bluuebunny/crossref_metadata_2025_split huggingface dataset:
Demography of Amboseli baboons, 1963–1983
Authors: Altmann Jeanne , Hausfater Glenn , Altmann Stuart A. 
Published: June 2005

AbstractRepeated censuses of a population of yellow baboons (Papio cynocephalus) in Amboseli National Park, Kenya, revealed a decrease from over 2,500 animals in 1963–1964 to 123 individuals in 1979, or from a density of about 73 to 1.8 baboons per km2 over a 15‐year period. Median group size decreased from 43 in 1964 to 27 in 1979. The largest and smallest groups declined the most; groups near the median have maintained fairly stable size and age distributions. The population seemed to have stabilized by 1983 at approximately 150 animals in six groups (median group size 28; density 2.2/km2). Although baboon population and group size appeared to be stable during 1963–1964, the age distribution and demographic parameters (age‐specific mortality and natality for one social group) during that year indicate that the population decline had already started. The rate of population decline was greatest in the 1964–1969 period and remained appreciable during the next 5 years. The decline of the baboon population was paralleled by that of other Amboseli savannah woodland mammalian species and took place during a period of very high mortality of fever trees (Acacia xanthophloea) and extensive invasion of the area by halophytes, a transition brought on by rising ground water and consequent elevation of the soil salinity zone. In this and several other primate populations, mortality of infants and juveniles appears to be the demographic variable most sensitive to environmental change.
Sexual dimorphisms in dental dimensions of higher primates
Authors: Oxnard Charles E. , Lieberman Susan S. , Gelvin Bruce R. 
Published: June 2005

AbstractDental dimensions and distributions of dental dimensions of males and females were compared for great apes (Pan, Gorilla, and Pongo, and humans (Homo). The results were examined and discussed with reference to fossil primates Sivapithecus and Ramapithecus. The analyses focused on patterns of sexual dimorphism, both with regard to mean dimensions and the distribution of those dimensions. Sex differences in mean canine dimensions were large and significant for Gorilla and Pongo, significant but smaller for Pan, and small but occasionally significant for Homo. The dispersions of measures were greater for males than for females in Gorilla and Pan but did not differ significantly for Pongo or Homo. Examination of the noncanine teeth revealed complex sex differences. In the anterior teeth, sex differences in mean dimensions were generally apparent for Gorilla and Pongo, less so for Pan, and least of all in Homo. The patterns of dispersion of measures of anterior teeth differed markedly from those of the canines. Pan exhibited the same pattern for anterior and canine teeth. Gorilla showed the opposite pattern. Pongo and Homo showed similar dispersions for males and females in many cases. Sex differences in posterior teeth followed the pattern of the canines for Gorilla and were absent for Pan. Pongo exhibited mean differences in dimensions across sex, but dispersions were similar. The pattern for Homo was most like that of Pongo, but with fewer significant differences. The genera differed with regard to the number of significant differences in means or dispersions along the tooth row. It is clear that the patterns of dimorphism differ qualitatively across all extant genera of great apes and humans. It appears that the pattern for Homo most closely resembles that of Ramapithecus, whereas Pongo most closely resembles Sivapithecus. The patterns for Gorilla and Pan appear to be unlike either of the fossil forms. It is suggested that the qualitatively distinct patterns of dental sexual dimorphism indicate substantial flexibility during recent primate evolution and that the degree of structural flexibility demonstrated provides a basis for appreciating potential for plasticity of gender differences in behavioral, social, and cultural systems.
Reproduction in the slender loris (Loris tardigradus malabaricus)
Authors: Izard M. Kay , Rasmussen D. Tab 
Published: June 2005

AbstractA breeding colony of slender lorises (Loris tardigradus malabaricus) was studied to obtain data for comparison with other prosimian species, to contribute reproductive information for improving management of captive lorises, and to resolve some uncertainties in the literature regarding reproduction in the slender loris. At the Duke University Primate Center, a female slender loris reached sexual maturity at approximately ten months of age and conceived at one year of age. The length of the estrous cycle was 29–40 days, with copulation occurring over two consecutive days during estrus. Gestation length was 166–169 days. Litter size for each six births was one. Conception did not occur during an immediate post‐partum estrus, but four months after birth, resulting in a 9 1/2‐month interbirth interval. There was no evidence of reproductive seasonality. Lactation lasted between five and seven months. Reproductive rates of slender lorises are among the lowest of primates less than 500 g. Differences in reproductive parameters may exist between different subspecies of slender lorises.
Effects of ovarian hormones on the behavior of captive Macaca fascicularis
Authors: Zumpe Doris , Michael Richard P. 
Published: June 2005

AbstractTo examine the effects of ovarian hormones on the behavior of female Macaca fascicularis and their male partners, daily 1‐hr behavior tests were conducted while ovariectomized females were (1) untreated, (2) given estradiol benzoate (EB) (5 μg subcutaneously [s.c.]/day), (3) given estradiol benzoate together with increasing doses of progesterone (P) (5 mg, 10 mg, and 20 mg. s.c./day), and (4) given testosterone propionate (TP) (0.25 mg s.c./day) (six pairs, 540 tests). Weekly blood samples were analyzed by radioimmunoassay for plasma hormone levels (81 samples). Estrogen treatment produced plasma estradiol levels similar to those of intact females during the late follicular phase of the menstrual cycle. Additional progesterone at the lowest dose produced plasma progesterone levels similar to or somewhat higher than those during the midluteal phase, while higher doses produced supraphysiological levels. Androgen treatment resulted in plasma levels well above the physiological range. Hormone treatments produced highly significant effects on the sexual, social, and aggressive interactions of the pairs. As in rhesus monkeys, estrogen increased male and female sexual activity, and increasing doses of additional progesterone reversed these effects. Unlike in rhesus monkeys, testosterone propionate increased both female sexual motivation (invitations) and also male sexual activity and ejaculatory performance. The direction of the hormone‐dependent changes in grooming and aggressive interactions confirmed earlier results with intact females and indicated that aggressive interactions and male grooming times were highest, and female grooming times were lowest, when copulatory activity was at its height.
Sequences and timing of dental eruption in Bolivian captive‐born squirrel monkeys (Saimiri sciureus)
Authors: Galliari C. A. , Colillas O. J. 
Published: June 2005

AbstractSquirrel monkeys, colony‐born from Bolivian parents, were studied to establish the sequences and timing of eruption for deciduous and permanent teeth. Infants were born with a naked gingiva, and in only one monkey was di1 present at birth. The eruption of the lower deciduous teeth preceded their upper counterparts with the exception of di2, dc, and dpm2. No significant differences were found between the right and left quadrants of the mandible and maxilla. No significant sexual differences were found in the age of eruption. By the age of 14 weeks, all deciduous teeth had erupted. The sequence of eruption of the replacement teeth was different from that of milk teeth. The differences lie in the delayed eruption of canine teeth and in the inverted sequence, from the back to the front, of the premolar series. Significant sexual differences were found in total eruption (TE) for PM3 and I2 (P < 0.05) and highly significant differences (P < 0.01) in TE and initial eruption (IE) for C1, females being more precocious than males. The age at which monkeys completed dental eruption was highly variable, 103–119 weeks for males and 89–112 weeks for females. Differences were found when our results were compared with those of Long and Cooper [1968] for Colombian squirrel monkeys.
Species differences in adrenocortical activity of new world primates: Response to dexamethasone suppression
Authors: Mendoza Sally P. , Moberg Gary P. 
Published: June 2005

AbstractThe effect of dexamethasone‐induced alteration of adrenocortical activity was assessed in two species of New World primates: Saimiri sciureus and Callicebus moloch. Basal and stress levels of corticosteroids were determined following treatment with three doses of dexamethasone (0, 50, or 500 μg/kg). Saimiri showed substantially higher basal levels of corticosteroids than did Callicebus and a greater incremental corticosteroid response to physical restraint. Dexamethasone was found to reduce basal corticosteroids in both species, although this effect was greater for Callicebus than for Saimiri Moreover, the adrenocortical response to physical restraint was reduced by dexamethasone treatment in Callicebus but not in Saimiri. The pattern of results suggests that the species differ in the mechanisms mediating adrenocortical activity.
Infant‐directed behavior in young rhesus monkeys: Sex differences and effects of prenatal androgens
Authors: Gibber Judith R. , Goy Robert W. 
Published: June 2005

AbstractYoung (3–4 years old) laboratory‐reared rhesus monkeys were observed in five 15‐minute tests with 1–15‐day‐old infants. Males and females were equally likely to investigate infants. Females communicated more with infants by grin‐lipsmacking and gurgling–‐gestures that were not shown by any males. More females presented the ventrum to infants than did males. Females contacted infants more than did males by grooming, crouching over, and having full body contact with them. To see whether prenatal androgens produced the male pattern of response, we conducted similar tests with pseudohermaphrodites (prenatally androgenized genetic females) and neonatally castrated males. On most sexually dimorphic behaviors, pseudohermaphrodites behaved more like females than like males. Castrated males, like females and pseudohermaphrodites, crouched over infants more than did intact males. Castrated males differed from females only on one infant‐directed response, the grin‐lipsmack. These comparisons showed that defeminization of the repertoire of infant‐directed responses was measurable only in intact males. We conclude accordingly that prenatal androgens alone are not responsible for defeminization of this repertoire and that a contribution from postnatal androgens is likely to be necessary.
Individuality in the songs of wild agile gibbons (Hylobates agilis) of Peninsular Malaysia
Authors: Haimoff Elliott H. , Gittins S. Paul 
Published: June 2005

AbstractRecordings were made and analyzed of the female dominated duet songs by eight adult pairs of wild agile gibbons from two sites in Peninsular Malaysia. A statistical analysis of their songs revealed that individuality occurred throughout the females' songs from both sites. Individuality in gibbon songs may allow singing individuals to more efficiently and effectively locate and identify neighboring nonmate conspecifics.
Songs of hybrid gibbons (Hylobates lar × H. muelleri)
Authors: Tenaza Richard 
Published: June 2005

AbstractTwo hybrid offspring, one male and one female, were produced by a Hylobates muelleri female mated to a Hylobates lar male at Micke Grove Zoo, Lodi, California. Songs of the hybrids were studied at adulthood and compared to the parental‐type songs. The hybrid female song is uniquely different from either parental type. The hybrid male song resembles the male song of H. lar, but contains an element that may be unique to H. muelleri. The study demonstrates the utility of sound‐spectographic analysis of hybrid vocalizations to further understanding of primate behavioral inheritance.
Multidimensional scaling of macaque social interaction
Authors: Maxim Peter E. 
Published: June 2005

AbstractObservations of social behavior in 120 pairs of rhesus macaques were organized into three matrices: male‐male interactions, female‐female interactions, and male‐female interactions. The alternating least‐squares dimensional analysis (ALSCAL‐4) was applied to each matrix to derive one‐, two‐, three‐, and four‐dimensional solutions. For each matrix, the two‐dimensional solution gave the best fit with least stress. The loadings for each category on the two dimensions were then compared with previously derived message statements for those categories and the messages were corrected as needed to conform to these analyses. For all three matrices, the two dimensions underlying social behaviors were dominance or submissiveness by the self, and a positive or negative affiliative relationship bias to the pairmate.
Human predation and Kloss's gibbon (Hylobates klossii) sleeping trees in Siberut Island, Indonesia
Authors: Tenaza Richard , Tilson Ronald L. 
Published: June 2005

AbstractKloss's gibbons (Hylobates klossii) and Mentawai langurs (Presbytis potenziani) on Siberut Island, Indonesia, both sleep in emergent trees 34–55m tall, situated on crests and upper slopes of hills. They differ in that 91% of gibbon sleeping trees examined were free of lianas, whereas 89% of langur sleeping trees were draped with thick, woody lianas hanging from the branches to the ground. Because indigenous hunters climb lianas to shoot primates in treetops, gibbons are less susceptible than langurs to nocturnal human predation. Hence, the gibbons' preference for—and apparent control of—the limited supply of vineless trees gives them an advantage over langurs.
Social status and reproductive success of male Macaca fascicularis
Authors: Shively Carol , Smith David Glenn 
Published: June 2005

AbstractDominant males of nonseasonally breeding species should have more opportunity than seasonal breeders to monopolize access to estrous females and thus enhance their reproductive success. They may also use other strategies for maximizing reproductive success such as producing offspring by relatively high ranking females. To test these hypotheses, the paternity of 35 (80%) of 44 Macaca fascicularis offspring, born over a 28‐month period, was established using electrophoretically and serologically defined genetic markers. The social ranks of each of the seven potential fathers and 26 potential mothers were determined by recording outcomes of dyadio agonistic interactions. No evidence could be found to support either hypothesis. Further, in view of previously reported significant, positive correlations between male social rank and sexual activity rates in this study group, sexual activity rates do not appear to predict the number of offspring a male sires in this species.
Perimenstrual behavior changes among female yellow baboons: Some similarities to premenstrual syndrome (PMS) in women
Authors: Hausfater Glenn , Skoblick Barbara 
Published: June 2005

AbstractAlthough numerous studies have documented changes in the behavior of nonhuman primate females around the time of ovulation, very little attention has been paid to behavior changes around the time of menstruation. Yet such information is obviously relevant to under standing the origins and etiology of the adverse mood and behavior changes experienced premenstrually by many women. Analysis of data obtained during 115 hours of observation on 13 female Amboseli (Kenya) baboons (Papio cynocephalus) during 24 menstrual periods showed that prior to and during the time of menstrual onset, these individuals exhibited distinct changes in their activity budgets, nearest‐neighbor distances, and patterns of social interaction. Furthermore, in comparison to females around the time of ovulation, perimenstrual females showed increased rates of agonistic interaction and decreased (but nonzero) rates of sexual interaction with adult males. These premenstrual and perimenstrual behavior changes among female yellow baboons thus show some intriguing similarities to several commonly reported behavioral symptoms of premenstrual syndrome (PMS) in women.
Dental sexual dimorphisms in some extant hominoids and ramapithecines from China: A quantitative approach
Authors: Lieberman Susan S. , Gelvin Bruce R. , Oxnard Charles E. 
Published: June 2005

AbstractStudies of sexual dimorphism in the dental dimensions of some extant and fossil hominoids have been carried out by means of univariate statistical methods [Oxnard et al., 1985]. The study reported here extended these studies with multivariate statistical methods (canonical variates analyses). The extant genera studied were Gorilla, Pan, Pongo, and Homo. The fossil teeth interpolated were those of the recently discovered ramapithecines from Yunnan Province, China. For both extant and fossil species, the lengths and breadths of all maxillary and mandibular teeth were used except for the third molar, which was excluded because of its absence in so many human subjects. The nature of sexual dimorphism in the dentition of extant apes and humans was assessed, and the positions of the fossil teeth within the multivariate results for the extant forms was examined. Among the apes, the greatest sexual dimorphism was seen in Gorilla; the least was seen in Pan. Three different patterns of sexual dimorphism were apparent among the three ape species. The maxillary and mandibular patterns were different in Gorilla and Pan but more similar in Pongo. The African apes showed greater differences between variances for each sex and of each jaw; these features may have evolved most recently. The conventional notion that sexual dimorphism is mainly due to size and size‐related shape effects along a single continuum or axis was rejected. The interpolation of the fossil data placed Sivapithecus close to each of the more dimorphic apes, especially Pongo, but also showed that it had higher order differences from the extant forms studied. Ramapithecus was most similar to Homo. These results have implications both for the role of sexual dimorphism in the evolution of higher primates and for the phylogenetic relationships among them.
Gestation length in Tarsius bancanus
Authors: Izard M. Kay , Wright Patricia C. , Simons Elwyn L. 
Published: June 2005

AbstractA gestation length of 178 days was determined for Tarsius bancanus based on a vaginal smear containing whole sperm. This value replaces the only previously reported information on gestation length in tarsiers, a rough estimate of approximately 6 months for T. syrichta.
Visual monitoring of threatening objects by captive tamarins (Saguinus labiatus)
Authors: Caine Nancy G. 
Published: June 2005

AbstractCaptive social groups of red‐bellied tamarins (Saguinus labiatus) were observed in the presence of threatening, inanimate objects. The tamarins monitored the stimuli over the course of the 20‐minute trials by conducting brief, periodic visual checks of the objects. The average number of checks per subject per trial was stable both across trials and between groups, and individual differences in rates varied relatively little around the group means. These data generate the hypothesis that there is a species‐typical execution of vigilance in the presence of mildly threatening objects. This execution takes the form of brief visual inspections of the stimulus, usually by one tamarin at a time, at a fairly consistent rate. The discussion of the data takes place in the context of the behavioral ecology of callitrichid species.
Learning set formation in a group of Guinea baboons (Papio papio): Importance of the behavioral variable measured
Authors: Lepoivre Hugues , Pallaud Berthille 
Published: June 2005

AbstractA recent report of one‐trial learning in a group of saddle‐back tamarins (Saguinus fuscicollis) conflicted with views of learning set formation based on traditional techniques employing isolated subjects. An experiment is reported in which a group of Guinea baboons (Papio papio) was given a series of discrimination and habit reversal tasks. Both one‐trial learning and learning set formation occurred. Analysis of spatial behavior revealed that the group learned in a single trial to discriminate stocked from unstocked zones. Improvement in successes (reinforced “digging”) was progressive but not rapid, indicating learning set formation. It appears that outcomes depend on the behavioral variables chosen.
Reproduction in the vervet monkey (Cercopithecus aethiops): I. Testicular volume, testosterone, and seasonality
Authors: Eley R. M. , Else J. G. , Gulamhusein N. , Lequin R. M. 
Published: June 2005

AbstractTo test whether the male could contribute to the birth peak seen in both wild and captive vervets, testicular volume and peripheral testosterone concentration were measured monthly in nine adults throughout a 14‐month period. Volume was an average of 15% greater during the months of June to September, the period of natural breeding activity in the wild, than at other times of the year. Testosterone concentration rose throughout the time period but did not correlate with testicular volume. Quarterly biopsies of the right testis in animals either used for or withheld from breeding revealed the presence of spermatozoa and the existence of spermatogenesis throughout the year. There was no correlation of testicular volume with breeding status or biopsy. If these results from individually caged animals are representative of group‐caged and wild animals, then such small seasonal changes are unlikely to affect year‐round breeding. Therefore, a physiological contribution by the male to natural birth peaks seen in the wild and captivity is not readily apparent.
Isolation of females prior to parturition reduces neonatal mortality in Galago
Authors: Izard M. Kay , Simons Elwyn L. 
Published: June 2005

AbstractEighteen years of birth records for three species of Galago at the Duke University Primate Center were examined to determine the effects of isolation of pregnant females on neonatal mortality rates. Isolation significantly decreased neonatal mortality rates in all three species over neonatal mortality rates in infants born to unisolated females. The frequency of cannibalism of infants did not differ between isolated and unisolated females. Secondary sex ratio differed significantly from 1:1 for all three species, but higher mortality in males in the first 10 days of life resulted in sex ratios that did not differ from 1:1 in G. garnettii and G. crassicaudatus.
Effect of separation distance on isolation call structure in squirrel monkeys (Saimiri sciureus)
Authors: Masataka Nobuo , Symmes David 
Published: June 2005

AbstractIsolation calls of captive squirrel monkeys were recorded by separating infants from their natal group members and then permitting vocal contact between the “lost” baby and the group at systematically varied distances. Separated infants gave longer calls at greater separation distances from their natal group members, and responding adults and juveniles similarly extended the length of their vocalizations. In the longer variants, a highfrequency element was prolonged, which is considered to be an example of the net advantage of a “frequency window” in the ambient noise of environments.