Zoo Biology最新文献

There have been few published accounts of bottlenose dolphin (Tursiops truncatus) group introductions in human care and even fewer reports of signature whistle usage within this context. Here, we describe behavior and signature whistle production before, during, and after the introduction of a recently stranded and rehabilitated young male to an existing group of two adult dolphins, a male and female. Signature whistle production increased for the adult male and female, but not for the young male being introduced. Whistles were detected from each of the dolphins on the day of introduction, which is consistent with the reports involving wild dolphin signature whistle usage before intermixing.

For social animals, group living can serve to buffer against stressors. However, changes in the social environment may also represent a stressor leading to changes in glucocorticoids-hormones responsible for maintaining homeostasis under stressful conditions. We studied glucocorticoids in captive bonobos (Pan paniscus), a social species of great ape with a complex social organization. We monitored bonobos in captivity before, during, and after a change occurred in their social environment; when a new group member was introduced at the facility. We repeatedly measured individuals' cortisol (corrected for creatinine, or variation in the concentration of samples) from urine samples and found individuals of the established group did not change in cortisol during or following their introduction to a novel bonobo individual. The emigrating bonobo, however, had elevated cortisol upon arrival which decreased as she was introduced to each existing bonobo at the facility. These results suggested that the new individual may have experienced stronger stressors relative to resident individuals during this captive introduction. We recommend based on the results from this study, that social animals be introduced to new group members carefully, and to avoid prolonged social isolation for new animals. When changes in social dynamics are driven by human caretakers rather than initiated by the animals themselves, care should be taken to mimic natural dispersal patterns when possible.

Cetaceans' mammary slits, situated bilaterally to the genital slit, have been identified as an instrumental metric for the quantitative assessment of alterations in genital morphology. Increase in the intermammary distance in bottlenose dolphins (Tursiops truncatus) associate modification of the genitalia, which occurs immediately before parturition. In certain mammalian taxa, estrus phase is characterized by conspicuous swelling of the external genitalia. Consequently, this study aimed to investigate potential fluctuations in the intermammary distance in bottlenose dolphins associated with the estrus with a specific focus on discerning morphological alterations occurring concurrently during estrus. The intermammary distance was meticulously measured across seven ovulation cycles in three female dolphins. The intermammary distance was significantly longer on estrus days than on nonestrus days (p < 0.05). Furthermore, the intermammary distance displayed notable positive correlation with serum estradiol concentrations. These results support the findings that alterations in the intermammary distance are closely associated with the estrus and are indicators of concurrent morphological modifications. Conversely, positive correlations between the intermammary distance and body weight in two subjects underscore the considerable influence of alterations in body shape. Quantification of the intermammary distance represents a promising noninvasive modality for detecting estrus in bottlenose dolphins.

This pilot investigation sought to evaluate the effectiveness of water opacity as an agonism-mitigation strategy in an all-male group of Nile crocodiles (Crocodylus niloticus). Crocodile behavior was monitored over 95 observation hours, split approximately equally between transparent water and opaque water conditions. In addition to agonism rates, the crocodiles' use of water was evaluated to ensure the change in their habitat did not disrupt utilization of the water, which is an important component of their thermoregulatory processes. Agonism rates were approximately equal between the transparent and opaque water conditions. The proportion of the group in water was lower in the opaque condition though the mean difference between conditions suggests that approximately two more crocodiles (out of a group size that ranged from 21 to 18 individuals) were in water in the transparent condition than opaque condition. Overall, these findings suggest the opaque water had little to no effect on the crocodiles' behavior as measured here. However, the opaque water may have increased environmental complexity. In nature, crocodiles navigate opaque water utilizing chemosensory and integumentary sensory modalities that are likely underutilized in transparent water commonly provided to crocodilians living in human care. Further research is needed to understand how opaque water may be enriching for crocodilians.

There is a need to assess the impact of husbandry and exhibitry practices on under-studied taxa, including reptiles and amphibians, to ensure animals experience good welfare. It is common practice to house snakes in enclosures on paper substrate, particularly when off-exhibit. We investigated the impacts of substrate provision (mulch or newspaper) and associated cleaning practices on nine long-nosed viper (Vipera ammodytes meridionalis) clutch mates over a 3-year period. We assessed health parameters, food consumption, growth, fecal and shed quality, and glucocorticoids in feces and shed skin. Snakes housed on newspaper were less likely to eat, had lower fecal quality, and demonstrated higher fecal and shed glucocorticoids; no other treatment effects were observed. Male snakes had higher fecal and shed glucocorticoids, and were more likely to defecate, had higher defecation counts, and had shorter inter-defecation intervals compared to females. Enclosures with a mulch substrate were significantly more humid than those with a newspaper substrate; enclosure temperature did not vary with substrate. We suggest differences in snakes by treatment are due to a combination of lower humidity offered by newspaper substrate and more frequent changing of newspaper substrate, which depletes the scent cues deposited by the enclosure occupant, creating more physiological arousal and potentially more stress when the animal is reintroduced to a less familiar enclosure. Our findings suggest that housing snakes on newspaper could have long-term fitness and health consequences.

Magellanic penguins (Spheniscus magellanicus) are migratory and the most abundant penguin species occurring in Brazil. Anthropogenic threats compromise their winter migration, leading to a significant number of debilitated individuals to be stranded on Brazilian beaches. Rescued penguins are taken to rehabilitation centers for medical treatment and evaluated for reintroduction; if non-releasable, they are either euthanized or kept in permanent captivity. Obtaining sufficient blood volume is critical for the accurate diagnosis and ongoing management of many diseases and health conditions. Moreover, blood drawing in Sphenisciformes can be challenging, particularly in severely debilitated penguins. Here we describe an alternative technique for blood collection in Magellanic penguins through the dorsal coccygeal vein, which is suitable for both debilitated and healthy animals. Although the coccygeal vein is not a standard site for blood collection in penguins, it may be considered as an alternative if peripheral veins are presenting very low pressure or have been exhausted/inaccessible.

Among European Association of Zoos and Aquaria (EAZA) Ex-situ Programs (EEPs), both African and Asian elephant populations represent good models of the benefits of collective, unified action to contribute to the conservation of threatened species. However, the management of mature male elephants poses distinct challenges for both population sustainability and animal wellbeing. Identifying the goals and challenges of institutional members as they relate to male elephant management will inevitably aide in the planning of future management strategies and identify areas for collaboration with other ex-situ elephant populations. The purposes of this study were (1) to survey EAZA facilities housing adult male elephants to understand institutional priorities around musth management, male socialization, and semen collection to compare them to population-wide recommendations; and (2) to compare patterns to those obtained from a recent survey of Association of Zoos and Aquariums (AZA) accredited facilities. We received responses from 55 facilities, holding 76 adult male elephants. The highest priorities were natural breeding and male socialization; assisted reproductive techniques (e.g., semen collection) were not prioritized at the institutional level, despite emphasis by the EEPs. Further, while most facilities acknowledged the importance of managing elephants around musth, few had formalized monitoring programs. Compared to AZA institutions, EAZA facilities had similar goals and challenges, with lower reliance on and capacity for collecting semen. These results underscore the specialized care that male elephants require to achieve population sustainability and uphold high animal welfare standards, with clear opportunities for knowledge sharing with AZA counterparts.

White rhinos (WR, Ceratotherium simum) are grazers and black rhinos (BR, Diceros bicornis) are browsers; this difference has been related to BR being more challenging in terms of husbandry. Previous reports indicated that BR in zoos often receive diets with a higher proportion of easily digestible compounds compared to other rhino species. Additionally, BR are susceptible to iron overload disorder (IOD). We compared the feeding methods and recommendations, and sampled diets and feces of 117 WR and 82 BR across 41 European zoos. The few available data for free-ranging animals were also incorporated. The percentage of forage in the total estimated dry matter intake was 93% for WR and 77% for BR, matching fecal parameters indicating a higher diet digestibility in BR. BR received higher levels of (pelleted) compound feeds and produce than WR. Nevertheless, dietary fiber levels were similar to that reported for free-ranging specimens in both species. Zoo diets were higher in several minerals (Na, P, Cu, Zn) than natural diets. However, zoo BR received diets with similar iron content to that described in free-ranging BR diet items and fecal iron levels were not higher than those in the few samples of free-ranging BR available, suggesting that iron levels in zoo BR diets are not overly excessive. Consequently, IOD appears to be more complex, associated with iron bioavailability and possibly non-dietary causes. Grass hay was used in 100% of WR and 36% of BR (all BR facilities used lucerne hay). BR feces had levels of abrasive silica comparable to those of free-ranging WR and much higher than free-ranging BR, matching reports of excessive tooth wear in adult BR. Browse provision for BR could not be quantified but appeared low in general; no alternative forages (like sainfoin) were fed. Efforts to consistently provide high amounts of browse to BR must be increased and forage should be low in iron and abrasive silica.

The Harpy Eagle (Harpia harpyja), one of the largest birds of prey in the world, is threatened with extinction throughout its entire area of occurrence in the Neotropics. While conservation efforts for the wild populations are crucial, it is also important to focus on ex situ conservation actions. To achieve this, understanding the genetic characteristics of the captive population is essential to prevent inbreeding and loss of genetic diversity over time. In this study, we employed a next generation sequencing strategy to develop a new set of primers for microsatellite regions specific to the Harpy Eagle. These markers were validated in Harpy Eagle individuals maintained in captivity at Brazilian zoos and conservation institutions. We characterized these captive individuals using ten highly polymorphic microsatellite loci to estimate relatedness and individual identification at > 95% accuracy. The same effect can be achieved with four loci. Additionally, we developed a statistical test to further refine relationship estimates. Paired with robust sex markers, the new set of microsatellite markers presented here the potential to guide ex situ management strategies, aiming for better reproductive pairings and the maintenance of genetic diversity of the Harpy Eagle.

After-hours events are a popular way for modern zoos and aquariums to engage the local community, increase attendance, and generate additional income. Using fecal glucocorticoid metabolite (fGM), behavioral, and sound level monitoring, we analyzed whether cheetahs (Acinonyx jubatus) and giraffes (Giraffa camelopardalis sp.) showed any significant changes in response to three types of event "treatments" at the Oregon Zoo: (1) "concerts" with significantly elevated sound levels; (2) "other" evening events which constituted popular events with minimal sound disruptions, and (3) "control" when no evening events took place. We found significantly higher sound pressure levels in both habitats during "concert" event types with no significant differences between the remaining event types. Both cheetahs and giraffes exhibited subtle behavior changes during each event type, such as increased instances of "not visible" for cheetahs and a slight increase in the rate of "social interaction" for giraffes. However, no significant changes in fGM concentrations were measured for any individual animal across all the different event types. Yet there were some significant differences in fGM concentrations between the 2 years of data collection as well as some differences in fGM variability driven primarily by individual differences within each species. Results from this study, therefore, emphasize the highly individualistic nature of behavior and physiological responses to events of any type and illustrate how important it is to measure responses of each individual, when feasible, rather than focusing on an overall species typical response.