Publications

Kleespies MW, Haller A, Feucht V, Becker M, Dierkes PW, Burger AL (2025) Journal of Zoo and Aquarium Research 13(1), 1-9

• The aim of this study is to examine which factors influence how intensively visitors engage with the content of exhibition panels on the subject of giraffes.

• The signs with general information about the biology of giraffes were viewed significantly longer than the signs with information about the habitat or species protection. Furthermore, the positioning of the information panels also plays an important role.

Feucht V, Dierkes PW, Kleespies M (2024) Sustainable Development

• In a Germany-wide survey, university students from 18 programs responded to how important they perceive the Sustainable Development Goals (SDGs) to be and how connected they are to nature.

• The programs differ significantly in their perceptions of the SDGs and their connection to nature, but there are more similarities than one might expect. There is a general consensus on which goals are more important. In addition, SDG 15 (life on land) correlates with connection to nature.

• Universities should be encouraged to increase education on sustainable development and integrate it into all study programs.

Gübert J, Dierkes PW (2024) Discover Animals 1, 37

• This study focuses on the use of space by nocturnal animals in indoor enclosures. A total of 50 individuals from 15 ungulate species were studied, and 25,938 hours of video material from 2,358 nights in 14 zoos were evaluated.

• The analysis shows that most individuals usually use only a small part of the indoor enclosure at night and have preferred lying places.

Kleespies MW, Hahn-Klimroth M, Dierkes PW (2024) npj Biodiversity 3, 21

• Using a novel method, we show here that there are eight distinct response types across the 37 countries studied that differ in their perceptions of the drivers of biodiversity loss.

• Our results demonstrate how future decision-makers around the world evaluate the drivers of biodiversity loss. The findings serve as a starting point for decision-makers to tailor education programs and policy measurements to the circumstances in their countries.

Mebus H, Schneider S, Dierkes PW, Burger-Schultz AL (2024) Frontiers in Conservation Science 5, 1462664

• In this study, a comprehensive 24-hour observational analysis of three female reticulated giraffes was conducted.

• The findings provide insights into behavioral rhythms and social behaviors of giraffes, which are essential for effective zoo management and conservation strategies.

Bähler I, Federer K, Davis L, Weber S, Burkevica A, Schneider S, Dierkes PW, Clauss M (2024) Journal of Zoo and Aquarium Research, 12(3), 172-184.

• Food-based environmental enrichment such as scatter-feeding is an important strategy to augment animal welfare in zoos. During scatter-feeding sessions, meerkats show more foraging, as well as being more active and visible overall. The overall foraging behaviour of zoo-housed animals during scatter-feeding (36% of the total daily activity) is nearly identical to that reported for free-ranging animals (37% of the total daily activity).

• The results show that automatic scatter-feeding is a viable and effective tool to improve indicators of welfare in meerkats and potentially other animals.

Feucht V, Dierkes PW, Haeser-Kalthoff A, Kästner A, Mager C, Reichhardt S, Schröder L, Spengler T, Steinert I, Ugolini P, Waked F, Kleespies MW (2024) Environmental Education Research

• Education is an important task of modern zoos. Evaluating environmental education helps to better understand educational work and to optimize its impact.

• Using the zoo as an example, we present instruments that can be used to measure the impact of educational programs on connection to nature, interest in species conservation, environmental concern, and attitudes towards biodiversity loss by using a questionnaire.

MW Kleespies, DD Dörge, N Peter, AV Schantz, A Skaljic, V Feucht, AL Burger-Schulz, PW Dierkes, S Klimpel (2024) Biological Invasions

• Invasive species are one of the main reasons for the decline in global biodiversity. This study investigates how different stakeholder groups in Germany perceive invasive species.

• It was found that the number of invasive animal and plant species in Germany was roughly correctly estimated in all groups, but the economic damage caused by invasive species was substantially underestimated.

S Schneider, L von Fersen, PW Dierkes (2024) Frontiers in Conservation Science 5, 1405243

• In this study, we present an innovative approach that leverages a convolutional neural network (CNN) for the detection, isolation and classification of manatee vocalizations from long-term audio recordings.

• The ability to differentiate between call categories will allow for ongoing monitoring of important information such as stress, arousal, and calf presence, which may aid in the conservation and management of manatees in critical habitats.

I Seyrling, M Clauss, PW Dierkes, AL Burger-Schulz (2024) Zoo Biology 43(4): 340-353

• We observed the behavior of two tigers for 104 days 24/7.

• Changes in feeding and fasting schedules reduced pacing from 6% to 3% of the day.

• A gorge-fast schedule structured time beyond a daily rhythm.

F Zoelzer, D dos Santos Monteiro, PW Dierkes (2024) Frontiers in Mammal Science 3, 1380915

• We analyzed the 16s rRNA from 525 fecal samples of 14 zoo-housed species belonging to different phylogenetic groups including herbivores, carnivores and omnivores. We found significant differences in the bacterial taxa correlated with these groups.

• Based on these results, we developed a logistic ensemble model, that predicts the diet and based on these findings either the herbivorous digestive system or the carnivorous host-family from a given fecal microbiota composition.

L Scherer, L Bingaman Lackey, M Hahn-Klimroth, DWH Müller, M Roller, MF Bertelsen, J Jebram, PW Dierkes, M Clauss (2024) Journal of Zoo and Aquarium Research 12(2), 88-101

• Global zoo giraffe data was analysed for historical developments of juvenile and adult survivorship, assessing the data with various demographic measures and comparing it to that of populations from natural habitats.

• Zoo giraffe survivorship is now generally above that observed in natural habitats.

MW Kleespies, V Feucht, TJ Tille, AM Bambach, E Gricar, M Claus, MMG Konertz, L Kokott, V Rupp, V Bergmann, V Wenzel, PW Dierkes (2024) Measurement: Interdisciplinary Research and Perspectives, 1-15

• Environmentally friendly behaviour in the private sector is an important factor that influences nature and the environment and can therefore contribute to overcoming environmental problems.

• The scale for environmentally friendly behaviour (PPB) developed in this study was validated on 7000 people and can be used as a suitable measuring instrument for environmentally friendly behaviour in the private sector.

MW Kleespies, A Scheersoi, PW Dierkes, V Wenzel (2024) European Journal of Educational Research 13 (2), 795-811

• Situational interest is an important factor that has a major influence on learning success in both school and non-school learning situations.

• The results of this study show that the scale developed here is a practicable instrument for measuring situational interest, taking all its components into account. It can help teachers to evaluate their educational programmes.

   

M Hahn-Klimroth, PW Dierkes, MW Kleespies (2024) Data Science Journal 23 (13),  1–17

• In this study, an unsupervised learning based approach for such research data is presented by proposing a procedure that works in three phases: Data preparation, clustering of questionnaires, and measurement of similarity based on the obtained clustering and features of each group.

   

AL Burger-Schulz, E Thiel, J Fennessy, S Fennessy, PW Dierkes (2023) Frontiers in Mammal Science 2, 1243883
 

• The aim of this study was to measure the inactivity and REM sleep of giraffes in Namibia and to investigate their nocturnal behavioural rhythms. Three giraffes were tagged with an accelerometer GPS device for this purpose.
• This study demonstrates a biphasic inactivity rhythm of giraffes with short REM sleep episodes in their natural habitat.

J Gübert, M Hahn-Klimroth, G Schneider, PW Dierkes  (2023) Ecology and Evolution 13, e10777

• In the present study, the nocturnal rhythms of 192 individuals of 18 ungulate species from 20 European zoos were investigated with regard to the behavioural positions standing, head up and head down (the typical REM sleep position).

• Differences were found between individuals of different ages, but no differences were found in relation to sex. In most species, the proportion of lying down during the night increased significantly. In addition, a high degree of rhythmicity was consistently observed.

AL Burger, PW Dierkes (2023) Frontiers Young Minds 11, 1086538

• In this article, children and young people will learn in which position giraffes sleep, how little they actually sleep at night and how a sleeping giraffe is well protected by other giraffes!

MW Kleespies, PW Dierkes (2023) Frontiers in Sustainability 4, 1249328

• Universities and higher education institutions play an important role in today's society by educating future decision-makers.
• Promoting a connection with nature is an important starting point for sustainable behaviour and should be integrated into university education in a targeted manner. Possible starting points are discussed in the article.

PW Dierkes (2023) Zooquaria, 118, 22-23

• The benefits of long-term collaborative partnerships between zoos and universities are discussed in the article.

M Henrich, S Formella-Zimmermann, J Gübert, PW Dierkes (2023) Frontiers in Education, 8, 1216318

• Behavioural biology is a field that fascinates students. To make the most of the various benefits of teaching in this area, a practical approach should be taken.
• In the study, 171 students were surveyed in an out-of-school student laboratory called "KILab - Behavioural Biology" using the Technology Acceptance Model (TAM). The study shows that the use of video recordings and software for behaviour analysis is in principle suitable for use in education.

J Gübert, M Hahn-Klimroth, PW Dierkes (2023) Frontiers in Ethology, 2, 1219977

• In the current study, the nocturnal behavior of 196 individuals of 19 ungulate species in 20 European zoos is studied. The underlying data consist of 101,629 h of video material from 9,239 nights.
• The results indicate that age, body size, and feeding type are the most important factors influencing nocturnal behavior across all species.

V Feucht, PW Dierkes, MW Kleespies (2023) Sustainability Science.

• The present study investigates empirically how university students differ in their view of nature’s value. For this purpose, 1885 students from 13 different majors across Germany were surveyed.
• While all groups showed high levels of agreement with intrinsic and instrumental values, the groups differed strongly in their relational perception of nature.

F Zoelzer, S Schneider, PW Dierkes (2023) Ecology & Evolution 13, e10066.

• Our objective was to determine whether species-specific and individual-specific clustering patterns were observed in the fecal microbiota of wildebeest (Connochaetes taurinus) and tigers (Panthera tigris).

• In order to identify species or individual clusters, we applied two different agglomerative hierarchical clustering algorithms –a community detection algorithm and Ward's linkage.

• Our results showed that both, species-specific and individual-specific clustering is possible, but more reliable results were achieved when applying dynamic time warping which finds the optimal alignment between different time series.

   

MW Kleespies, PW Dierkes (2023) Biological Conservation 283, 110093

• To measure connectedness to nature, over 4200 environmental science students in 41 countries were surveyed using an online questionnaire.

• The study examines the relationship between environmental science students' connectedness to nature and six wealth indicators.

• The results of the study suggest that, on average, environmental students in wealthier countries have a weaker relationship with people and nature than students in less wealthy countries.

MW Kleespies, M Hahn-Klimroth, PW Dierkes (2023) Environmental Challenges, 100712

• We studied students' perceptions of the planetary boundaries in 35 countries. Using a spectral clustering algorithm, countries were grouped into 5 clusters

• Different indicators were used to explain the cluster result. Prosperity, natural resources and forest area provide explanations for the results.

MW Kleespies, PW Dierkes (2022) Frontiers Young Minds 10, 662905

• This article explains for children and teens whether a 1-hour guided zoo tour can improve high school students' connection with nature. We also tested the effects of five additional activities (feeding giraffes or meerkats, a behind-the-scenes look, a talk with an animal keeper, and a visit to the petting zoo).

• Our study provides evidence for the effectiveness of brief environmental education programs that reconnect people with nature to nature.

MM Spiriti, FM Melchiori, PW Dierkes, L Ferrante, F Bandoli, P Biasetti, B de Mori (2022) Animals 12(20), 2802

• In this paper, we report on the development and initial testing of the Zoo Ethical Reputation Survey (ZERS), an instrument that uses a survey to analyze public opinion on characteristics that may influence a zoo's reputation, with a focus on ethical issues.

I Seyrling, PW Dierkes, AL Burger (2022) Animals 12, 2367

• In this study, the daily and nocturnal activity budgets of six lions (Panthera leo) and five cheetahs (Acinonyx jubatus) were investigated.

• Our results show that lions and cheetahs, regardless of husbandry, exhibit increased activity at dusk and feeding times. Resting behaviour is more pronounced at night in both species, with cheetahs showing a shorter total sleep duration than lions.

S Schneider, K Hammerschmidt, PW Dierkes (2022) Animals 12, 2020

• Unsupervised clustering algorithms are widely used in ecology and conservation to classify animal sounds, but also offer various advantages in basic research and contribute to the understanding of acoustic communication. Unsupervised clustering algorithms are widely used in ecology and conservation to classify animal sounds, but also offer various advantages in basic research and contribute to the understanding of acoustic communication.

• In this paper, we analyse different clustering methods and give an overview of their strengths and weaknesses in classifying bioacoustic data.

• The presented software CASE uses a multidimensional feature extraction method to achieve better clustering results, especially for frequency-modulated vocalisations.

MW Kleespies, PW Dierkes (2022) Humanit Soc Sci Commun 9, 218

• This study examined how important students in 41 countries rate the 17 Sustainable Development Goals.

• It was shown that the three pillars of sustainability (social, economic, environmental) are reflected, but considered to be of different importance in different countries.

• The results provide stakeholders with important information on how the SDGs should be promoted in their country.

J Gübert, M Hahn-Klimroth, PW Dierkes (2022) Ecology & Evolution 12 (3), e8701

• This paper contains two sections with different objectives:
• The first is a case study of 25 eland (Tragelaphus oryx) from 5 EAZA zoos, with a total of 11,411 hours of video footage from 822 nights, providing the first detailed description of eland nocturnal behaviour.
• The second objective is to present an open-source software package called BOVIDS, based on the latest machine learning techniques and designed for large-scale studies of nocturnal ungulate behaviour.

MW Kleespies, V Feucht, M Becker, PW Dierkes (2022) Journal of Zoological and Botanical Gardens 3 (1), 56-68

• Probably most widespread environmental education program in the zoo is the guided tour. This study therefore aims to test whether a one hour zoo tour has an influence on the participants’ connection to nature and attitude towards species conservation.
• 269 people who had voluntarily registered for a zoo tour were surveyed before and after the tour. The results prove the positive influence of a very simple environmental education program, even for people with a preexisting high level of connection to nature and positive attitude towards species conservation.

Effects of Positive Reinforcement Training and Novel Object Exposure on Salivary Cortisol Levels under Consideration of Individual Variation in Captive African Elephants (Loxodonta africana)

S Hambrecht, AK Oerke, M Heistermann, J Hartig, PW Dierkes (2021) Animals 11 (12), 3525

• The study aimed to find out whether training and enrichment in the form of a novel object induced physiological changes in captive African elephants. We repeatedly sampled the saliva of ten animals (three zoos) before and after training and the exposure to a novel object for the analysis of cortisol and as a measure of stress and arousal.
• We found higher salivary cortisol levels before and low levels after training. A novel object, in contrast, moderately increased the salivary cortisol levels. We conclude that the higher cortisol values before training could be due to anticipation of the training event. A novel object, in contrast, may have evoked arousal, which led to the observed moderate cortisol increase.

MW Kleespies, L Doderer, PW Dierkes, V Wenzel (2021) Frontiers in Psychology 12, 774333

• The purpose of this study was to develop and test a scale for interest in nature, the Nature Interest Scale (NIS). We selected nine items based on the three dimensions of the psychological interest construct to represent interest in nature. In different steps we tested the factor structure, validity and reliability of the NIS and showed the applicability.
• This study provides a valid and reliable measurement tool for individual interest in nature that can be used for future research.

F Zölzer, AL Burger, PW Dierkes (2021) Animal Microbiome 3: 77

• 621 fecal samples from 31 species were characterized by sequencing the V3–V4 region of the 16S rRNA gene using Illumina MiSeq
• Whereas the microbiota of Carnivora is highly variable and inconsistent within and between species, Perissodactyla and Ruminantia show fewer differences across species boundaries.
• Low-abundance bacterial families show higher fluctuations in the fecal microbiota than high-abundance ones.

MW Kleespies, N Álvarez Montes, AM Bambach, E Gricar, V Wenzel, PW Dierkes (2021) Environmental Education Research 27 (10), 1421-1439

• The study investigated which factors influence attitudes towards species conservation with a total of 3347 participants in seven different countries.
• A mediator analysis provided evidence that the number of visits to zoos, in addition to the direct effect on attitudes towards species conservation, also has a relevant indirect effect with interest in animals as mediators.

S Schneider, S Goettlich, C Diercks, PW Dierkes (2021) Animals 11 (11): 3064

• Captive meerkats show biologically relevant and selective responses to potential acoustic threats before rapidly returning to baseline activity.
• Feature and cluster analysis further revealed the preservation of the graded structure of emitted alarm calls in the zoo.

MW Kleespies, T Braun, PW Dierkes, V Wenzel (2021) Sustainability 13 (4), 1761

• Study 1 provides important information about what children consider to be nature and what they associate with this term.
• Based on study 1, an illustrated measuring instrument for connection to nature could be developed and tested in study 2 on a large number of students.
• In study 3, the instrument was tested together with other established nature connection instruments on the actual target group, students with disabilities.

AL Burger, J Hartig, PW Dierkes (2021) Zoo Biology 40(3): 171-181

• Nocturnal activity budgets of 63 giraffes from 13 different zoos.
• Giraffes spent about half of the 14-hour observation period resting on the ground, either lying down or in REM sleep position.
• Nocturnal behavior of giraffes in zoos likely depends more on individual characteristics such as age, subspecies, and maternity than on environmental factors.

S Schneider, PW Dierkes (2021) Journal of Zoological and Botanical Gardens 2 (2), 146-163

• The software LASER provides very accurate results even under difficult recording conditions, for example in zoos and allows reliable detection of vocalizing individuals within a group.
• In combination with an automated analysis of the bioacoustics data, long-term monitoring would be possible in the future, identifying calls of interest (positive and/or negative) and collecting information on behavioral aspects, social structures, and animal welfare.

M Hahn‐Klimroth, T Kapetanopoulos, J Gübert, PW Dierkes (2021) Ecology & Evolution 11(11): 6015-6032

• Long-term evaluation of behavior using a deep learning software
• Classification of four different behavioral states of different African ungulates
• Optimization of evaluation results by applying post-processing rules

MW Kleespies, PW Dierkes (2020) PloS One 15 (11), e0242004

• We compared the connection to nature scores (using the inclusion of nature scale (INS) and connectedness to nature scale (CNS) and RV (relational values) scores of biologically interested high school students (n = 417) with first year (n = 593) and advanced biology (n = 223) students.
• The gender comparison of RVs and connection to nature showed a significant higher RV score for females while INS and CNS did not show a gender difference

AL Burger, J Fennessy, S Fennessy, PW Dierkes (2020) Ecology & Evolution 10(6): 2917-2927

• First findings on nocturnal behavior patterns of wild Angolan giraffes
• Nocturnal behavior and the influence of ecological factors such as group size, season, and habitat use were analyzed
• Among a group of giraffes at a resting site, several individuals were vigilant while other group members lay down or assumed a sleeping position.
• Simultaneous assumption of sleeping positions within a group was rarely observed.

MW Kleespies, J Gübert, A Popp, N Hartmann, C Dietz, T Spengler, M Becker, PW Dierkes (2020) Frontiers in Psychology 11 (1804), 1-14

• A 1 h guided tour at a zoo increases connection to nature for an age group that is less interested in the topic of zoo and animals. Especially students with an initially low or medium level of connection to nature benefit from the guided tours.
• Small additions (e.g. keeper talks or feeding) to the tour can improve the result, but not all add-ons show similar positive effect.

F Zoelzer, C Engel, PW Dierkes, AL Burger (2020) Journal of Zoo and Aquarium Research 8 (3), 175-180

• Using video recordings of 30 individuals over 12 nights, all allonursing events were analysed using the continuous behaviour sampling method.
• Substantial differences were observed among the four zoos in the frequency and nightly course of allonursing behaviour. In all zoos, allonursing occurred in roughly two periods during the night, which were highly variable in length according to the zoo.

MW Kleespies, PW Dierkes (2020) Sustainability 12 (10), 4277

• This study examined the extent to which high school students, teacher trainees in biology, and biology bachelor students can identify the causes of the global biodiversity loss.
• A new questioning tool was developed and tested on 889 participants.
• It was found that people who felt more connected to nature were more capable of assessing the main causes of risk for global biodiversity

AL Burger, J Hartig, PW Dierkes (2020) Applied Animal Behaviour Science 229 (105012), 1-10

• This study investigated the nightly activity budget of 63 giraffe (Giraffa camelopardalis) from 13 EAZA institutions.
• To analyse rest-activity rhythms of three age classes of giraffe during the dark phase of the night, linear mixed models were applied. Our results show that activity increases with increasing age of giraffe.

S Hambrecht, AK Oerke, M Heistermann, PW Dierkes (2020) Zoo Biology 39 (3), 186-196

• The results demonstrated that salivary cortisol levels of captive African elephants follow the expected diurnal variation characterized by high morning and low afternoon levels during baseline conditions (routine management).
• Salivary cortisol is a useful minimally invasive measure of physiological stress provided that the animals are willing to cooperate and samples can be collected during or immediate (i.e., within a few hours) after the stressor.

J Kögler, I Barbosa Pacheco, PW Dierkes (2020) Journal of Zoo and Aquarium Research 8 (2), 124-132

• This paper evaluates the quantitative research productivity of the 71 members of the Association of Zoological Gardens (Verband der Zoologischen Gärten, VdZ) and analyses aspects of ist qualitative outcome.

MW Kleespies, PW Dierkes (2020) Frontiers in Psychology 11: 209

• We conducted three studies to analyze an existing measurement tool for RVs (relational values) and compared the construct with the concept of connection to nature.
• The results show that RVs and connection to nature are not fundamentally distinct constructs, but overlap.
• Study 3 confirmed RVs as a multidimensional construct with three factors: care, community, and connection.