Dr Sue Walker

Head of Science

  • Qualifications BSc MSc PhD
  • Focus area
  • Location
    Africa At the Zoo
  • Additional Information Chair EAZA Reproductive Management Group
    Vice Chair of Ethics & Special Initiatives: International Society of Wildlife Endocrinology
    Member EAZA Research Committee
    Vice Chair of Nature's SAFE

My remit within the zoo is to strategically drive Chester Zoo Science forward though the provision of an evidence-based approach to our conservation initiatives, the development of collaborative science partnerships in academia and industry and develop science training and professional development opportunities.    

Our vision for Chester Zoo science is that it is applied and has conservation impact. It enables and advances conservation activities through scientific evidence, trains and empowers ourselves and others with relevant scientific skills to take conservation action and it influences and informs policy and management to prevent extinction.

I am passionate about delivering opportunities for applied scientific training.  Over the past 10 years I have established Chester Zoo’s Science Scholars and Fellows scheme and our science industrial placement opportunities all of which aims to maximise our conservation impact by providing evidence to influence conservation management, while expanding and equipping a new generation with the skillset required to address global conservation challenges.

I have worked within zoo science and the field of animal reproductive science for over 25 years. I joined Chester Zoo in 2007 as the zoo’s Wildlife Endocrinologist, became Scientific Manager in 2013 and Head of Department in 2014. Previous to this I worked within reproductive biology departments at the University of Guelph, Toronto Zoo, Smithsonian Conservation Biology Institution and the University of Liverpool. I co-founded EAZA Reproductive Management Group and the International Society of Wildlife Endocrinology and I am a member of the EAZA Research Committee.  I have set-up wildlife endocrinology laboratories around the globe in six different countries. My personal research interests are aimed at providing answers that will lead to effective population management and long-term population fitness.

Our science department believes what makes us unique is our ability to care for, breed, and support populations of a diverse range of wildlife while simultaneously engaging and inspiring people to care and act for nature. Consequently, the science we focus includes both biological and social sciences including expertise in Behaviour and Welfare, Conservation Physiology and Reproduction, Population Health and Ecological Monitoring and Social Sciences.  We are cross-cutting within the organization and work with several teams, supporting a variety of conservation projects with evidence to inform decision making.

Key publications

Edwards K, Pilgrim M, Brown  JL , Walker S.L, 2019 Irregular Ovarian Cyclicity is Associated with Adrenal Activity in Female Eastern Black Rhinoceros (Diceros bicornis michaeli) General and Comparative Endocrinology 289:113376  https://doi.org/10.1016/j.ygcen.2019.113376

Antwis R, Edwards KE, Unwin B, Walker S.L, 2019 Rare gut microbiota associated with breeding success, hormone metabolites and ovarian cycle phase in the critically endangered eastern black rhino. TSS Microbiome 7(1) https://doi.org/10.1186/s40168-019-0639-0

Morrison J., Higginbottom T.P., Symeonakis E., Jones M.J., Omengo  F., Walker S.L, Cain B. 2018 Detecting vegetation change in response to confining elephants in forests using MODIS time-series and BFAST.  Remote Sensing, 10(7), 1075. https://doi.org/10.3390/rs10071075

Cowl, V. B., Walker, S. L., Feltrer, Y. 2018. Assessing the efficacy of deslorelin acetate implants (Suprelorin®) in alternative placement sites. Journal of Zoo and Wildlife Medicine, 49(1), 1-8. https://doi.org/10.1638/2017-0153R.1

Lea, J.M., Walker, S.L., Kerley, G.I., Jackson, J., Matevich, S.C., Shultz, S. 2017 Noninvasive physiological markers demonstrate link between habitat quality, adult sex ratio and poor population growth rate in a vulnerable species, the Cape mountain zebra. Functional Ecology, 32(2), 300-312. https://doi.org/10.1111/1365-2435.13000

Yarnell, Y. and Walker, S. L. 2017.  Environmental conditions impact upon faecal glucocorticoid metabolite concentrations; a case study in Grevy’s Zebra (Equus grevyi). African Journal of Wildlife Research, 47(2): 138–143. https://doi.org/10.3957/056.047.0138

Wong, E.P., Yon, L., Walker, S.L., Purcell, R., Campos-Arceiz, A. 2016. Concentrations of faecal glucocorticoid metabolites in Asian elephant’s dung are stable for up to 8 h in a tropical environment. Conservation Physiology, 4(1). https://doi.org/10.1093/conphys/cow032

Edwards, K.E., Trotter, J., Jones, M., Steinmetz, H., Walker, S.L. 2015. Investigating temporary acyclicity in a captive group of Asian elephants (Elephas maximus): relationship between management, adrenal activity and social factors. General and Comparative Endocrinology, 225, 104-116. 10.1016/j.ygcen.2015.09.011

Sanderson, J.L., Nichols, H.J., Marshall, H.H., Vitikainen, E.I.K., Thompson, F.J, Walker, S.L., Cant, M.A., Young, A.J. 2015. Elevated glucocorticoid concentrations during gestation predict reduced reproductive success in subordinate female banded mongooses. Biology Letters, 11(10). http://rsbl.royalsocietypublishing.org/content/11/10/20150620

Edwards, K.L., Walker, S.L., Dunham, A.D., Pilgrim, M., Okita-Ouma, B., Shultz, S. 2015. Low birth rates and reproductive skew limit the viability of Europe’s captive eastern black rhinoceros Diceros bicornis michaeliBiodiversity and Conservation,24(11), 2831-2852. https://doi.org/10.1007/s10531-015-0976-7

Edwards, K.L., Shultz, S., Pilgrim, M. and Walker, S.L. 2015. Male reproductive success is correlated with testosterone in the eastern black rhinoceros (Diceros bicornis michaeli), General and Comparative Endocrinology, 213, 40-49.https://doi.org/10.1016/j.ygcen.2014.12.015

Edwards, K.L., Shultz, S., Pilgrim, M., Walker, S.L. 2014. Irregular ovarian activity, body condition and behavioural differences are associated with reproductive success in female eastern black rhinoceros (Diceros bicornis michaeli). General and Comparative Endocrinology, 214, 186-194. https://doi.org/10.1016/j.ygcen.2014.07.026

Antwis, R.E., Purcell, R., Walker, S.L., Narayan, E., Fidgett, A.L., Preziosi, F.R. 2014. Effects of visible implanted elastomer marking on physiology traits of frogs. Conservation Physiology, 2(1), 1-9. https://doi.org/10.1093/conphys/cou042

Sanderson, J., Young, A., Hodge, S., Kyabulima, S., Walker, S.L., Cant, M. 2014. Hormonal mediation of a carry-over effect in a wild cooperative mammal. Functional Ecology, 28(6), 1377-1386.  https://doi.org/10.1111/1365-2435.12307

Edwards, K.L., McArthur, H.M., Liddicoat, T., Walker, S.L. 2014.  A practical field extraction method for non-invasive monitoring of hormonal activity in black rhinoceros, Diceros bicornis. Conservation Physiology, 2(1). https://doi.org/10.1093/conphys/cot037

Watson, R., Munro, C., Edwards, K., Norton, V., Brown, J.L., Walker, S.L. 2012. Development of a versatile enzyme immunoassay for non-invasive assessment of glucocorticoid metabolites in a diversity of taxonomic species. General and Comparative Endocrinology, 186, 16-24. https://doi.org/10.1016/j.ygcen.2013.02.001

Partners and Collaborators