Ramon J. Rhine

Baboon diet: a five-year study of stability and variability in the plant feeding and habitat of the yellow baboons (Papio cynocephalus) of Mikumi National Park, Tanzania.

The habitat and plant feeding of 64 well-habituated, individually identified adult male and female yellow baboons was studied for 5 years at Mikumi National Park, Tanzania. Variation across the years showed that a study of only one or two years would have been incomplete and misleading. The list of baboon food species obtained from Mikumi is considerably larger and more diverse than any previously reported. One to six plant parts were eaten from each of more than 180 species. The 25 most common tree genera all contained species used for food. Of the 50 most common grass, shrub and herb genera, 93% included plant foods. Using months in which a species was eaten during at least one year of the study, 21 staple species were eaten during a mean of 8.86 months and 7 were eaten in all 12 months. Although many foods were from commonly available plant species, 15 such species were only rarely eaten. The number of parts of a species eaten per month and an estimate of the amounts eaten per month both varied with temperature and rainfall, being lowest near the end of the cool, dry season. There were substantial differences from year to year in the timing and amount of food production of many species; nevertheless, the same broad feeding pattern was repeated in each of the 5 years of the study. Despite yearly variation in food availability, 14 or more staples and other common foods were eaten in any given month. If crops of many of these foods were to fail, a large number of less commonly eaten species could be substituted. Baboons are eclectic feeders that appear to be optimizing their diet by selective feeding from among a wide array of available foods in an ever-changing floristic environment.

Adult Male Positioning in Baboon Progressions: Order and Chaos Revisited

Evidence of nonrandom positioning among adult males is crucial for a protection theory of the spatial organization of baboon progressions. In a recent study it was suggested that systematic positioning of troop members other than mothers and infants is so slight and rare that progressions may be regarded as essentially random. This suggestion depends upon debatable methodological points presumably downgrading previous findings of nonrandom order. Reanalysis of data from this study revealed numerous analytical and statistical problems, as well as serious calculation and other errors, and showed that the findings are consistent with results of the present and previous research. Adult males tended toward the front or back of progressions, a tendency which was intensified in potentially dangerous situations. Dominant males were disproportionately more often frontward and subordinate males rearward. Nonrandom order, which was found for a variety of circumstances at high levels of statistical significance, was unusually general in that it occurred in 6 studies, 7 troops, 2 species, and 5 locations. Such generality is consistent with a protection theory postulating phylogenetic underpinnings of a sociospatial organization which allows an advanced primate to adapt to terrestrial coexistence with predators.

The nature of a primary feeding habit in different age-sex classes of yellow baboons (Papio cynocephalus).

Two feeding habits of 30 baboons selected equally from five age-sex classes were studied at Mikumi National Park, Tanzania. The finding, gathering, and preparing of sedge corms and of seeds of tamarind fruit were described in detail. Adults obtained these foods faster than younger animals, although even small juveniles and weaned infants were efficient in gathering and preparing them. While gathering sedges or tamarinds, adult males sat in one place longer than others and obtained more food per sitting. Adults ate more pieces of food per minute than juveniles, but adult rates of eating did not differ by sex. The adult rate of food intake was inconsistent with the assumption of different food requirements for males and females of a species with pronounced sexual dimorphism.

An empirical comparison of one-zero, focal-animal, and instantaneous methods of sampling spontaneous primate social behavior

InJ. Altmanns review of methods used to sample spontaneously occurring social behavior, the one-zero method, which has a history of over 40 years of use with human and animal research, was severely criticized and was the only technique for which no use whatsoever was recommended. Substantial justification for this recommendation would raise serious questions about widely cited primate research from laboratories at Cambridge, Wisconsin, and elsewhere, where one-zero sampling has been often used.Altmanns nonempirical consideration of one-zero sampling is based upon assumptions which are sometimes unnecessarily limiting or probably incorrect and which are not supported by any data. An empirical comparison of one-zero sampling with two techniques considered useful byAltmann reveals contradictions in her recommendations and suggests that the one-zero method is a convenient way to combine the actual rate and duration of a spontaneously occurring behavior into a single index of social relatedness.

Variation and consistency in the social behavior of two groups of stumptail macaques (Macaca arctoides)

Social interactions of two five-member groups of stumptail macaques were observed. Behavior of all but one of these animals has been reported in two previous studies. In the third study, high-ranking females maintained their positions in the dominance order when the alpha male with whom they were previously associated was either removed from the group or displaced by a male added to the group. The results of all three studies indicated a tendency for interaction among animals holding adjacent hierarchical ranks. The data suggested that one function of selective grooming was pacifying the grooming partner, and that one function of selective adult play was behavior testing under conditions of moderate arousal.

The Order of Movement of Yellow Baboons (Papio cynocephalus)

The spatial organization of progressing baboons is thought to serve a protective function considered important in their adaptation to a terrestrial existence. Progression positions of identified black infants, adult males, and other yellow baboons were determined from repeated samples of troop movements. Spatial positioning by demographic class was similar to that previously found for three troops of anubis baboons living in two different habitats. Such consistency across species and habitats seems unlikely unless it arises from a common genetic background or common ontogenetic stabilizing mechanism.

Properties of one-zero scores in observational studies of primate social behavior: The effect of assumptions on empirical analyses

Empirical analyses of techniques for observing spontaneous social behavior have been guided by implicit assumptions about the techniques’ validity, reliability, and comparability. The actual duration and actual frequency of a behavior have been used as intuitive standards of validity. Noncorrespondence among absolute values obtained from these measures and from one-zero scores has been taken to mean that one-zero scores are invalid. An analysis of macaque and gelada grooming relationships demonstrated how unjustified assumptions about absolute values can affect conclusions. A statistical comparison of four types of observation scores, and a multiple-regression analysis of one-zero scores, contradicted assumptions made previously about reliability and validity. The four methods were comparable and all were reasonably accurate.

Lifetime reproductive success, longevity, and reproductive life history of female yellow baboons (Papio cynocephalus) of Mikumi National Park, Tanzania

The relationship between longevity and lifetime reproductive success (LRS) was studied in free‐ranging female baboons of Mikumi National Park, Tanzania. A severe population decline occurred between the 12th and 20th years of the study. The total sample consisted of 72 females born and reaching adulthood before the start of the population decline. There were 27 females who were adult at the start of the study and 45 who became adult within the 12 years prior to the decline. The subjects were studied until all 72 were dead and all of their offspring were either dead or at least six years old; this took 24 years. The relationship of longevity to LRS was statistically significant for the total sample and for both sub‐samples, with 70% of the total variance in LRS accounted for by longevity. Longevity was linked to LRS via a chain of statistically significant relationships: The longer the life span, the longer the reproductive life; the longer the reproductive life, the more offspring produced; the more offspring produced, the higher the LRS. Mean LRS, life span, and reproductive longevity all differed between the two sub‐samples. Since the sub‐samples were time‐linked to a population decline affecting longevity, either sub‐sample separately would fail to reflect the broader picture. This illustrates the importance of appreciable sample sizes from long‐term studies in helping understand the dynamics between life history estimates and ecological conditions in variable environments. Am. J. Primatol. 51:229–241, 2000.

A Generalizability Analysis of Subjective Personality Assessments in the Stumptail Macaque and the Zebra Finch.

Psychometric findings are reported from two studies concerning the construct validity, temporal stability, and interrater reliability of the latent common factors underlying subjective assessments by human raters of personality traits in two nonhuman animal species: (a) the Stumptail macaque (Maraca arctoides), a cercopithecine monkey; and (b) the Zebra finch (Poephila guttata), an estrildid songbird. Because most theories of animal personality have historically implied that certain personality constructs should be relatively universal across taxa, parallel analyses of similar data are reported for two phylogenetically distant species of subject using the same psychometric methods. Each of the samples was drawn from a socially-housed colony of the same species: that of macaques consisted of 5 mature adult fem ales and 8 of their adult offspring and that of finches consisted of 5 adult individuals. A modified version of the 1978 Stevenson-Hinde and Zunz (SHZ) list of personality items was applied to the macaques at various times during the eight years from 1980-1988 and to the finches during 1992. This study also used the three SHZ scales - Confident, Excitable, and Sociable - originally derived from principal components. Generalizability analyses were used to assess the construct validity, temporal stability, and interrater reliability of the hypothesized factors. Both Stumptail macaques and Zebra finches manifest measurable personality factors that are highly valid across multiple items, stable across multiple years, and reliable across multiple raters. The same model fits both species, as predicted by theory. The construct validity of the factors is slightly higher for the finches than for the macaques, although the interrater reliability is somewhat lower. This study illustrates how generalizability analysis can be used to test prespecified confirmatory factor models when the number of individual subjects is quite small.

Interaction patterns of two newly formed groups of stumptail macaques (Macaca arctoides)

Shortly after two groups of stumptail macaques were formed, their individual and social behavior was observed. Similar overall behavior of the two groups arose from different interaction patterns within the groups. Hierarchical stabilities and instabilities were related to selective affilliation patterns. The main instabilities were found at the top of the hierarchy of one group and in the middle of the other. The roots of later changes in group structure were displayed in individual association preferences.