Zoo Biology最新文献

Human interference reduces wild felid populations. Somatic cell nuclear transfer and the use of induced pluripotent stem cells are potential conservation strategies. To improve the efficiency of these strategies, it is essential to establish adequate protocols for the synchronization of cells in the G₀/G₁ phase of the cell cycle. Cell cycle synchronization can arrest cell cycle progression by inhibiting factors involved in cell duplication. However, this step varies among wild felids and has not been successful in some species. In addition, the effect of this step on cell applications remains unclear. Therefore, this review highlights the primary differences among wild felids that can cause this variability, the most promising results, and the methods used. Finally, the importance of cell cycle synchronization in biotechnologies involving the nuclear reprogramming of somatic cells in wild felid conservation is highlighted.

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.

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.

Southern Ground-hornbills (SGHs) are listed as Vulnerable globally, and Endangered in South Africa, Namibia and Swaziland, due to poisoning, habitat loss and persecution. Successful conservation breeding and rearing of redundant second-hatched chick protocol has been established to supplement natural SGH populations in an attempt mitigate a declining population. However, captive rearing is costly and susceptible to loss of birds through conspecific aggression. Maximising the efficacy of reproductive output in captive settings and ensuring successful reintroductions of captive-reared birds to wild populations is of paramount importance if this species is to persist. Therefore, it is important to untangle the predictors of what drives mortalities in captive birds, particularly, through conspecific aggression. Using a database of captive SGH mortalities collected over 46 years we investigated whether variables such as season, age, relatedness, sex and husbandry predicted the occurrence of conspecific aggression in SGH. Aggression among adult, non-related birds particularly during SGH breeding season (austral spring) was the most predictable form of conspecific aggression. It was inferred that aggression is normally directed at non-related birds outside of already established social groups or at younger, related birds that are not dispersing from groups when reaching sexual maturity. Variables such as season, age, relatedness and husbandry were therefore all useful for predicting the potential and avoidable occurrence of an aggression event. Male birds were most often the aggressors. Making use of such variables to manage birds in a captive setting, move birds before sexual maturity and maintaining birds in known and accepted social structures could greatly improve management in SGH breeding facilities and optimise the efforts for re-establishing natural SGH populations.

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 shell of crocodilian eggs is highly fragile, especially during the early stages of development, making them susceptible to cracking during laying or collection, often resulting in embryo mortality. While numerous studies have explored various techniques for artificially incubating eggs to improve hatching success, particularly concerning issues with eggshells, there is limited information available on this topic for crocodilians. The objective of this research was to assess the hatching and survival success of cracked eggs using the windowing method and ex ovo incubation of Caiman latirostris (C. latirostris) embryos in a culture vessel. We used fertile eggs with cracked shells for the windowing eggs (WE) and ex ovo incubation (EE) treatments, and fertile noncracked eggs shell as control treatment. To ensure contamination-free incubation, all eggs were cleaned with alcohol. In the WE treatment, an eggshell section was removed, while in the EE treatment, embryos were removed from the eggshells. Each treatment was incubated in a culture vessel containing an aqueous antimicrobial solution at 31 ± 1°C. After 38 days of incubation in the culture vessel, the hatching success rates were as follows: 66.67% for WE, 0% for EE, and 100% for the control. Subsequently, the survival of hatchlings from the WE and control groups was 100%. The results suggest that incubation in artificial culture vessels enhances the viability and hatching success of C. latirostris cracked eggs. It works as an effective antimicrobial barrier maintaining sterile conditions and does not interfere with embryonic development. Moreover, the WE method offers unique possibilities for the monitoring of developmental studies and other manipulations of crocodilian embryos. However, the EE method is not advisable, as it does not reproduce the conditions inside the egg.

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.

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.

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.

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.