Zoo Biology最新文献

Zookeepers working with felids were asked to complete an online survey to examine their perceptions of animal welfare. A total of 121 zookeepers in an AZA-accredited zoo completed the survey. Results from this study suggest that institutional offerings of professional development programming in animal welfare have the greatest potential to influence zookeeper perceptions of animal welfare. Participants also identified four areas of improvement for felid welfare, including 1) larger and more dynamic spaces, 2) increased attention to behavioral husbandry, 3) more unique diet presentations, and 4) the ability for the animal to remain out of the view of the public. In addition, there appear to be differences in perception between traditionally described "small cat" and "large cat" keepers in terms of the ability to deliver the Five Freedoms.

Movements of four adult giant trevally Caranx ignobilis were tracked using passive acoustic telemetry after being released from uShaka Sea World Aquarium in Durban, South Africa, where they had been kept on display for a period of 8 years. All four individuals were detected on a large network of deployed acoustic receivers for a minimum of 3 months to a maximum of over 6 years. Their movements were compared to 43 wild-caught and tagged C. ignobilis over a similar period and two individuals adopted movement behavior similar to that of their conspecifics, including repeated annual seasonal migrations to a known spawning aggregation site. This study shows that with good animal husbandry, indigenous fish kept in captivity can be released back into the wild and not only survive but adopt natural movement behavior and contribute to future generations of their species.

Few studies have addressed the nutritional ecology of galagos. Observations of galagos in the wild reveal that they rely on fruits and invertebrates to varying degrees depending on their availability. We conducted a 6-week comparative dietary analysis of a colony of captive-housed northern greater galagos (Otolemur garnettii), which included five females and six males with known life histories. We compared two experimental diets. The first was fruit dominated and the second was invertebrate dominated. For each diet, we examined dietary intake and apparent dry matter digestibility over the course of 6 weeks. We found significant differences between the apparent digestibility of the diets, with the "invertebrate" diet being more digestible than the "frugivorous" diet. The lower apparent digestibility of the "frugivorous" diet was driven by the higher fiber contents of the fruits provided to the colony. However, variation in apparent digestibility of both diets was found among individual galagos. The experimental design used in this study may provide useful dietary data for the management of captive colonies of galagos and other strepsirrhine primates. This study may also be helpful for understanding the nutritional challenges faced by free-ranging galagos through time and across geographic space.

Magnesium chloride in high concentration is used for euthanasia of jellyfish to limit overpopulation and for predatory species consumption, but its use could lead to magnesium bioaccumulation and subsequent negative effects in consumers. Two species of scyphozoan jellyfish (Cassiopea andromeda and Aurelia aurita) were subjected to freezing (control), or magnesium chloride baths (144 g/L), with subsequent 30 min baths (one or two) in fresh artificial saltwater and submitted for inductively coupled plasma analysis to determine tissue concentration. Frozen jellyfish consistently yielded the lowest magnesium concentrations, while magnesium chloride euthanized individuals contained the highest concentrations in both species. C. andromeda displayed a significantly higher (p < .05) magnesium absorption capacity than A. aurita in both trials. Single and double baths significantly decreased magnesium concentrations (p < .05) in both species, however, magnesium remained consistently elevated compared to frozen specimens. This study demonstrated species-specific magnesium accumulation in jellyfish posteuthanasia and that rinsing was an effective method to limit excessive magnesium that could be deleterious to animals in public display aquaria. Magnesium concentrations of tissue and receiving water should be tested if magnesium chloride euthanasia is utilized for dietary supplementation in small bodies of water.

While courtship and breeding in birds is a topic of much study, behaviors of nocturnal species are difficult to observe. This study provides an ethogram and comparative analysis of relevant breeding and nonbreeding behaviors of three captive tawny frogmouth (Podargus strigoides) pairs at the Saint Louis Zoo. Infrared cameras were used to record nighttime activity, and 30 h of footage per pair were analyzed. Notable behaviors included a significant increase in nest-building activity in a pair 9-13 days before egg-laying, and a difference in the use of copulation signals between the two breeding females, with one accepting copulation attempts more readily than the other. Bill gaping behavior was determined to not be directly related to courtship. These results provide a preliminary description of tawny frogmouth behaviors during the breeding season and provide a basis on which further studies of both captive and wild tawny frogmouths can build.

To improve animal welfare based on suitable social housing conditions, it is important to understand the factors that trigger high-stress responses. Wild giraffes live in a fission-fusion society and males and females are rarely in the same herd for a long period. The captive condition of belonging to a herd with the same individuals for months or years is uncommon in nature. To understand the effect of male presence on female stress levels, fecal glucocorticoid metabolite (fGCM) levels and social interactions in two captive female giraffes were investigated. Additionally, the effect of enclosure size and temperature on fGCM level and social interactions were examined. The results showed no significant difference in the fGCM levels of females based on male presence. The frequency of agonistic behavior by the dominant female toward the subordinate female was significantly increased when a male was present. The subordinate female was significantly less likely to approach the dominant female and showed decreased affiliative and agonistic interactions toward the dominant female when a male was present. The frequencies of agonistic interactions between females were higher in the small enclosure regardless of male presence. Low temperature triggered higher fGCM levels and increased agonistic interaction in an aged female. The findings of this study suggest that these multiple factors should be considered individually to promote the welfare of captive giraffes.

The European mink (Mustela lutreola) is one of the most threatened small carnivores, listed as Critically Endangered on the IUCN Red List. Tallinn Zoo started a conservation breeding operation in 1980, which in 1992 was shaped into the European mink EEP Program to maintain a demographically and genetically healthy population in captivity. Since 2000, mink have been translocated on a yearly basis from the breeding facility in the zoo to Hiiumaa Island (Estonia) until the formation of the wild island population in 2016. Maintaining a healthy genetic structure in a captive population was a priority, so genetically the least valuable animals, according to calculations made by a population management program, were used for translocation. This study aims to assess the amount of genetic diversity passed from an ex situ population on to the island population. Comparisons of the genetic diversity were made by mitochondrial, microsatellite and nuclear markers. In addition, our results were combined with the pedigree data from the European mink EEP Studbook to further evaluate the flow of genetic diversity from the founder population to the established wild population. According to the findings, the island population's allelic richness was comparable to that of the founder population, and no evidence was found that its genetic structure had diverged from that of the founder population. It seems that the formation of the island population has been a gradual process of no more than the last seven yearly translocations.

Seed pods represent an under-utilized and valuable dietary resource for zoos because they encourage naturalistic extractive foraging behavior and because seeds pods, like leafy browses, are more fiber-rich than most dietary items typically offered in zoos. The primary goal of this study was to examine the effects of honey locust (Gleditsia triacanthos) seed pods on the behavior and macronutrient intake of zoo-housed François' langurs (Trachypithecus francoisi; n = 3) and prehensile-tailed porcupines (Coendou prehensilis; n = 2) using a pre- versus postdiet implementation design. From December 2019 to April 2020, we recorded behavior using instantaneous interval sampling and daily macronutrient intake via dietary intake records. We found that time spent feeding increased (p < .001) and stereotypic behaviors decreased (p < .001) for the François' langur group during the seed pod phase. The prehensile-tailed porcupines also exhibited increased time spent feeding and decreased inactivity (p < .001 for all comparisons) during the experimental seed pod phase. We found no differences in macronutrient intake for the François' langur group. The female prehensile-tailed porcupine consumed more neutral detergent fiber (NDF) in the seed pod phase (p = .003) and the male consumed more crude protein, NDF, nonstructural carbohydrates, and crude fat (p < .001 for all comparisons). We stress that honey locust seed pods are a fiber-rich (i.e., ~40%-55% NDF by dry weight) dietary option for zoo-housed folivores and promote positive welfare by encouraging naturalistic foraging behavior and may help increase foraging time and decrease stereotypic behaviors.

Gastric ulcers have been reported in a range of cetacean species. Bottlenose dolphins (Tursiops spp.), the most common cetacean species held in captivity, are known to experience gastric ulcers in both wild and captive environments. Documented causes of gastric ulceration include bacterial infection by Helicobacter sp., parasitic infections, high dietary histamine and foreign body ingestion. Gastric ulceration without any obvious cause might be related to stress. Currently, the most accurate way to determine the presence of gastric ulcers in captive dolphins is through direct examination of the stomach mucosa using endoscopy (gastroscopy); a procedure that requires substantial animal training and specialised medical equipment. In this study, we investigate whether cytology of the gastric fluid, collected through the less intensive method of intubation, can be used as an alternative to gastroscopy to predict the presence and severity of gastric ulcers in eight captive bottlenose dolphins at uShaka Sea World, South Africa. An ulcer grading scale was developed to quantify the severity of the dolphins' gastric ulcers observed using gastroscopy. Gastric ulcer severity was then compared with the cytological data collected from gastric fluid samples taken during the gastroscopic examinations. The cytological findings were consistent with other studies, but ulcer severity was not found to be linked to the cytological parameters measured. From these results we suggest that routine cytology of the gastric fluid is not a viable alternative to gastroscopy for diagnosing gastric ulcers in bottlenose dolphins.

The potential impact of human presence on captive animal behavior has recently been the focus of considerable research interest, especially following 2020 and 2021 periods of enforced closure as a result of COVID-19 opening restrictions. It is important to investigate whether human presence represents an enriching or stressful stimulus to a range of zoo-housed species. In 2020, during an easing of lockdown restrictions, investigations of the "visitor effect" and "observer effect" were carried out, using the giant otter (Pteronura brasiliensis) as a model species. To investigate the impact of both visitor and observer presence, otter behavior and space use was recorded for a pair of on-show and a pair of off-show otters. Observations were conducted using either a human observer, or cameras, allowing the researchers to investigate otter behavior when no one was present at the exhibits. The Electivity Index was used to assess the otters' use of four enclosure zones. Overall, otter behavior was significantly impacted by observer presence, though the impact of an observer differed between individual otters. Visitors had a minimal effect on otter enclosure use, whereas observers had a greater impact, whereby otters used their pools less frequently and houses more frequently when observers were present. However, this change in zone use differed between individuals, with more dominant otters tending to make use of indoor zones more often when observers were present. Zoos should consider the potential impact of human presence on their animals and use both behavior and space use when conducting their investigations.