Department of Animal Ecology and Tropical Biology


Dr. Mark Otieno
Georg Forster Experienced Research Fellow of the Alexander von Humboldt Foundation
Office No. C041
Department of Animal Ecology and Tropical Biology / Biocenter
Universität Würzburg
Am Hubland, 97074
Würzburg, Germany
E-mail: mark.otieno@uni-wuerzburg.de
ORCiD: 0000-0002-8509-3298
webiste: https://otienolab.com


  1. Impacts of farm management and landscape context on pollination of legume crops in lower Franconia, Germany


Legume crop production benefits from pollination, an essential ecosystem service that is known to increase yield, and quality of an estimated 75% of all global crops, supplying humans with essential micro-nutrients. Both the composition and configuration of the landscapes surrounding farms and the management practices are key factors driving the abundance and diversity of wild pollinators. At present, the determinants of unmanaged bee abundance and pollination services are rarely understood well enough to guide farmers who want to use them for pollination, leaving farmers dependent on honeybees for pollination. By focusing on field beans (Vicia faba L.: Leguminosae), an economically important crop grown in Lower Franconia, Germany, the project aims to quantify context-specific contributions of economically-important pollinators with a view of promoting farm management tactics and landscape elements that support unmanaged bee fauna. It is envisaged farmers will gain knowledge and awareness of the economic contribution of unmanaged bees to their businesses and will increase the use of pest and farm management approaches that reduce risk to bees. It is also envisaged that the findings from this research will be adopted by farmers in other regions with similar cropping systems.

  1. Influence of elevated levels of ozone and carbon dioxide on flower visitation by bees and consequences for field bean seed set


Recent studies link increased levels of ozone and carbon dioxide to plant performance and plant-herbivore interactions, but interactive effects on plant-pollinator interactions and ecosystem services have been rarely studied. This project experimentally tested, whether elevated levels of these two gases alter plant growth, flower visitation and yield in field beans (Vicia faba Leguminosae). In a full-factorial experimental set-up, plants were exposed to (i) ambient levels of carbon dioxide and ozone (control), (ii) carbon dioxide-enriched (900 ppm), (iii) ozone-enriched (120 ppb) or (iv) carbon dioxide (900 ppm) + ozone (120 ppb) - enriched treatments. The project examined how flowering phenology, flower visitation by two wide-spread bee pollinators, Bombus terrestris and Osmia cornuta, and consequent yields responded to the treatments.  Carbon dioxide enrichment enhanced visitation by B. terrestris, consequently resulting in increased seed set whereas elevated ozone negatively affected visitation of O. cornuta to the flowers and seed set. With rising levels of greenhouse gases, both the direct and indirect effects of carbon dioxide and ozone on bees pollinating legumes are likely to become widespread.

  1. Flower visitors of Streptocarpus teitensis: Implications for conservation of a critically endangered African violets species in Kenya


The African violets are endangered plant species restricted mainly to the Eastern Arc Mountains biodiversity hotspots found in Kenya and Tanzania. These plants grow well in shaded environments with high humidity. Given the primarily restricted geographical range of the African violets and anecdotal evidence of dependence on insect vectors to facilitate their reproduction, understanding their pollination biology is vital for its conservation.  We conducted an empirical study to establish the role of flower visitors in the reproduction of a locally endemic and critically endangered species of the African violets in Taita Hills, Kenya (Streptocarpus teitensis).  The study found S. teitensis to enhance its fruit set by up to 47.83 % when flowers are visited by insects. This plant shared a network of flower visitors with 22 other wild co-flowering plants species including a locally endemic species, Impatiens teitensis. We also found the amount of forest cover in the surrounding landscape to have a positive influence on the abundance of insect visitors to S. teitensis flowers. From these findings, it is important to safeguard the flower visitors shared between the African violets and co-flowering plants. This will potentially reduce the risks associated with pollinator losses and enhance the chances of survival for this critically endangered species.

  1. Conserving an endangered African wild coffee species through management of its pollinators in Taita Hills biodiversity hotspots of Kenya


This project aimed at establishing the role of insect flower visitors in the reproductive success of a locally endemic species of the African wild coffee, (Coffea fadenii Bridson: Rubiaceae), to propose measures of promoting its conservation through pollinator and habitat management. Specifically, the study aimed at (i) establishing the relationship between flower visitor abundance and pollination of C. fadenii, (ii) developing a network of co-flowering plants visited by flower visitors of C. fadenii  and, (iii) quantifying the influence of the amount of forest cover in the surrounding landscape on both the diversity and abundance of flower visitors and pollination of C. fadenii.


2006 – 2011       Ph.D., Agroecology

University of Reading, United Kingdom

Thesis title: “Assessing the drivers of pollinator and natural pest enemy communities in pigeon pea and field beans crops.”

2002 – 2005       M.Sc., Animal Ecology

Kenyatta University, Kenya

Thesis title: “The effects of herbivory on interactions of pollinators and flowers in Acacia spp. (Fabaceae, Mimosoideae) in Laikipia District of Kenya.”

1998 – 2002       B.Ed. (Sc), Biological Sciences

Kenyatta University, Kenya

Short Courses

Agroecological approaches for sustainable intensive Agriculture, pedagogy, bee course, wildlife management and conservation, GIS applications, statistical modelling, systematic review, research methods in savannah ecology.


2019 – date: Alexander von Humboldt - Georg Forster Experienced Research Fellow, Universität Würzburg, Germany

Researching crop pollination and pest control services in Germany designed to promote the transfer of knowledge and methods to advance research development in Kenya.

2013  – 2019: Lecturer, University of Embu, Kenya

Taught courses in: General and applied entomology, ecology, agroecosystem management, environmental biology, biodiversity and conservation science.

Developed MSc (Entomology) and BSc (Range Management) curricula.

Achieved above 95% aggregate score in student-lecturer evaluation from 2014 to 2019.

2013 – 2014: Postdoctoral Research Associate, Pennsylvania State University, USA

Coordinated the USDA-SCRI funded project on Integrated Crop Pollination for apple and pumpkin crops in the State of Pennsylvania, USA.

2012 – 2013: Training Coordinator, Tropical Biology Association, East and West Africa

Coordinated an EU –ACP funded DRECA programme (Developing Research Capacity among African Scientists) on proposal writing, designing projects, and publishing.

2009 – 2012: Research Scientist, University of Reading, UK

Wrote reviews on ecosystem services for poverty alleviation.

Developed protocols for the ESPA project on managing ecosystem services to reduce poverty and vulnerability in East African coffee landscapes.

Investigated the diversity and interactions of pollinator communities and crop flowers in England’s urban habitats.

2007: Consultant Ecologist, National Museums of Kenya, Kenya

Developed conservation and management tools for pollinator communities underpinning crop production in smallholder farmlands through an ecosystem approach to enhance sustainable agriculture.

2004 – 2006: Course Coordinator, Tropical Biology Association, Africa and Madagascar

Coordinated tropical ecology and conservation field courses in Kenya, Uganda, Tanzania and Madagascar.

2004: Consultant Ecologist, Biodiversity Conservation Programme, CDTF, EU

Conducted an ecological baseline survey in LUMO Community Wildlife Sanctuary and evaluated the project impact on local livelihoods.


2015 – 2019        Dean of Students, University of Embu

2015 – 2019        Secretary, Student Welfare Committee, University of Embu

                               Member, University Senate and over twenty five committees at University of Embu

2014 – 2019        Academic Leader, Range Management Program, University of Embu

2014                     Ag. Chairman, Department of Agricultural Resource Management, University of Embu

2010 – 2011       Students Mentor, Center for Agri-Environmental Research, University of Reading

2000 – 2002       Academic Representative, Department of Botany, Kenyatta University

Research Portfolio

My research experience spreads across working in Europe, North America and Africa. My current research project is investigating how landscape context (composition and configuration) and field scale factors influence beneficial insect community delivering pollination and pest control services to field beans (Vicia faba: Leguminosae) crop in Lower Franconia, Germany.  My goal is to use the information generated from the current project to promote farm management tactics and conserve landscape contexts that support beneficial arthropods in legumes cropping system in Bavaria.Further details appear under Research webpage.  Out of the current fellowship, I conducted a full-factorial greenhouse experiment on how two ubiquitous European bees, Bombus terrestris and Osmia cornuta, respond to flowers of field beans plants previously exposed to elevated levels of ozone and carbon dioxide.

In Kenya, my lab is implementing two projects on the conservation of a critically endangered African violet species and an endangered species of wild coffee through management of their pollinators.

My postdoctoral work at Pennsylvania State University involved supervising and conducting studies that defined the community composition and abundance of bees in pumpkin and apple crops in Pennsylvania, and the value of wild bees for providing pollination services in these crops. I evaluated the effects of landscape, habitat manipulation and supplementation with managed bees on bee abundance and pollination services. This work resulted in the increased ability of pumpkin and apple growers to pay more attention to the pollinators in their farms and cut back on managed bee rentals as they realized they had substantial native bee populations in fields surrounded by suitable habitat.

I also worked as a Research Scientist on a joint project between the University of Reading and University of Bristol (UK) where we studied pollinator communities underpinning crop production and wild flower species in urban landscapes across South East England. During this time, I organized project development workshops and wrote reviews on Ecosystem Services for Poverty Alleviation (ESPA) on coffee productions systems in East Africa and pollinators of African crops.

I consulted for the National Museums of Kenya on an FAO/GEF/UNEP project aimed at developing conservation and management tools for pollinator communities underpinning crop production through an ecosystem approach to enhance sustainable agriculture.

  1. Otieno, M., Joshi, N.K. and Rutschmann, B. (2020) Flower visitors of Streptocarpus teitensis: Implications for conservation of a critically endangered African violet species in Kenya. PeerJ. Accepted Article ID: 49540.  In press.
  2. Nderitu, W.P., Jonsson, M., Arunga, E., Otieno, M., Muturi, J.J. and Wafula, G.O. (2020) Tomato leaf miner (Tuta absoluta) incidence and severity in Kirinyaga County, Kenya. East African Agricultural and Forestry Journal. Accepted Article ID: TEAF-2019-0020R1. In press.
  3. Otieno, M., Steffan-Dewenter, I., Potts, G. S., Kinuthia, W., Kasina, M.J., Garratt, P.D.M. (2020). Enhancing legume crop pollination and natural pest regulation for improved food security in changing African landscapes. Global Food Security. Volume 26, 100394 https://doi.org/10.1016/j.gfs.2020.100394
  4. Nderitu, W.P., Jonsson, M., Arunga, E., Otieno, M., Muturi, J.J. and Wafula, G.O. (2020) Combining Host Plant Resistance, Selective Insecticides, and Biological Control Agents for Integrated Management of Tuta absoluta. Advances in Agriculture. Vol. 2020, Article ID 6239491, https://doi.org/10.1155/2020/6239491.
  5. Döke, A.M., McGrady, C.M., Otieno, M., Grozinger, C.M. and Frazier, M. (2019) Colony Size, Rather Than Geographic Origin of Stocks, Predicts Overwintering Success in Honey Bees (Hymenoptera: Apidae) in the Northeastern United States. Journal of Economic Entomology. doi.org/10.1093/jee/toy377.
  6. Nderitu, W.P., Muturi, J.J., Otieno M., Arunga, E. and Jonsson, M. (2018) Tomato Leaf miner (Tuta absoluta) (Meyrick 1917) (Lepidoptera: Gelechiidae) prevalence and farmer management practices in Kirinyanga County, Kenya. Journal of Entomology and Nematology, doi.org/10.5897/JEN2018.0208.
  7. Lichtenberg E., Otieno, M., et al.  (2017) A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes. Global Change Biology: DOI: 10.1111/gcb.13714.
  8. Otieno, M., Joshi, N.K., Rajotte, E.G., Fleischer, S.J. and Biddinger D.J. (2016) Proximity to Woodland and Landscape Structure Drives Pollinator Visitation in Apple Orchard Ecosystem. Frontiers of Ecology and Evolution. DOI: dx.doi.org/10.3389/fevo.2016.00038.
  9. Stanley, D. Otieno, M., Steijven, K., Piironen, T., Willmer, P. and Nuttman, C. (2016) Pollination ecology of Desmodium setigerum (Fabaceae) in Uganda; Do big bees do it better?  Journal of Pollination Ecology. Vol. 18.
  10. Otieno M., Sheena C.S., Woodcock, B.A., Wilby, A., Vogiatzakis, I.N., Mauchline, A.L., Gikungu, M.W. and Potts S.G. (2015). Local and landscape effects on bee functional guilds in pigeon pea crops in Kenya. Journal of Insect Conservation. 19(4); 647-658. DOI: 10.1007/s10841-015-9788-z.
  11. Garibaldi, L.A., Otieno, M. et al. (2015) Trait matching of flower visitors and crops predicts fruit set better than trait diversity. Journal of Applied Ecology. 52 (6); 1436-1444. DOI: 10.1111/1365-2664.12530.
  12. Joshi N. K., Leslie, T., Rajotte, E.G., Kammerer, M.A., Otieno M. and Biddinger, B.J. (2015). Comparative trapping efficiency to characterize bee abundance, diversity, and community composition in apple orchards. Annals of the Entomological Society of America. 108(5):785-799. DOI: 10.1093/aesa/sav057.
  13. Garibaldi, L.A., Otieno, M. et al. (2013). Wild insects enhance global crop pollination even when honey bees are abundant. Science: 339(6127); 1608-1611.
  14. Kennedy, C., Otieno, M. et al. (2013). A global quantitative synthesis of local and landscape effects on native bee pollinators across heterogeneous agricultural systems. Ecology Letters. 16(5); 584-599.
  15. Norfolk, O., Sadiki, L., Broughton, B., Otieno, M. and Nuttman, C. (2013) Tea breaks: how flower-visitors can benefit from un-planned floral buffer-strips in a Tanzanian tea plantation. African Journal of Ecology. 51; 380–384.
  16. Otieno, M., Woodcock, B.A., Wilby, A., Vogiatzakis, N.G., Mauchline, A.L., Gikungu, M and Potts, S.G. (2011) Local management and landscape drivers of pollination and biological control services in a Kenyan agro-ecosystem. Biological Conservation. 144 (10); 2424-2431.
  17. Nuttman, C.V., Otieno, M., Kwapong, P.K., Combey, R., Willmer, P.G. and Potts, S.G. (2011) Aerial pan-trapping: a method for assessing insect pollinators in tree canopies. Kansas Journal of Insect Science. 84(4); 260 - 270.

Research Grants

  1. Alexander von Humboldt Foundation grant to assess the local and landscape factors driving field beans (Vicia faba) pollination and pest regulation in Germany.
  2. British Ecological Society - Ecologists in Africa grant to investigate wild coffee pollination in biodiversity hotspots of south-eastern Kenya.
  3. The Mohamed bin Zayed Species Conservation Fund to study African violet pollination in Taita Hills, Kenya.
  4. National Resource Conservation Service - Conservation Innovation Grant.
  5. British Ecological Society Small Ecological Project Grant.
  6. University of Reading Alumni Grant to present PhD work at the INTECOL Conference in Brisbane, Australia.
  7. British Ecological Society Student Grant.
  8. Society for Conservation Biology Travel Grant.

Research Collaborations

Universidad Nacional de Río Negro, Argentina: 2020 - 2022

Contributing to a global project exploring the predictive ability of data-driven, statistical and mechanistic models on crop pollination (https://unrn.academia.edu/LucasGaribaldi).    

Agroscope, Switzerland: 2020 - 2021 

Collaborating on the “Poshbee” project by contributing data on the effect of pesticide use on bee community composition aimed at understanding how much pesticide exposure in bees is modulated by their functional traits such as body size or phenology (https://www.agroscope.admin.ch/agroscope/en/home/topics/environment-resources/biodiversity-landscape/research-projects/ensure-wild-honey-beens-pollination.html).      

University of Cambridge, UK: 2019 - 2020 

Engaged in the “Nudging for Nature” project aimed at identifying behaviourally informed interventions for effective biodiversity conservation (https://www.facebook.com/tropicalbiologyassociation/posts/kicking-off-2020-with-a-mini-alumni-reunion-for-tba-alumni-mark-otieno-diogo-ver/2848899438465024/).

University of Washington, USA: 2014 - 2017                                                     

Contributed data to a global synthesis on the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes (http://entomology.wsu.edu/david-crowder/research/).                                                                                                                               

Universidad Nacional de Río Negro, Argentina: 2012 – 2013      

Contributed to a project focusing on the role of wild pollinators in setting fruits in a set of crops across the planet (https://unrn.academia.edu/LucasGaribaldi).                                                      

National Center for Ecological Analysis and Synthesis, USA: 2011 – 2013         

Contributed to a project on global quantitative synthesis of the effects of local and landscape elements on wild bee pollinators in agroecosystems (https://www.nceas.ucsb.edu/workinggroups/restoring-ecosystem-service-degraded-landscapes-native-bees-and-crop-pollination).