Impaired reconciliation in rhesus macaques with a history of early weaning and disturbed socialization

An attempt had been made to create five social groups from rhesus macaques with a history of early separation from their mothers, early weaning and hand feeding and, in most cases, previous housing in single cages. We investigated the exchange of affiliative behaviours after an aggressive encounter and selective attraction to the former opponent, a phenomenon previously well described in rhesus monkeys and called reconciliation. Evidence for reconciliation was only found in one of the five groups studied (corrected conciliatory tendency=13%). This group consisted of younger animals that had, at least temporarily, been living together after separation from their mothers. In the other groups studied, containing animals with a varied background, aggressive interactions were not followed by affiliative behaviours or attraction between former opponents. Our results indicate that the use of reconciliatory behaviours in adult monkeys is dependent upon social training. Lack of functional reconciliation might be one of the explanations to the severe and uncontrolled aggression previously found in groups of rhesus macaques created from animals with disturbed early socialization.     

Age- and dominance-related variation in feeding time among free-ranging female rhesus monkeys

Observations were made on the feeding behavior of 34 lactating rhesus females (Macaca mulatta) at Tughlaqabad, India. Consistent interindividual differences in feeding times were found and two sources of this variation were identified. Time spent feeding was found to decline with female age; rhesus mothers 4–6 years old spent over 40% more time feeding than did females 11–15 years of age. When the animals were divided into high- and low-status groups, dominance was also found to relate to individual feeding times; high-status females spent more time feeding that did low-status females, but this difference was evident only when the effect of female age was held constant. The age effect is probably an expression of age-related variation in nutritional requirements due to growth in the youngest subject and, perhaps, a declining basal metabolic rate in the oldest. We speculate that the comparatively weak dominance effect is due less to the aggressive interruption of feeding bouts than it is to a presumed greater vigilance on the part of subordinant mothers in monitoring their infants' whereabouts.     

The effect of urban and rural habitats and resource type on activity budgets of commensal rhesus macaques (Macaca mulatta) in Bangladesh

Macaques are characterized by their wide distribution and ability to adapt to a variety of habitats. Activity budgets are affected by habitat type, season, and food availability in relation to differing age–sex class and individual requirements. We conducted a comparative study on two commensal rhesus groups, one living in a rural village and the other in the center of urban Dhaka, Bangladesh. The study was conducted in three different seasons between 2007 and 2009 in order to evaluate how habitat type and season affects their behavioral activities. Differences in food type and its availability between these two habitats were mainly responsible for the variations in activity budgets between groups. Feeding time in the rural group was significantly longer than that in the urban group. In contrast, grooming and object manipulation/play were significantly greater in the urban than the rural group. Seasonal variations in all major behaviors were significantly affected by group, with more time spent feeding in summer than in winter/dry season, and more time spent grooming and moving in winter/dry season than summer in the rural group. In contrast, time spent resting was greater in the monsoon and summer seasons than the winter/dry season in the urban group. Grooming time was greater in the winter/dry season than the monsoon and summer seasons. In both groups, immature of both sexes spent significantly more time on feeding and object manipulation/playing and less time resting than adults. Adult females spent more time grooming than males and immatures, of both sexes, in both groups. Moreover, the rural group spent most of their time feeding on garden/crop produce and wild plant food resources, while the urban group spent more time feeding on provisioned foods. These results showed that differences in the activity budgets of rural and urban dwelling macaques were due largely to the differences in available food resources. Commensal rhesus macaques show a high degree of behavioral flexibility in response to habitat and resource variability, and knowledge of these differences is important for the conservation and management of highly commensal primates.     

Insulin Levels,Physical Activity,and Urinary Catecholamine Excretion of Obese and Non-Obese Rhesus Monkeys

The hypothesis that spontaneous obesity in rhesus monkeys is associated with abnormalities in energy expenditure was tested. Obese (n=7) and non-obese (n=5) monkeys were described in terms of body size and composition, food intake, and physical activity. Additionally, the relationships among fasting and stimulated insulin levels in serum, C-peptide levels in serum and urine, and urinary catecholamines were examined. Obese animals had primarily abdominal deposition of excess body fat, as indicated by markedly elevated abdominal circumferences and skin-fold thicknesses. Food intake did not differ between groups. Physical activity was much lower in the obese group. Obese monkeys had markedly higher serum insulin and C-peptide levels in the fasted state and in response to an intravenous glucose challenge. Urinary excretion of C-peptide and catecholamines was measured during successive 2-day periods of ad libitum feeding, food deprivation, and refeeding in order to examine potential differences between groups in sympathoadrenal activity and their relationship to insulin secretion. C-peptide excretion was greater for obese and decreased for both groups during food deprivation. Urinary dopamine (DA), norepinephrine (NE), and epinephrine (E) levels were significantly greater for obese animals in all conditions. DA excretion was lowest during deprivation and E excretion was lowest during refeeding, whereas NE excretion was relatively unaffected by feeding condition. The overall patterns of C-peptide and catecholamine excretion were qualitatively similar for both groups, and there were no reliable differences between obese and non-obese in their responses to the feeding manipulation. The results suggest that hyperinsulinemia associated with obesity in rhesus monkeys is linked to increased catecholamine secretion and a resistance to cate-cholaminergic action.     

Dominance and feeding competition in captive rhesus monkeys

The feeding behavior of 16 adult female rhesus monkeys living in three captive social groups was observed. Estimates of relative food intake, feeding rate, and location of feeding in relation to food sources were compared between females of different dominance ranks. Higher-ranking females had greater access to feeding sites and were supplanted or threatened less frequently while feeding than subordinates. However, no consistent differences in estimates of total intake were found between females of high and females of low rank. The effects of dominance on feeding behavior were most pronounced in the group receiving the least food relative to estimates of overall group nutritional requirements. Higher-ranking females, both over the long term and during the study period, tended to produce more surviving offspring. The effects of dominance on reproductive performance appeared to be less related to food intake than to competitive and aggressive interactions, potentially resulting in higher levels of stress for subordinates.     

The relationship between time of feeding and aggression in a group of captive hamadryas baboons

The relationship between time of feeding and aggression in a one-male unit of captive hamadryas baboons was studied to determine if feeding once a day, at a designated time and in measured amounts leads to a high level of aggressive behavior. The performance of maintenance behaviors did not differ between pre-feeding and post-feeding periods, however, aggressive behavior significantly decreased after feeding.     

Time Learning and Anticipatory Activity in Groups of Arctic Charr

Time learning and anticipatory activity were studied in five groups of 16–17 Arctic charr (Salvelinus alpinus) using self‐feeding devices with individual recognition (PIT (Passive Integrated Transponders)‐tags). The fish were kept under a LD 12:12 h cycle and periods of free access to the food were alternated with periods of time‐limited (2 h) access to food. Self‐feeding activity was significantly related to the light period in unrestricted conditions while related to the feeding periods during time‐limited access to food. The fish learned to concentrate their feeding activity to the restricted mealtime (>50% of the daily self‐feeding activity) within 10 d. The food anticipatory activity, measured as an increased self‐feeding activity before the feeding time and as aggressive interactions close to the trigger, was significant in both cases. The dominant individuals increased the trigger activity in advance of the time‐restricted reward period and subdominant individuals approached the trigger also in advance, inducing aggressive interactions. Thus, anticipating and learning a temporally predictable food source was pronounced in groups of self‐feeding Arctic charr.     

Effect of Group Size on Time Budgets of Sichuan Snub-Nosed Monkeys (Rhinopithecus roxellana) in Shennongjia National Nature Reserve, China

Group size influences intragroup scramble competition, which in turn influences time budgets in some primates, and may impact age–sex classes differently. There is a great deal of debate about whether folivorous primates, e.g., colobines, experience significant feeding competition. Unlike most colobines, Sichuan snub-nosed monkeys (Rhinopithecus roxellana) live in extraordinarily large groups and eat mainly lichens supplemented by seasonal plant food. We examined the effect of group size on time budgets in this species by studying two groups of different sizes in the same habitat in Shennongjia National Nature Reserve, China (study periods: August 2006–July 2008 for the larger group, November 2008–July 2009 for the smaller group). Results showed that the distribution of activities throughout the day did not differ between groups, but that time budgets did differ. Specifically, the monkeys spent more time moving and less time resting in the larger group than in the smaller group. Intergroup comparisons for each age–sex class indicated that adult females (but not adult males or juveniles) in the larger group spent more time moving and less time resting, and tended to spend more time feeding compared to those in the smaller group. The results suggested that increased scramble competition was occurring for adult females in the larger group. We provided preliminary evidence for the existence of intragroup scramble competition in Rhinopithecus roxellana.     

Status-dependent foraging behaviour in coral reef wrasses

Field observations using underwater video were used to reveal differences in the duration and frequency that fish engaged in daily behaviours such as chasing, searching, feeding, and travelling, according to their social patterns [passive or aggressive terminal phases (TPs), pair-spawning, or promiscuous groups] and intraspecific status (terminal or initial colour phases). Marked differences were apparent according to status, but this was not consistent among the three species; TP Cheilinus fasciatus tended to swim in longer bouts with less frequent searching or feeding than initial phase (IP) conspecifics; TP Cirrhilabrus punctatus exhibited less frequent feeding and travelling than IP conspecifics, while the most aggressive species Stethojulis bandanensis displayed no significant intraspecific differences. We highlight the importance of social context and individual status when examining fish foraging activities and the utility of underwater video for recording the duration and frequency that fish engage in essential daily activities.     

Effect of different level of roughage availability and contrast levels of concentrate supplementation on flavour of goat milk

Rancid and tart flavours are the most common off-flavours in Norwegian goat milk. In a feeding trial, we examined the effects of different levels of concentrate and of supplementary hay feeding on the occurrence of these off-flavours. Forty-eight experimental goats grazed cultivated pasture in the lowland during spring and autumn, and mountain pasture in summer. Twenty-four of the goats were fed 0.2 kg/day of concentrate (low concentrate, LC) and the remaining 24 goats 0.7 kg/day (high concentrate, HC). Twelve animals in LC and HC groups grazed freely, while the remaining goats in the two groups were given feeding challenges (limited periods of roughage restriction and ad libitum hay feeding). This was done to examine the effect of differing roughage availability on milk flavour. The animals fed low level of concentrate and with free grazing represented the control group. During the challenge periods, the goats were kept indoors and fed 0.2 kg hay/day for 2 days (roughage restriction) or hay according to appetite for 2 days (ad libitum feeding). At least 10 days of uninterrupted grazing were allowed between the challenges. Milk samples for sensory and chemical analysis were taken at the end of the challenge periods.The level of concentrate feeding did not influence the flavour of the milk when the goats were on lush spring pasture. However, the low level of concentrate feeding (LC) increased the frequency of off-flavour during the mountain and autumn experimental periods (P < 0.05).In the end of the mountain experimental period when the frequency of rancid/tart flavour increased in all groups, the sensory quality of milk produced by goats fed hay ad libitum (S1) had better taste ratings (P < 0.001) than milk from goats that were grazing. When the goats were given restricted amounts of hay, they adapted to the treatment by reducing their milk yield. In the spring and mountain experimental periods, restricted roughage feeding resulted in higher fat content and better taste ratings, especially in the group fed low level of concentrate (LC/S1). However, this connection was not clear in the autumn.Probably, the goats are able to handle a negative energy balance as long as mobilizable body reserves exist, but start to produce milk with lower dry matter content and higher frequencies of rancid/tart flavour when the body reserves are empty and the energy deficit is still pronounced.It is concluded that increasing the level of concentrate and feeding hay supplements will reduce the frequency of flavour defects at times when grazing is suboptimal or the pasture is of medium or low quality.     

Juvenile growth and aggression in diploid and triploid Chinook salmon Oncorhynchus tshawytscha (Walbaum)

Multilocus heterozygosity, aggressive and feeding behaviour, plasma cortisol levels and growth rate were evaluated among three groups of juvenile Chinook salmon Oncorhynchus tshawytscha : diploid, triploid and mixed groups of diploid and triploid fish. There was no difference between diploid and triploid fish in measurements of heterozygosity calculated using seven microsatellite loci, and these measurements did not correlate with performance measurements including feeding rate and growth rate. Aggression trials that examined small groups of fish revealed that after 4 days together in tanks, triploid fish were significantly less aggressive during feeding than diploid fish or fish in mixed groups. At the end of the trials, however, plasma cortisol levels did not differ among the three groups. Thirty-day growth trials in duplicate tanks of 60 fish revealed no difference in growth rate among diploid, triploid and mixed groups, but plasma cortisol levels were significantly lower in triploid fish than in either diploid fish or the mixed fish. Overall, independent of the above differences in aggressive behaviour and cortisol levels, these results suggest similar performance in diploid and triploid Chinook salmon, and thus provide support for the viability of triploid Chinook salmon culture in commercial aquaculture.     

Symbiotic ants as an alternative defense against giraffe herbivory in spinescent Acacia drepanolobium

Summary We explore here the occurrence of aggressive ants in an apparently symbiotic relationship with the savanna tree Acacia drepanolobium and their effects on giraffe herbivory on the Athi-Kapiti Plains, Kenya. Trees taller than 1.3 m were more likely to be occupied by aggressive ants in the genus Crematogaster than were shorter trees. Ants wereconcentrated on shoot tips, the plant parts preferred by giraffes. Trees with relatively more foliage had more swarming ants than did trees with less foliage. The feeding behavior of individual freeranging giraffes on Acacia drepanolobium was studied. Giraffe calves exhibited a strong sensitivity to Crematogaster ants inhabiting A. drepanolobium, feeding for significantly shorter periods on trees with a greater number of aggressive ants. Older giraffes were apparently less sensitive to ants, and did not feed for shorter periods on trees with fuller foliage, despite significantly greater ant activity on these plants. The thorns of A. drepanolobium are significantly shorter than are the thorns of A. seyal, a species without symbiotic ants, a pattern that may indicate a trade-off between ants and thorns as defenses.     

Social Contact Following Severe Aggression in Rhesus Macaques (Macaca mulatta): A New Test of the Consolation Hypothesis

Previous studies on macaque species revealed no evidence of consolation: affiliative contact between the loser of an aggressive interaction and a third party. However, typically, the researchers used short observation periods and latency to make first affiliative contact as a dependent measure. Based on social stress buffering literature, I predicted that by employing longer observation periods and percentage of time in affiliative contact as a dependent measure, I would be more likely to detect increases in affiliative contact following aggression. I observed adult female rhesus macaques for 1 hr after they received severe aggression and for 1 hr after some affiliative contact, and measured time spent in affiliative contact using instantaneous recording at 30-sec intervals. Contrary to prediction, victims of attack did not spend a greater percentage of time in affiliative contact postaggression as compared to postaffiliation. Subjects were also less likely to initiate contact with other individuals and were more likely to have contact with individuals that were dominant to their aggressor, following aggression. These results provide converging evidence that affiliative contact is not increased following aggression in macaques. I discuss the failure to bear out the predictions based on the social stress buffering literature in terms of rhesus social dynamics, the nature of aggression as a stressor, and possible mechanisms for the social stress buffering effect.     

Seasonal changes in the use of feeding resources by fish in stands of aquatic macrophytes in an Amazonian floodplain,Brazil

This study aimed to characterize the food intake by the fish assemblage inhabiting aquatic macrophytes stands, evaluating the changes in food availability among the periods of the hydrologic cycle and the trophic responses of the fish assemblage along with food availability. Fish sampling was conducted in stands of aquatic macrophytes (predominantly Paspalum repens, Poaceae) along banks of the Trombetas River during the four hydrologic periods (rising, high, receding, and low water level) that represent different phenological conditions of the habitat. The food consumption by the fish assemblage was analyzed for 41 species with stomach contents. The assemblage fed mainly on aquatic insects, periphytic algae and detritus. Food availability analysis showed that food resources changed among periods. Fifteen species were present in more than one period and most of those species showed dietary changes along with the hydrologic cycle, feeding mainly on invertebrates in the rising water period and periphytic algae and detritus in receding and low water periods. Only four species showed sufficient numbers to be analyzed in relation to diet and food availability along the at least three hydrologic periods, two of which showed a positive correlation between diet and food availability for three of the four periods; the other two species did not show this correlation, and presented omnivorous habits. In all cases, the selectivity values for the most important food items were near zero, indicating that intake was not motivated by feeding preference. Our results suggest that both trophic plasticity and omnivorous diets are important adaptations for species that inhabit temporally variable habitats such as aquatic macrophytes stands.     

Effects of Mixed-species Foraging Groups on the Feeding and Aggression of Juvenile Parrotfishes

Many parrotfishes (Scaridae) co-occur in mixed-species aggregations as juveniles, but diverge in resource use and social structure as adults. Focal observations of three juvenile parrotfishes (Scarus coeruleus, Sparisoma aurofrenatum, and Sparisoma viride) were conducted on inshore patch reefs in the Florida Keys to determine how feeding and aggressive interactions vary with group participation. All three species spent more time in groups than alone, most often in groups of less than ten individuals. Feeding rates were significantly higher for S. viride when foraging in groups than when alone. All species fed most often from Halimeda, and overall diet composition was similar for fish whether feeding in groups or alone. The frequency of aggressive interactions varied with group participation. Focal S. aurofrenatum were more aggressive when in groups than when alone, and both S. aurofrenatum and S. viride were attacked more often by damselfishes when they were alone than when in groups. In contrast, feeding rates, diet breadth, and aggressive interactions of S. coeruleus were less affected by group participation. Small mixed-species aggregations of coral reef fishes may be large enough for individuals to assume some of the benefits of group participation while at the same time avoiding the costs of competition realized in larger groups.     

Effects of social and inanimate enrichment on the behavior of yearling rhesus monkeys

Certain types of inanimate environmental enrichment have been shown to positively affect the behavior of laboratory primates, as has housing them in appropriate social conditions. While social housing is generally advocated as an important environmental enhancement, few studies have attempted to measure the influence of social conditions on the effects of inanimate enrichment or to compare the relative merits of social and inanimate enhancements. In the present study, inanimate enrichment (predominately physical and feeding enhancements) resulted in increased species-typical behavior for socially restricted subjects. However, social enrichment (living in groups) appeared to be more beneficial for young rhesus monkeys, leading to increased species-typical activities and decreased abnormal activities. The behavior of one cohort of yearling rhesus monkeys (Macaca mulatta) housed in small peer groups was compared with the behavior of four yearling cohorts housed in single cages. Half the animals in each cohort received a three-phase enrichment program and the rest served as controls. Group-housed yearlings spent significantly more time feeding and exploring and significantly less time behaving abnormally, self-grooming, and drinking than did singly housed yearlings. Enriched subjects spent significantly more time playing by themselves, and significantly less time self-grooming and exploring than did controls. Among group-housed subjects only, there were no differences between enriched and control monkeys. Captive primates should be housed socially, whenever appropriate, as the first and most important step in an enrichment program, with the provision of inanimate enhancements being considerably less important. Limited resources for inanimate enrichment programs instead should be focused on those individuals who can not be housed socially. © 1996 Wiley-Liss, Inc.     

Social interactions among female rhesus macaques (Macaca mulatta) during the nonbreeding season: Responses to the introduction of males

When rhesus monkeys are observed in social groups during the breeding season, increases in interfemale aggression coincide with midcycle increases in sexual activity between males and females. However, some investigators have suggested that both aggressive and affiliative interactions between females are influenced by the presence or absence of males, irrespective of menstrual cycle stage. In the present study, social interactions among members of a captive group of rhesus females were measured during the non-breeding season in response to the introduction of rhesus males. Ovariectomized rhesus females (estrogen-treated or untreated) served as stimulus controls. Tests with males were characterized by significantly decreased interfemale proximity and grooming and significantly increased aggression from that seen in tests with stimulus females or in the absence of stimulus animals. Only interfemale proximity declined significantly during stimulus female tests, but results suggest that this may merely reflect a decline in this behavior that occurs across the course of the day. Estrogen treatment did not alter either the aggressive or affiliative behavior of stimulus females or group female response to stimulus females. The possibility is discussed that changes in interfemale interactions during tests with males reflect female interest in interacting with the male, particularly under social conditions that may limit such interactions.     

Effects of sugar feeding supplemented with three plant extracts on some parameters of honey bee colonies

Sugar feeding is crucial to bee colonies during periods without natural nectar resources. The health and the development of bee colonies are affected by the sugar feeding type. Also, some materials can be added to the sugar feeding to boost the ability of bee colonies to withstand parasites. Three materials (mint, cinnamon, and chamomile) are used commonly to control bee parasites (e.g. Varroa mites). In the present study, the effects of these materials on the development and health of bee colonies were assessed. Sugar candy supplemented with these materials plus sugar candy only as a control group were tested. Bee colonies were fed with these feeding types weekly. Then, some parameters were evaluated. The results showed the suitability of the tested feeding types to bee colonies. Building of wax foundations was accelerated in cinnamon group. This group had also the lowest infestation rates with Varroa mites, suggesting a specific role of cinnamon in Varroa control. The colony development was significantly better in chamomile group than the other groups. Mint group showed no variations than the control group in most parameters. All feeding types showed safety to bees based on morphological characteristics and bee survival results. Practically, cinnamon is advised when building of wax combs is required while chamomile is recommended when increasing strength of colonies is needed. The role of cinnamon in controlling Varroa is recommended for further investigations.     

Seasonal variability in spatial defence by free-ranging rhesus monkeys (Macaca mulatta)

Data on the rhesus monkeys (Macaca mulatta) of Cayo Santiago demonstrate both intergroup and seasonal variability in spatial defence. Of the five groups only one defends an area, and only during the birth season. The four non-defensive groups share two feeding stations and live in such close proximity that spatial defence would require high outputs of energy. In contrast, the group that maintains an exclusive area has its own feeding station and lives in semi-isolation on an easily defensible end of the island. Its defence of this end of the island during the birth season provides a protected area for infants and assures the group exclusive access to flowering and fruiting plants. Relaxation of this defensive behaviour during the mating season maximizes opportunities for intergroup matings.     

Influence of Fruit Availability on Fruit Consumption in a Generalist Primate,the Rhesus Macaque <Emphasis Type="Italic">Macaca mulatta</Emphasis>

Fluctuations in resource availability occur in all ecosystems. To survive, species must alter their foraging strategies according to the quantity, quality, and distribution of available food. The rhesus macaque (Macaca mulatta), a commensal primate, is considered a generalist omnivore and very few studies have addressed how its feeding strategies change with respect to resource availability. We examined dietary diversity and frugivory levels in a group of rhesus macaques at the Buxa Tiger Reserve in northern India across one year. Using behavioural observations of diet and phenological monitoring, we found that although rhesus macaques fed on 107 food items including leaves, flowers, fruits, seeds, and insects, fruits made up ca. 74% of their diet. Fruit consumption correlated positively with fruit availability, but fruit preference appeared to play an important role; 16% of all the fruit species they fed on accounted for >50% of all fruit feeding observations. We suggest that afforestation programs involving preferred fruit species at the agricultural land–forest interface would prevent forest groups of rhesus macaques from gravitating toward human habitations and reduce conflict over anthropogenic resources. We further propose that the movement of certain primates in the direction of human habitations may be contingent on resource availability and food preference rather than an inherent propensity to gravitate to anthropogenic areas.