A stereo music system as environmental enrichment for captive chimpanzees

Music has been shown to have beneficial effects on humans but little is known about the effects of music on nonhuman primates in biomedical research settings. The authors monitored the effects of music on the behavior of captive chimpanzees and found that music had significant positive effects, including a reduction in agitated and aggressive behaviors.     

Primate puzzleboard: A simple environmental enrichment device for captive chimpanzees

An environmental enrichment device was designed and evaluated for captive chimpanzees. The puzzleboard consisted of a 61-cm, square piece of clear plastic with holes of various sizes drilled into the center. The puzzleboard was bolted to the roof of a chimpanzee enclosure. Flavored primate treats were arranged on top of the board, and the chimpanzee used a finger to manipulate the food across the board to be retrieved through the larger holes. The behavior and puzzle use of 29 chimpanzees housed in eight groups were evaluated while the device was empty and while filled with food. For each group, four 1-hr scan samples were recorded for each condition. Data showed that an average of 40 min elapsed from the time the puzzleboard was filled to the last recorded contact by a subject. Mean individual use ranged from 4.8 to 23.8 min/hr. Female chimpanzees used the puzzle significantly more often than did males. Aggressive, affiliative, inactive, and self-directed behaviors were significantly reduced when the puzzle was filled. In addition, the puzzleboard was inexpensive, sturdy, and easily constructed, mounted, and operated.     

Controllability in environmental enrichment for captive chimpanzees (Pan troglodytes)

This study considers the use of nonsocial environmental enrichment by captive chimpanzees at the Primate Foundation of Arizona. The goal was to determine whether a relationship existed between controllability of enrichment items by captive chimpanzees and frequency of use. The study measured controllability, the ability of nonhuman animals to alter aspects of their environment by the potential destructibility of the enrichment item. This study examined additional factors that may affect enrichment use: individual age, sex, rearing history, social group composition, and availability of outdoor access. The chimpanzees in the study used destructible items—the enrichment category with the highest level of controllability—more than indestructible items across all age, sex, and rearing classes. Thus, controllability seems to be an important factor in chimpanzee enrichment. Younger individuals and groups with outdoor access used enrichment more than did older individuals and groups with indoor-only access. Individual sex, rearing history, and social group composition had minimal effects on enrichment use. These results support the importance of control to captive chimpanzees and further enable captive management to customize enrichment programs to the needs of particular animals.     

Guidelines for developing and managing an environmental enrichment program for nonhuman primates.

Before implementing an environmental enrichment program for nonhuman primates, several issues should be considered. The assignment of enrichment tasks can be made to caretakers, a dedicated "enrichment technician," volunteers, students or individuals with training in behavioral science. Determining the enrichment techniques to be used must take into account personnel time available; the species, age, sex, and individual histories of the nonhuman primates; and experimental protocols for which animals are being maintained. Identifying the most beneficial way to use the available personnel time must be tailored for each institution. To meet federal regulations, records must be kept of the environmental enhancements available to each nonhuman primate. Good record-keeping will allow appropriate evaluation of the program. This evaluation should involve the animals' responses to the enrichment opportunity, cost and durability of enrichment items, human and nonhuman safety considerations, and personnel required. The well-being of captive nonhuman primates will be most improved if well-informed decisions are made in developing and managing environmental enrichment programs.     

Visual monitoring of threatening objects by captive tamarins (Saguinus labiatus)

Captive 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.     

Successful feeding enrichment for captive chimpanzees

An analysis of a feeding enrichment program for captive chimpanzees was completed to determine the effects of that program on the incidence of agonistic and abnormal behaviors by using 41 adult chimpanzees in six social groups. Four feeding enrichment procedures were implemented simultaneously in the experimental phase of this ABA design study. The procedures were planned to elicit time-consuming, noncompetitive feeding, theorizing a consequent reduction in agonism and detrimental abnormal behaviors typically occurring in captive chimpanzees. The 270 hours of data were collected over a 6-month period. A multivariate analysis of variance result supported the hypothesis, as the barrage of feeding enrichment techniques significantly reduced agonism and abnormal behaviors. This study's significance lies in its application of the scientific method to improving the husbandry of captive primates.     

Demographic review of a captive colony of callitrichids (Callithrix kuhlii)

Although reports on colony demographics for a variety of callitrichid species are available in the literature, to date there has not been a detailed examination of Wied's black tufted-ear marmoset (Callithrix kuhlii). The purpose of this study is to present colony demographics for C. kuhlii from the University of Nebraska at Omaha's Callitrichid Research Center from 1991 to 2002. C. kuhlii are currently held in a number of zoological parks in the United States and abroad; however, the University of Nebraska at Omaha held the only breeding colony in North America. Here we report data on lifespan, sex ratio, litter size, and interbirth interval (IBI) for that captive breeding colony.     

Infant survival and number of helpers in captive groups of common marmosets (Callithrix jacchus)

In a colony of captive marmoset monkeys (Callithrix jacchus), the survival rate of infants up to the age of 90 days after birth was analyzed with special reference to the number of members in the group. The number of group members (newborns excluded) varied between two (parents only) and 18 (parents plus non-reproductive helpers); the number of adult group members varied between two and 15. Five hundred ninety-two live-born, parent-reared infants of 263 litters from 56 breeding females were included in the analysis. The greatest reproductive success was observed in groups of ten to 11 members or four to five adults, including the parents. However, the survival rate was fairly constant over group size at approximately 80% of an expected maximum value and no significant correlation was observed between the total number of group members and infant survival rate, or between the number of adult members and infant survival. While helpers may be necessary to increase the survival rate of infants in wild groups, help of non-reproductive animals is not required in captivity, where energetic demands are comparatively low and ecological constraints absent. Under laboratory conditions the parents' skill in infant handling and the mother's physical condition, i.e., the ability to provide enough milk for the infants, is likely to be the most important factor for infant survival. © 1993 Wiley-Liss, Inc.     

饲养条件下非人灵长类的营养需求

非人灵长类的营养学研究越来越受到国际和国内社会的关注。我国是世界上实验灵长类动物的最大产出国。进一步了解和发展非人灵长类营养学将有利于提高我国非人灵长类的饲养水平和饲料资源的利用效率,推动整体产业的发展。为此本文介绍了近年来国际上非人灵长类营养学方面的研究进展和国家饲料配比的相关规定,阐述了各营养成分的作用、缺乏症状和改善案例。旨在丰富相关方面的科学信息,增加对非人灵长类营养
需求的理解。     

Habituation to environmental enrichment in captive sloth bears—effect on stereotypies

The benefits to captive animals of environmental enrichment (EE) are widely recognized. Few studies have, however, studied how to maximise the effect of EE. One issue with EE programs seems to be habituation to the enrichment device. To study the effect of habituation to EE, 14 captive sloth bears (Melursus ursinus) were subjected to two different EE treatments. Treatment one presented EE (logs with honey containing holes) for five consecutive days, whereas treatment two presented EE on intermittent days for five days. Intermittent presentations tended to reduce habituation toward the EE. Both consecutive and intermittent presentations significantly reduced stereotypies; however, the consecutive presentations had a longer‐lasting effect. Explorative behaviors increased in both treatments, consistent with earlier findings that EE increase levels of natural behaviors. Other behaviors were unaffected by the EE presentations. The results show that intermittent presentation of EE objects may secure the interest of the animals, but continuous access to enrichment may be more efficient in reducing stereotypies in the long run. Zoo Biol 29:705–714, 2010. © 2010 Wiley‐Liss, Inc.     

Trabecular bone structure in the mandibular condyles of gouging and nongouging platyrrhine primates

The relationship between mandibular form and biomechanical function is a topic of significant interest to morphologists and paleontologists alike. Several previous studies have examined the morphology of the mandible in gouging and nongouging primates as a means of understanding the anatomical correlates of this feeding behavior. The goal of the current study was to quantify the trabecular bone structure of the mandibular condyle of gouging and nongouging primates to assess the functional morphology of the jaw in these animals. High‐resolution computed tomography scan data were collected from the mandibles of five adult common marmosets (Callithrix jacchus), saddle‐back tamarins (Saguinus fuscicollis), and squirrel monkeys (Saimiri sciureus), respectively, and various three‐dimensional morphometric parameters were measured from the condylar trabecular bone. No significant differences were found among the taxa for most trabecular bone structural features. Importantly, no mechanically significant parameters, such as bone volume fraction and degree of anisotropy, were found to vary significantly between gouging and nongouging primates. The lack of significant differences in mechanically relevant structural parameters among these three platyrrhine taxa may suggest that gouging as a habitual dietary behavior does not involve significantly higher loads on the mandibular condyle than other masticatory behaviors. Alternatively, the similarities in trabecular architecture across these three taxa may indicate that trabecular bone is relatively unimportant mechanically in the condyle of these primates and therefore is functionally uninformative. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.     

Interactions between infant growth and survival: Evidence for selection on age-specific body weight in captive common marmosets (Callithrix jacchus)

The objective of this study is to investigate factors influencing infant survival in captive common marmosets. We investigated the influence of age-specific weight, litter size, caging, and the presence of helpers on survival to 6 months of age in 189 Callithrix jacchus infants. Infant survival was analyzed using Cox Proportional Hazards regression, and fitness functions were plotted to explore the relationship between survival and growth. Results indicate that weights at birth and 120 days significantly affect future survival probability. Litter size significantly influences survival prior to 60 days of age with larger litters having poorer survival. Males and females did not have significantly different survival and the presence of helpers in the group did not influence survival probability. Patterns of survival with respect to age-specific weights suggest stabilizing selection on birth weight and directional selection on weight at 120 days of age. Am. J. Primatol. 42:269–280, 1997. © 1997 Wiley-Liss, Inc.     

Characteristics of reproductive biology and proximate factors regulating seasonal breeding in captive golden-headed lion tamarins (Leontopithecus chrysomelas)

Reproduction is highly demanding in terms of energy expenditure, and the costs and benefits associated with postponing or investing in a reproductive effort are crucial determinants of an individual's fitness. Understanding the reproductive potential of a species under varying ecological conditions offers important insights into the dynamics of its social system. This study provides the first detailed analysis of the reproductive potential of wild- and captive-born golden-headed lion tamarins (Leontopithecus chrysomelas) under captive conditions, based on studbook data compiled during 1984-2000. Litters produced by wild-born females breeding in captivity are similar in size to litters observed in the wild, but smaller than litters of captive-born females. The more stringent ecological conditions experienced by wild-born females during maturation may result in a lifelong effect on litter size. However, interbirth intervals are shorter for wild-born than captive-born females. The relatively smaller burden of infant care that results from having smaller litters may allow wild-born females to sustain the next pregnancy sooner. Reproduction in the Brazilian captive population is highly seasonal for both wild-born females and females born in captivity in Brazil. Changes in photoperiod over a year provide a proximate explanation for changes in the proportion of conceptions and births per month. Outside Brazil, breeding occurs year-round, and no clear birth peak is apparent. Information from field reports that could be used to relate this finding to ecological factors, such as resource availability, is unavailable.     

Comparison of several types of enrichment for captive felids

Enrichment can increase the complexity of the captive environment and possibly enhance captive animals' well‐being by stimulating active behaviors and reducing stereotypical behaviors commonly seen in zoo felids. In this study, three different enrichment items were added to outdoor enclosures of felids at the Montgomery Zoo to test their effects on activity levels and stereotypic pacing. Bones, frozen fish, and spices (cinnamon, chili powder, and cumin) were presented over a 3‐month period to six species of felids: cheetah, cougar, jaguar, lion, ocelot, and tiger. Proportion of time spent engaging in active behaviors and stereotypic pacing were compared before, during, and after treatments. All treatments resulted in a significant increase in activity level from baseline (bones: +15.59%; frozen fish: +35.7%; spices: +12.38%). Effects of enrichment items on activity levels were not sustained 7 days after removal. Proportion of time spent pacing significantly decreased during presentation of spices (?21.25%) and frozen fish (?26.58%), but not with the addition of bones. However, only the effect of frozen fish on stereotypic behavior was sustained 7 days after removal of the enrichment item. In conclusion, bones, spices, and frozen fish are inexpensive and easy‐to‐administer enrichment items that may be used to increase active behaviors of captive felids. Zoo Biol 26:371–381, 2007. © 2007 Wiley‐Liss, Inc.     

Effects of different environmental enrichment devices on cage stereotypies and autoaggression in captive cynomolgus monkeys

Autoaggression and stereotypies in individually housed cynomolgus monkeys were compared in a standard primate cage and an enriched playpen environment. Stereotypy and autoaggression were markedly reduced in the playpen, but reappeared on return to the home cage. Some of the various activities available in the playpen but not others engaged the animals' attention.     

Thirty years later: enrichment practices for captive mammals

Environmental enrichment of captive mammals has been steadily evolving over the past thirty years. For this process to continue, it is first necessary to define current enrichment practices and then identify the factors that limit enhancing the quality and quantity of enrichment, as well as the evaluation of its effectiveness. With the objective of obtaining this information, an international multi‐institutional questionnaire survey was conducted with individuals working with zoo‐housed mammals. Results of the survey showed that regardless of how important different types of enrichment were perceived to be, if providing them was particularly time‐consuming, they were not made available to captive mammals as frequently as those requiring less staff time and effort. The groups of mammals provided with enrichment most frequently received it on average fewer than four times per day, resulting in less than two hours per day spent by each animal care staff member on tasks related to enrichment. The time required for staff to complete other husbandry tasks was the factor most limiting the implementation and evaluation of enrichment. The majority of survey respondents agreed that they would provide more enrichment and carry out more evaluation of enrichment if it was manageable to do so. The results of this study support the need for greater quantity, variety, frequency, and evaluation of enrichment provided to captive mammals housed in zoos without impinging on available staff time. Zoo Biol 29:303–316, 2010. © 2009 Wiley‐Liss, Inc.     

Stereotypic behavior and fecal cortisol level in captive giant pandas in relation to environmental enrichment

Stereotypic behavior is exhibited by a wide range of captive animals. Its association with hormones, especially elevated cortisol level and lack of naturalistic stimuli in the environment, has been little studied. This study hypothesizes that stereotypic behavior is caused by stress due to lack of appropriate, naturalistic stimuli in the environment. Using four adult pandas (Ailuropoda melanoleuca) in the Beijing Zoo from March–July in 2003, we tested the following predictions: 1) stereotypic behavior and fecal cortisol level will not change associated with the progress of reproductive state; 2) there is a positive correlation between the occurrence of stereotypic behavior and fecal cortisol level; and 3) environmental enrichment by adding a naturalistic stimulus will reduce both stereotypic behavior and fecal cortisol level. We did not find any significant differences in the occurrence of stereotypic behavior and fecal cortisol level but did find a significant difference in the total time engaged in displaying the stereotypic behavior among the three estrous periods. The level of stereotypic behavior was correlated with elevated fecal cortisol level. Enrichment simply by adding a naturalistic stimulus did not show significant effects on stereotypic behavior, or on fecal cortisol level. Our results supported the second prediction, but did not completely support the first and the third ones perhaps because of the small sample size. Additionally, our results showed that stereotypic behavior might be a response to a heightened level of cortisol. Zoo Biol 0:1–15, 2006. © 2006 Wiley‐Liss, Inc.     

Body size and scaling of the hands and feet of prosimian primates

The hands and feet of primates fulfill a variety of biological roles linked with food acquisition and positional behavior. Current explanations of shape differences in cheiridial morphology among prosimians are closely tied to body size differences. Although numerous studies have examined the relationships between body mass and limb morphology in prosimians, no scaling analysis has specifically considered hand and foot dimensions and intrinsic proportions. In this study, we present such an analysis for a sample of 270 skeletal specimens distributed over eight prosimian families. The degree of association between size and shape was assessed using nonparametric correlational techniques, while the relationship between each ray element length and body mass (from published data and a body mass surrogate) was tested for allometric scaling. Since tarsiers and strepsirrhines encompass many taxa of varying degrees of phylogenetic relatedness, effective degrees of freedom were calculated, and comparisons between families were performed to partially address the problem of statistical nonindependence and "phylogenetic inertia." Correlational analyses indicate negative allometry between relative phalangeal length (as reflected by phalangeal indices) and body mass, except for the pollex and hallux. Thus, as size increases, there is a significant decrease in the relative length of the digits when considering all prosimian taxa sampled. Regression analyses show that while the digital portion of the rays scales isometrically with body mass, the palmar/plantar portion of the rays often scales with positive allometry. Some but not all of these broadly interspecific allometric patterns remain statistically significant when effective degrees of freedom are taken into account. As is often the case in interspecific scaling, comparisons within families show different scaling trends in the cheiridia than those seen across families (i.e., lorisids, indriids, and lemurids exhibit rather different allometries). The interspecific pattern of positive allometry that appears to best characterize the metapodials of prosimians, especially those of the foot, parallels differences found in the morphology of the volar skin. Indeed, relatively longer metapodials appear to covary with flatter and more coalesced volar pads, which in turn slightly improve frictional force for animals that are at a comparative disadvantage while climbing because of their larger mass. Despite the essentially isometric relationship found between digit length and body mass across prosimians, examination of the residual variation reveals that tarsiers and Daubentonia possess, relative to their body sizes, remarkably long fingers. Such marked departures between body size and finger length observed in these particular primates are closely linked with specialized modes of prey acquisition and manipulation involving the hands.     

Contrafreeloading in grizzly bears: implications for captive foraging enrichment

Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non‐nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced “chow” diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food‐restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife. Zoo Biol 29:484–502, 2010. © 2009 Wiley‐Liss, Inc.