The historical development of zoo elephant survivorship

In the discussion about zoo elephant husbandry, the report of Clubb et al. (2008, Science 322: 1649) that zoo elephants had a “compromised survivorship” compared to certain non-zoo populations is a grave argument, and was possibly one of the triggers of a large variety of investigations into zoo elephant welfare, and changes in zoo elephant management. A side observation of that report was that whereas survivorship in African elephants (Loxodonta africana) improved since 1960, this was not the case in Asian elephants (Elephas maximus). We used historical data (based on the Species360 database) to revisit this aspect, including recent developments since 2008. Assessing the North American and European populations from 1910 until today, there were significant improvements of adult (≥10 years) survivorship in both species. For the period from 1960 until today, survivorship improvement was significant for African elephants and close to a significant improvement in Asian elephants; Asian elephants generally had a higher survivorship than Africans. Juvenile (<10 years) survivorship did not change significantly since 1960 and was higher in African elephants, most likely due to the effect of elephant herpes virus on Asian elephants. Current zoo elephant survivorship is higher than some, and lower than some other non-zoo populations. We discuss that in our view, the shape of the survivorship curve, and its change over time, are more relevant than comparisons with specific populations. Zoo elephant survivorship should be monitored continuously, and the expectation of a continuous trend towards improvement should be met

Retention of solutes and particles in the gastrointestinal tract of a grazing cervid : Père David’s deer (Elaphurus davidianus)

Ruminants are classified into three groups, according to their feeding behaviour: browsers, intermediate feeders and grazers. Corresponding to their dietary preferences, multiple morphological and physiological adaptations have been described, resulting in another classification: moose-type' and cattle-type' ruminants. Digesta retention patterns in the gastrointestinal tract (GIT) and reticulorumen (RR) are considered major criteria to distinguish these types, as cattle-type ruminants show shorter retention of fluids (measured by a solute marker) than of particles, while in moose-type ruminants, both are retained for more similar periods. To what extent these digestive types are specific to phylogenetic lineages is still unclear. We measured mean retention times (MRTs) of solutes and particles (2 and 20mm) in the strictest grazing cervid: the Pere David's deer (Elaphurus davidianus; n=5; body mass=155.0 +/- 14.5kg). The MRTs of solutes, small and large particles in the GIT were 34 +/- 4, 60 +/- 7 and 69 +/- 9h, respectively. The ratio of the MRT of small particles versus solutes in the RR was 2.0 +/- 0.1, similar to other cattle-type ruminants. The results confirm the hypothesis that Pere David's deer can be classified as cattle-type ruminants, corresponding to both dietary preferences and previously described morphological traits. The results complement previous findings, showing that both cattle-type and moose-type physiologies are found among bovids as well as cervids, indicating that these digestion types can be considered convergent adaptations

Retention of solutes and particles in the gastrointestinal tract of a grazing cervid: Père David’s deer (Elaphurus davidianus)

Ruminants are classified into three groups, according to their feeding behaviour: browsers, intermediate feeders and grazers. Corresponding to their dietary preferences, multiple morphological and physiological adaptations have been described, resulting in another classification: ‘moose-type’ and ‘cattle-type’ ruminants. Digesta retention patterns in the gastrointestinal tract (GIT) and reticulorumen (RR) are considered major criteria to distinguish these types, as cattle-type ruminants show shorter retention of fluids (measured by a solute marker) than of particles, while in moose-type ruminants, both are retained for more similar periods. To what extent these digestive types are specific to phylogenetic lineages is still unclear. We measured mean retention times (MRTs) of solutes and particles (2 and 20mm) in the strictest grazing cervid: the Père David’s deer (Elaphurus davidianus; n = 5; body mass = 155.0 ± 14.5 kg). The MRTs of solutes, small and large particles in the GIT were 34 ± 4, 60 ± 7 and 69 ± 9 h, respectively. The ratio of the MRTof small particles versus solutes in the RR was 2.0 ± 0.1, similar to other cattle-type ruminants. The results confirm the hypothesis that Père David’s deer can be classified as cattle-type ruminants, corresponding to both dietary preferences and previously described morphological traits. The results complement previous findings, showing that both cattletype and moose-type physiologies are found among bovids as well as cervids, indicating that these digestion types can be considered convergent adaptations

Digestive anatomy, physiology, resting metabolism and methane production of captive maras (Dolichotis patagonum)

The digestive physiology of maras (Dolichotis patagonum) has not been investigated in detail. Maras have a particular limb anatomy facilitating a unique cursoriality among rodents. This may also have led to additional adaptations such as a reduced volume of the gastrointestinal tract. We performed macroanatomical measurements of, and determined mean particle size along, the digestive tract of 10 semi-free-ranging animals (7.04 ± 1.05 kg). Additionally, we measured CH4 emission in five captive animals (7.67 ± 0.98 kg) fed a diet of pelleted lucerne, and measured food intake, digestibility, and digesta mean retention time (MRT) of a solute and three particle markers (fed at < 2, 10 and 20 mm particle size). The digestive tract contents represented 11.1 ± 1.4% of body mass, similar to other mammals and rodents, and there was slight indication of selective small particle retention in the caecum. Secondary peaks in marker elimination patterns suggested the possibility of caecotrophy. The MRTs were 15.4 h for the solute and 13.6 h, 13.3 h and 13.3 h for the three particle markers, respectively. At a dry matter intake of 61 ± 12 g kg body mass-0.75 d−1, the maras digested organic matter and neutral detergent fibre to 48 ± 8% and 34 ± 10%, respectively, which is in the lower range of results from horses fed on a diet with a similar fibre content. The respiratory quotient (CO2/O2) was 0.93 ± 0.03, the resting metabolic rate 346 ± 35 kJ kg body mass-0.75 d−1, and CH4 emissions averaged at 3.85 ± 0.47 L d−1 and 14.5 ± 5.2 L per kg dry matter intake; this at a CH4/CO2 ratio of 0.042 ± 0.004. Thus, the methane yield was of a magnitude expected for a hypothetical ruminant of this body mass. The results are consistent with the general understanding of hystricomorph rodent digestive physiology, including caecotrophy, but do not indicate a reduction of digestive capacity to support cursoriality. These results, and those obtained from other hystricomorph rodents, suggest that CH4 production may be more prominent in rodents than previously thought

Digestive anatomy, physiology, resting metabolism and methane production of captive maras (Dolichotis patagonum)

ISSN:1095-6433ISSN:0300-9629ISSN:1531-433

Long-Term Olfactory Memory in African Elephants

African elephants are capable of discriminating scents up to a single changed molecule and show the largest reported repertoire of olfactory receptor genes. Olfaction plays an important role in family bonding. However, to the best of our knowledge, no empirical data exist on their ability to remember familiar scents long-term. In an ethological experiment, two mother-daughter pairs were presented with feces of absent kin, absent non-kin, and present non-kin. Video recordings showed reactions of elephants recognizing kin after long-term separation but only minor reactions to non-kin. Results give the empirical implication that elephants have an olfactory memory longer than 1 year and up to 12 years and can distinguish between kin and non-kin just by scent. These findings confirm the significance of scent for family bonds in African elephants

Methane production by two non-ruminant foregut-fermenting herbivores: the collared peccary (Pecari tajacu) and the pygmy hippopotamus (Hexaprotodon liberiensis)

Methane (CH4) production varies between herbivore species, but reasons for this variation remain to be elucidated. Here,we report open-circuit chamber respiration measurements of CH4 production in four specimens each of two non-ruminantmammalian herbivores with a complex forestomach but largely differing in body size, the collared peccary (Pecari tajacu, mean body mass 17 kg) and the pygmy hippopotamus (Hexaprotodon liberiensis, 229 kg) fed lucerne-based diets. In addition, food intake, digestibility and mean retention times were measured in the same experiments. CH4 production averaged 8 and 72 L/d, 18 and 19 L/kg dry matter intake, and 4.0 and 4.2% of gross energy intake for the two species, respectively. When compared with previously reported data on CH4 production in other non-ruminant and ruminant foregut-fermenting as well as hindgut-fermenting species, it is evident that neither the question whether a species is a foregut fermenter or not, or whether it ruminates or not, is of the relevance previously suggested to explain variation in CH4 production between species. Rather, differences in CH4 production between species on similar diets appear related to species-specific differences in food intake and digesta retention kinetics

Causes of mortality in a population of black-footed cats in central South Africa

No abstract available.BIOS2 NSERC CREATE program; Cincinnati Zoo; Kölner Zoo; McGregor Museum; Omaha's Henry Doorly Zoo & Aquarium; Rufford Fund for Nature Conservation; San Diego ZooWildlife Alliance; SOS Félins & Co.; The International Society of Endangered Cats (ISEC), Canada; The Living Desert; Zoological Association of America (ZAA); Zoo-Verein Wuppertal e. V.http://www.wileyonlinelibrary.com/journal/aje2023-06-06hj2022Centre for Veterinary Wildlife StudiesParaclinical Science

Sourcing high tissue quality brains from deceased wild primates with known socio‐ecology

The selection pressures that drove dramatic encephalisation processes through the mammal lineage remain elusive, as does knowledge of brain structure reorganisation through this process. In particular, considerable structural brain changes are present across the primate lineage, culminating in the complex human brain that allows for unique behaviours such as language and sophisticated tool use. To understand this evolution, a diverse sample set of humans' closest relatives with varying socio-ecologies is needed. However, current brain banks predominantly curate brains from primates that died in zoological gardens. We try to address this gap by establishing a field pipeline mitigating the challenges associated with brain extractions of wild primates in their natural habitat. The success of our approach is demonstrated by our ability to acquire a novel brain sample of deceased primates with highly variable socio-ecological exposure and a particular focus on wild chimpanzees. Methods in acquiring brain tissue from wild settings are comprehensively explained, highlighting the feasibility of conducting brain extraction procedures under strict biosafety measures by trained veterinarians in field sites. Brains are assessed at a fine-structural level via high-resolution MRI and state-of-the-art histology. Analyses confirm that excellent tissue quality of primate brains sourced in the field can be achieved with a comparable tissue quality of brains acquired from zoo-living primates. Our field methods are noninvasive, here defined as not harming living animals, and may be applied to other mammal systems than primates. In sum, the field protocol and methodological pipeline validated here pose a major advance for assessing the influence of socio-ecology on medium to large mammal brains, at both macro- and microstructural levels as well as aiding with the functional annotation of brain regions and neuronal pathways via specific behaviour assessments