Research interests

I am an evolutionary ecologist interested in the sociality-health-fitness-nexus in wildlife. More specifically, I am aiming at furthering our understanding of how interactions between pathogens and their hosts shape host genetics, physiology, behaviour, and sociality. I use a combination of observational and molecular methods, including detailed focal protocols, social relationship indices and social network analyses on the behavioural side as well as genetics and genomics, parasite microscopy and enzyme-immunoassays on the molecular side. To date, I have had the fantastic opportunity to work with two highly social mammals with vastly different social systems: Barbary macaques (Macaca sylvanus) and meerkats (Suricata suricatta). I am also interested in the effects of life history trajectories on health and fitness, the interplay between behaviour and immune signalling, and the effects of senescence on host physiology, behaviour and immune competence. 

The questions that keep me up at night and I would love to shed a light one are:

  • How do infections impact host physiology and behaviour, particularly social behaviour?
  • Which factors contribute to host exposure, susceptibility and resistance to pathogens?
  • How are pathogens transmitted through a social network, and which characteristics make individuals, groups or populations vulnerable to or resilient against the spread of disease?
  • What is the (relative) role of immune gene diversity and specific immune genes for infection risk?
  • How are mating and/ or dispersal choices influenced by immune genes, and what are the resulting fitness effects?
  • (How) do pathogens shape host population genetics?

Always eager to broaden my mind, I am also delving into the fascinating world of bioinformatics, programming and data science, and teaching.


Scientific projects

I have been addressing the interplay between pathogens and host health and behaviour from different angles: 

In my Ph.D., I capitalized on routine anthelmintic treatment of my study population of Barbary macaques, allowing me to use an experimental study design. Working completely non-invasively, I used a range of physiological markers and detailed behavioural observation to investigate both directions of the host-pathogen relationship between the macaques and their gastrointestinal parasites: I investigated the effect of parasite infections on individual social behaviour, immune function and physiology to assess the costs of infections. I also assessed the behavioural and physiological host characteristics contributing to individual reinfection risk, simultaneously measuring parasite exposure and susceptibility.

Currently, I am privileged to be part of a collaboration with the Kalahari Meerkat Project and benefit from the wealth of long-term data available. I am working on tuberculosis infections reported in the study population since the late 1990s, aiming at quantifying and explaining variation in tuberculosis infection courses. I am focussing on the role of host immune genes for susceptibility and resistance to infections, assessing major histocompatibility complex (MHC) gene composition and functional diversity. Beyond the level of individual susceptibility and resistance, I am investigating the possibility of TB-mediated selection and the corresponding effect of the pathogen on population dynamics. Another research trajectory are the Trace-amine-associated receptors, which are implicated to play a role in olfactory communication and mate choice, to test whether they are involved in meerkats migration and mate choice decisions, in concert with MHC constitution.


Müller-Klein N, Risely A, Schmid D W, Manser M, Clutton-Brock T, Sommer S (2022). Two decades of tuberculosis surveillance reveal disease spread, high levels of exposure and mortality, and marked variation in disease progression in wild meerkats. Transboundary and Emerging Diseases.

Sadoughi B, Anzà S, Defolie C, Manin V, Müller-Klein N, Murillo T, Ulrich M, Wu D (accepted) Parasites in a social world: Lessons from primates. In: Animal Behavior and Parasitism. Edited by Vanessa Ezenwa, Sonia Altizer, and Richard Hall, Oxford University Press.

Risely A, Schmid D, Müller-Klein N, Wilhelm K, Clutton-Brock T, Sommer S (2022) Gut microbiota individuality is contingent on temporal scale and age in wild meerkats. Proceedings of the Royal Society B.

Donadio J, Risely A, Müller-Klein N, Wilhelm K, Clutton-Brock T, Manser M B, & Sommer S (2022). Characterizing tuberculosis progression in wild meerkats (Suricata suricatta) from fecal samples and clinical signs. The Journal of Wildlife Diseases, 58(2), 309-321.

Schülke O, Anzà S, Crockford C, De Moor D, Deschner T, Fichtel C, Gogarten J, Kappeler P, Manin V, Müller-Klein N, Prox L, Sadoughi B, Touitou S, Wittig R, Ostner, J. (2022). Quantifying within-group variation in sociality—covariation among metrics and patterns across primate groups and species. Behavioral Ecology and Sociobiology, 76(4), 1-18.

Behringer V, Müller-Klein N, Strube C, Schülke O, Heistermann M, Ostner J (2021). Responsiveness of fecal immunoglobulin A to HPA-axis activation limits its use for mucosal immunity assessment. American Journal of Primatology, 83(12), e23329.

Gogarten J, Calvignac-Spencer S, Nunn C, Ulrich M, Saiepour N, Nielsen H, Deschner T, Fichtel C, Kappeler P, Knauf S, Müller-Klein N, Ostner J, Robbins M, Sangmaneedet S, Schülke O, Surbeck M, Wittig R, Sliwa A, Strube C, Leendertz F, Roos C, Noll A (accepted) Metabarcoding of eukaryotic parasite communities describes diverse parasite assemblages spanning the primate phylogeny. Molecular Ecology Resources.

Müller-Klein N, Heistermann M, Strube C, Schülke O, Ostner J (2019) Exposure and susceptibility drive reinfection with gastrointestinal parasites in a social primate.
Functional Ecology, 33, 1088 – 1098.

Müller-Klein N, Heistermann M, Strube C, Morbach Z, Lilie N, Franz M, Schülke O, Ostner J (2019) Physiological and social consequences of gastrointestinal nematode infection in a nonhuman primate. Behavioural Ecology, 30 (2), 322–335.

Paschek N, Müller N, Heistermann M, Ostner J, Schülke O (2019) Subtypes of aggression and their relation to anxiety in Barbary macaques. Aggressive Behaviour, 45, 120 – 128.

Müller N, Heistermann M, Strube C, Schülke O, Ostner J (2017) Age, but not anthelmintic treatment, is associated with urinary neopterin levels in semi-free ranging Barbary macaques. Scientific Reports, 7, 41973.

Müller N, Ostner J, Schülke O, Walter L (2014) Towards the non-invasive assessment of MHC genotype in wild primates: Analysis of wild Assamese macaque MHC-DRB from faecal samples. American Journal of Primatology, 3, 230 – 238.


  • Dr. Nadine Müller-Klein
    Institute of Evolutionary Ecology
    and Conservation Genomics
    University of Ulm
    Albert-Einstein-Allee 11
    89081 Ulm
    Tel: +49 731 5022686
    Email: nadine.mueller-klein()
  • nadine.mueller.klein()