Showing papers in "Zoo Biology in 2000"

Reproductive endocrine monitoring of elephants: An essential tool for assisting captive management

Abstract: Considerable information now is available about the basic reproductive biology of elephants, especially females. However, as important as this knowledge is, it no longer is enough to simply compile it into a database. The potential exists for using endocrine monitoring techniques to solve real problems. This review summarizes our current knowledge of elephant endocrinology and offers suggestions on how to use the technology to maximize reproductive potential. The estrous cycle can be monitored through the analysis of serum progestogens, primarily 5α-reduced compounds, and consists of an 8- to 12-week luteal phase and a 4- to 6-week inter-luteal period. Proof of ovarian cyclicity currently is mandatory before Species Survival Plan breeding recommendations are approved. However, because many adult females are not cycling normally, the reproductive monitoring of all cows throughout their life span is now encouraged. Complete endocrine evaluations in conjunction with ultrasound examinations and behavioral assessments are needed to identify causes of reproductive failure and develop mitigating treatments. Progestogen analyses also are effective for monitoring pregnancy, but only if longitudinal samples are collected. Alternatively, pregnancy can be diagnosed in occasional samples using serum prolactin or possibly relaxin measurements after 20 weeks of gestation. Parturition can be predicted on the basis of the rapid decrease in progestogens that occurs about 2–5 days before birth. An updated model of ovarian dynamics during the estrous cycle suggests that two waves of follicular development occur 3 weeks apart during the non-luteal phase, possibly under the control of follicle-stimulating hormone. Each follicular wave culminates in a luteinizing hormone (LH) surge, with the second surge inducing ovulation and corpus luteum formation. The functional significance of the first, anovulatory LH surge is under investigation, but from a practical perspective it can be used to schedule breeding (by artificial insemination or natural mating) to coincide with the ovulatory LH surge. Less is known about the reproductive biology of bulls, aside from the fact that musth is associated with dramatic changes in androgen secretion. Studies are needed to determine whether poor libido and inadequate semen quality observed in some mature elephants are due to testicular steroidogenic dysfunction. When blood samples cannot be collected for routine hormone analysis, gonadal activity can be monitored non-invasively through the measurement of excreted steroid metabolites (males: androgens; females: estrogens, progestogens) in urine and feces. Lastly, suggestions for future research priorities are provided. Zoo Biol 19:347–367, 2000. © 2000 Wiley-Liss, Inc.

Social structure and helping behavior in captive elephants

Abstract: Selective pressures on individual behavior serve to mold social structure and subsequent levels of cooperation in social species, including elephants. Adult Asian (Elephas maximus) and African (Loxodonta africana) elephants have complex social societies that differ markedly between the sexes. Elephant social structure and cooperative behavior may have evolved in part to prepare young elephants to meet the challenges of an expansive environment, predators and parasites. In captivity, such forces are relaxed or eliminated, yet captive elephants display a similar repertoire of behaviors as their wild counterparts. Elephants live in herds of related adult females from several generations. This female social unit is centered on calves and the matriarch. Adult males reside in bachelor herds, singly, or frequent female groups, depending on male age and reproductive condition. In captivity, female elephants are usually housed together, although group size is smaller than in the wild, whereas adult males are generally housed separately from other elephants. Beyond these general similarities between wild and captive settings, captive elephants are housed in a wider range of group sizes, degrees of relatedness, and age structures than would be typical in the wild. This variation in social structure can be used to explore questions about cooperative behavior. Following a comparison of wild and captive social structures for elephants, three such potential avenues for study are discussed. Specifically, research with captive elephants could shed light on the development of social behavior, the functional significance of allomothering, and the ability of elephants to recognize kin or social group members. Beside the potential theoretical implications and insight into wild elephant behavior, the examination of social behavior also has important ramifications for the management of animals in captivity. Zoo Biol 19:447–459, 2000. © 2000 Wiley-Liss, Inc.

Ultrasonography of the Urogenital Tract in Elephants (Loxodonta africana and Elephas maximus): An Important Tool for Assessing Male Reproductive Function

Abstract: The success rate of captive elephant breeding programs worldwide is poor. Along with undiagnosed reproductive disorders in females and fatal diseases such as the newly discovered herpesvirus infection, male infertility now is considered a major contributing factor in the failure to maintain self-sustaining captive populations. To address questions related to male reproductive dysfunction, approximately 309 ultrasonographic assessments combined with semen collection were performed in captive (n = 10) and wild (n = 4) African (Loxodonta africana) and captive (n = 61) Asian (Elephas maximus) elephants. Bulls ranged from 4 to 50 years of age and were examined at 9 institutions in North America, 13 in Europe, 2 in Africa, and 7 in Asia. About half of the reproductive assessments were performed in protected contact situations with elephants handled in a restraint device, and half involved assessments of trained Asian bulls managed in free contact. Four wild African and two Asian elephant bulls were evaluated after receiving general anesthesia. Transrectal ultrasound was used to characterize the morphology and functionality of the entire urogenital tract, including the testes and accessory sex organs. Bulls were categorized on the basis of breeding status (breeders vs. non-breeders) and social history (i.e., type of interaction with conspecifics and keepers). Most of the bulls were non-breeders (designated Types I–V). Type I (n = 3 African, 6 Asian) and Type V (n = 1 Asian) were immature and castrate, respectively. On the basis of keeper evaluations, Type II bulls (n = 2, 4) were subordinate to older cows and keepers, whereas Type III bulls (n = 4, 28) were dominated by other bulls. Type IV (n = 1, 8) were older bulls of unknown history that exhibited numerous testicular pathologies resulting in poor semen quality. Non-breeding bulls included those that were exposed to females, but failed to breed, as well as those that had no opportunities to breed. Type VI individuals (n = 4, 14) were proven breeders. The percentage of observable reproductive tract pathology in adult males was remarkably low (14%), even in older bulls. However, apparent infertility of non-organic cause (i.e., not due to specific anatomical abnormalities) in these otherwise healthy bulls was high (32%). Semen quality varied markedly in ejaculates collected from the same bull, as well as from different bulls. In conclusion, although many of these bulls could serve as semen donors for natural mating or artificial insemination, the inconsistent production of good-quality ejaculates raises questions as to the reliability of these individuals to participate in breeding programs. The apparent inhibitory effect of suppressive social interactions on reproductive potential also needs to be investigated. Ultrasound examinations combined with semen collection should be conducted periodically to estimate the reproductive value of each bull and determine whether altered management strategies are needed to enhance captive breeding. Zoo Biol 19:333–345, 2000. © 2000 Wiley-Liss, Inc.

How chemical signals integrate Asian elephant society: The known and the unknown

Abstract: The importance of chemical senses to elephants was recognized in anecdotal observations by ancient humans. Modern scientific tools, such as molecular biological techniques, highly sensitive gas chromatographic/mass spectrometric instrumentation, and statistically valid ethological methods, have allowed the study of real events of chemical communication between elephants. Such communication encompasses long- and short-range navigation, relationship recognition, and inter- and intra-sexual exchange of reproductive condition, metabolic state, and social status. Asian elephants emit large amounts of complex chemical mixtures in breath and urine, and in secretions from the temporal gland, inter-digital glands, and ears. Some emitted chemicals originate in blood and may be metabolic products; others are secretory products, at times apparently under hormonal control. The wide variety of emitted compounds includes hormones, proteins, and volatile compounds; selected volatile ketones and an acetate ((Z)-7-dodecenyl acetate) function as chemical signals and a pheromone, respectively. Some of these specific chemicals identified in emissions from Asian elephants dwelling in the United States have been found to be present in exudates from elephants in India. This similarity is demonstrable for three metabolic conditions: pregnancy in females and pre- and post-musth in males. Future chemical communication studies on male elephants should focus on musth and its relevance to reproduction and male social structures. Such investigations should include hormones, metabolites, brain chemistry, and possible primer pheromones. For females, the factors influencing possible estrous synchrony, what role primer pheromones play in female reproduction, how chemical signals influence social behavior, and whether luteinizing hormone influences pheromone production are among remaining fundamental questions.

Asian elephants are not self‐sustaining in North America

Abstract: Demographic analysis of the captive Asian elephants in North America indicates that the population is not self-sustaining. First year mortality is nearly 30%, but perhaps more important, the fecundity is extremely low (Mx = 0.01–0.02) throughout the prime reproductive years. Without continued importation or a drastic increase in birth rates, the Asian elephant population in North America will drop to approximately 10 elephants in 50 years and be demographically extinct. Model mortality and fecundity curves needed to establish a self-sustaining Asian elephant population in North America show that fecundity must increase four to eight times the historical rates. Emerging techniques such as artificial insemination may assist in making the goal of a self-sustaining population more realizable by allowing reproduction by the numerous females that do not have access to a male, but other obstacles exist as well. A self-sustaining population will present challenges such as maintaining the significant number of male offspring that will be produced. Importation of young females from documented self-sustaining populations overseas is one option that would alleviate the need for a self-sustaining Asian elephant population in North America and the number of imports per year would be minimal. Zoo Biol 19:299–309, 2000. © 2000 Wiley-Liss, Inc.

Phytochemical and mineral components of foods consumed by black howler monkeys (Alouatta pigra) at two sites in Belize

Abstract: We analyzed the chemical composition of the diets of eight groups of free-ranging black howler monkeys (Alouatta pigra) in Belize, Central America. The study groups were located in two different forests: the Community Baboon Sanctuary (CBS) and the Cockscomb Basin Wildlife Sanctuary (CBWS). Two of the study groups were translocated from the CBS to CBWS 3 months into the study, and we compared the diets of groups in the two forests. Young and mature leaves, fruits, flowers, and fig samples (n = 144) were analyzed for water content, crude and available protein, fiber, simple sugars, and minerals. Statistically significant differences were found among the plant parts in all measures except acid-detergent fiber. Dietary foliage in CBS was higher in water content and protein but lower in simple sugars than dietary foliage in CBWS. We suggest that changes in the selection of plant parts by primates may be related to differences in the nutritional content of those parts. These data may be useful in developing optimal diets for captive howler monkeys. Zoo Biol 19:95–109, 2000. © 2000 Wiley-Liss, Inc.

A preliminary study of the behavioral effects of feeding enrichment on African elephants.

Abstract: Although commonly practiced with many species, feeding enrichment in elephants is understudied. The behavioral effects of feeding enrichment were tested in three African elephants by substituting an equal dry weight of browse for hay in an ABA design. The results showed a significant increase in feeding and significant decreases in drinking and inactivity when the browse was present. Additionally, changes in feeding, inactivity, and time spent in contact were observed outside the time the browse was actually presented, although the relationship of these changes to the experimental methodology is unknown. A significant increase in visibility to zoo visitors during the browse conditions demonstrates that browse is an effective, naturalistic method for increasing visibility as well as species-typical behaviors. Managers of captive elephants should consult with a nutritionist to address issues of energetics, nutritional content, and secondary compounds when using browse as feeding enrichment. Zoo Biol 19:485-493, 2000. Copyright 2000 Wiley-Liss, Inc.

State of the North American African elephant population and projections for the future

Abstract: The African elephant has historically received less attention in the captive community than the Asian elephant. One manifestation of this lack of attention is that only 25 African elephant calves had been born in captivity in North America as of 1 January 1999. With the recent attention to both elephant species, it is imperative to evaluate the African elephant’s potential to maintain a self-sustaining population in North America. Review of the raw data indicates that African elephants have reproduced poorly and experienced low juvenile survival in North America. However, using realistic life table models,the future of the North American African elephant population can be predicted. The current population is relatively young compared to the captive Asian elephant population and has a much greater potential to become self-sustaining with increased focus and efforts toward reproduction. Unlike the Asian elephant population, the African elephant population may be able to become self-sustaining without further importation, if reproduction and juvenile survivorship increase significantly in the next 10 years. Zoo Biol 19:311–320, 2000. © 2000 Wiley-Liss, Inc.

Ultrasonography of the estrous cycle in female African elephants (Loxodonta africana)

Abstract: The endocrinology of the elephant estrous cycle has been well characterized, but little emphasis has been placed on evaluating corresponding changes in the reproductive tract. Ultrasound was used to document changes in reproductive tract morphology throughout the estrous cycle in four cycling female African elephants. During a 7-month period, frequent ultrasound examinations (n = 190) during the luteal and non-luteal phase were compared with serum progesterone and luteinizing hormone (LH) concentrations during a 7-month period. Ultrasonographic images documented vaginal and cervical edema and changes in mucus consistency during the non-luteal phase. The cross-sectional diameter of the endometrium showed a dramatic increase during the non-luteal phase and followed cyclic changes. A different pattern of follicular development on the ovary was associated with the two LH surges. Follicle growth associated with the first, anovulatory LH surge was characterized by the formation of multiple small follicles, in contrast to the maturation of a single large follicle at the second, ovulatory LH (ovLH) surge. Ovulation and the subsequent formation of a corpus luteum (CL) were observed only after the ovLH surge. Ultrasound data in combination with endocrine assessments suggest that the African elephant is non-ovulatory, although multiple non-ovulatory luteal structures developed during the late nonluteal phase of each cycle. Both ovulatory CL and non-ovulatory luteal structures were present only through one cycle and regressed at the end of the luteal phase in conjunction with the drop in serum progesterone. We conclude that

Tuberculosis in elephants in North America

Abstract: Within the past 4 years, tuberculosis (TB) has emerged as a disease of concern in elephants. The population of elephants in North America is declining [Wiese, 1997], and transmissible diseases such as TB may exacerbate this trend. Guidelines for the Control of Tuberculosis in Elephants, which require the screening of all elephants for TB, were instituted in 1997 [USDA, 1997; 2000]. Between August 1996 and May 2000, Mycobacterium tuberculosis was isolated from 18 of 539 elephants in North America, indicating an estimated prevalence of 3.3%. Isolation of the TB organism by culture is the currently recommended test to establish a diagnosis of TB; however, culture requires 8 weeks. Further research is essential to validate other diagnostic tests and treatment protocols. Zoo Biol 19:393–403, 2000. © 2000 Wiley-Liss, Inc.

Increasing calcium levels in cultured insects

Abstract: Low calcium (Ca) contents and low calcium:phosphorus (Ca:P) ratios of mealworm larvae and house crickets can result in imbalances of Ca and phosphorus (P) in diets of avian species when these insects form more than a minor proportion of the diet. Appropriate dietary Ca and Ca:P levels are particularly important for normal growth and bone development in chicks, especially of long-legged species such as bustards. Two experiments were carried out to evaluate the efficacy of a selection of practicable dietary options for increasing the Ca levels and Ca:P ratios of cultured mealworm larvae and immature house crickets used for feeding bustards. Dietary treatments contained higher levels of Ca than the insects' standard culture diet components but similar P levels. Dietary treatment significantly increased Ca level and Ca:P ratio of both mealworm larvae and immature house crickets but did not affect P content of either species. Acceptable insect Ca and Ca:P levels were achieved by maintaining insects on commercial high-Ca diet products for as little as 24 hours. Other factors that may have influenced the Ca levels of mealworm larvae and house crickets include physical form and overall nutrient composition of their diets. Zoo Biol 19:1–9, 2000. © 2000 Wiley-Liss, Inc.

Orangutan Use of Vertical Space in an Innovative Habitat

Abstract: This study measured use of vertical space in an innovative habitat for three adolescent orangutans (Pongo pygmaeus). The indoor habitat was innovative in two main ways: a flooded floor and retractable skylights. It included four large molded trees and interwoven vines throughout 1,620 m3 of space. The exhibit was divided into four vertical levels: skylights, upper canopy, lower canopy, and flooded floor. Five trained observers made instantaneous scans of the exhibit every 5 minutes, in 1-hour blocks of time over a 10-month period, logging 180 hours of observations. One location (of 55) and one behavior (of 53) were noted at each interval. Behaviors were collapsed to form five categories: solitary inactivity, solitary activity, social inactivity, social activity, and eating/drinking. Results showed the orangutans favored the upper canopy, which contained many tree limbs for sitting and reclining. The orangutans next favored the lower canopy and the skylights, especially those skylights that were out of public view. The habitat’s flooded floor was avoided (they used it just 1% of the time), as planned by the exhibit designers who intended to showcase these arboreal primates in trees, not on the ground. When compared with wild orangutans, we considered few of their behaviors to be atypical: foraging/eating plastic (vines) and stereotyped behaviors. Overall, the unique design of the habitat provided opportunities for a range of species-typical behaviors, varying by vertical level, demonstrating the importance of providing sufficient vertical space for orangutans. Zoo Biol 19:239–251, 2000. © 2000 Wiley-Liss, Inc.

Variation in stereotypic behavior related to restraint in circus elephants

Abstract: The purpose of this study was to determine the effect of penning and chaining on circus elephant behavior. The behaviors of 10 Asian elephants (Elephas maximus) and three African elephants (Loxodonta africana) were videotaped for at least 24 hours at each of six performance locations. At four of these locations, the elephants were restrained in electric-wire pens on turf and at two locations the elephants were restrained via leg chains on macadam. Instantaneous scan sampling at 5-minute intervals during each observation period was conducted to determine the frequency of occurrence of seven behavior categories: aggression, comfort, ingestion, locomotion, resting, social, and stereotypy. Stereotypies and social interaction (P 0.6254). Variation in stereotypic activity was related to age (P = 0.0001), with younger elephants more likely to show stereotypic activity than older elephants. Zoo Biol 19:209–221, 2000. © 2000 Wiley-Liss, Inc.

Videotapes as enrichment for captive chimpanzees (Pan troglodytes).

Abstract: The effectiveness of showing videotapes to captive chimpanzees as an environmental enrichment was quantitatively tested. The responses of 10 subjects (3 adult males and 7 adult females) to videotapes of chimpanzees engaging in a variety of behaviors, to videotapes of other animals and humans, and to television programs were compared. Data collection consisted of 20-minute, continuous sampling tests while various videotapes were shown. A total of 400 tests were conducted. Multivariate analysis of variance was applied to measure differences in the duration of eight categories of behavior across videotapes of varying content. No general behavioral differences in response to the tapes based on sex or housing were revealed. However, with the behavior of monitor-watching analyzed alone, we found that individually housed subjects watched the videotapes more than socially housed subjects. When viewing time was averaged across all videotapes, the chimpanzees watched the monitor a mean of 38.4% of the time available. The chimpanzees' behavior varied significantly only when they were watching the videotapes of various human and chimpanzee activities and not when watching a blank screen. A Pearson's correlation indicated that subjects habituated to repeated presentations of the videotapes, although the effect was small numerically. Although this type of enrichment did not extensively alter behavior, it did occupy a significant portion of the subjects' activity budget; thus, the amount of time spent watching the video stimuli indicated that videotapes may be a useful enrichment for captive chimpanzees. Zoo Biol 19:541-551, 2000. Copyright 2000 Wiley-Liss, Inc.

Reproductive inefficiency in male black-footed ferrets (Mustela nigripes).

Abstract: The black-footed ferret (Mustela nigripes), once considered extinct, has benefited from captive breeding and subsequent reintroduction into native habitat. A high proportion of females (>90%) exhibit estrus in captivity during the spring breeding season. However, many males considered to be prime-breeding age (1-3 years old) fail to sire offspring. Breeding records in 1995 revealed that 40 of 73 males (55%) managed under the Black-Footed Ferret Species Survival Plan did not reproduce, despite being provided opportunity. The present study was conducted to determine the incidence and etiology of male reproductive failure in 1996 and 1997. In 1996, 38 of 69 (55%) 1- to 3-year-old males failed to sire offspring. Likewise, 35 of 60 (58%) males did not reproduce in 1997. Overall, 21% of adult males failed to sire young in three consecutive breeding seasons (1995-1997). Electroejaculate traits (ejaculate volume, sperm concentration, motility, morphology, and acrosomal integrity) from 29 proven breeder males were not different (P > 0.05) from those of 23 males that did not sire young (nonproven breeders). However, six categories of reproductive failure were identified for the 73 prime-breeding age, nonproven males: 1) underdeveloped testes (22%); 2) improper breeding position with the female (25%); 3) excessive aggression toward estrous females (9%); 4) copulation with no sperm detected at postcoital lavage (19%); 5) copulation with sperm in the vaginal lavage but no resulting pregnancy (18%); and 6) copulation with no vaginal lavage performed and no resulting pregnancy (7%). These data indicate that combined behavioral and physiologic factors, but not overall sperm quality, influence reproductive performance in male black-footed ferrets managed in captivity. Zoo Biol 19:517-528, 2000. Copyright 2000 Wiley-Liss, Inc.

Birth sex ratio in captive mammals: Patterns, biases, and the implications for management and conservation

Abstract: Sex allocation theory predicts that a female should produce the offspring of the sex that most increases her own fitness. For polygynous species, this means that females in superior condition should bias offspring production toward the sex with greater variation in lifetime reproductive success, which is typically males. Captive mammal populations are generally kept in good nutritional condition with low levels of stress, and thus populations of polygynous species might be expected to have birth sex ratios biased toward males. Sex allocation theory also predicts that when competition reduces reproductive success of the mother, she should bias offspring toward whichever sex disperses. These predicted biases would have a large impact on captive breeding programs because unbalanced sex ratios may compromise use of limited space in zoos. We examined 66 species of mammals from three taxonomic orders (primates, ungulates, and carnivores) maintained in North American zoos for evidence of birth sex ratio bias. Contrary to our expectations, we found no evidence of bias toward male births in polygynous populations. We did find evidence that birth sex ratios of primates are male biased and that, within primates, offspring sex was biased toward the naturally dispersing sex. We also found that most species experienced long contiguous periods of at least 7 years with either male- or female-biased sex ratios, owing in part to patterns of dispersal (for primates) and/or to stochastic causes. Population managers must be ready to compensate for significant biases in birth sex ratio based on dispersal and stochasticity. Zoo Biol 19:11–25, 2000. © 2000 Wiley-Liss, Inc.

A postcryogenic comparison of membrane fatty acids of elephant spermatozoa

Abstract: Cryogenic protocols have been successful in storing spermatozoa collected from African elephants (Loxodonta africana). However, these same protocols and modifications of these protocols have failed to preserve spermatozoa collected from Asian elephants (Elephas maximus) [Buice et al., 1995, Proceedings of the Association of Zoo Veterinary Technicians, Baltimore, MD; O’Brien et al., 1997, Second International Elephant Research Symposium, Springfield, MO]. Because the success or failure of cryogenic freezing may rely on differences in membrane composition, a postcryogenic comparison of the membrane fatty acid composition of spermatozoa isolated from African and Asian elephants was studied. The spermatozoa of African elephants possessed significantly higher levels of docosahexaenoic acid (22:6, n-3) and docosapentaenoic acid (22:5, n-6) as compared to the spermatozoa of Asian elephants. Meanwhile, the spermatozoa of Asian elephants had higher levels of myristic acid (14:0), arachidonic acid (20:4, n-6), and docosatetraenoic acid (22:4, n-6) as compared to the spermatozoa of African elephants. The most abundant membrane fatty acid was docosahexaenoic acid (22:6, n-3). The percentage of membrane docosahexaenoic acid (22:6, n-3) in the spermatozoa of African elephants was 68.13 ± 0.52 as compared to 42.88 ± 0.87 in the spermatozoa of Asian elephants (t = 31.48, P ≤ 0.0001). Zoo Biol 19:461–473, 2000. © 2000 Wiley-Liss, Inc.

Multi-male captive groups of endangered dama gazelle: Social rank, aggression, and enclosure effects

Abstract: A study carried out in four multi-male groups of captive dama gazelle (Gazella dama mhorr) characterized the social rank order of males and possible enclosure effects on aggression rate. A strong relationship between rank and age was found. The results also showed that dominant individuals in the two smallest enclosures were more aggressive than their herdmates, suggesting a more stressful environment, which might precipitate unstable or challenged hierarchies when the animals live in a more restricted enclosure. Subordinate males performed submissive responses at a higher frequency, irrespective of the size of the enclosure. The frequency of interactions between the gazelles, on the other hand, was affected by enclosure size, since high-ranking males showed higher values than low-ranking males in the two smallest enclosures. Frequencies of aggressive acts, retreats, and related interactions were similar in all the herds. Implications for the management of the species in captivity are discussed. Zoo Biol 19:121–129, 2000. © 2000 Wiley-Liss, Inc.

Development of Restoration Techniques for Hawaiian Thrushes: Collection of Wild Eggs, Artificial Incubation, Hand-rearing, Captive-breeding, and Re-introduction to the Wild

Abstract: From 1995 to 1999, two species of endemic Hawaiian thrushes, `Oma`o (Myadestes obscurus) and Puaiohi (M. palmeri), were captive-reared and re-introduced into their historic range in Hawai`i by The Peregrine Fund, in collaboration with the U.S. Geological Survey–Biological Resources Division (BRD) and the Hawai`i State Department of Land and Natural Resources. This paper describes the management techniques that were developed (collection of wild eggs, artificial incubation, hand-rearing, captive propagation, and release) with the non-endangered surrogate species, the `Oma`o; techniques that are now being used for recovery of the endangered Puaiohi. In 1995 and 1996, 29 viable `Oma`o eggs were collected from the wild. Of 27 chicks hatched, 25 were hand-reared and released into Pu`u Wa`awa`a Wildlife Reserve. Using the techniques developed for the `Oma`o, a captive propagation and release program was initiated in 1996 to aid the recovery of the endangered Puaiohi. Fifteen viable Puaiohi eggs were collected from the wild (1996–1997) to establish a captive breeding flock to produce birds for re-introduction. These Puaiohi reproduced for the first time in captivity in 1998 (total Puaiohi chicks reared in captivity 1996–1998 = 41). In 1999, 14 captive-bred Puaiohi were re-introduced into the Alaka`i Swamp, Kaua`i. These captive-bred birds reproduced and fledged seven chicks in the wild after release. This is the first endangered passerine recovery program using this broad spectrum of management techniques (collection of wild eggs, artificial incubation, hand-rearing, captive-breeding, and release) in which re-introduced birds survived and bred in the wild. Long-term population monitoring will be published separately [BRD, in preparation]. Zoo Biol 19:263–277, 2000. © 2000 Wiley-Liss, Inc.

Advanced age influences chimpanzee behavior in small social groups

Abstract: Management strategies for captive chimpanzees (Pan troglodytes) must begin to take into account the increasing age of the captive chimpanzee population. This study represents a baseline assessment of the relationship between advancing age and behavior among male and female chimpanzees living in pairs and trios in indoor/outdoor runs. Data collected on 14 old individuals (30‐44 years old) and 20 younger adult individuals (11‐22 years old) totaled 240 hours. Levels of agonistic and affiliative social behavior, non-social activity, abnormal behaviors, and behavioral indicators of anxiety were evaluated. In the same captive setting, the behavior of old chimpanzees was significantly different from younger chimpanzees. Old chimpanzees showed less aggression and moved about their enclosures less. Old females behaved submissively more often than younger adult females; the reverse was found among males. However, affiliative social behavior occurred at similar levels in old and younger adult chimpanzees, implying continued need for social housing with advancing age. The effect of enrichment devices may differ for aged female chimpanzees, given their submissiveness and the lower levels of object manipulation found in aged subjects. These results suggest that aging in chimpanzees may be accompanied by altered patterns of social interaction, requiring careful attention to the compatibility of social partners. Zoo Biol 19:111‐119, 2000. © 2000 Wiley-Liss, Inc.

Breeding behavior in a flock of Chilean flamingos (Phoenicopterus chilensis) at Dublin zoo

Abstract: The breeding behavior of a flock of Chilean flamingos was observed over a 3-month period during the peak of breeding activity. This species’ habitat is becoming increasingly vulnerable, and concern has been raised over a decline in wild stocks numbers in the past two decades. Breeding programs in zoos have been established, but with limited success because little is known about the precise criteria and conditions required for breeding these animals. This study was undertaken to gain insight into the breeding behavior of captive Chilean flamingos. A catalogue of mating rituals, nest acquisition and defense, and egg incubation behavior was obtained. The results suggest that new additions to the colony may trigger breeding in the subsequent year and that rainfall has little effect on captive reproductive success. Individually identifiable flamingos were followed throughout the breeding season and detailed quantitative data on their nesting, copulation, and social interactions were obtained. Zoo Biol 19:227–237, 2000. © 2000 Wiley-Liss, Inc.

Social attachment in giraffe: response to social separation.

Abstract: Attachment relationships between animals are often studied by separating a pair of individuals and recording their subsequent behavior. Studies of non-human primates have shown that separation results in changes that are indicative of both psychological and physiological stress. Similar results have been found in several non-primate species with differing social structures. This study examined the behavior of two female giraffe at Zoo Atlanta after the removal of the resident male. Data were collected on the giraffe before and after separation, using an instantaneous scan sampling technique to record levels of activity, social behaviors, solitary behaviors, proximity, and habitat utilization. After the removal of the resident male, both giraffe exhibited increased levels of activity, stereotypical behavior, contact behavior (particularly neck-rubbing), and decreased habitat utilization. These results are similar to those found in earlier primate separation studies, supporting the hypothesis that complex social structure is not necessary for the formation of social attachments. Because social separation is often accompanied by behavioral and physiological indications of stress, an understanding of the variables involved in a species' response to separation is vital to the promotion of the psychological and physical well-being of captive animals. Zoo Biol 19:41–51, 2000. © 2000 Wiley-Liss, Inc.

Review of a newly recognized disease of elephants caused by endotheliotropic herpesviruses

Abstract: There are two newly recognized herpesviruses that cause a fatal disease syndrome in elephants. They are known as the elephant endotheliotropic herpesviruses, of which one is fatal for Asian elephants (Elephas maximus) and the other for African elephants (Loxodonta africana) [Richman et al., Science 283:1171–1176, 1999a]. The disease syndrome affects predominantly young elephants and has been described in North America [Richman et al., J Wildl Dis 36:1–12, 2000], Europe [Richman et al., Verhandlangsbericht des 39 International Symposium uben Erkrankungen der Zoo und Wildtiere, Wien, 39:17–21, 1999b; Ossent et al., Vet Pathol 27:131–133, 1990], and Israel [Richman et al., Verhandlangsbericht des 39 International Symposium uben Erkrankungen der Zoo und Wildtiere, Wien, 39:17–21, 1999b]. The predominant clinical signs for both species include lethargy, edematous swellings of the head, neck, and thoracic limbs, oral ulceration, cyanosis of the tongue, and death of most elephants in 1–7 days [Richman et al., J Wildl Dis 36:1–12, 2000]. Three affected young Asian elephants recovered after a 3–4-week course of therapy with the anti-herpesvirus drug famciclovir [Richman et al., J Wildl Dis 36:1–12, 2000; Schmitt and Hardy, J Elephant Managers Assoc 9:103–4, 1998]. Additional reported herpesvirus-associated lesions in otherwise healthy elephants include localized skin papillomas in African elephants [Richman et al., Science 283:1171–1176, 1999a; Jacobson et al., J Am Vet Med Assoc 189:1075–8, 1986], proliferative vulval lymphoid patches in African elephants [Richman et al., Science 283:1171–1176, 1999a; Munson et al., J Zoo Wildl Med 26:353–8, 1995], and pulmonary nodules in African elephants [Richman et al., J Wildl Dis 36:1–12, 2000; McCulley et al., Onderstepoort J Vet Res 38:225–236, 1971]. Recent findings suggest that these localized herpesvirus-associated lesions in healthy African elephants may be one source of the herpesvirus that causes disseminated disease and death in the Asian species [Richman et al., Science 283:1171–1176, 1999a] and the African species [Richman et al., J Wildl Dis 36:1–12, 2000]. These findings have implications for management practices in facilities keeping both African and Asian elephants and in protecting natural elephant habitats from virulent forms of the virus. Zoo Biol 19:383–392, 2000. © 2000 Wiley-Liss, Inc.

Blood values in wild and captive Komodo dragons (Varanus komodoensis).

Abstract: The Komodo dragon (Varanus komodoensis) is the largest living lizard and occupies a range smaller than that of any other large carnivore in the world. Samples from 33 free-ranging animals at five localities in Komodo National Park, Indonesia were evaluated to assess underlying health problems. To build a comparative database, samples from 44 Komodo dragons in both Indonesian and U.S. zoos were also analyzed. Tests performed included complete blood counts, clinical chemistry profiles, vitamin A, D(3), and E analyses, mineral levels, and screening for chlorinated pesticides or other toxins in wild specimens. Blood samples from wild dragons were positive for hemogregarines, whereas captive specimens were all negative. Total white blood cell counts were consistently higher in captive Komodo dragons than in wild specimens. Reference intervals were established for some chemistry analytes, and values obtained from different groups were compared. Vitamin A and E ranges were established. Vitamin D(3) levels were significantly different in Komodo dragons kept in captive, indoor exhibits versus those with daily ultraviolet-B exposure, whether captive or wild specimens. Corrective measures such as ultraviolet-permeable skylights, direct sunlight exposure, and self-ballasted mercury vapor ultraviolet lamps increased vitamin D(3) concentrations in four dragons to levels comparable with wild specimens. Toxicology results were negative except for background-level chlorinated pesticide residues. The results indicate no notable medical, nutritional, or toxic problems in the wild Komodo dragon population. Problems in captive specimens may relate to, and can be corrected by, husbandry measures such as regular ultraviolet-B exposure. Zoo Biol 19:495-509, 2000. Copyright 2000 Wiley-Liss, Inc.

Feed intake, diet utilization, and composition of browses consumed by the Sumatran rhino (Dicerorhinus sumatrensis) in a North American zoo

Abstract: The Sumatran rhino (Dicerorhinus sumatrensis), presently indigenous to the Malay peninsula and the islands of Sumatra and Borneo, is faced with extinction. It is estimated that fewer than 400 individuals still exist in the wild. In response, concerted efforts have been made to maintain and breed this species in captivity, and proper diet and nutrition underlie reproduction. The present feeding trial characterizes a diet fed to three Sumatran rhinos at the Cincinnati Zoo and Botanical Garden. The diet consists of mixed alfalfa/orchard grass hay, a variety of browses, grain pellets, produce (apples and bananas), and a vitamin E supplement. All three rhinos maintained body weight (614–761 kg), regular patterns of bowel movements, and fecal consistency and composition throughout the three 5-day trials. Dry matter intake (DMI) ranged from 1.40 to 2.49% of body mass. Browse contributed by far the majority of nutrients to the diets in this study, from 62 to 83% of DMI. The nutrient composition of six species of subtropically grown browses (two from differing locations, for a total of eight browses characterized) showed that leaves did not differ from twigs in water or lignin content, but leaves contained higher concentrations of protein (both crude and bound) and ash, as well as lower fiber fractions. Of the macrominerals analyzed, only phosphorus differed between leaves and twigs, with twigs containing significantly more. No differences were seen between leaves and twigs in iron, molybdenum, or zinc content, but leaves contained lower concentrations of copper and higher concentrations of manganese and selenium compared with twigs from the same plants. Dry matter digestibility averaged approximately 50%. The only overt imbalances detected when comparing rhino diets with nutrient recommendations for domestic equids were excess calcium relative to phosphorus intake and low copper intake. These data, combined with information on native browse composition, intake, and digestibility, should greatly assist in providing suitable diets for this highly endangered species. Zoo Biol 19:169–180, 2000. © 2000 Wiley-Liss, Inc.

A method for encouraging maternal care in the giant panda

Abstract: We developed a method to facilitate maternal care in a giant panda (Ailuropoda melanoleuca) female that rejected her cub immediately after parturition. After removal of the cub, the female was systematically exposed to a regime of infant-related stimuli, including a surrogate toy panda, accompanied by infant vocalizations and urine, and the mother's own milk. The female displayed several measures of maternal behavior toward the surrogate, for example, spending 61% of her time holding the surrogate in positions typical for the species. There was some evidence that maternal proficiency increased across the 4 weeks of the experiment. Results also indicate that the female was responsive to both infant vocalizations and urine, but not milk. After a transitional period in which we assisted the female in her efforts to nurse and groom the infant, all maternal care-giving responsibilities were returned to the mother. Over the next 3 months, the pattern of maternal care followed the species-typical course of declining mother-infant contact, grooming, overall interaction time, and responsiveness to the cub's vocalizations. This study marks the first successful reunification of a giant panda mother with an infant separated at birth and, it is hoped, will serve as a model for similar efforts elsewhere. Zoo Biol 19:53–63, 2000. © 2000 Wiley-Liss, Inc.

Seasonal energy utilization in bamboo by the red panda (Ailurus fulgens)

Abstract: Seasonal energy intake and digestion of bamboo by red pandas were measured in energy balance trials at the field station at an altitude of 3,100 m in Yele Natural Reserve, Mianning County of Sichuan Province, Peoples Republic of China. Two-week trials were conducted at monthly intervals by feeding animals with only natural bamboo browse, Bashania spanostachya, from May to November 1995. Results demonstrated that energy intake, digestible energy, and digestibility differed significantly among seasons and diets. Energy digestibilities were high in summer-autumn, intermediate in spring, and low in winter. These variations correlated positively with the nutrient contents of bamboo. The daily metabolic energy requirement measured varied from 2,603.3 kJ in the spring to 3,139.8 kJ in the summer-autumn to 2,740.8 kJ in the winter. The results also showed that shoots were more easily digested than leaves and exhibited the highest digestibility. Restricted by the capacity of digestive tracts, red pandas poorly utilized the energy provided by bamboo as indicated by the lower energy digestibility (averaging 26.47% for leaves and 44.08% for shoots among the seasons). To fulfill their daily energy requirements, red pandas ingested a large amount of energy from bamboo leaves, which varied from 10,145.8 kJ in the spring, 12,045.1 kJ in the summer-autumn, and 12,276.9 kJ in the winter to maximize the rate of energy intake. Zoo Biol 19:27–33, 2000. © 2000 Wiley-Liss, Inc.

Maracas for Macaca? Evaluation of three potential enrichment objects in two species of zoo-housed macaques.

Abstract: One group each of Barbary macaques and stump-tailed macaques, both zoo-housed, received hard replica fruits in three experimental conditions: as empty (“unresponsive”) objects, as maracas that rattled when manipulated (“simple responsive”), and as objects from which food items could be extracted (“foraging devices”). Both groups manipulated the replica fruits most when they functioned as foraging devices, and responsiveness tended to decrease within sessions in all conditions. Thus, objects that increased the animals' sense of control in addition to providing food rewards appeared particularly suitable as enrichment devices, although novelty and indirect behavioral effects point to the need for thorough evaluation of enrichment interventions. Zoo Biol 19:181–191, 2000. © 2000 Wiley-Liss, Inc.