Zoo Biology最新文献

While there is no consensus about whether insects are sentient, the possibility alone raises an important question for zoos and aquariums. What ethical responsibilities, if any, do zoos and aquariums have concerning their feeder insects? There has been very little scholarly discussion of these questions. This is not surprising, as scholars have largely ignored feeder animals. So, this paper takes up two tasks. First, it surveys the main welfare-focused ethical questions associated with feeder animals generally and feeder insects in particular. The aim here is to identify the main considerations that bear on a full assessment of the ethics of using feeder animals as a resource, thereby facilitating future research. Second, in the interest of making practical recommendations in the face of significant moral complexity and uncertainty, this paper adopts a standard institutional ethical framework-the 3Rs-and considers its implications for the use of feeder insects.

Welfare audits that contain behavior and enclosure use assessments are commonly used in zoos and aquaria. However, the two components are often used separately from one another, and many enclosure use studies are limited by analytical problems, despite the fact that enclosure use indices such as Entropy, modified Spread of Participation Index, and Electivity Index are available. The dawning of behavior monitoring apps has facilitated zoo behavioral research, but some of the original challenges experienced when analyzing enclosure use remain. There is a need, therefore, to make enclosure use indices compatible with modern behavior recording apps, and to provide ways in which behavior and space use can be analyzed together. ZooMonitor, a behavior recording app created by Lincoln Park Zoo and built by Tracks Data Solutions, is frequently used by zoo researchers, and as such is a good focus for developments in enclosure use analysis. This paper introduces a new ShinyApp, entitled the Enclosure MonitoR Use (EMU). This new app uses ZooMonitor-based behavior and XY enclosure use data to evaluate animal data. The app is able to (1) provide heat maps of space use, showing where each behavior occurs, and (2) facilitate the use of enclosure use indices, whilst also generating indices for individual behaviors. These tools have the potential to identify areas that an animal finds valuable in its exhibit for specific behavior types and can be used to inform exhibit design decisions. EMU also allows researchers to look beyond the previous assumptions that an animal should use all its exhibit to experience the best welfare. In combination with ZooMonitor, this tool removes many obstacles that prevent detailed analysis of animal space use. Future developments of EMU may further facilitate animal space use studies.

The giant anteater (Myrmecophaga tridactyla) is a unique species in risk of extinction nationally and internationally due to ongoing environmental and anthropogenic pressures, therefore requiring continuous conservation efforts. Under human care, obesity and nutrition-related diseases are major concerns. Body condition scoring (BCS) is an important tool for assessing animal fitness in natural and ex situ environments. This study aims to evaluate the applicability and reliability of BCS and morphometric measures, associated with ultrasound measurements of subcutaneous fat thickness (SFT), as tools to estimate the body condition of giant anteaters. Twenty free-ranging and twenty-two zoo-kept giant anteaters were assessed. The animals were weighed and classified by BCS, followed by biometric measurements and calculations of two body condition indices-the ratio index (RI) and the condition index 2 (ICC2). Subcutaneous fat measurements were taken by ultrasound in the lumbar, hip and flank of the captive anteaters. Captive animals exhibited higher body mass, BCS, measures of forearm, thorax, abdomen, neck, femur, tibia, humerus, RI and ICC2 compared to their free-ranging counterparts. Body mass correlated positively with all parameters except SFT. BCS showed moderate to strong correlations with body mass, RI, ICC2, thoracic, and abdominal circumferences. SFT correlated with BCS. Free-ranging anteaters consistently showed moderate BCS, while captive ones ranged from lean to obese, with relevant subcutaneous fat accumulation in the flank and hip. The resulting BCS protocol for the species was considered adequate to evaluate nutritional status under both free-range and managed-care conditions.

Birds of prey are renowned for their excellent visual acuity, but they are often not given visual access consistent with their natural behavior when housed under managed care. Often, these birds are housed under managed care after sustaining injuries, which prohibits their return to the wild. In addition, many of these rescued raptors do not have the same history of acclimation to human presence as other zoo animals due to being wild-hatched. These factors lead to a potential welfare concern for raptors under managed care, which may not appropriately address their natural and individual histories. We assessed how the removal of a visual barrier (two large doors) may have affected behavior and space use of two bald eagles (Haliaeetus leucocephalus) housed at Zoo Miami. Before the visual barrier being removed, the eagles could not see people approaching their habitat from one out of two possible sides. We found that for one individual, stress behaviors such as gular fluttering significantly decreased after the removal of the visual barrier, and resting significantly increased. The birds also utilized their habitat more evenly after the visual barrier was removed and were seen at higher, more species-typical altitudes within the habitat. These findings suggest that increased environmental visual access for zoo-housed raptors may be a simple way to improve their overall welfare.

Captive-release programs are an increasingly popular conservation strategy to combat wild extinctions. However, it is critical to determine if translocating animals from captive colonies ("source populations") leads to the establishment of new wild populations that are both stable and self-sustaining. To fill this knowledge gap, we provide a case study from the dusky gopher frog (Lithobates sevosus) reintroduction program to serve as an example for other critically endangered amphibians. In this study, we provide quantitative information on the reintroduction and survivorship of zoo-bred individuals that are released into the wild. This unique opportunity is the culmination of close to 20 years of collective efforts across multiple agencies. By taking advantage of the key monitoring window shortly after initial releases, we can formally declare the first successfully reintroduced, breeding population of dusky gopher frogs founded solely from a captive-bred colony.

Previous observations of Rio Sao Francisco piranhas (Pygocentrus piraya) at Cleveland Metroparks Zoo revealed frequent aggressive interactions, which were associated with the injury and death of some individuals. Fishes are known to increase aggressive behavior when available space is limited. We compared the behavior of the piranhas longitudinally across three different space/density conditions: (1) in a group held in a small aquarium before the death of one individual, (2) in the same group after the death of one individual, (3) and in one individual of the group after it was later moved into a larger, multispecies aquarium. In the smaller aquarium, individuals maintained stable positions in the tank and remained inactive except to behave aggressively toward each other, retreat, or feed when food was offered. After the death of one individual, aggression decreased significantly but so did overall activity, including swimming behavior. After one individual was moved to a larger aquarium, it exhibited a striking increase in the amount of time spent swimming. Our data suggest that the well-being of P. piraya, and possibly other species of piranhas, might be better in large aquariums than in the small single-species exhibits often used in zoos and public aquariums. This study takes an important step in addressing the psychological and social well-being of bony fishes, an underrepresented area of research in zoos and aquariums.

Knowledge of the radiographic anatomy of rodent skulls is essential for accurately interpreting extra-oral radiographs, a non-invasive diagnostic tool commonly used in veterinary practice. Due to the complexity of the skull and the potential for distortion in two-dimensional views, a systematic evaluation of anatomical structures is necessary. This study identifies the most clinically relevant anatomical landmarks on standard extra-oral radiographic views of the skull and mandible in various rodent species, including a cane rat, two woodchucks, and seven common mole rats. Specimens were evaluated with bone and soft tissue intact, as well as dried skulls, to identify key anatomical features. The findings highlight distinct species-specific variations despite general similarities in skull structure. These landmarks were catalogued to aid veterinary professionals in interpreting rodent radiographs. Improved recognition of these structures enhances diagnostic accuracy, enabling better assessment of normal anatomy and potential pathological conditions in rodent patients.

Assessing steroid hormones through feces provides invaluable insight on the stress and reproductive physiology of wildlife, and has been broadly applied to monitor the health and welfare of wild animals managed under human care. This study utilized fecal hormone monitoring to evaluate adrenal and gonadal activity in 18 captive lions (Panthera leo) across five Spanish zoological institutions, focusing on how biological and management factors affect these metrics. We analyzed fecal glucocorticoid metabolites (FGM) concentrations and, additionally in females, fecal progesterone (FPM), estradiol (FEM), and androgen (FAM) metabolites in relation to their reproductive status. Results indicated significant variability in FGM levels among individuals, with no consistent trends influenced by sex or zoo environment, including changes in the frequency of providing environmental enrichment at two zoos. Importantly, reproductive status significantly impacted adrenal and gonadal hormone levels; ovariectomized lionesses showed lower concentrations of FGM, FPM, and FEM compared to intact and deslorelin-implanted females, the latter of which exhibited higher and more variable FAM levels. These findings advance our understanding of hormone patterns in lions and suggest implications for their management in captivity.

Captive management of endangered species is a common conservation strategy. Monitoring the endocrine response related to reproduction and the increase of fecal cortisol metabolites is key to evaluating reproductive well-being and condition. We noninvasively assessed the endocrine status of captive European minks (Mustela lutreola) housed at Foundation for Research in Ethology and Biodiversity [FIEB] (a Spanish biodiversity conservation center) by measuring fecal glucocorticoid cortisol metabolite levels and testosterone, and progesterone metabolite levels. Males showed higher fecal cortisol and testosterone metabolite levels while no differences in fecal progesterone metabolite levels were found between sexes. Fecal levels of the three hormones were positively correlated. Individuals born in FIEB had lower fecal cortisol metabolites than those born in other centers and their values did not increase due to captivity duration. Hormone values obtained in FIEB could serve as a reference for this species management. However, further studies are required to ensure the well-being and reproductive success of captive and wild populations.

This essay briefly presents the perspectives of multiple stakeholders regarding the care of captive marine mammals. Based on extant literature and professional experiences, the expectations, biases, and obstacles are described for the following perspectives: facilities, staff, guests, activists, scientists, third-party accreditations, governmental agencies, and marine mammals. All identified human stakeholders advocate for the animals, but the stakeholders have differing perspectives. The purpose of the article is to identify areas of impasse and areas of overlap to identify possible compromises to move toward a less contentious dichotomy. A summary of a recent case study involving the recently deceased killer whale, Tokitae, in managed care for 50+ years and the late-life transfer planned to return her to the Pacific Northwest provides an opportunity to illustrate the roles of each stakeholder involved. Also, several other cetacean examples are briefly summarized to illustrate the differing perspectives. Ultimately, compromises may be difficult given the disparate values and mindsets of the stakeholders. It seems that science should be allowed to weigh into this debate rather than allowing media attention, half-truths, and emotional appeals to govern policy and business models.