Zoo Biology最新文献

Territorial advertising in lions involves a suite of behaviors such as patrolling, scent marking, spraying, and vocalizing. In their native tropical habitat, wild lions are primarily nocturnal, capitalizing on cooler temperatures and darkness for effective hunting and minimizing thermoregulation stress. By extension, their territorial behaviors, notably the striking vocal advertising known as "roaring," are predominantly nocturnal. However, atypical diurnal territorial activity has been reported for captive lions in some captive settings, including Fota Wildlife Park (FWP) in Ireland. This study investigates the influence of seasonal weather conditions on the temporal distribution patterns of territorial vocalizations by a pride of captive Asiatic lions living at high latitudes in FWP, where extended audio recordings were regularly made from mid-summer to mid-winter 2021. Consistent with typical behaviors of their wild counterparts in the tropics, the captive lions at FWP exhibited persistent crepuscular peaks of roaring activity throughout the study. However, as the seasons passed, these peaks of roaring activity immediately after sunset and, to a lesser extent, just before dawn clearly followed the substantial seasonal changes in the timing of these two daily synchronizing stimuli at such high latitude. While most roaring activity occurred during the hours of darkness, consistent with prior observations at FWP during the winter, they nevertheless also roared at all hours of the day throughout all seasons, including the summer months. Persistent daytime territorial vocalizations in captive settings are therefore probably more likely related to environmental factors other than cool weather in this temperate captive setting.

A zoo-housed male Francois langur (Trachypithecus francoisi) displayed frequent territorial behaviors toward visitors, generating concern he may be experiencing negative visitor effects. After visual and physical barriers were unsuccessful at reducing these behaviors, he was prescribed anxiolytic medication. Our objective was to understand the effects of visitors on this male after reaching a therapeutic dose of anxiolytic medication. We analyzed effects of visitor presence (whether the exhibit was open or closed to the public) and number (weekdays vs. weekends, gate count). Behavior and physiological biomarkers were analyzed using linear and generalized linear models, respectively. Behaviors included time spent engaged in vigilance as well as rates of fast locomotion displays, leaping-and-hitting the barrier, grimacing, and rough scratching. Biomarkers included cortisol, dehydroepiandrosterone-sulfate (DHEA-S), the cortisol/DHEA-S ratio, testosterone, and immunoglobulin A (IgA). The langur performed more leap-and-hit barrier when the exhibit was open (β = 0.750, SE = 0.282, p = 0.013), on weekends (β = 0.618, SE = 0.277, p = 0.034), and with higher gate counts (β < 0.001, SE < 0.001, p = 0.004). Initially positive associations between rough scratching and visitor number were not significant when accounting for temperature. Cortisol/DHEA-S ratios trended toward significantly lower when the exhibit was open and IgA showed evidence of a potential dither effect, although the latter is ambiguous. No other behaviors or biomarkers were associated with visitor-related variables. We also compared behavior and physiology before and during anxiolytic medication as well as relationships between behaviors and biomarkers. Taken together, the balance of visitor effects appears neutral. Furthermore, considering other evidence, the langur does not appear to have diminished well-being.

Leatherback sea turtles (Dermochelys coriacea) have been successfully housed in captive conditions for over 1 year while receiving a gelatin-based artificial diet. However, the levels of gelatin in the feed formulations for this species were not optimized. Here, 2-month-old juvenile leatherback sea turtles (n = 3 per treatment, 393-394 g initial weight) were given feed formulations containing 2%, 4%, and 6% of gelatin by weight (designated 2G, 4G, and 6G, respectively). Survival, growth, and feed utilization of head-started leatherback sea turtles were monitored for 8 weeks. Nonlethal techniques were used to assess nutrient availability (fecal digestive enzyme activities and fecal thermal properties) and health status (carapace elemental composition and hematological parameters). No mortality was observed during the feeding trial of leatherback sea turtles. Significant improvements (p < 0.05) in growth and feed utilization were observed in the 4G and 6G groups. The quadratic polynomial equation predicts that the levels of dietary gelatin that promote growth and feed utilization were 4.53% (r = 0.8774, n = 9) and 4.77% (r = 0.9474, n = 9), respectively. Turtles in the 4G group had the highest activities of fecal pepsin and lipase (p < 0.05) while other digestive enzyme activities were maintained (trypsin, chymotrypsin, and amylase). Also, this group of turtles showed better nutrient bioavailability, as evidenced by the peaks and thermal characteristics observed in thermograms of fecal matter. No adverse effects of dietary gelatin were observed on carapace elemental composition and hematological parameters (p > 0.05). Findings from the current report provide a practical feed formulation for head-starting leatherback sea turtles, and for zoo or aquarium programs.

Research on positive animal welfare has prompted exploration and implementation of methods to stimulate the behavioral repertoires of zoo-housed species. We investigated the impact of a modified feeding method on the behavioral diversity, activity budgets, and social relations of five African lions at Zoo Antwerpen. The original method involved daily individual feedings indoors while the modified method provided group feedings three times a week outdoors. Observations spanned 6 weeks (3 weeks per method and a 1-week habituation period in between), yielding 150 h of behavioral data using continuous focal sampling. Results indicated a significant increase in behavioral diversity with the modified method across all observed time (p < 0.001). This was accompanied by an increase in active (for females, p < 0.001) and exploratory behaviors (p < 0.001). Time spent feeding did not change significantly. Inactivity levels shifted (p < 0.001), aligning more closely with natural wild lion behavior patterns. In the modified method, lions spent more time feeding and exploring on feeding days compared to fasting days (p < 0.001 and p = 0.009). Inactivity was lower on feeding days (p = 0.001), while overall activity levels did not change significantly. Social network analyses showed no significant changes in agonistic or affiliative behaviors, indicating the feeding method change had limited effects on social relations. In conclusion, our study underscores the importance of feeding methods in promoting natural behaviors and enhancing welfare outcomes for zoo-housed African lions, emphasizing the need for tailored management strategies to support natural behaviors and welfare.

Zoos fill an important role in connecting humans with nature, especially given an increasing rate of both urbanization and biodiversity loss. With the advent of new technologies, however, there are many alternatives to experiencing biodiversity firsthand. We tested if the type of animal encounter at a zoo (in-person animal viewing without touch, in-person animal viewing with touch, or video-recorded animal viewing) and/or animal species (elephant or stingray) affected zoo visitor knowledge, emotional affect, empathic concern, and/or conservation intent. A total of 300 zoo members were randomly assigned to 6 different animal encounter conditions. We found that participants who viewed video-recordings of animals had significantly lower scores on all outcomes, except knowledge, than those who viewed animals in-person. There were no significant differences between in-person animal viewing without touch and in-person animal viewing with touch. Moreover, we found that stingray participants had lower scores on all outcomes compared to elephant participants. We suggest extensions of this study and discuss potential implications for the future role of zoos.

Foot and hoof problems are one of the most common health concerns for giraffes (Giraffa camelopardalis) held in captivity. However, very limited information is available on the foot pathology for free-roaming giraffes. A free-roaming giraffe (Giraffa camelopardalis giraffa) situated within a small Free State game reserve presented with limping, and provided a unique opportunity to examine and treat the apparent foot injury. After being sedated and restrained, radiographs were taken in the field. A lateral fracture was diagnosed in the proximal pastern bone of the right front leg of the giraffe. Hoof trimming was used in an attempt to provide treatment and relief to the animal's gait and appearance. The occurrence and treatment of this hoof injury could provide insight on similar pathology in zoo environments.

Species recovery efforts may require establishment of ex situ populations to supply augmentation or reintroduction projects. The Eastern Massasauga (Sistrurus catenatus) is a small rattlesnake with an ex situ breeding program maintained by a consortium of conservation breeding centres. Small population size in human care has restricted the supply of animals for in situ conservation, thus, the development of improved ex situ breeding protocols was recommended. The objectives of our retrospective study were to (1) describe and compare reproductive traits between two groups of Massasauga litters born in human care: wild-bred litters (i.e., conceived in the wild) and zoo-bred litters, (2) test for factors associated with improved reproductive output in zoo-bred litters, and, (3) make recommendations for standardizing ex situ breeding protocols. Data were collected on Massasauga birth events that occurred from 2000 to 2020 at 13 North American zoos and partner facilities. Six outcomes related to litter size and survival of offspring were compared between zoo-bred (n = 43) and wild-bred litters (n = 51). Odds ratios were used to test for correlations between nine predictor variables and four response variables in zoo-bred litters. We found higher mean litter size and number of live young per litter in wild-bred litters (12 and 10, respectively) compared to zoo-bred litters (6 and 2). Wild-bred litters more often contained live young and less often contained unfertilized ova (98% and 34% of litters, respectively) than did zoo-bred litters (58% and 81%). Experimentation on the effectiveness of alternative mating practices is warranted to improve reproductive output in human care, thereby increasing capacity to support in situ conservation.

The Pickersgill's reed frog, Hyperolius pickersgilli (Raw 1982), is an Endangered frog species endemic to a narrow central coastal region of KwaZulu-Natal, South Africa. The Johannesburg Zoo's Amphibian Research Project breeds H. pickersgilli for release to the wild. This study aimed to determine if hatching plasticity occurs in this species in relation to direct disturbance of clutches by water spray, misting the containers housing the clutches to maintain the relative humidity above 75% is essential husbandry. Several clutches were assigned to either an undisturbed group or a disturbed group. Tadpoles from clutches mist-sprayed with reverse osmosis water on day 4 after oviposition hatched at a younger age than from undisturbed clutches. The disturbed H. pickersgilli tadpoles began hatching on average 10 s after the introduced disturbance on day 4 from the point of being laid, when the tadpoles were at Gosner stage 21 and still had yoke sacs attached, whereas the undisturbed developing embryos hatched at 6.6 days on average at Gosner stage 21 but when many of the tadpoles did not have yoke sacs attached. The proportion of the embryos that hatched did not differ significantly between the undisturbed clutches and the disturbed clutches. Tadpoles hatching from H. pickersgilli clutches with no direct disturbance had a greater survival rate at 30 days after hatching and therefore an increased likelihood of survival than tadpoles from disturbed clutches. Maintaining clutches undisturbed by essential husbandry methods is preferable in H. pickersgilli ex situ breeding programs.

Understanding the factors that structure animal microbiomes across different species and environments is increasingly valuable to wildlife care and conservation efforts. Diet is a well-established driver of gut microbiome structure and function, and formulating nutritionally balanced diets is vital to ex situ animal care and management. Prebiotic dietary items can promote beneficial microbial communities in the guts of ex situ wildlife. Animal fibers (skin, hair, and connective tissue) can act as prebiotics for carnivores, influencing gut microbiome structure and function. Social interactions and differing environmental exposures can further shape animal microbiomes, with evidence of group and environmental signatures in the microbiomes of some social species. To test for respective patterns of diet and social group, we used 16S rRNA sequencing to track the gut microbiomes of two groups of African painted dogs (Lycaon pictus) housed at the Cincinnati Zoo & Botanical Garden. The diet of one group was shifted to include increased whole prey (e.g., rabbits), representing an uptick in animal fiber intake. We found that, despite both groups sharing a diverse set of core microbes, there were distinct group signatures in the dogs' microbiomes, a pattern that grew stronger over time. Furthermore, although the diversity of gut bacteria showed minimal variation between groups and over time, the overall microbial composition and the abundance of specific taxa varied significantly between groups and with increased dietary whole prey. The results of this study further demonstrate the value of zoo populations for understanding the factors that drive animal microbiome structure and highlight the influence of management decisions in shifting animal microbiomes.

Addressing the presence of stereotypies - repetitive, functionless behaviors - has been at the forefront of contemporary welfare research in zoos. Stereotypies present themselves in many different forms, dependent on the biology of a species, internal and external motivational factors, individual animals' history, and early development. In the case of giraffes, a popular and charismatic species found in zoos, stereotypies concerning the mouth and tongue - oral stereotypies - are especially prevalent. Various hypotheses have been developed in tandem with the observation of giraffe oral stereotypies, mostly surrounding their motivations pertaining to food acquisition. Such hypotheses suggest that oral stereotypies persist due to (1) unfulfilled natural feeding behaviors, (2) nutritional and behavioral discrepancies in food presentation, and/or (3) an imbalance between concentrate grain and dietary fiber. Findings from recent literature suggest that the implementation of complex feeders, increased browse allotment, and a diet that is overall more closely representative of what wild giraffes receive has helped to decrease instances of oral stereotypy. An integrative approach employing each of these hypotheses is recommended to address the multifaceted mechanisms that may underly giraffe oral stereotypy. The most recent studies in this area have already begun to incorporate such approaches, and future studies would benefit from the continued consideration of multiple motivational factors when addressing oral stereotypy in zoo-housed giraffes.