bluuebunny/crossref_metadata_2025 huggingface dataset:
Diet of wild chimpanzees (Pan troglodytes verus) at Mt. Assirik, Senegal: I. Composition
Authors: McGrew W. C. , Baldwin P. J. , Tutin C. E. G.
Published: June 2005

The composition of the diet of a savanna‐living population of wild chimpanzees (Pan troglodytes verus) at Mt. Assirik in Senegal is presented. The study site had a prolonged dry season, high temperatures, and vegetation dominated by grasses. Data came from direct observation, fecal specimens, and feeding traces; thus, strict criteria for acceptance of the indirect data were specified. Composition of diet was given in terms of species and family of prey, parts eaten, life‐form, type of habitat, and criteria for inclusion. Forty‐three species of plants with 60 parts were eaten; mostly fruits, from trees, in woodland. Nine species of animal prey were eaten, mostly social insects. An additional 41 species of plants with 53 parts were classed as likely to be eaten by chimpanzees, mostly on the grounds of their being eaten by sympatric anthropoids. Overall, the diet of the apes at Mt. Assirik resembles that of this species elsewhere in Africa, but the size of the dietary repertoire seems small and the proportion of low‐quality foodstuffs high. The latter are mostly time‐consuming to collect or tedious to obtain or process, and include underground storage organs.
Excretion of radiolabeled estradiol metabolites in the slow loris (Nycticebus coucang)
Authors: Perez Lorelei E. , Czekala Nancy M. , Weisenseel Karen A. , Lasley Bill L.
Published: June 2005

The excretion pattern of estradiol was studied in the slow loris Nycticebus coucang) and the ring‐tailed lemur (Lemur catta) in order to compare steroid excretion in two representative prosimian species. Daily urinary estrone conjugate measurements in the female loris provided little information when applied over prolonged periods. As a result of these negative data, a metabolic study was performed to determine if estrogen excretion patterns in the slow loris differed from those in the lemur, where urinary assays proved a useful tool in characterizing reproductive cycles. Radio‐labeled estradiol was injected intravenously, and serial urine and fecal collections were analyzed for radiolabeled metabolites. The results of these studies demonstrate that more than 92% of the radiolabel was excreted in the feces of the loris, in contrast to only 16% excreted in the feces of the lemur.
Copulatory patterns of primates as viewed in broad mammalian perspective
Authors: Dewsbury Donald A. , Pierce John D.
Published: June 2005

The goals of this review are to classify the patterns of copulatory behavior displayed by various species of primates, to compare them to the patterns of nonprimate mammalian species, and to search for correlates of the various patterns. Copulatory patterns are classified in relation to the presence or absence of four defining attributes: a lock, thrusting during intromissions, multiple intromissions, and multiple ejaculations. Literature on copulation in 67 primate species is reviewed, and a tentative classification is proposed for 33 primate species. Although neither social organization nor genital morphology provides a fully satisfactory relationship, there are indications that variations in copulatory behavior are related to variations in genital morphology.
Flow microfluorometric analysis of peripheral blood mononuclear cells from nonhuman primates: Correlation of phenotype with immune function
Authors: Ahmed‐Ansari A. , Brodie A. R. , Fultz Patricia N. , Anderson Daniel C. , Sell K. W. , McClure H. M.
Published: June 2005

A panel of monoclonal antibody reagents has been identified that can be used for routine monitoring of subsets of peripheral blood mononuclear cells (PBMC) from Macaca mulatta (rhesus macaques), Macaca nemestrina (pig‐tailed macaques), and Cercocebus atys (sooty mangabeys). The procedure uses fluorescein and phycoerythrin conjugates of the monoclonal antibodies in appropriate combinations, so that two‐color microfluorometric analyses can be readily performed on as little as 1.2 ml of EDTA blood. PBMC from a total of 20 normal adult rhesus macaques, 21 normal adult pig‐tailed macaques, 4 SIV− sooty mangabeys, and 16 SIV+ adult sooty mangabeys were analyzed with the panel of monoclonal reagents and flow microfluorometry. The mean frequency, absolute numbers, and range for each subset in these nonhuman primate species are described. Sooty mangabeys appeared markedly different from the other two primate species. The PBMCs from the mangabeys had a higher mean frequency and absolute number of total T cells, Leu‐3a+/18− T cells, suppressor (Leu−2a+) T cells, which were HLA‐DR+, and IL‐2R+ cells. Functional helper, suppressor, natural killer (NK), lymphokine activated killer (LAK), and antigen‐presenting cell studies were also performed to correlate phenotype with immune function. Data indicate that Leu−3a+ T cells (CD4+) and Leu−2a+ T cells (CD8+) in these primate species represent human equivalents of helper and suppressor T cells, respectively. NK and LAK effector cells in the rhesus and pig‐tailed macaques appear to be predominantly Leu−19+. In contrast, Leu−2a+ cells appear to be the predominant NK and LAK effector cell in sooty mangabeys. These data provide a basis for routine evaluation of lymphocyte subsets in these nonhuman primate species, and provide a means to correlate phenotype with immune function.
Determining acrosomal status of the cynomolgus monkey (Macaca fascicularis) sperm by fluorescence microscopy
Authors: Cross Nicholas L. , Morales Patricio , Fukuda Masaru , Behboodi Esmail
Published: June 2005

The acrosome of Macaca fascicularis sperm cannot be distinguished by conventional light microscopy, so determining whether sperm are acrosome‐intact or‐reacted is difficult. We describe methods for labeling the acrosomal region of sperm with two different probes: fluoresceinated Pisum sativum agglutinin and anti‐sperm antiserum. Acrosome‐intact sperm are much more heavily labeled in the acrosomal region than are acrosome‐reacted sperm, providing a simple means of differentiating the two types of sperm. The two probes detect similar numbers of acrosome‐reacted sperm following treatment with the divalent cation ionophore, A23187.
Characteristics of the circadian activity rhythm in common marmosets (Callithrix j. jacchus)
Authors: Erkert Hans G.
Published: June 2005

The circadian activity rhythm of the common marmoset, Callithrix j. jacchus was investigated by long‐term recording of the locomotor activity of 15 individuals (5 males, 10 females) from 1.5 to 8 years old, both under constant illumination and under LD 12:12. The mean period of the spontaneous circadian rhythm was 23.2 ± 0.3 h. Neither sex‐specific differences nor a systematic influence of light intensity on the spontaneous period were observed, but the period was dependent on the duration of the trial and on the age of the individual. Due to the short spontaneous period, in LD 12:12 there was a distinct advance of the activity phase with respect to the light time and a masking of the true onset of activity by the inhibitory direct effect of low light intensity during the dark time. After an 8 h delay shift of the LD 12:12, re‐entrainment of the circadian activity rhythm required an average of 6.8 ± 0.7 days; the average re‐entrainment time after an 8 h phase advance of the LD cycle was 8.6 ± 1.3 day. This directional effect is ascribed to characteristics of the phase‐response curve. No ultradian components were observed, either in the LD‐entrained or the free‐running circadian activity rhythm.
Female dominance rank and behavior during artificial menstrual cycles in social groups of rhesus monkeys (Macaca mulatta)
Authors: Zumpe Doris , Michael Richard P.
Published: June 2005

We recently reported (Michael & Zumpe: American Journal of Primatology 15:157–170, 1988) evidence for the hypothesis that copulations by pairs of rhesus monkeys are linked more closely to the ovulatory phase of the female's menstrual cycle when a male has access to several females in different cycle phases rather than access to females in the same cycle phase. We have now used data from this earlier study to assess the role of female dominance. Artificial menstrual cycles were induced with hormone injections in two of four ovariectomized females in eight social groups (each consisting of one male and four females). The artificial cycles were either synchronized or offset by 7‐day increments. There were differences in the behavioral interactions of the higher‐ranking (dominant) and lower‐ranking (subordinate) hormone‐treated females in each group. The amount of male sexual activity received by dominant and subordinate females differed little, but dominant females initiated significantly more sexual activity (P<.0001) than did subordinate females. Dominant females were significantly more aggressive (P<.0001) toward other females and received more direct and redirected aggression from males. Males generally initiated and maintained more social contacts with dominant than with subordinate females, and dominant females were less active than subordinates in initiating and maintaining social interactions with males. The findings provide new evidence for both female mate competition and mate choice by males for higher‐ranking females.
Hominoid dental variability and species number at the late Miocene site of Lufeng, China
Authors: Kelley Jay , Etler Dennis
Published: June 2005

The large hominoid sample from the late Miocene site of Lufeng, China, has been variously claimed to contain either one or two species, but very few metric data in support of either position have been published. We calculate coefficients of variation for the dental remains both for the two presumed species and for the pooled sample as a whole using the summary statistics published by Wu & Oxnard (Wu & Oxnard: American Journal of Primatology 5:303–344, 1983a, Nature 306:258–260, 1983b). These are compared to the same measures of single‐sex and combined‐sex samples of extant hominoids. We also present metric characterizations of male and female canines of extant great apes, with which we evaluate the gender composition of the Lufeng canine sample. In a two‐species alternative, the two presumed species have measures of variability and canine representation that are more compatible with single‐sex samples representing males and females, respectively. The pooled dental sample has measures of variability within the ranges of single species of extant great apes. We conclude there is a single large hominoid species represented at Lufeng that is highly sexually dimorphic. The phylogenetic relationships of this species are briefly considered. It is generally primitive in craniodental morhpology and is unlikely to be a member of the Sivapithecus‐Pongo clade.
The reproductive status of nonbreeding group members in captive golden lion tamarin social groups
Authors: French Jeffrey A. , Inglett Betty J. , Dethlefs Theresa M.
Published: June 2005

Reproductive activity is limited to only one female in many species of callitrichid primates (marmosets and tamarins): daughters and subordinate females do not produce offspring. A suppression of ovulatory cyclicity is responsible for the lack of reproductive activity in three species of callitrichids studied to date. This study evaluated the endocrine status of golden lion tamarins (Leontopithecus rosalia) housed as daughters or sons in family groups and of individuals housed in isosexual peer groups. Daughters 17 months of age and older and a subordinate female had high levels of estrogen excretion. Mean levels of estrogen excretion in these females were similar to those of nonpregnant, breeding adult females (17.14 ± 6.82 versus 11.93 ± 6.33 μg/mg creatinine, respectively). Estrogen profiles were similar to those of breeding adult females, with sinusoidal cycles in estrogen excretion. Younger daughters in family groups (10 and 12 months old) showed markedly lower levels of estrogen excretion (0.84 ± 0.58 μg/mg creatinine). Estrogen profiles lacked the sinusoidal nature of cycles in older daughters and breeding females, and elevations in estrogen excretion occurred frequently and remained elevated for 1 or 2 days. Plasma testosterone levels in males varied widely, but mean concentrations did not differ among males housed in different social conditions. These results suggest that older daughters and subordinate females may be capable of expressing normal ovarian function in the presence of a breeding adult female. This finding may account for two unusual observations in the lion tamarin: the high level of female‐female aggression and the presence of groups in the wild with more than one actively breeding female.
Parasites of free‐ranging Cayo Santiago macaques after 46 years of isolation
Authors: File Sharon , Kessler Matt J.
Published: June 2005

Three hundred and thirty seven Macaca mulatta from a population that had been isolated on a small island off the coast of Puerto Rico for 46 years were examined for parasites. Anatrichosoma cynamolgi (26%), Strongyloides fuelleborni (54%); Trichuris trichiura (23%); and Balantidium coli (2%) were detected. Toxoplasma antibodies were found in 10% of the sera examined. Milk was examined for Stronglyloides, and blood was examined for microfilariae and protozoa, but no parasites were found in these specimens. The animals in this colony harbored intestinal parasites but were in excellent physical condition, with a high reproductive rate and a low mortality rate. It is concluded that the presence of intestinal and tissue parasites has little measurable effect on the overall health of rhesus in this free‐ranging environment.
A twenty‐year study of long‐term and temporary dominance relations among stumptailed macaques (Macaca arctoides)
Authors: Rhine Ramon J. , Cox Roberta L. , Costello Michael B.
Published: June 2005

Consistent individual differences in long‐term dominance are a basic underlying assumption of hypotheses linking dominance and reproductive success. Long‐term and temporary dominance of a colony group of stumptailed macaques was studied for 20 years. There were two variously constituted groups for the first 4 years and a single group for the last 16. Stumptails displayed the matrilineal dominance organization found for several other cercopithecine species. A method was devised to standardize ranks so they could be compared over the years across groups of varying size and composition. No animal maintained the same dominance rank over the entire period of the research or over the last 16 years, but there was considerable consistency over long periods. Although occupants of the male and female alpha positions changed several times, one female was dominant for 18 of the 20 years. She was dominant in 1968, at the start of the study, and at its end in 1988 at which time her 18‐year‐old son was the dominant male. Variation in dominance ranks was greatest among members of mid‐ranking matrilines and least for the lowest ranking. The same female or her son were the lowest ranking animals of their groups in all samples taken over the entire 20 years.
Consumption of cyanogenic bamboo by a newly discovered species of bamboo lemur
Authors: Glander Kenneth E. , Wright Patricia C. , Seigler David S. , Randrianasolo Voara , Randrianasolo Bodovololona
Published: June 2005

Three species of bamboo‐eating lemurs were found to be sympatric in the southeastern rain forests of Madagascar. Sympatric species generally differ in habitat utilization or diet, but these three closely related bamboo lemurs lived in the same habitat and all ate bamboo. Behavioral observation revealed that they did select different parts of the bamboo, and chemical analyses confirmed that there was a difference in the secondary compound content present in those selections. The growing tips of Cephalostachyum ef uiguieri selected by the golden bamboo lemur (Hapalemuraureus) contained 15 mg of cyanide per 100 g fresh weight bamboo while the leaves of C. perrieri selected by the gentle bamboo lemur (H. griseus)and the mature culms of C. cf uiguieri selected by the greater bamboolemur (H. simus) did not contain cyanide. Since each individual golden bamboo lemur ate about 500 g of bamboo per day, they daily ingestedabout 12 times the lethal dose of cyanide. The mechanism by which this small primate avoids the acute and chronic symptoms of cyanide poisioning is unknown.
Sex differences in the acquisition of communicative competence by pigtail macaques (Macaca nemestrina)
Authors: Gouzoules Harold , Gouzoules Sarah
Published: June 2005

Previous study of captive pigtail monkeys (Macaca nemestrina) revealed that victims of an attack by a group member employed one of four acoustically different recruitment calls (Gouzoules&Gouzoules: Animal Behaviour 37:383–401, 1989). The calls appear to provide allies with information pertinent to decisions about fight intervention. Each call was associated with an agonistic context distinguished by the relative rank of the opponent and the severity of the attack. Monkeys younger than 3 years of age were significantly less likely to use a contextually appropriate call than were older animals and their calls tended to be acoustically less like the prototype for a given context. Analyses reported on here revealed that, among juveniles, females were more proficient than males in both the proper contextual use and the production of these calls. These findings suggest parallels with human sex differences in the development of communicative competence. The evolutionary origins for these sex differences in macaque vocal development may be based in the different life history patterns males and females exhibit.
Increased cage size does not alter heart rate or behavior in female rhesus monkeys
Authors: Line Scott W. , Morgan Kathleen N. , Markowitz Hal , Strong Sharon
Published: June 2005

Newly proposed federal regulations will mandate that singly caged non‐human primates be kept in cages larger than the current minimum standard, or be given 4 hours in an exercise cage per week. In order to evaluate the effectiveness of increasing cage size in improving well‐being, the behavioral and heart rate responses of 10 female rhesus monkeys (Macaca mulatta) to three different cage sizes were measured. With the exception of vocalizations, no significant differences in behavior were obtained. Grunts increased in the largest cage, following the birth of an infant in a cage within view of the test cages. No differences with respect to cage size were found in heart rate or activity level, although there were significant variations at different times of day. We conclude that modest increases in cage size are less likely to enrich the environment of singly caged laboratory primates than are changes in social opportunities or increases in environmental complexity.
Capacitation and the acrosome reaction in squirrel monkey (Saimiri sciureus) spermatozoa evaluated by the chlortetracycline fluorescence assay
Authors: Kholkute S. D. , Lian Ye , Roudebush W. E. , Dukelow W. R.
Published: June 2005

Capacitation and the acrosome reaction in squirrel monkey seminal spermatozoa diluted in Tyrode's medium (TALP) and TC‐199 were monitored by a chlortetracycline (CTC) fluorescence assay. Four CTC patterns, similar to those found in human sperm, were readily characterized by fluorescent staining on the heads of the spermatozoa. The appearance of the capacitated (CP) pattern was dependent on the concentration of the bovine serum albumin. Acrosomal loss was observed in a maximum of 15% of the sperm in the populations studied here. Calcium ionophore A23187 (5 μM to 20μM) induced acrosomal loss in 60–70% of capacitated spermatozoa. However in freshly ejaculated sperm incubated under capacitating conditions or in spermatozoa incubated in Ca+ +‐free medium, A23187 failed to induce acrosomal loss. Furthermore, spermatozoa incubated in the presence of seminal plasma or spermatozoa obtained following a 1‐hour “swim‐up” procedure showed an identical timecourse of appearance of the CP pattern, indicating the lack of effect of seminal plasma on capacitation in the squirrel monkey.
Parental behavior and infant development in ruffed lemurs (Varecia variegata) in a northeast Madagascar rain forest
Authors: Morland Hilary Simons
Published: June 2005

Parental behavior and infant development of black and white ruffed lemurs (Varecia variegata) were studied on Nosy Mangabe Island in northeast Madagascar. Ruffed lemur females produced twins, prepared nests for neonates in the trees, transported infants by mouth, and parked them in the trees. During two consecutive birth seasons, the average birth rate for nine females was 0.58. Two females reproduced in one social group. Lactating females spent most of their time resting with their infants or foraging for food. Infants developed rapidly and were fully mobile by 3–4 months. No female reproduced successfully in 2 consecutive years. In 1988, infant mortality within 3 months of birth was very high (64%). Accidental falls may have been one major cause. Adults of both sexes, including a reproductive female, exhibited alloparental behavior such as guarding infants and nonmaternal nursing. Alloparental care may increase the likelihood of infant survival. Some of these observations are not compatible with the idea that ruffed lemurs live in small pair‐bonded groups, as other researchers have suggested.
Predator recognition in cotton‐top tamarins (Saguinus oedipus)
Authors: Hayes Sheryl L. , Snowdon Charles T.
Published: June 2005

Captive social groups of cotton‐top tamarins (Saguinus oedipus) were presented with inanimate and animate stimuli to determine (1) if the tamarins recognize a snake as a dangerous stimulus and (2) whether the tamarins' response was specific to snakes. Fourteen pairs of tamarins were presented with a live boa constrictor, artificial flowers, and an empty box. Animals visually fixated for a longer period of time and emitted a greater frequency of mild alarm, strong alarm, and mobbing vocalizations during the presentations of the snake than during the presentations of either the flowers or the empty box. However, 97% of the alarm and mobbing vocalizations were emitted from only nine of the 28 individuals. In addition, there was no significant increase in locomotory activity and no significant change in avoidance behavior, as would be expected from reports on wild tamarins responding to snakes. Nine of the 14 pairs of tamarins were presented with a laboratory rat, leaves, and an empty box. The laboratory rat was used to test the animals' response to a moving, non‐food, non‐predatory stimulus. Animals visually fixated for a longer period of time and emitted a greater frequency of strong alarm and mobbing vocalizations during the presentations of the rat than during the presentations of either the leaves or the empty box. Of the 18 tamarins, seven individuals emitted 91% of the alarm and mobbing vocalizations. There was no significant difference between the number of mild alarm, strong alarm, and mobbing vocalizations emitted during the presentations of the snake and during the presentations of the rat. Results of this study suggest that captive cotton‐top tamarins do not demonstrate an alarm response specific to snakes but may simply display fear to moving objects. In addition, the tamarins did not respond to the snake with the degree of behavioral or vocal intensity, as has been reported in wild tamarins.
Subspecific morphological variation in the saddle‐back tamarin (Saguinus fuscicollis)
Authors: Cheverud James M. , Moore Allen J.
Published: June 2005

Hershkovitz (Living New World, Volume 1. Chicago, University Press of Chicago, 1977, pp. 618–627, 634–666) identified 13 subspecies of Saguinus fuscicollis based on coat color variation on the head, neck, and shoulders. Other morphological differences among the subspecies are unknown. It has been suggested, however, that several of the taxa may be distinct at the specific level. In this report, we examine the level and pattern of facial morphological variation among the subspecific populations to evaluate their taxonomic status.

Eleven facial measurements were recorded from the left side of 104 saddle‐back tamarin crania. Significant morphological variation among the subspecies in facial heights and depths was detected with discriminant function analysis. Analyses of morphological differences between subspecies and among individual specimens relative to geographical and evolutionary distances (based on the metachromatic theory) were performed by using quadratic assignment procedures. These analyses indicate an absence of geographically related morphological variation across the species range while phylogenetic relationships are reflected in morphological similarities among groups and individuals. This finding is consistent with the formation of subspecific populations by relatively small founding populations budding off from a larger parent population, invading a new interfluvial basin, and then remaining relatively isolated, as suggested by Hershkovitz (Living New World Monkeys, Volume 1. University of Chicago Press, Chicago, 1977).
Heart rate and social status among male cynomolgus monkeys (Macaca fascicularis) housed in disrupted social groupings
Authors: Kaplan Jay R. , Manuck Stephen B. , Gatsonis Constantine
Published: June 2005

The relationship between social status and telemetrically recorded heart rate (HR) was studied among 29 adult male cynomolgus monkeys (Macaca fascicularis) which had been maintained in six social groups (n = four or five) for 26 months. The membership of each group was reorganized periodically (20 times in 26 months) by shifting monkeys from group to group in a way that maximized each animal's exposure to social strangers. The social behavior of all animals was monitored, via focal sampling, twice per week; social status was based on the outcome of agonistic encounters and was determined every 2 weeks. For four nights on each of two occasions (months 13 and 25 of the experiment), the HRs of all animals were sampled 12 times per hour, 30 seconds per sample between 1800 h and 0900 h. A more limited nocturnal HR sampling was performed during the first month of the experiment. The behavioral observations revealed that, despite the repeated social reorganization, some monkeys were habitually dominant in their groups while others were consistently subordinate. Further, those monkeys falling above the median in dominance status had significantly lower HRs than their subordinate counterparts (104 vs. 117 beats per minuts; P = 0.01). The effect was observed irrespective of the month in which observations were made, and was corroborated by more limited observations made at the beginning of the experiment. Finally, those few monkeys which rose or fell in rank were characterized by inverse changes in HR, supporting the hypothesis that behavioral factors influence HR (rather than visa versa).
Metabolic abnormalities among free‐ranging Macaca mulatta on Cayo Santiago: Comparisons with Macaca mulatta at Sabana Seca
Authors: Howard Charles F. , Kessler Matt J. , Schwartz Susan
Published: June 2005

Free‐ranging rhesus macaques (Macaca mulatta) were examined on the island of Cayo Santiago (CS), Puerto Rico, with intravenous glucose tolerance tests (IV‐GTTs). Results were compared to monkeys derived from the island, but subsequently housed in corrals or gang cages at Sabana Seca (SS). Glucose clearance was similar among CS and SS macaques (range 2.99 to 4.50%min); both CS and SS males had significantly greater fasting serum glucose levels (63 ± 1 and 61 ± 2 mg/dl, respectively) than females; concentrations in CS and SS nonpregnant females (49 ± 3 vs. 52 ± 1 mg/dl) were significantly greater than CS and SS pregnant females (38 ± 3 vs. 41 ± 2 mg/dl) at each location. Fasting insulin was significantly less for male CS than for male SS macaques (means of 34 vs. 51 μU/ml); female averages were similar at both locations (range 48 to 61 μU/ml). The acute increment of insulin secretion for CS males was less than for SS males (85 vs. 136 μU/ml) but there were no differences between CS and SS females. The weight and body mass of CS macaques were generally greater than SS macaques. Hyperinsulinemic macaques > 10 years had greater weight and body mass compared to age‐matched controls. Genetics may play a major role in expression of these impairments since the incidence on CS varied from 0 to 54% among the matrilines examined.
Notes on the sexual behavior of the proboscis monkey (Nasalis larvatus)
Authors: Yeager Carey P.
Published: June 2005

Proboscis monkey (Nasalis larvatus) sexual behavior was studied at the Tanjung Puting National Park in Kalimantan Tengah, Indonesia, for 12 months. Data were collected on one‐male groups and all‐male groups using event sampling for copulations, presents, and same‐sex mounts. Proboscis monkeys follow typical colobine patterns of sexual behavior with females soliciting copulations through head shaking, pout face, and the presentation of the hindquarters. Males appear to be single‐mount ejaculators. Harassment of copulating pairs and female‐female competition for a mate were observed. Same‐sex mounts (female‐female and male‐male) were also observed. Additional data are needed to evaluate their function.
Composition of the diet of lowland gorillas at Lopé in Gabon
Authors: Williamson Elizabeth A. , Tutin Caroline E. G. , Rogers M. Elizabeth , Fernandez Michel
Published: June 2005

This report describes the composition of the diet of lowland gorillas, Gorilla gorilla gorilla, at Lopé in central Gabon. This population inhabits mature evergreen tropical forest and is not habituated to human observers. Data were collected during 6 years of an ongoing long‐term study, from feeding‐trails and by direct observation, but mostly by fecal analysis. Gorillas ate 182 plant foods from 134 species and 36 families. The fruit diet was diverse: 95 species were consumed, most with succulent pulp, and some immature seeds were eaten. Fruit remains were recorded in 98% of dung. Vegetative parts of Aframomum and Marantaceae formed staple foods, as they were abundant, accessible, and available year‐round. Soil and social insects were also ingested; remains of weaver ants were recorded in one third of feces. More foods have been recorded for gorillas at Lopé than elsewhere and this is the most frugivorous population studied so far.
Inanimate environmental enrichment for group‐housed rhesus macaque infants
Authors: Champoux Maribeth , Digregorio Gayle , Schneider Mary L. , Suomi Stephen J.
Published: June 2005

The behavior of peer‐reared infant rhesus macaques raised in enriched and nonenriched housing conditions was examined in order to evaluate the utility and effectiveness of object enrichment in a group housing setting. Environmental enrichment consisted of apparatuses designed to promote motor activity and to provide response‐contingent feedback. Four animals in each condition were tested over a 14‐month period. Behavioral observations were conducted in the home cage and during several test situations specifically designed to assess behavioral and affective responses to novelty and mild stressors. Monkeys in the enriched condition exhibited fewer behavioral and affective signs of disturbance than control infants in all observation conditions.
The relationship of serum estradiol and progesterone concentrations to the enzyme immunoassay measurements of urinary estrone conjugates and immunoreactive pregnanediol‐3‐glucuronide in Macaca mulatta
Authors: Shideler S. E. , Munro C. J. , Tell L. , Owiti G. , Laughlin L. , Chatterton R. , Lasley B. L.
Published: June 2005

Paired urine and serum samples from four conceptive and six nonconceptive ovarian cycles of seven adult Macaca mullatta were analyzed by radioimmunoassay (RIA) for circulating estradiol (E2) and progesterone (Po), and urinary estrone conjugates (E1C) and immunoreactive preganediol‐3‐glucuronide (iPDG) using enzyme immunoassay (EIA). Nonconceptive cycles exhibited a fivefold increase in urinary E1C and serum E2 levels from follicular phase levels to the preovulatory peak. Linear correlation between urinary E1C and serum E2 nonconceptive cycle hormone levels was significant (P <0.01, r = 0.69). Luteal phase levels of iPDG and serum Po levels were approximately parallel in nonconceptive cycles. Similarly, conceptive cycle urinary E1C levels and serum E2 measurements had a correlation coefficient that was significant (P<0.01, r = 0.45). Nonconceptive and conceptive cycle iPDG and Po levels were significantly correlated (P = 0.05, r = 0.63, and P<0.01, r = 0.66, respectively). These data demonstrate that EIA measurements of ovarian hormones in daily urine samples can be used to accurately monitor ovarian function and early pregnancy in Macaca mulatta.
Premises, promises, and problems of primatology
Authors: Mason William A.
Published: June 2005

The premises and promises of primatology stem from its focus on a unique biological group whose members are related by evolutionary descent, and from its commitment to discover all there is to know about these animals. The essential multidisciplinary character of primatology is implicit in this commitment. Evolutionary theory provides the field of primatology with its reason for being and its intellecutal coherence, and is the basis for transforming a diversity of potentially disparate and autonomous disciplines into a mutually reinforcing array of interdependent components within a common enterprise. A powerful adjunct to evolutionary theory is the comparative perspective. The distinguishing characteristic of this perspective is its concern with similarities and differences among primate species at all levels of structure and function. It aims to establish shared traits, to distinguish between homologous processes and convergent effects, to identify trends and specializations, and to understand the historical antecedents of living species. Some of the problems that primatology faces can be traced to its multidisciplinary character. The vitality of primatology depends on the continuing infusion of new methods, new findings, and new ideas. This requires an active process of interdisciplinary communication and mutual education. It is also essential to promote basic research on all aspects of primate biology and to affirm the singular importance of the nonhuman primates as a resource for understanding the natural world and the principles that govern its workings. Conservation is the most formidable and intractable problem confronted by modern primatology. Primate conservation is part of the larger problem of preserving biological diversity in the face of accelerating destruction of natural ecosystems. Primatology has made important contributions to conservation and will continue to do so. The scope and complexity of the problem, however, require the cooperative efforts of many different interest groups.
Effects of the presence of a second male on pair‐tests of captive cynomolgus monkeys (Macaca fascicularis): Role of dominance
Authors: Zumpe Doris , Michael Richard P.
Published: June 2005

In social macaques, sexual, aggressive and social interactions between a male and female occur in a complex setting in which the presence of other members of the group may exert powerful, long‐lasting effects. We have studied the effects of the presence of a second male, either immediately before or during pair tests, on the behavioral interactions of male cynomolgus monkeys with their female partners. Twenty‐minute tests were conducted in a large room containing a small compartment that confined a second male. Each of 8 males served in turn both as a test male and as a second male (stimulus male)(4 females, 8 male–female pairs, 480 pair‐tests). After 5 weeks of pair‐testing with a stimulus male absent to establish behavioral baselines, the test conditions were changed daily during the next 5‐week period in the following way: (1) pair‐test immediately after the test male was observed with the stimulus male (Mondays), (2) control pair‐test (Tuesdays), (3) pair‐test in the presence of the stimulus male (Wednesdays), and (4) control pair‐test (Thursdays). A final 5‐week control period of pair‐testing followed with the stimulus male absent. Stimulation of a test male by a second male either immediately before or during the pair‐test had highly significant but different effects. Ejaculatory activity increased in tests that followed stimulation, mainly in males dominant to the stimulus male, while sexual and social activity decreased in tests during stimulation, but mainly in males subordinate to the stimulus male. The findings suggested that dominance confers a mating advantage on males even when there is no opportunity for mating interference or active mate competition.
Consistency in maternal behavior within families of free‐ranging rhesus monkeys: An extension of the concept of maternal style
Authors: Berman Carol M.
Published: June 2005

This paper assesses the extent to which free‐ranging rhesus monkeys (Macaca mulatta) on Cayo Santiago show consistent mother–infant interaction with individual infants over time and consistent maternal styles from one infant to another. Inter‐pair differences in several measures of mother–infant interaction related to proximity and contact were correlated positively and highly significantly between 6‐week age periods. Analysis of variance methods were used to show that, after the first 6 weeks, these measures of interaction were also more similar among pairs with the same mother (i.e., families) than among pairs with different mothers. Differences between families were also consistent between age periods, and appeared to be due primarily to differences between mothers rather than to differences between sets of infant siblings. The results suggest that the concept of maternal style can be used to describe variation between both individual Cayo Santiago mother–infant pairs and between individual Cayo Santiago mothers.
Reproductive performance and excretion of urinary estrogens and gonadotropins in the female pygmy marmoset (Cebuella pygmaea)
Authors: Ziegler Toni E. , Snowdon Charles T. , Bridson William E.
Published: June 2005

By retrospective review of colony records and determinations of urinary hormones we have described the reproductive profile of the female pygmy marmoset (Cebuella pygmaea). The pygmy marmoset is a nonseasonal breeder and gives birth to twins 76% of the time with single births occurring 16% and triplet births 8% of the time. Interbirth intervals ranged from 149–746 days. First births occurred to females between 24–42 months of age and 5–27 months post pairing. We measured urinary estrone, estradiol and estrone conjugates along with immunoreactive luteinizing hormone/chorionic gonadotropin (LH/CG). The postpartum LH peak occurred a mean of 15.6 days following parturition. The conception rate was 69% following the postpartum ovulation. Levels of CG rose a mean of 19 days following the LH peak in conceptive cycles and remained elevated for a mean of 76 days. Gestational length was a mean of 141.9 days from the LH peak to parturition. Only one female of the five studied displayed ovarian cycles which were a mean of 27 days in length. Estradiol was the predominant urinary estrogen, however both estrone and estradiol were excreted in extremely high concentrations. LH peaks were discrete with urinary estrogens increasing at the time of the LH peak and remaining elevated throughout the luteal phase of the cycle.
Primate origins: Lessons from a neotropical marsupial
Authors: Rasmussen D. Tab
Published: June 2005

The didelphid Caluromys shows evolutionary convergence towards prosimians in having a relatively large brain, large eyes, small litters, slow development, and agile locomotion. The selection pressures that favored the emergence of primate‐like traits in Caluromys from a generalized didelphid ancestor may be analogous to the selection pressures favoring the initial divergence of primates from a primitive nonprimate ancestor, and thus Caluromys provides an independent test of the arboreal hypothesis (Smith: Annual Report of the Board of Regents of the Smithsonian Institution 1912:553–572, 1913), the visual predation hypothesis (Cartmill: The Functional and Evolutionary Biology of Primates, pp. 97–122, 1972), and the angiosperm exploitation hypothesis (Sussman: American Journal of Primatology, in press) of primate origins. Quantitative data on free‐ranging C. derbianus in Costa Rica demonstrate that it is highly arboreal, uses visually directed predation to capture arthropod prey, and makes extensive use of terminal branch foraging, where it feeds on small angiosperm products. These observations are consistent with predictions from each model of primate origins, thus suggesting that the hypotheses are not mutually exclusive but are interdependent. The initial divergence of primates probably involved exploitation of the rich angiosperm products and associated insects found in fine terminal branches; visually directed predation may have evolved as an efficient method of insect capture in the terminal branch milieu.
Reassessment of age of sexual maturity in gibbons (hylobates spp.)
Authors: Geissmann Thomas
Published: June 2005

From studies of both wild and captive animals, gibbons are thought to reach sexual maturity at about 6 to 8 years of age, and the siamang (Hylobates syndactylus) at about 8 to 9 years. However, a review of the literature reveals that in most cases the exact age of the maturing animals was not known and had to be estimated. This study presents seven case reports on captive gibbons of known age. Captive males of the white‐cheeked crested gibbon (H. leucogenys leucogenys) and of the siamang (H. syndactylus) can breed at the age of 4 and 4.3 years, respectively. Similarly, hybrid females (H. lar × H. moloch) and siamang females can breed at 5.1 and 5.2 years, respectively. This finding may help to improve the breeding success of captive gibbon populations. It is not clear whether gibbons reach sexual maturity earlier in captivity or whether sexual maturity is also reached by 5 years of age in the wild. Possible implications for the interpretation of group size regulation and of reproductive strategies of wild gibbons are discussed.
Proboscis monkey (Nasalis larvatus) social organization: Intergroup patterns of association
Authors: Yeager Carey P.
Published: June 2005

Proboscis monkey (Nasalis larvatus) social organization was studied at the Natai Lengkuas station, Tanjung Puting National Park in Kalimantan Tengah, Indonesia. Data were collected on ten one‐male groups and two all‐male groups using scan sampling and event sampling during follows, and through evening census surveys. Proboscis monkeys were found to form stable one‐male groups. Specific groups associated at their sleeping sites, in a manner similar to the fission‐fusion pattern described for hamadryas and gelada baboons. Analyses performed on these associations indicated that the groups formed two separate bands. These separate bands appear to be a secondary level of organization, distinct from the primary level of organization, the one‐male and all‐male groups. This is the first evidence for such a two‐tiered system of organization in an arboreal colobine species. Proboscis monkeys closely resemble gelada baboons in their organizational pattern. In both species, adult females direct the majority of their affiliative behavior towards their offspring and other adult females, males do not engage in active herding, all‐male groups are present, and one‐male groups do spend time apart from other groups. Home ranges of both groups and of bands of proboscis monkeys overlapped extensively; temporal avoidance between bands may have been mediated by early morning vocalizations and branch shaking displays.
Effects of woodchips and buried food on behavior patterns and psychological well‐being of captive rhesus monkeys
Authors: Byrne Gayle DiGregorio , Suomi Stephen J.
Published: June 2005

The effects of adding woodchip litter to bare‐floored pens, burying monkey chow in the woodchips, and scattering sunflower seeds in woodchips was studied in 2 stable social groups of rhesus macaques (Macaca mulatta) to ascertain the effects of these manipulations on levels of foraging, exploration, abnormal behavior, social interactions, and urinary cortisol levels. The addition of woodchips increased exploration and feeding levels and decreased social interactions. Burial of regular monkey chow in woodchips had little effect on behavior beyond that of the woodchips alone, increasing exploration and decreasing passivity. The addition of sunflower seeds to the woodchips encouraged increased feeding and exploration and led to decreases in passivity and social interaction. There was little discernible effect of woodchip enrichment on urinary cortisol values. In contrast to some previous studies, there was no effect of wood chips or sunflower seeds on the occurrence of agonistic interactions, play, or abnormal behavior patterns.
Homosexual incest avoidance among females in captive Japanese macaques
Authors: Chapais Bernard , Mignault Christiane
Published: June 2005

This paper reports a systematic pattern of homosexual incest avoidance among females in a captive group of Japanese macaques (Macaca fuscata) culled from the Arashiyama‐West troop known for its high rates of female homosexuality. The study group included three matrilines and two generations. Between eight and 11 females were sexually active over four consecutive mating seasons, and all engaged in both heterosexual and homosexual activity. While all females performed homosexual acts with almost all possible non‐kin partners, they systematically avoided homosexual interactions with their mother, daughters, and sisters. This pattern could not be explained either in terms of kin not being simultaneously in estrus, kin avoiding affiliative interactions in general, or non‐kin utilizing the tension‐reducing effect of estrus to affiliate exclusively with each other. In contrast to homosexual females, heterosexual pairs of relatives (brother‐sister, mother‐son) were sometimes incestuous. Assuming that female homosexuality expresses the reproductive strategy of females unconstrained by male influence, the present results point to the strong tendency of females to avoid incest and suggest that males are primarily responsible for the reported exceptions to incest avoidance.
Breech delivery and birth‐related behaviors in wild mantled howling monkeys
Authors: Moreno Luisa I. , Salas Isabel C. , Glander Kenneth E.
Published: June 2005

The breech birth of an infant mantled howling monkey was observed on February 12, 1990. The mother assisted the successful delivery by pulling on the infant's tail and hindleg. No other members of the social group attended the mother or demonstrated any interest in the birth process.
Primate origins and the evolution of angiosperms
Authors: Sussman Robert W.
Published: June 2005

Traditionally, the morphological traits of primates were assumed to be adaptations to an arboreal way of life. However, Cartmill [1972] pointed out that a number of morphological traits characteristic of primates are not found in many other arboreal mammals. He contends that orbital convergence and grasping extremities indicate that the initial divergence of primates involved visual predation on insects in the lower canopy and undergrowth of the tropical forest. However, recent research on nocturnal primates does not support the visually‐oriented predation theory. Although insects were most likely important components of the diets of the earliest euprimates, it is argued here that visual predation was not the major impetus for the evolution of the adaptive traits of primates. Recent paleobotanical research has yielded evidence that a major evolutionary event occurred during the Eocene, involving the angiosperms and their dispersal agents. As a result of long‐term diffuse coevolutionary interactions with flowering plants, modern primates, bats, and plant‐feeding birds all first arose around the Paleocene‐Eocene boundary and became the major seed dispersers of modern tropical flora during the Eocene. Thus, it is suggested here that the multitude of resources available on the terminal branches of the newly evolved angiosperm, rain forest trees led to the morphological adaptations of primates of modern aspect.