Effects of combination birth control on estrous behavior in captive western lowland gorillas, Gorilla gorilla gorilla

Combination birth control pills (CBC) are one of the most common birth control methods used for western lowland gorillas (Gorilla gorilla gorilla) housed in zoos. Since zoos are interested in maintaining as many natural behaviors as possible, it is important to know how contraception may affect social and sexual interactions among group members. Although some data are available regarding the influence of the pill on sexual behavior in human females, no data are available on its effects on gorilla estrous behavior. We examined temporal trends of estrous, aggressive, affiliative, and activity budget data in four females on CBC at the Lincoln Park Zoo in Chicago, IL. Behavioral data were collected using point sampling, all-occurrence records, and one-zero sampling. Estrous behavior occurred in less than 1% of observations. Using all-occurrence and one-zero sampling, estrous behavior occurred more frequently in week one of the cycle than any other week. The focal females exhibited affiliative, aggressive, and activity budget data evenly across their cycles. There were also no temporal trends in proximity to the silverback. Females varied by the types of estrous behavior they exhibited. We give a hormonal explanation for the prevalence of estrous behaviors in week one, and recommendations for effective behavioral sampling of gorilla estrous behavior.     

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.     

One-zero sampling in the study of primate behavior

One-zero (Hansen) frequency, the proportion of time samples during which a certain behavior occurs, measures a linear combination of prevalence (the proportion of time an animal spends in a behavior) and of incidence (the number of bouts of a behavior per hour) with a non-negligible perturbation due to the clustering characteristics of behavior relative to the time interval length. The exact relationship is derived theoretically and demonstrated empirically usingLeger's data base of chimpanzee behavior. It is recommended that, whenever possible, time sampling methods other than One-zero Sampling be used in the study of behavior.     

On the utility of aPost Hoc correction procedure for one-zero sampling duration estimates

Numerous previous studies have shown that one-zero sampling in direct observation systematically overestimates behavioral durations. Apost hoc correction procedure has been proposed and demonstrated to be capable of removing most of the systematic errors found in one-zero duration estimates. However, the remaining errors for some individual observation sessions can still be quite substantial in practical terms. In this paper, the condition under which thepost hoc correction procedure will produce results with negligible systematic errors in one-zero duration estimates is identified.     

Some sampling considerations in the quantitation of monkey behavior under field and captive conditions

Observations of monkey behavior were made on free-ranging and corral-enclosedMacaca mulatta. Two sampling techniques were used: focal animal and group observations. Group observations measured frequencies of social behavior whereas focal observations used time samples which estimated durations of social and nonsocial activities as well as frequencies of social behavior. Analysis of concordance within and between sampling techniques revealed that short duration focal time samples provide a reliable estimate of total frequencies of social behaviors derived using group observations and furthermore, allows the recording of important nonsocial activities not easily recorded in terms of frequencies. Focal time sampling is advantageous for certain types of studies where the equal distribution of observation time between individuals is important, particularly in the field where visibility is often limited and individuals can only be observed continuously for short periods of time. This work was supported by grants from the H. F. Guggenheim Foundation, Dr.H. C. Robinson, Jr., and USPHS grants MH 24607 and MH 25642.     

Effects of Temporal Sampling Patterns of All-occurrence Recording in Behavioural Studies: Many Short Sampling Periods Are Better than a Few Long Ones

All-occurrence recording is generally thought to yield unbiased results. However, its accuracy and power to detect real effects may depend on the temporal patterning of the observation periods. Although several studies evaluated the suitability of time-sampling methods (one-zero and instantaneous sampling), there has not been an evaluation of various temporal patterns of the ‘all-occurrence’ method to date. Here we present an empirical comparison of time-sampling and all-occurrence recording methods, based on a large data set, with special reference to various temporal patterns of all-occurrence recording. The three different sampling methods were imposed on raw data protocols. The scores, obtained by the use of each method and temporal pattern, were compared with true values from the corresponding continuous video recordings. The accuracy and power of each method was estimated by comparison of medians and magnitudes of effect (r_m), respectively. We were able to confirm results of earlier studies on the suitability of time-sampling methods (one-zero and instantaneous sampling), but we found that different temporal patterns of all-occurrence sampling yielded magnitudes of effect that differed from true value magnitudes. We conclude that behavioural studies may reveal different results, even when all conditions are the same, only because of power differences of different temporal pattern of the observation periods, for example 1 × 15 min versus 15 × 1 min. Recommendations are made about appropriate application of methods.     

Some effects of a discrete trial procedure on differentiation learning by Japanese monkeys

Employing newly developed equipment, which permitted presentation of discriminative stimuli and the response manipulandum separately, the present study reexamined the results ofMcClearn's (1957) study on differentiation learning. When a discrete trial procedure analogous toMcClearn's was used, the subjects (two Japanese monkeys;Macaca fuscata fuscata) persisted in responding on S- trials, replicatingMcClearn's results. However, when a free operant procedure was used, in which the response manipulandum was continually available, the subjects made few responses during S- trials and showed almost complete differentiation. It was concluded that the discrete presentation of the manipulandum itself has some obstructive effects on differentiation, or successive discrimination learning.     

Allogrooming and social status: An assessment of the contributions of female behavior to the social organization of hamadryas baboons (Papio hamadryas)

Three isosexual social groups, each containing ten subadult female hamadryas monkeys (Papio hamadryas) were studied for seven months to test three hypotheses dealing with the assumptions underlyingSeyfarth's (1977) model of allogrooming and social organization. Aggression, avoid and allogrooming behaviors were used as criteria for studying the social organization of the groups. UsingLandau's (1951) index and discriminant analyses, we found that each of the three isosexual female social units conformed to a model of social organization having a non-linear hierarchy and only two major strata: a dominant animal and subordinates who were largely undifferentiated. This aspect of social organization is similar to the normal one-male unit leader harem form of social organization that is typical of hamadryas. However, since no male was present, the role of unit leader was filled by a female. The length of allogrooming bouts and the amount of allogroom received was affected by the social status of the recipient, with high status individuals receiving more than low status individuals. Social peers were not observed competing for access to high status individuals and did not exchange most of their grooming among themselves. We found that the assumptions underlyingSeyfarth's (1977) model were not appropriate for the type of social organization typically found in hamadryas monkeys, thus suggesting the need for further modification of the model so that it fits available data.     

A study of reliability and its hierarchical structure in observed chimpanzee behavior

The overall excellence of the reliability of a system of behavioral observations based onGoodall's glossary of chimpanzee behavior is demonstrated, as well as the reliability of the majority of individual behaviors in the system. Non-random misclassifications are systematically analyzed to yield information on the structure of observed behavior. These findings are applied (1) to improving the system further, and (2) to assessing factors which apparently obscure distinctions between observable patterns of behavior for use in future development of observational systems.     

An empirical evaluation of instantaneous and one-zero sampling of chimpanzee behavior

The behavior category in progress at theend of every 15 seconds of observation of chimpanzee behavior was recorded (instantaneous sampling) as was the occurrence or nonoccurrence of all defined categoriesduring every 15 second observation interval (one-zero sampling). The scores obtained using the above procedures were then correlated with the percent of net observation time, hourly rate, and mean bout duration of the behavior categories. One-zero sampling scores correlated very strongly with percent of net observation time and moderately with hourly rate and mean bout duration. Instantaneous sampling scores correlated very strongly with percent of net observation time and moderately with hourly rate and mean bout duration.     

The estimation of population size,migration rates and survival in a stratified population

Summary Estimates of survival, migration rates, and population size are developed for a triple catch marking experiment onn (n>-2) areas with migration among all areas and death in all areas occurring, but no recruitment (birth). This repressents the extension to three sampling times of the method ofChapman andJunge (1956) for estimates in a stratified population. The method is further extented to allow for ‘losses on capture’.     

Weaning of free-ranging infant baboons (Papio cynocephalus) as indicated by one-zero and instantaneous sampling of feeding

Weaning from the nipple and the use of solid foods were studied by one-zero and instantaneous sampling during the first year of life for 46 baboon infants. By the end of 1 year, infant baboons were nearing independence from the mother for nourishment and transportation and were competently foraging for insects and several plant foods. Using on-nipple as an index of waning dependence and the transition from riding on the mother to walking as a validity criterion, the two sampling methods yielded comparable scores which were valid indicants of developing independence.     

Ultrastructural study on the release of neurosecretory material from the sinus gland of the land crab,Gecarcinus lateralis

Summary Sites of release of neurosecretory material were examined in a neurohemal organ of decapod crustaceans, the sinus gland of the land crab, Gecarcinus lateralis. Such discharge into the circulation seems to occur primarily at interfaces between the neurosecretory axons and the acellular stromal sheath which is interposed between parenchyma and hemolymph. The evidence obtained from electron micrographs of adult specimens indicates that more or less intact secretory granules are released into the extraaxonal space primarily by the process of exocytosis. Synaptic-type vesicles are clustered in parts of neurosecretory axons facing the stromal sheath. Such vesicles are thought to result from rearrangement of membranes temporarily fused at the release site and to a minor degree from fragmentation of neurosecretory vesicles within the axon. The presence of nonmarginal vesicles and the occasional appearance of free intraaxonal dense material are interpreted as indications of a second, probably less frequent, mode of release of neurosecretory material.Supported by grants AM-3984, NB-00840, and NB-05219 from the U.S.P.H.S., administered by Dr. Berta Scharrer.I am greatly indebted to Mrs. Sarah Wurzelmann for her excellent technical assistance. I thank Dr. Dorothy E. Bliss for contributing the animals used in this study, and Mr. Murray Altmann for technical advice.     

Grouping of the wild spider monkey

Ateles generally lives in small temporary subgroups. The authors studied the grouping of the monkey for two months and obtained data concerning the subgroup size, composition, and inter-individual relationships. In general, the data agreed with that obtained byKlein (1972). However, they discovered that large subgroups of the monkey were observed only in relation to the utilization of a special place, the “salado” site. The authors discuss the reason for this. Criticism is given ofKlein's suggestions that the unique grouping ofAteles is a form of social adaptation to its palm-fruit eating behavior and that peripheral males exist in its social structure.     

The development of infant play in a captive group of lowland gorillas (Gorilla gorilla gorilla)

Three infant gorillas born at the Yerkes Regional Primate Research Center of Emory University were studied during their first year and one-half of life for various aspects of behavior, including solitary and social play, using both focal animal and one-zero sampling. The appearance of play in these infants followed a developmental trend, beginning with mother-infant play, and followed by solitary play, and then social play among peers. Mothers were initially very vigilant, repeatedly interrupting infant peer play bouts, this relaxing toward the end of the first year. Evidence for a possible sex difference in active social play is presented.     

The acetic acid bacteria, 1941–1961

Summary Leifson's (1954) differentiation of the acetic acid bacteria into (1)Acetobacter—peritrichously flagellated and acetate oxidising, and (2)Acetomonas—polarly flagellated and acetate non-oxidising, has, by various workers, been (a) fully confirmed, (b) doubted, or only partly accepted, and (c) denied altogether. Also the priority ofAcetomonas overGluconobacter has been questioned, as has also facile mutability inAcetobacter. By a critical comparative review of all the publications concerned, and by the experimental examination of the various cultures claimed to contraveneLeifson's correlation, we have attempted to clarify the confusion, and to give a clear picture of the true position, which is really quite simple. The result of so doing has been to vindicateLeifson's findings in every case, to refute criticism of facile mutability inAcetobacter, and to show whyGluconobacter Asai cannot claim priority overAcetomonas Leifson.     

The Zbinden method for the micro-estimation of copper after preliminary deposition of the metal by electrolysis

Summary Zbinden's method for estimating micro quantities of electrolytically separated copper by reversal of current has been investigated. Though the theoretical basis of the method proved to be more intricate than was to be expected fromZbinden's papers, standardization of the experimental conditions resulted in the development of a simple method for the determination of from 10–100g of copper. This method is very well adapted to routine work and may be carried out by untrained or hardly trained personnel.Without doubt essentially the same procedure may be used for the estimation of greater quantities of copper. In that case standardization at a higher amperage of the dissolving current seems advisable.     

On the use of hansen frequencies for estimating rates of behavior

When the occurrence of a behavior is governed by aPoisson process over time, then the mean rate of behavior can be estimated usingHansen frequencies, which record whether the behavior has occurred at least once or not at all in each of several time periods. Here this estimate of the mean rate of behavior, based onHansen frequencies, is compared with the usual estimate, and its properties as an estimate of the mean rate of behavior are discussed in cases where the behavior is not governed by aPoisson process.This research was supported in part by Navy Grant N00014-67-A-0285-0009 to the Department of Statistics, University of Chicago, and by a grant from the Alfred P. Sloan Foundation to the Department of Theoretical Biology.     

Variables influencing one-zero and instantaneous time sampling outcomes

Previous studies have shown that instantaneous time sampling results are more highly correlated with true duration than are one-zero sampling results. One-zero results, however, reflected a composite of both duration and frequency better than did instantaneous results. It is shown in this analysis that these outcomes are the logical result of the definitions of the two sampling modes. When interval lengths meet specific requirements, correct frequency counts can be obtained with either mode and systematic duration error with one-zero sampling can be eliminated by subtracting frequency from the number of intervals scored ‘one.’     

Water renewal in reservoirs,and its relation to body size and egg numbers in copepods

Summary In a study of four species of centropagid copepods, particularly Boeckella minuta Sars, occurring in south-east Queensland, Australia, body length was found to correlate with the rate of water renewal in the reservoir. Ravera & Tonolli's explanation for interpopulational differences in lengths of copepods has thus been confirmed. There was also a positive correlation between body length and egg number in ovigerous females.Sex ratio (females/males) increased with the rate of water renewal, this providing for relatively more females to be present when population numbers were smaller.

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Zusammenfassung In einer Untersuchung von vier Spezies zentropagischer Kopepoden, besonders Boeckella minuta Sars, die sich bei Südostqueens-land, Australien, finden, wurde entdeckt, daß die Körperlänge mit dem Wassererneuerungsgrad in dem Reservoir in Beziehung steht. Ravera & Tonolli's Erklärung für die Verschiedenheiten in Körperlängen von Kopepoden zwischen der Bevölkerung ist, auf diese Weise, bestätigt worden. Es gab auch eine positive Wechselbeziehung zwischen der Körperlänge und der Anzahl Eier in eiertragenden Weibchen.Das Geschlechtsverhältnis (Weibchen/Männchen) wurde grösser mit dem Wassererneuerungsgrad, wodurch etwas mehr Weibchen anwesend Bind, wenn die Bevölkerungszahl kleiner war.