Zoo Biology最新文献

Little is known about the reproductive biology of the endangered spinetail devil ray (Mobula mobular). Here, we describe the reproductive behavior, estimates of age, size at maturity, embryonic development in the uterine cavity, and the morphology of a neonate produced by a male and female ray kept in Osaka Aquarium KAIYUKAN for 7.5 years. The reproductive behaviors observed included initiation, endurance, evasion, pre-copulation positioning, copulation, and separation. The disc widths (DW) of male and female rays displaying reproductive behaviors were 203 and 204 cm, respectively. The male was estimated to be 7.7 years old after elongation of claspers, while the female was estimated to be 8.9 years old at first mating. A neonate was born 464 days after successful copulation, weighing 11.32 kg, with a DW of 104 cm. These observations are consistent with those of previous studies conducted on wild individuals. This is one of the few reports on the reproductive behavior of spinetail devil ray. Research conducted on this species in captivity is expected to help fill the knowledge gaps for this poorly studied species.

A zoo-based, 11-year-old, uniparous southern black rhinoceros (Diceros bicornis minor) failed to conceive after weaning a calf. Behavioral observation and fecal progestagen monitoring confirmed irregular estrous cycles. Serial transrectal reproductive ultrasound examination revealed the cause to be recurrent anovulatory hemorrhagic follicles (AHFs). After four consecutive abnormal cycles dominated by AHFs, rational hormone therapy was implemented. Injectable prostaglandins, progesterone, estradiol, and a GnRH analog were given strategically to disrupt AHFs, boost normal estrus behavior, and promote ovulation. Oxytocin was added to the treatment regimen when transient accumulations of intraluminal uterine fluid consistent with endometritis were observed ultrasonographically. Oral diazepam was given judiciously for anxiolysis after the animal developed an aversion to injection. Treatment, which proceeded over eight cycles, was eventually associated with the restoration of normal behavioral estrus and ovulation. The rhinoceros conceived after natural mating and induced ovulation, delivering a healthy calf 490 days later, the longest reported gestation for the species.

The Sichuan golden snub-nosed monkey (Rhinopithecus roxellana) is a rare and endangered species endemic to China that occupies a particularly important position in the evolutionary history of Rhinopithecus species. Oral health is a crucial aspect of overall well-being in both humans and nonhuman primates. We review the current limited literature on the dental characteristics and dental pathologies related to the golden snub-nosed monkey, based on skeleton data and morphological evidence. The results indicated that this species possesses dental characteristics that are remarkably different from that of other primates such as larger-sized molars with blunt cusp crests, tiny incisor teeth, and strong mandibles with well-developed masticatory muscles. From limited research, dental diseases include caries, periodontal diseases, tooth loss, tooth wear, and other diseases, which can be found in most primates, including golden snub-nosed monkeys. In conclusion, these physiological features have gradually adapted to different environments to meet the requirements of their function. Understanding the tooth characteristics and dental health status of R. roxellana can provide valuable insights into their evolutionary history, dietary habits, and overall health, which is of great significance for the conservation of the entire population. An epidemiological survey and safe and effective inspection methods of the dental health of golden snub-nosed monkeys should be conducted to facilitate conservation behaviors that presented in the future. It is also recommended that zoos link diet and dental health to improve animal welfare.

The global decline of species necessitates intensive conservation efforts, including ex-situ breeding programs to safeguard endangered populations. However, managing welfare and reproduction in zoological gardens can present several challenges. This study aims to explore behaviors and endocrinological responses of two specimens of fossa (Cryptoprocta ferox) under human care. One hundred and twenty hours of observation through focal animal sampling continuous recording and 67 fecal samples were collected. From fecal samples, cortisol (FCM), progesterone (FPM), and testosterone (FTM) metabolites' concentrations were analyzed using Radio Immuno Assay. According to our results, higher FTM (p < 0.05) and FPM levels at the beginning of the study, showing a potential alignment with the breeding season. When the male entered the female outdoor area, he recorded longer durations of seeking and marking behaviors (p ≤ 0.01), along with lower FCM levels (p < 0.05), suggesting an enriching effect. In the same period, the female's FCM level was higher (p ≤ 0.01), indicating potential stress. When both animals were in their respective outdoor areas, the FCM level of the female remained significantly higher (p < 0.05), and the male showed a peak in pacing duration (p < 0.01), implying a potential stress or frustration status. In her indoor area, the female exhibited significantly shorter durations of locomotion, marking, and seeking (p < 0.01) and did not show any abnormal behavior, likely due to the reduced complexity of the environment. However, we cannot exclude that her complete visual and olfactory separation from the male and visitors may also have contributed to a decrease in her overall stress levels. The findings highlight the interplay between hormonal fluctuations and behavioral responses in the two zoo-housed fossa, providing essential insights for fostering their well-being and facilitating conservation efforts.

Regurgitation and reingestion (R/R) and coprophagy are common behaviors exhibited by primates living in human care. To reduce this undesirable behavior in two troops of western lowland gorillas (Gorilla gorilla gorilla), the diet was modified by increasing fiber (by increasing browse) and decreasing starch (by reducing but not eliminating biscuits). We monitored behavior before, 3 weeks after, and 1 year after the diet change. One year after the diet change, the family group's diet was modified by adding more fruit to facilitate training. We documented significantly increased feeding activity for both troops, with time spent feeding doubling for one troop. Some individuals initially increased R/R or coprophagy behaviors but these increases were not significant, and 1 year after the diet change R/R was significantly reduced in the silverback male who had been known to exhibit R/R up to multiple times per day. In the family troop, coprophagy later decreased when animals were reunited and spent more time outdoors (for reasons unrelated to the diet change study), but this was not significant. This is the first published study to assess the behavioral effects of a high-fiber, low-starch diet on gorillas one full year after the diet change was made, and we demonstrated that the diet continued to positively impact some individuals' behavior. We discuss implications of our findings and suggest future directions for institutions that seek to reduce these behaviors in primates without necessarily completely eliminating biscuits from their diets.

Browsers are animals that consume significant proportions of leaves, twigs, and bark from woody plants. These species have evolved morphological, physiological, and behavioral adaptations to subsist on a specialized diet. In zoos and other managed care facilities, the provision of browse in appropriate amounts helps promote positive animal welfare. Feeding on browse fulfills behavioral needs and reduces stereotypies, promotes satiety, and provides opportunities for dietary choice and control. However, there are several obstacles that can prevent institutions from providing browse, including physical and chemical hazards, palatability issues, and the difficulty in quantifying the nutritional value of browse. In addition, providing large enough quantities of browse can be challenging, and fresh browse may be especially difficult to provide for zoos in temperate climates. We describe the methods currently utilized to preserve browse and discuss their strengths and weaknesses. We recommend areas of future research for browse provision in zoos.

Molecular genetic analyses are effective in revealing the origin, kinship, and genetic diversity of zoo animals. In this study, we carried out the genetic characterization of captive founder individuals of the South American fur seal (Arctocephalus australis) in Japanese zoos and aquariums based on analyses of mitochondrial sequences and nuclear microsatellite loci. In mitochondrial DNA analysis, the haplotype diversity and nucleotide diversity of the overall population were 0.8949 and 0.0119, respectively. Microsatellite DNA analysis revealed that the observed heterozygosity within the overall population was 0.722. In addition, we did not detect genetic bottlenecks. The results from two kinds of DNA analyses indicated that the genetic diversity in this captive population was equivalent to that previously reported in wild populations. The detected mitochondrial haplotypes were the same as or phylogenetically close to those previously reported in wild populations in southern Brazil, Uruguay, Argentina, and southern Chile but diverged from those previously reported in a wild population in Peru. Genetic clustering analyses using microsatellite genotypes revealed that no clear genetic structures in this captive population.

Providing nutritionally balanced diets is a key aspect of successful husbandry and can help support sustainable ex situ populations. This study focuses on the diets of zoo-housed colobus monkeys (Colobus angolensis and C. guereza) and langurs (Trachypithecus cristatus and T. francoisi) across AZA institutions. We utilized survey responses from 34 institutions to (1) document the extent of dietary variation with regard to food categories and macronutrients offered, (2) assess interspecific variation in diets offered, and (3) identify important aspects of browse provisioning among institutions. A total of 95 different food items and 229 common-name browse types were offered across institutions. Leafy greens was the only food category offered at every institution. The proportion of root and non-root vegetables in the diet was highly variable. Nonstructural carbohydrates were the most variable macronutrient, and their concentrations were considerably higher than those food items consumed by free-ranging colobines. Conversely, neutral detergent fiber and acid detergent fiber contents were more consistent across institutions but were notably lower than those of free-ranging colobine food items. There were no significant interspecific differences in diets with regard to food categories or macronutrients offered. There was substantial variation in how frequently browse was offered, how it was regarded across zoos (either as diet, enrichment, or both), and whether or how it was quantified. This study provides context for future studies examining whether and how diet and macronutrient intake impact the behavior, health, and welfare of these populations.

Ozark hellbender (Cryptobranchus alleganiensis bishopi, Grobman 1943) populations in Missouri and Arkansas have been federally listed as endangered since 2011. As part of the comprehensive recovery plan for the subspecies, the Saint Louis Zoo WildCare Institute's Ron and Karen Goellner Center for Hellbender Conservation, in collaboration with the Missouri Department of Conservation, Arkansas Game and Fish Commission, and the U.S. Fish and Wildlife Service, established a conservation breeding and head-starting program to augment and create self-sustaining wild populations. We examined how the river of origin and egg origin (i.e., Zoo-bred or wild-bred) influenced various growth and mortality responses of Zoo-reared Ozark hellbenders. River of origin significantly predicted most larval and long-term Zoo-reared Ozark hellbender growth responses, with our results concurring with observed differences in wild populations and known genetic relationships between Ozark hellbender populations. Mortality of Zoo-reared Ozark hellbenders was often predicted by river of origin and egg origin with Zoo-bred hellbenders having significantly higher proportional mortality responses relative to wild-bred hellbenders. Further exploration of this egg origin relationship revealed differences between the Zoo breeding group generations with higher proportional mortality rates for hellbenders from the less mature second-generation breeding group relative to hellbenders from the first-generation breeding group and wild-bred hellbenders. Ultimately, our results provide baseline data on Zoo-bred and wild-bred Ozark hellbenders in the program, help identify differences in growth and mortality responses between Ozark hellbender populations, and contribute to existing evidence supporting distinct populations of Ozark hellbenders in Missouri to aid in targeted conservation strategies.

Populations of Ozark hellbenders (Cryptobranchus alleganiensis bishopi, Grobman 1943) in Missouri and Arkansas are federally listed as endangered. The Saint Louis Zoo WildCare Institute's Ron and Karen Goellner Center for Hellbender Conservation, in collaboration with the Missouri Department of Conservation and US Fish and Wildlife Service, has developed a sustainable conservation breeding and head-starting program, a priority for species recovery. Using 9 years of program data, we examined various egg production, egg development, and mortality responses of Zoo-bred Ozark hellbenders. Our results identified river of origin and breeding location as important predictors of egg production responses including average breeding female total lengths as well as brooding male clutch size, total egg count, and the estimated number of female clutches, respectively. We found that breeding group generation was a significant predictor of Zoo-bred hellbender egg development responses with hellbenders from the first breeding group generation ovipositing later and producing eggs that hatch later and develop longer than hellbenders from the second-generation breeding group. These responses are consistent with females from the first breeding group generation being larger at the time of reproduction. Breeding group generation was also a significant predictor of proportional egg and total mortality, while the proportion of hatchling mortality was best predicted by breeding location, and the proportion of larval mortality was best predicted by river of origin. Ultimately, our results provide baseline metrics for the program and identify areas for further inquiry to maximize the success of future conservation breeding and head-starting efforts at the Zoo.