Zoo Biology, Uni Frankfurt


Environmental Behavior in the Private Sphere–Development and Evaluation of the Personal Pro-Environmental Behavior (PPB) Scale

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.

Measuring Interest: Development and Application of a Three-Dimensional Situational Interest Short Scale

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.


An unsupervised learning approach to evaluate questionnaire data--what one can learn from violations of measurement invariance

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.


Accelerometry reveals nocturnal biphasic sleep behavior in wild giraffe

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.

Nocturnal behavioral patterns of African ungulates in zoos

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.

Big Mama is watching you—A bedtime story about how giraffes sleep

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!

Connection to nature for sustainable development at universities - What should be done?

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.

Research partners

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

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

Students’ technology acceptance of computer-based applications for analyzing animal behavior in an out-of-school lab

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.

A large-scale study on the nocturnal behavior of African ungulates in zoos and its influencing factors.

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.

The different values of nature: a comparison between university students’ perceptions of nature’s instrumental, intrinsic and relational values.

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.

Time series cluster analysis reveals individual assignment of microbiota in captive tiger (Panthera tigris) and wildebeest (Connochaetes taurinus)

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.


Connection to nature of university students in the environmental field—An empirical study in 41 countries

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.

How university students assess the planetary boundaries: A global empirical study

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.

Can a guided zoo tour improve connection to nature?

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.

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

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.

Diurnal and Nocturnal Behaviour of Cheetahs (Acinonyx jubatus) and Lions (Panthera leo) in Zoos

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.

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

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.

The importance of the Sustainable Development Goals to students of environmental and sustainability studies—a global survey in 41 countries

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.

BOVIDS: A deep learning-based software for pose estimation to evaluate nightly behavior and its application to Common Elands (Tragelaphus oryx) in zoos

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.

Environmental education in zoos—Exploring the impact of guided zoo tours on connection to nature and attitudes towards species conservation.

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)

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.

Nature Interest Scale (NIS) - Development and evaluation of a measurement instrument for individual interest in nature.

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.

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

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.

Identifying factors influencing attitudes towards species conservation – a transnational study in the context of zoos

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.

Discrimination of acoustic stimuli and maintenance of graded alarm call structure in captive meerkats.

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.

Measuring Connection to Nature – A Illustrated Extension of the Inclusion of Nature in Self Scale

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.

Biological and environmental factors as sources of variation in nocturnal behavior of giraffe.

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.

Localize Animal Sound Events Reliably (LASER): A new software for sound localization in zoos.

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.

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

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

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

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

Nightly selection of resting sites and group behavior reveal antipredator strategies in giraffe.

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.

Connecting high school students with nature – how different guided tours in the zoo influence the success of extracurricular educational programs.

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.

A comparative study of nightly allonursing behaviour in four zoo- housed groups of giraffes (Giraffa camelopardalis).

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.

Personal assessment of reasons for the loss of global biodiversity—an empirical analysis.

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

Shedding light into the dark: age and light shape nocturnal activity and sleep behaviour of giraffe.

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.

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

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.

Evaluating the quantitative and qualitative contribution of zoos and aquaria to peer-reviewed science.

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.

Exploring the construct of relational values: an empirical approach.

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.