps.
-
foraging energetics in patas monkeys Erythrocebus patas and tantalus monkeys cercopithecus aethiops tantalus implications for reproductive seasonality
American Journal of Primatology, 2000Co-Authors: Naofumi NakagawaAbstract: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
Primates, 2000Co-Authors: Naofumi NakagawaAbstract: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.
-
differential habitat utilization by patas monkeys Erythrocebus patas and tantalus monkeys cercopithecus aethiops tantalus living sympatrically in northern cameroon
American Journal of Primatology, 1999Co-Authors: Naofumi NakagawaAbstract: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. Am. J. Primatol. 49:243–264, 1999. © 1999 Wiley-Liss, Inc.
Lynne A Isbell - One of the best experts on this subject based on the ideXlab platform.
-
decline in the geographical range of the southern patas monkey Erythrocebus patas baumstarki in tanzania
Oryx, 2009Co-Authors: Yvonne A De Jong, Lynne A Isbell, Thomas Butynski, Claire LewisAbstract:The southern patas monkey Erythrocebus patas baumstarki is a subspecies thought to be endemic to central north Tanzania but its distribution and abundance is not well documented. We therefore review what is known about the historical and current distribution of the south- ern patas. It appears that, at present, the southern patas occurs in three populations, in the Serengeti, Mt Kiliman- jaro and Arusha. Since 1995 the gaps among these three populations have become larger, thereby increasing their isolation. The available data suggest that, at present, south- ern patas occur over c. 20,700 km 2 (c. 2.3% of Tanzania's land surface area). In 1995 this was c. 30,800 km 2 (c. 3.5% of the land surface area). As such, the geographical range of the southern patas has declined by c. 33% since 1995. There are unlikely to be . 900 southern patas today, and there could be , 150. Our recommendations are to (1) maintain an internet accessed database (patasBase) into which sight- ings of the southern patas can be entered, (2) interview members of local communities to assess past and current distribution and abundance of the southern patas, (3) con- duct field studies to obtain more detailed information on the distribution, abundance, and conservation status of patas in Tanzania, (4) undertake ecological and behavioural re- search on selected groups of southern patas, and (5) prepare and implement a conservation action plan for the southern
-
demography and life histories of sympatric patas monkeys Erythrocebus patas and vervets cercopithecus aethiops in laikipia kenya
International Journal of Primatology, 2009Co-Authors: Lynne A Isbell, Truman P Young, Karin Enstam Jaffe, Anne A Carlson, Rebecca L ChancellorAbstract:Mortality patterns are thought to be strong selective forces on life history traits, with high adult mortality and low immature mortality favoring early and rapid reproduction. patas monkeys (Erythrocebus patas) have the highest potential rates of population increase for their body size of any haplorhine primate because they reproduce both earlier and more often. We report here 10 yr of comparative demographic data on a population of patas monkeys and a sympatric population of vervet monkeys (Cercopithecus aethiops), a closely related species differing in aspects of social system, ecology, and life history. The data reveal that 1) adult female patas monkeys have significantly higher mortality than adult female vervets; 2) infant mortality in patas monkeys is relatively low compared to the norm for mammals because it is not significantly different from that of adult female patas monkeys; and 3) infant mortality is significantly higher than adult female mortality in vervets. For both species, much of the mortality could be attributed to predation. An epidemic illness was also a major contributor to the mortality of adult female patas monkeys whereas chronic exposure to pathogens in a cold and damp microenvironment may have contributed to the mortality of infant vervets. Both populations experienced large fluctuations during the study period. Our results support the prediction from demographic models of life history evolution that high adult mortality relative to immature mortality selects for early maturation.
-
interspecific and temporal variation of ant species within acacia drepanolobium ant domatia a staple food of patas monkeys Erythrocebus patas in laikipia kenya
American Journal of Primatology, 2007Co-Authors: Lynne A Isbell, Truman P YoungAbstract:The ants that live in the swollen thorns (domatia) of Acacia drepanolobium are staple foods for patas monkeys (Erythrocebus patas). To obtain a better understanding of these insects as resources for patas monkeys, we sampled the contents of 1,051 swollen thorns (ant domatia) over a 22-month period from December 1999 to September 2001, in Laikipia, Kenya. First, we confirmed that of the four species of ants that live on A. drepanolobium, Crematogaster sjostedti, the competitively dominant ant in this system, does not rear significant brood in the swollen thorns and is therefore not a major food item of patas monkeys. Second, across the other three species that do use swollen thorns for rearing their brood, C. nigriceps, C. mimosae, and Tetraponera penzigi, the number of worker ants per swollen thorn increased with increasing competitive dominance. Third, although there was considerable month-to-month variation in the number of workers, immatures, and especially alates (winged reproductives) within species, there was less variation across species because ant production was asynchronous. Variation in domatia contents was poorly related to rainfall for each of the three species. Finally, distal thorns held more alates and fewer workers than interior thorns, and branches higher off the ground held more alates and more workers than lower branches. For the numerically dominant C. mimosae, higher branches held significantly more immature ants than did lower branches. Ants are reliable food resources for patas monkeys, and are probably more reliable than many plant resources in this highly seasonal environment. We estimate that patas monkeys may get as much as a third of their daily caloric needs from these ants year-round. As ants and other insects are widely consumed by primates, we suggest that greater consideration be given to species differences in animal food choices and that further studies be conducted to examine the degree to which ants influence
-
male demography female mating behavior and infanticide in wild patas monkeys Erythrocebus patas
International Journal of Primatology, 2002Co-Authors: Karin L Enstam, Lynne A Isbell, Thomas W De MaarAbstract:Infanticide by males has been hypothesized to be a naturally selected behavioral strategy that increases the infanticidal male's reproductive success. The sexual selection hypothesis has been challenged via alternative, nonadaptive hypotheses that dispute its empirical and theoretical bases. Two of the most widely recognized alternatives are the social pathology hypothesis, in which infanticide results from overcrowding or recent human disturbance, and the generalized aggression hypothesis, in which infanticide is an epiphenomenon of increased male aggression. We report the first case of infanticide in wild, seasonally breeding patas monkeys (Erythrocebus patas) living at a low population density in a stable habitat, conditions which do not support the social pathology hypothesis. Its exceptional occurrence is consistent with the sexual selection hypothesis: over a 7-year period the infanticidal male was the only one of 13 resident males that was not present during the actual conception season but was present during the following birth season. Also consistent with this hypothesis, mothers were differentially targeted for male aggression, which increased sevenfold during the days surrounding the infanticide and then decreased to baseline levels after the infanticide. Aggression targeted at mothers does not support the generalized aggression hypothesis. As predicted by the sexual selection hypothesis, females began soliciting mating immediately after the infanticide, despite its occurrence in the nonconceptive season.
-
rank differences in ecological behavior a comparative study of patas monkeys Erythrocebus patas and vervets cercopithecus aethiops
International Journal of Primatology, 1999Co-Authors: Lynne A Isbell, Jill D. Pruetz, Michelle Lewis, Truman P YoungAbstract:One of the central dichotomies in primate behavior is between species in which there are relationships among females that include stable dominance relationships, and those in which the relationships include weak or unstable dominance relationships. This dichotomy has been attributed to differences in food resources, with stable dominance hierarchies occurring in species that feed on usurpable foods. We compared rank-related differences in nonagonistic behaviors considered to be tightly linked to ecology in broadly sympatric vervets (Cercopithecus aethiops) and patas monkeys (Erythrocebus patas), two closely related cercopithecines that are exemplars of this dichotomy, with the expectation that vervets would exhibit stronger rank differences than patas monkeys in these behaviors. Overall, rank explained more than twice as much variation among vervets as among patas monkeys in ranging behavior, activity budgets, and diet. Vervets did not, however, exhibit stronger rank differences when they used Acacia xanthophloea habitat, in which foods are more usurpable, compared to Acacia drepanolobium habitat, in which foods are less usurpable. In Acacia drepanolobium habitat, to which patas are restricted, higher-ranking vervets converged in behavior with patas monkeys to a greater extent than lower-ranking vervets, suggesting that social constraints interfere with the foraging efficiency of lower-ranking vervets even in habitats in which there are fewer opportunities to usurp foods.
Truman P Young - One of the best experts on this subject based on the ideXlab platform.
-
demography and life histories of sympatric patas monkeys Erythrocebus patas and vervets cercopithecus aethiops in laikipia kenya
International Journal of Primatology, 2009Co-Authors: Lynne A Isbell, Truman P Young, Karin Enstam Jaffe, Anne A Carlson, Rebecca L ChancellorAbstract:Mortality patterns are thought to be strong selective forces on life history traits, with high adult mortality and low immature mortality favoring early and rapid reproduction. patas monkeys (Erythrocebus patas) have the highest potential rates of population increase for their body size of any haplorhine primate because they reproduce both earlier and more often. We report here 10 yr of comparative demographic data on a population of patas monkeys and a sympatric population of vervet monkeys (Cercopithecus aethiops), a closely related species differing in aspects of social system, ecology, and life history. The data reveal that 1) adult female patas monkeys have significantly higher mortality than adult female vervets; 2) infant mortality in patas monkeys is relatively low compared to the norm for mammals because it is not significantly different from that of adult female patas monkeys; and 3) infant mortality is significantly higher than adult female mortality in vervets. For both species, much of the mortality could be attributed to predation. An epidemic illness was also a major contributor to the mortality of adult female patas monkeys whereas chronic exposure to pathogens in a cold and damp microenvironment may have contributed to the mortality of infant vervets. Both populations experienced large fluctuations during the study period. Our results support the prediction from demographic models of life history evolution that high adult mortality relative to immature mortality selects for early maturation.
-
interspecific and temporal variation of ant species within acacia drepanolobium ant domatia a staple food of patas monkeys Erythrocebus patas in laikipia kenya
American Journal of Primatology, 2007Co-Authors: Lynne A Isbell, Truman P YoungAbstract:The ants that live in the swollen thorns (domatia) of Acacia drepanolobium are staple foods for patas monkeys (Erythrocebus patas). To obtain a better understanding of these insects as resources for patas monkeys, we sampled the contents of 1,051 swollen thorns (ant domatia) over a 22-month period from December 1999 to September 2001, in Laikipia, Kenya. First, we confirmed that of the four species of ants that live on A. drepanolobium, Crematogaster sjostedti, the competitively dominant ant in this system, does not rear significant brood in the swollen thorns and is therefore not a major food item of patas monkeys. Second, across the other three species that do use swollen thorns for rearing their brood, C. nigriceps, C. mimosae, and Tetraponera penzigi, the number of worker ants per swollen thorn increased with increasing competitive dominance. Third, although there was considerable month-to-month variation in the number of workers, immatures, and especially alates (winged reproductives) within species, there was less variation across species because ant production was asynchronous. Variation in domatia contents was poorly related to rainfall for each of the three species. Finally, distal thorns held more alates and fewer workers than interior thorns, and branches higher off the ground held more alates and more workers than lower branches. For the numerically dominant C. mimosae, higher branches held significantly more immature ants than did lower branches. Ants are reliable food resources for patas monkeys, and are probably more reliable than many plant resources in this highly seasonal environment. We estimate that patas monkeys may get as much as a third of their daily caloric needs from these ants year-round. As ants and other insects are widely consumed by primates, we suggest that greater consideration be given to species differences in animal food choices and that further studies be conducted to examine the degree to which ants influence
-
rank differences in ecological behavior a comparative study of patas monkeys Erythrocebus patas and vervets cercopithecus aethiops
International Journal of Primatology, 1999Co-Authors: Lynne A Isbell, Jill D. Pruetz, Michelle Lewis, Truman P YoungAbstract:One of the central dichotomies in primate behavior is between species in which there are relationships among females that include stable dominance relationships, and those in which the relationships include weak or unstable dominance relationships. This dichotomy has been attributed to differences in food resources, with stable dominance hierarchies occurring in species that feed on usurpable foods. We compared rank-related differences in nonagonistic behaviors considered to be tightly linked to ecology in broadly sympatric vervets (Cercopithecus aethiops) and patas monkeys (Erythrocebus patas), two closely related cercopithecines that are exemplars of this dichotomy, with the expectation that vervets would exhibit stronger rank differences than patas monkeys in these behaviors. Overall, rank explained more than twice as much variation among vervets as among patas monkeys in ranging behavior, activity budgets, and diet. Vervets did not, however, exhibit stronger rank differences when they used Acacia xanthophloea habitat, in which foods are more usurpable, compared to Acacia drepanolobium habitat, in which foods are less usurpable. In Acacia drepanolobium habitat, to which patas are restricted, higher-ranking vervets converged in behavior with patas monkeys to a greater extent than lower-ranking vervets, suggesting that social constraints interfere with the foraging efficiency of lower-ranking vervets even in habitats in which there are fewer opportunities to usurp foods.
-
movements of vervets cercopithecus aethiops and patas monkeys Erythrocebus patas as estimators of food resource size density and distribution
Behavioral Ecology and Sociobiology, 1998Co-Authors: Lynne A Isbell, Jill D. Pruetz, Truman P YoungAbstract:The effect of food resources on behavior has been difficult to measure. Here we use animals themselves to describe “effective” food abundance and distribution by comparing, relative to where individuals stopped to eat, movements of (1) adult females living in a small group of vervet monkeys (Cercopithecus aethiops) with those living in a large group and (2) vervets and patas monkeys (Erythrocebus patas). Although females in the large vervet group travelled farther and stopped to eat more often than females in the small vervet group, these differences resulted from foraging in Acacia drepanolobium habitat. In A. xanthophloea habitat, females in the large group travelled less far, travelled shorter distances between foods, and stopped as often as females in the small group. Greater foraging costs of females in larger vervet groups may be offset by access to home ranges of better quality. Compared to patas, vervets travelled shorter distances, moved shorter distances between food sites, stopped less often, and had longer feeding bouts, suggesting that foods of vervets are denser and larger, overall, than foods of patas. When vervets foraged in A. drepanolobium habitat, also the habitat of patas, their foraging behavior became more like that of patas. Vervets travelled farther, stopped more often, and spent less time at food sites in A. drepanolobium habitat than in A. xanthophloea habitat, suggesting that foods are smaller and less usurpable in A. drepanolobium habitat. Distance between foods, a component of food distribution, did not increase, however. The critical variable underlying usurpability of foods may be food site depletion time, a temporal measure.
Jill D. Pruetz - One of the best experts on this subject based on the ideXlab platform.
-
rank differences in ecological behavior a comparative study of patas monkeys Erythrocebus patas and vervets cercopithecus aethiops
International Journal of Primatology, 1999Co-Authors: Lynne A Isbell, Jill D. Pruetz, Michelle Lewis, Truman P YoungAbstract:One of the central dichotomies in primate behavior is between species in which there are relationships among females that include stable dominance relationships, and those in which the relationships include weak or unstable dominance relationships. This dichotomy has been attributed to differences in food resources, with stable dominance hierarchies occurring in species that feed on usurpable foods. We compared rank-related differences in nonagonistic behaviors considered to be tightly linked to ecology in broadly sympatric vervets (Cercopithecus aethiops) and patas monkeys (Erythrocebus patas), two closely related cercopithecines that are exemplars of this dichotomy, with the expectation that vervets would exhibit stronger rank differences than patas monkeys in these behaviors. Overall, rank explained more than twice as much variation among vervets as among patas monkeys in ranging behavior, activity budgets, and diet. Vervets did not, however, exhibit stronger rank differences when they used Acacia xanthophloea habitat, in which foods are more usurpable, compared to Acacia drepanolobium habitat, in which foods are less usurpable. In Acacia drepanolobium habitat, to which patas are restricted, higher-ranking vervets converged in behavior with patas monkeys to a greater extent than lower-ranking vervets, suggesting that social constraints interfere with the foraging efficiency of lower-ranking vervets even in habitats in which there are fewer opportunities to usurp foods.
-
Differences Between Vervets (Cercopithecus aethiops) and patas Monkeys (Erythrocebus patas) in Agonistic Interactions Between Adult Females
International Journal of Primatology, 1998Co-Authors: Lynne A Isbell, Jill D. PruetzAbstract:We examined agonistic interactions between adult females in wild, unprovisioned patas monkeys (Erythrocebus patas) and vervets (Cercopithecus aethiops). The dominance hierarchy of patas is far less clear than that of vervets. patas had fewer interactions per dyad, fewer dyads with interactions, and a high percentage (18%) of reversals in which lower-ranking females won in agonistic interactions with higher-ranking females. Although the rank ordering of the kinds of interactions patas and vervets displayed is similar, with avoidance being the most frequently observed agonistic response to approaches by other females, patas were chased and supplanted more often than vervets were. The resources over which females were supplanted also differ between species. Supplants over food comprise smaller proportion of total supplants patas than for vervets. patas appear to feed on less usurpable foods than vervets. We conclude that (1) Erythrocebus and Cercopithecus spp., except C. aethiops , should not be categorized with other Cercopithecinae, and C. aethiops should not be categorized with other Cercopithecus spp. and Erythrocebus , in discussions and analyses of relationships between females within groups and (2) ecological conditions, i.e., usurpability of foods, can override phylogenetic history as the selective pressure determining the nature of female competitive relationships within groups.
-
movements of vervets cercopithecus aethiops and patas monkeys Erythrocebus patas as estimators of food resource size density and distribution
Behavioral Ecology and Sociobiology, 1998Co-Authors: Lynne A Isbell, Jill D. Pruetz, Truman P YoungAbstract:The effect of food resources on behavior has been difficult to measure. Here we use animals themselves to describe “effective” food abundance and distribution by comparing, relative to where individuals stopped to eat, movements of (1) adult females living in a small group of vervet monkeys (Cercopithecus aethiops) with those living in a large group and (2) vervets and patas monkeys (Erythrocebus patas). Although females in the large vervet group travelled farther and stopped to eat more often than females in the small vervet group, these differences resulted from foraging in Acacia drepanolobium habitat. In A. xanthophloea habitat, females in the large group travelled less far, travelled shorter distances between foods, and stopped as often as females in the small group. Greater foraging costs of females in larger vervet groups may be offset by access to home ranges of better quality. Compared to patas, vervets travelled shorter distances, moved shorter distances between food sites, stopped less often, and had longer feeding bouts, suggesting that foods of vervets are denser and larger, overall, than foods of patas. When vervets foraged in A. drepanolobium habitat, also the habitat of patas, their foraging behavior became more like that of patas. Vervets travelled farther, stopped more often, and spent less time at food sites in A. drepanolobium habitat than in A. xanthophloea habitat, suggesting that foods are smaller and less usurpable in A. drepanolobium habitat. Distance between foods, a component of food distribution, did not increase, however. The critical variable underlying usurpability of foods may be food site depletion time, a temporal measure.
Armand Claude Noundo Djieyep - One of the best experts on this subject based on the ideXlab platform.
-
In vitro trypanocidal effect of sera from Erythrocebus patas (Red patas monkey) and Chlorocebus tantalus (Tantalus monkey) on Trypanosoma brucei brucei Plimmer & Bradford, 1899 and Trypanosoma congolense Broden, 1894
bioRxiv, 2020Co-Authors: Felicite Djieyep-djemna, Ishaya Haruna Nock, Thelma Aken'ova, Ezekiel Kogi, Armand Claude Noundo DjieyepAbstract:Anti-Trypanosoma brucei brucei and anti-Trypanosoma congolense activities of sera from two species of uninfected zoo-primates, Erythrocebus patas (red patas monkey) and Chlorocebus tantalus (tantalus monkey) were investigated. The sera were screened using thick films and haematocrit centrifugation technique (HCT), to ensure that the donor primates were not infected with trypanosomes. Trypanosoma brucei brucei (Federe strain) and Trypanosoma congolense were suspended in supplemented RPMI (Rossvelt Park Memorial Institute) 1640 medium and the motility of the parasite was used as index of viability after the addition of each test serum. The selected primate sera exhibited some degree of anti-Trypanosoma brucei brucei activities in vitro. Red patas monkey serum had an inhibition index of 0.27, while that of Tantalus monkey was 0.34, against Trypanosoma brucei brucei, with mean survival times of 22.00{+/-}1.73 hours for red patas monkey serum and 19.67{+/-}0.58 hours for tantalus monkey serum, which are significantly lower (P
-
in vitro trypanocidal effect of sera from Erythrocebus patas red patas monkey and chlorocebus tantalus tantalus monkey on trypanosoma brucei brucei plimmer bradford 1899 and trypanosoma congolense broden 1894
bioRxiv, 2020Co-Authors: Felicite Djieyepdjemna, Ishaya Haruna Nock, Ezekiel Kogi, Thelma Akenova, Armand Claude Noundo DjieyepAbstract:Anti-Trypanosoma brucei brucei and anti-Trypanosoma congolense activities of sera from two species of uninfected zoo-primates, Erythrocebus patas (red patas monkey) and Chlorocebus tantalus (tantalus monkey) were investigated. The sera were screened using thick films and haematocrit centrifugation technique (HCT), to ensure that the donor primates were not infected with trypanosomes. Trypanosoma brucei brucei (Federe strain) and Trypanosoma congolense were suspended in supplemented RPMI (Rossvelt Park Memorial Institute) 1640 medium and the motility of the parasite was used as index of viability after the addition of each test serum. The selected primate sera exhibited some degree of anti-Trypanosoma brucei brucei activities in vitro. Red patas monkey serum had an inhibition index of 0.27, while that of Tantalus monkey was 0.34, against Trypanosoma brucei brucei, with mean survival times of 22.00{+/-}1.73 hours for red patas monkey serum and 19.67{+/-}0.58 hours for tantalus monkey serum, which are significantly lower (P<0.05) than that of the control (30.00{+/-}0.00 hours). The selected primate sera had pronounced inhibitory activities against Trypanosoma congolense. Sera from the two species of primate had very high anti-Trypanosoma congolense activity showing an inhibition index of 0.91 for Red patas monkey serum and 0.90 for Tantalus monkey serum, with marked and significant reduction (P<0.05) in survival time of 7.00{+/-}1.73 hours in Red patas monkey serum and 7.67{+/-}0.58 hours in Tantalus monkey serum, compared with the control (74.00{+/-}1.00 hours). The in vitro anti-trypanosomal activity of the serum samples was shown to be cidal in nature. The activity was not associated with xanthine oxidase. This study revealed that sera from red patas monkey and tantalus monkey had a moderate anti-Trypanosoma brucei brucei activity and a very high anti-Trypanosoma congolense activity in vitro suggesting the presence of some non-specific materials. Authors SummaryThe mechanisms that allow trypanosomiasis-resistant animals to control blood trypanosomes are being investigated, to identify non-specific factors that kill trypanosomes or limit their proliferation, contributing to host resistance. For instance, xanthine oxidase has been isolated and identified as the protein that kills trypanosomes in Cape buffalo. Humans and several other primates are also known to be resistant to infection by several animal-specific trypanosome species. In this study, sera from some zoo primates, red patas monkey and tantalus monkey, tested on Trypanosoma brucei brucei and Trypanosoma congolense in vitro, showed a slight anti-Trypanosoma brucei brucei activity and a very high anti-Trypanosoma congolense activity. These activities were shown to be cidal in nature and not associated with the protein xanthine oxidase. The authors suggest that non-specific factors other than the enzyme xanthine oxidase might have accounted for the sera anti-trypanosomal activities.