Breaking the spell: Changes in the behavior of two zoo-kept tigers (Panthera tigris) after exposure to a distinct feast-and-fast feeding regime.

The behavior of zoo carnivores has received intense attention due to their propensity for locomotor stereotypies. We observed two adult male tiger (Panthera tigris) siblings kept together for the duration of 104 days by round-the-clock video observation. The period consisted of three baseline periods with the zoo's regular feeding regime of five feeding days per week interrupted by two individual fasting days, with feeding occurring in the evening (B1-B3 of 14 days each).

Time series cluster analysis reveals individual assignment of microbiota in captive tiger () and wildebeest ().

Fecal microbiota variability and individuality are well studied in humans and also in farm animals (related to diet- or disease-specific influences), but very little is known for exotic zoo-housed animals. This includes a wide range of species that differ greatly in microbiota composition and variation. For example, herbivorous species show a very similar and constant fecal microbiota over time, whereas carnivorous species appear to be highly variable in fecal microbial diversity and composition.

Development of A Tool for Assessing the Reputation of Zoos: The Zoo Ethical Reputation Survey (ZERS).

Nowadays, most zoos have taken prominent and active positions in endangered species conservation and educating visitors about the value of biodiversity. However, to be effective and trusted in their mission, they must act ethically and have a good reputation. Yet, the drivers that can influence their reputation are still little investigated, and there are still few studies focused on assessing the reputation of these institutions.

Diurnal and Nocturnal Behaviour of Cheetahs () and Lions () in Zoos.

Mammals are constantly exposed to exogenous and endogenous influences that affect their behaviour and daily activity. Light and temperature, as well as anthropogenic factors such as husbandry routines, visitors, and feeding schedules are potential influences on animals in zoological gardens. In order to investigate the effects of some of these factors on animal behaviour, observational studies based on the analyses of activity budgets can be used.

Introducing the Software CASE (Cluster and Analyze Sound Events) by Comparing Different Clustering Methods and Audio Transformation Techniques Using Animal Vocalizations.

Unsupervised clustering algorithms are widely used in ecology and conservation to classify animal sounds, but also offer several advantages in basic bioacoustics research. Consequently, it is important to overcome the existing challenges. A common practice is extracting the acoustic features of vocalizations one-dimensionally, only extracting an average value for a given feature for the entire vocalization.

Nature Interest Scale - Development and Evaluation of a Measurement Instrument for Individual Interest in Nature.

Interest is an important factor for successful learning that has been the subject of intensive research for decades. Although interest in nature is of great importance for environmental education, to date there is no valid and reliable measurement tool. Therefore, the purpose of this study was to develop and test a scale for interest in nature, the Nature Interest Scale (NIS).

Discrimination of Acoustic Stimuli and Maintenance of Graded Alarm Call Structure in Captive Meerkats.

Animals living in human care for several generations face the risk of losing natural behaviors, which can lead to reduced animal welfare. The goal of this study is to demonstrate that meerkats () living in zoos can assess potential danger and respond naturally based on acoustic signals only. This includes that the graded information of urgency in alarm calls as well as a response to those alarm calls is retained in captivity.

Unraveling differences in fecal microbiota stability in mammals: from high variable carnivores and consistently stable herbivores.

Background: Through the rapid development in DNA sequencing methods and tools, microbiome studies on a various number of species were performed during the last decade. This advance makes it possible to analyze hundreds of samples from different species at the same time in order to obtain a general overview of the microbiota. However, there is still uncertainty on the variability of the microbiota of different animal orders and on whether certain bacteria within a species are subject to greater fluctuations than others.

Deep learning-based pose estimation for African ungulates in zoos.

The description and analysis of animal behavior over long periods of time is one of the most important challenges in ecology. However, most of these studies are limited due to the time and cost required by human observers. The collection of data via video recordings allows observation periods to be extended.

Impact of biological education and gender on students' connection to nature and relational values.

The new concept of relational values (RVs) is gaining more and more attention in environmental research, but empirical analyses are still rare. However, this type of research is necessary because the RVs have an influence on environmental behavior. To evaluate the impact of biological education on attributing higher importance to RVs and connectedness to nature, we compared the connection to nature scores (using the inclusion of nature scale (INS) and connectedness to nature scale (CNS)) and RV scores of biologically interested high school students (n = 417) with first year (n = 593) and advanced biology (n = 223) students.

Connecting High School Students With Nature - How Different Guided Tours in the Influence the Success of Extracurricular Educational Programs.

Zoos attract millions of visitors every year, many of whom are schoolchildren. For this reason, zoos are important institutions for the environmental education of future generations. Empirical studies on the educational impact of environmental education programs in zoos are still rare.

Exploring the Construct of Relational Values: An Empirical Approach.

In recent environmental research, relational values (RVs) have emerged as a new group of values to explain environmental behavior. Although this new concept is attracting attention, empirical studies on the subject are still rare. On this basis, we have conducted three studies to analyze an existing measurement tool for RVs and compared the construct with the concept of connection to nature.

Diurnal variation of salivary cortisol in captive African elephants (Loxodonta africana) under routine management conditions and in relation to a translocation event.

The present study assessed the diurnal variation in salivary cortisol in captive African elephants during routine management (baseline) and in relation to a potential stressor (translocation) to evaluate to what extent acute stress may affect diurnal cortisol patterns. Under baseline conditions, we collected morning and afternoon saliva samples of 10 animals (three zoos) on different days in two study periods (n = 3-10 per animal, daytime and period). Under stress conditions, we sampled the transported cow (newcomer) and the two cows of the destination zoo before and after the transport in the morning and afternoon (n = 3-9 per animal, daytime and transport phase), as well as after the first introduction of the newcomer to the bull (n = 1 per animal).

Functional properties and cell type specific distribution of I(h) channels in leech neurons.

The hyperpolarisation-activated cation current (I(h)) has been described in many vertebrate and invertebrate species and cell types. In neurons, I(h) is involved in rhythmogenesis, membrane potential stabilisation and many other functions. In this work, we investigate the distribution and functional properties of I(h) in identified leech neurons of intact segmental ganglia.

Swelling-activated chloride channels in leech Retzius neurons.

During periods of high activity neurons are expected to swell due to the uptake of Cl(-). To find out whether leech Retzius neurons possess swelling-activated Cl(-) channels that facilitate Cl(-) efflux and, hence, volume recovery, we exposed the cells to hypotonic solutions. In hypotonic solutions, the cells slowly swelled but did not undergo a regulatory volume decrease.

Ionic mechanism of ouabain-induced swelling of leech Retzius neurons.

By using electrophysiological and microfluorimetric methods, we found that leech Retzius neurons swell after inhibition of the Na(+)-K(+) pump by the cardiac glycoside ouabain. To explore the mechanism of this swelling, we measured the effect of ouabain on [Na(+)](i), [K(+)](i), and [Cl(-)](i), as well as on the membrane potential, by applying triple-barrelled ion-sensitive microelectrodes. As shown previously, ouabain induced a marked [Na(+)](i) increase, a [K(+)](i) decrease, and a membrane depolarization, and it also evoked an increase in [Cl(-)](i).

Ca2+ influx into identified leech neurons induced by 5-hydroxytryptamine.

The role of 5-hydroxytryptamine (5-HT, serotonin) in the control of leech behavior is well established and has been analyzed extensively on the cellular level; however, hitherto little is known about the effect of 5-HT on the cytosolic free calcium concentration ([Ca(2+)](i)) in leech neurons. As [Ca(2+)](i) plays a pivotal role in numerous cellular processes, we investigated the effect of 5-HT on [Ca(2+)](i) (measured by Fura-2) in identified leech neurons under different experimental conditions, such as changed extracellular ion composition and blockade of excitatory synaptic transmission. In pressure (P), lateral nociceptive (N1), and Leydig neurons, 5-HT induced a [Ca(2+)](i) increase which was predominantly due to Ca(2+) influx since it was abolished in Ca(2+)-free solution.

L-type Ca2+ channel antagonists block voltage-dependent Ca2+ channels in identified leech neurons.

We investigated the effect of L-type Ca2+ channel antagonists on the Ca2+ influx through voltage-gated Ca2+ channels in leech Retzius, Leydig, AP, AE, P, and N neurons. The efficacy of the antagonists was quantified by monitoring their effect on the increase in the intracellular free Ca2+ concentration ([Ca2+]i; measured by Fura-2) that was induced by depolarizing the cell membrane by raising the extracellular K+ concentration. This K+-induced [Ca2+]i increase was blocked by the phenylalkylamines verapamil, gallopamil, and devapamil, the benzothiazepine diltiazem, as well as by the 1,4-dihydropyridine nifedipine.

Potentiometric measurement of cell volume changes and intracellular ion concentrations under voltage-clamp conditions in invertebrate nerve cells.

Because changes in cell volume might disturb the normal function of animal cells, most cells are endowed with volume-regulating mechanisms. Experimentally induced changes in cell volume are often paralleled by changes in the membrane potential, which might affect a variety of transport processes across the cell membrane and, in turn, volume regulation [1, 2]. We have shown previously that multi-barrelled ion-selective microelectrodes are useful tools for measurement of cell volume and the intracellular concentrations of ions that might be relevant to volume regulation [1].