Discover the most talked about and latest scientific content & concepts.

Journal: Zoo biology


With only three living individuals left on this planet, the northern white rhinoceros (Ceratotherium simum cottoni) could be considered doomed for extinction. It might still be possible, however, to rescue the (sub)species by combining novel stem cell and assisted reproductive technologies. To discuss the various practical options available to us, we convened a multidisciplinary meeting under the name “Conservation by Cellular Technologies.” The outcome of this meeting and the proposed road map that, if successfully implemented, would ultimately lead to a self-sustaining population of an extremely endangered species are outlined here. The ideas discussed here, while centered on the northern white rhinoceros, are equally applicable, after proper adjustments, to other mammals on the brink of extinction. Through implementation of these ideas we hope to establish the foundation for reversal of some of the effects of what has been termed the sixth mass extinction event in the history of Earth, and the first anthropogenic one. Zoo Biol. XX:XX-XX, 2016. © 2016 Wiley Periodicals, Inc.

Concepts: Species, Extinction, Rhinoceros, Dinosaur, White Rhinoceros, Rhinoceroses, Extinction event, Northern White Rhinoceros


Zoos and related facilities in North America currently manage five species in the primate family Lorisidae: the greater (Nycticebus coucang), Bengal (N. bengalensis) and pygmy (N. pygmaeus) slow lorises, red slender loris (Loris tardigradus), and potto (Perodicticus potto). We used an online survey to describe institutional housing and husbandry practices for these species and assess the extent to which practices are consistent with established guidelines. Our results show that most captive lorisids are housed solitarily or in pairs. Most individuals occupy a single exhibit space in a building dedicated to nocturnal animals. Facilities are commonly meeting recommendations for abiotic exhibit design and are providing animals with an enriched environment. However, pottos and slender lorises currently occupy exhibit spaces smaller than the recommended minimum, and the impact of cleaning protocols on olfactory communication should be critically evaluated. Few facilities are taking advantage of the benefits of positive reinforcement training for promoting animal welfare. Research is greatly needed on the effects of exhibit lighting on behavior, health, and reproduction; and to determine how best to manage the social needs of lorisids with naturally dispersed social structures. Although captive populations of slender lorises, pottos, and slow lorises are declining, we suggest that improved husbandry knowledge has the potential to positively influence population sustainability and to enhance future efforts to manage the growing pygmy loris population. Zoo Biol. 00:1-13, 2012. © 2012 Wiley Periodicals, Inc.

Concepts: Primate, Lorisidae, Loris, Slender loris, Lorises and galagos, Red Slender Loris, Slow loris, Pygmy Slow Loris


Egg binding is a common reproductive disorder in captive female reptiles leading to premature loss of breeding potential, or in severe cases death. It can result from failure to ovulate (and reabsorb) follicles; follicular stasis, or failure to lay eggs; dystocia. Reproductive status of female veiled chameleons (Chamaeleo calyptratus) in a research colony was assessed using enzyme immunoassay (EIA) of fecal reproductive hormones (estradiol; E2, progesterone; P, and testosterone; T) and their metabolites, ultrasound imaging of the reproductive tract, and receptivity to conspecific males. Periods of follicular growth (vitellogenesis) corresponded with increasing levels of E2, and following ovulation, a distinct change in morphology from round (follicles) to oval (eggs) structures, which was accompanied by a surge in P (>20-fold above baseline). P levels remained elevated throughout the gravid phase until just prior to oviposition. Length/width ratios of follicles and eggs were statistically different, but distinguishing a follicle from an egg based on the ratio was unreliable due to a large overlap in values. In animals that failed to ovulate on their first cycle, follicles began to recede but were not fully reabsorbed and could be distinguished from a second batch of follicles based on their echogenicity. Female receptivity to conspecific males was not related to cycle stage (i.e., previtellogenesis, vitellogenesis, or gravid) or reproductive hormone levels. This study demonstrates the use of ultrasonography and reproductive hormone analysis to assess phase of the reproductive cycle (pre- or post-ovulatory), or confirm ongoing follicular stasis. Zoo Biol. XX:XX-XX, 2014. © 2014 Wiley Periodicals, Inc.

Concepts: Male, Reproduction, Metabolism, Hormone, Luteinizing hormone, Reproductive system, Menstrual cycle, Veiled Chameleon


Best practices for carnivore enrichment encourage the diversity of species-typical behaviors, increased activity, and reduced stereotypic behavior; ideally considering the life-history and behavior of each species. African wild dogs (Lycaon pictus), or painted dogs, are social carnivores that have large home ranges and complex pack dynamics (e.g., variation in group size, relatedness, etc.). As there are relatively few studies on painted dog enrichment, the goal of this study was to compile a list of enrichment options used by institutions participating in the species survival plan (SSP). Representatives were asked to describe social groups (n = 45), enclosures (n = 21), enrichment practices (options, delivery frequency, perceived success), and overall best practices. Respondents (61%, n = 23) reported using options for all six enrichment categories recommended by the Canid Taxon Advisory Group: environmental enrichment devices, habitat, sensory, food, behavioral, and social. Perceived success was significantly higher for the food category, followed by the sensory and behavioral categories. All respondents reported delivering enrichment at least multiple times a month, and most reported multiple times per week. Enclosure size did not differ significantly for mixed-sex groups (n = 28) compared to single-sex groups (n = 17). We discuss respondents' suggestions for best practices and the need to record data to compare perceived success with actual behavioral effects, controlling for variation in group size and composition. Overall, respondents recommended a flexible approach, since not all painted dogs and groups respond in the same way to the enrichment options. Zoo Biol. XX:XX-XX, 2014. © 2014 Wiley Periodicals Inc.

Concepts: Canidae, African Wild Dog, Dhole, Group size measures


To the authors' knowledge there is currently no discrete index to measure the integrated intensity of a play bout in mammals, despite the potential for using intensity and duration of play bouts as a measure of physical activity and welfare. This study was developed to test an equation that quantified the intensity and duration of play bouts in a particularly gregarious mammal, African elephants (Loxodonta africana) housed at the San Diego Zoo Safari Park in Escondido, CA. To quantify these behaviors, we created a scale of intensity and a subsequent equation that produces an index value, giving each unique bout a score. A compilation of these scores provides a range of intensity of play behavior that is a representative value for that particular herd at that point in time, and thus a database to which later bouts can be compared. It can be argued that play behavior is an indicator of positive welfare, and if quantifiable, it is our belief that it can be used as an additional measure of positive welfare in zoo housed animals. Here we present the methods and technique used to calculate a standardized Integrated Play Index (IPI) that has potential for use in other socially living species that are known to exhibit play behavior. Zoo Biol. XX:XX-XX, 2015. © 2015 Wiley Periodicals, Inc.

Concepts: Mammal, Behavior, Elephant, Asian Elephant, Elephants, African elephant, African Bush Elephant, San Diego Zoo


Maintaining adequate welfare in captive elephants is challenging. Few studies have investigated overnight rest behavior in zoo elephants, yet time spent resting has been identified as a welfare indicator in some species. We investigated resting behavior in Asian elephants (Elephas maximus) in UK zoos, with the aim of identifying patterns or preferences in lying rest. Details of standing (SR) and lying (LR) rest behavior were identified by observing video footage of inside enclosures collected for 14 elephants (2 male, 12 female) housed at three UK zoos (Zoo A: 18 nights; Zoo B: 27 nights; Zoo C: 46 nights) from 16:00 to 08:30 (approximately). Elephants engaged in a mean of 58-337 min rest per night. Time of night affected mean duration of LR bouts (P < 0.001); longest bouts were observed between 22:01 and 06:00. Elephants showed a substrate preference when lying to rest; LR was not observed on concrete or tiled flooring. Where sand was available (to 11/14 elephants), all elephants engaged in LR on sand flooring. Only two elephants engaged in LR on rubber flooring (available to 7/14 elephants). Mean duration of rest bouts was greater when a conspecific was within two body lengths than when conspecifics were not (P < 0.01). Our study indicated that elephants show substrate preferences when choosing an area for rest and engage in more rest when conspecifics are in close proximity. The results of this study could be used as a basis for future studies investigating the link between rest and welfare in captive elephants. Zoo Biol. XX:XX-XX, 2015. © 2015 Wiley Periodicals, Inc.

Concepts: Elephant, Asian Elephant, Elephas, Elephantidae, Sri Lankan Elephant, Elephants, War elephant, Borneo Elephant


Free range exhibits are becoming increasingly popular in zoos as a means to enhance interaction between visitors and animals. However very little research exists on the impacts of visitors on animal behaviour and stress in free range exhibits. We investigated the effects of visitor number on the behaviour and stress physiology of Kangaroo Island (KI) Kangaroos, Macropus fuliginosus fuliginosus, and Red Kangaroos, Macropus rufus, housed in two free range exhibits in Australian zoos. Behavioural observations were conducted on individual kangaroos at each site using instantaneous scan sampling to record activity (e.g., vigilance, foraging, resting) and distance from the visitor pathway. Individually identifiable faecal samples were collected at the end of each study day and analysed for faecal glucocorticoid metabolite (FGM) concentration. When visitor number increased, both KI Kangaroos and Red Kangaroos increased the time spent engaged in visitor-directed vigilance and KI Kangaroos also increased the time spent engaged in locomotion and decreased the time spent resting. There was no effect of visitor number on the distance kangaroos positioned themselves from the visitor pathway or FGM concentration in either species. While there are limitations in interpreting these results in terms of fear of visitors, there was no evidence of adverse effects animal welfare in these study groups based on avoidance behaviour or stress physiology under the range of visitor numbers that we studied. Zoo Biol. XX:XX-XX, 2015. © 2015 Wiley Periodicals, Inc.

Concepts: Macropus, Kangaroo, Red Kangaroo


Little is known of the different freezing and thawing techniques for post-thaw survival of spermatozoa in Sambar deer. So, this study determined the effect of seminal plasma, egg yolk and glycerol extenders and their concentrations, plus cooling, freezing, and thawing protocols on the post-thaw quality of their semen. Semen samples were collected by electro-ejaculation from four Thai Sambar deer stags (Cervus unicolor equinus). As evaluated by post-thaw progressive motility and acrosome integrity removal of seminal plasma was beneficial; Tris-egg yolk was the most efficient extender; a 20% egg yolk concentration was better than the 0%, 10%, or 30%; and a 3% glycerol concentration was better than 5%, 7%, or 9%. Using the optimum dilution techniques, semen was loaded in 0.5 ml plastic straws. Cooling times from ambient temperature to 5°C in 3 hr resulted in higher post-thaw progressive motility and acrosome integrity than 1, 2, or 4 hr. Suspending the straws 4 cm above the surface for 15 min before plunging into liquid nitrogen was better than suspending at 2 or 6 cm. For thawing frozen semen, an intermediate thawing (50°C, 8 sec) protocol was more effective than the slower (37°C, 10 sec) or faster (70°C, 5 sec) thawing rates. Timed insemination following estrus synchronization of 10 hinds resulted in six confirmed pregnancies at 60 days. Five hinds delivered live fawns. This study provides an effective approach for semen cryopreservation and artificial insemination (AI), which should be valuable to scientists for genetics and reproductive management of Sambar deer in developing countries. Zoo Biol. XX:XX-XX, 2015. © 2015 Wiley Periodicals, Inc.

Concepts: Sperm, Spermatozoon, Semen, Cervus, Rusa, Sambar


The central bearded dragon (Pogona vitticeps) is one of the most popular pet lizards. However, little is known regarding their nutrient requirement, or their natural diet. Therefore, the stomach contents of 14 free-roaming P. vitticeps were determined by flushing. These stomach contents were described taxonomically, and analyzed for crude protein content as well as fatty acid content and composition. Most of the dry matter intake was in the form of animal material (61%) stemming from nine arthropod orders. The most abundant were alates of the termite Drepanotermes sp., accounting for 95% of the total number of prey items and more than half of the total dry matter (DM) intake. Plant material contributed 16% of the total DM intake. The diets were high in crude protein (41-50% DM) and the total fatty acid content was 14-27% of the DM intake. The main fatty acid was C18:1n9c (51-56% of total fatty acids), and polyunsaturated fatty acids (n3 and n6) comprised 6-8% of the total fat intake. Our data suggest that P. vitticeps is an opportunistic predator, which exploits the seasonal availability of prey. Based on our data and other studies, a diet consisting of several insect species, supplemented with leafy vegetables, rich in n3 FA’s, would best resemble the expected natural diet of P. vitticeps. Zoo Biol. XX:XX-XX, 2015. © 2015 Wiley Periodicals, Inc.

Concepts: Nutrition, Essential fatty acid, Fat, Central Bearded Dragon


Enrichment is a powerful tool to improve the welfare of animals under human care. Stress-related health and behavioral problems, as well as reproductive failure, are frequent in armadillos (Xenarthra, Cingulata, Dasypodidae) under human care, which hinders the development of successful ex situ conservation programs. Nevertheless, scientific studies on the effect of enrichment programs on armadillos are virtually non-existent. The objective of this study was to assess the impact of an enrichment program on the behavior of armadillos under human care. The behavior of 12 individuals of three species (Dasypus novemcinctus, D. sabanicola, and Cabassous unicinctus) maintained at Finca El Turpial, Villavicencio, Colombia, was recorded using scan sampling during three daily time blocks of 2 hr each before (4 weeks) and after (4 weeks) implementing an enrichment program. Enrichment did not stimulate the armadillos to change or extend their activity period. In general, activity levels were low during the entire study, and virtually no activity was recorded in the morning in any species, neither without nor with enrichment. The latter did, however, improve welfare by reducing abnormal and increasing natural foraging behaviors. All species were attracted by artificial termite mounds. Dasypus spp. showed special interest in cardboard boxes with food, while Cabassous was mainly attracted to hollow plastic balls filled with food. Our results suggest that separate enrichment programs need to be developed for different armadillo species, and that they should be applied during the time of day at which they are most active. Zoo Biol. XX:XX-XX, 2016. © 2016 Wiley Periodicals, Inc.

Concepts: Psychology, Mammal, Xenarthra, Armadillo, Dasypus, Armadillos, Southern Naked-tailed Armadillo, Cabassous