I am an evolutionary ecologist interested in species interactions, and especially host-parasite interactions, in a rapidly-changing world.
Currently my main focus is on the anthropogenic evolution of infectious organisms. Using experimental lab and field approaches we investigate what changes for parasites (in an evolutionary sense) when host populations become crowded (see here). We also study populations of hole-nesting birds to understand how parasitic faunas in the wild are affected by environmental change, and what this in turn may mean in terms of selection on their hosts.
Here at UiB I am part of the Evolutionary Ecology group but also interact with the Ecological and Environmental Change Research Group, the Theoretical Ecology Group, the Fish Disease Group, and the University gardens where we have field sites.
In a on Mastodon @AMennerat@ecoevo.social
Parasite movements: insights from mark-recapture. A. Mennerat (invited talk), Gordon Research Conference in Movement Ecology, Lucca, June 2023
How does host crowding affect parasite life histories? A mark-recapture in the ectoparasitic salmon louse (Lepeophtheirus salmonis). A. Folk, M. Heino, A. Mennerat (talk), 8th meeting of the Evolutionary Demography Society, March 2023, Paris
Evolution of resistance against vaccines versus drugs (in Norwegian)
Timing of incubation in relation to weather: a study in blue tits and great tits across Europe. L. Hansen Simonsen, F. Coursey & A. Mennerat (poster) 9th international hole-nesting birds conference, Oxford, September 2022
Nåtidens evolusjon. Naturen 144 (03), 72-77 (Fægripris 2020, for popular science article award)
Utvalgets kraft / The power of selection (exhibition, UiB's Natural History Museum)
En vitenskap for fremtiden / A science for the future (exhibition, UiB's Natural History Museum)
The meaning of life is 36.8 (in norwegian)
Sex & Gender (in norwegian)
BBC Earth News: Blue tits embrace aromatherapy
Documentary movie: medication in blue tits (Jacques Mitsch, ARTE 2014: from minute 28'50 onwards)
I have since 2004 held various positions and taught at various levels (from bachelor to doctoral courses), and on a broad range of topics (mainly: evolutionary biology, ecology, behavioural ecology, and parasitology). Currently I am the course coordinator (and main teacher) for the BIO210 course, Evolutionary Biology.
2020-2024 Alexius Folk (main supervisor)
2015-2020 Camilla Håkonsrud Jensen (co-supervisor)
2013-2017 Mathias Stølen Ugelvik (co-supervisor)
Marie Hauso (2022, main supervisor) Should I stay or should I go? The factors affecting male dispersal in an ectoparasite, the salmon louse (Lepeiophtheirus salmonis)
Lisa Hansen Simonsen (2022, main supervisor) Phenological responses of breeding birds to weather variation across Europe
Kiran G. Lee (2021, co-supervisor) The effect of the COVID pandemic on the gender gap in research productivity within academia
Steinar Trengereid (2020, main supervisor) Influence of sex ratio on mating behaviour in a ectoparasite
Marie Danielsen (2017, main supervisor) Effects of perceived predation risk on extra-pair mating in blue tits (Cyanistes caeruleus)
Simon Miljeteig (2015, co-supervisor) Neighborhood effects of extra-pair mating on female fitness: testing model predictions on data from blue tits (Cyanistes caeruleus)
Camilla Håkonsrud Jensen (2014, co-supervisor) Intensive aquaculture: life history responses in energy allocation towards offspring in salmon lice (Lepeophtheirus salmonis)
Pauline Jacquemart (2014, main supervisor) The reproduction - survival tradeoff in Drosophila suzukii
Loris Petry (2014, co-supervisor) Wooden ravines in intensive farmland: climatic and epidemiological refugia for carabid beatles?
Marie Héraude (2013, main supervisor) Reproductive flexibility in an invasive species (Drosophila suzukii)
Stéphanie Robert (2007, co-supervisor) Direct benefits of mate choice and colour signals in the blue tit (Cyanistes caeruleus)
Nicolas Saulnier (2006, main supervisor) Olfaction and consequences of the use of aromatic plants in nests of the blue tit (Cyanistes caeruleus)
Folk, A. and Mennerat, A. 2023. Methods for tagging an ectoparasite, the salmon louse Lepeophtheirus salmonis. BioRxiv, DOI: 10.1101/2023.08.31.555695
Håkonsrud Jensen, C. Weidner, J., Giske, J., Jørgensen, C., Eliassen, S. and Mennerat, A. 2023. Adaptive host responses to infection can resemble parasitic manipulation. Ecology and Evolution, 13:e10318, DOI: 10.1002/ece3.10318
Lee K.G.L., Mennerat A., Carter A, Lukas D, Dugdale H and Culina A. 2023. The effect of the COVID-19 pandemic on the gender gap in research productivity within academia. eLife, 12:e85427, DOI: 10.7554/eLife.85427
Skorping, A. and Mennerat, A. 2022. Hvorfor bør vi være mindre bekymret for utvikling av resistens mot vaksiner enn mot medikamenter? Naturen 146 (4), 145-148, https://doi.org/10.18261/naturen.146.4.3
Eliassen, S., Krama, T., Luoto, S., Krams, R., Mennerat, A., Jõers, P., Elferts, D., Rantala, M.J., and Krams, I.A. 2022. Reply to Jan T. Lifjeld et al.: Female agency and fitness benefits of mixed-paternity broods remain. Proceedings of the National Academy of Sciences 119 (30) e2207741119, https://doi.org/10.1073/pnas.2207741119
Krams, I.A., Mennerat, A., Krama, T., Krams, R., Jõers, P., Elferts, D., Luoto, S., Rantala, M.J., and Eliassen, S. 2022. Extra-pair paternity explains cooperation in a bird species. Proceedings of the National Academy of Sciences 119 (5) e2112004119, https://doi.org/10.1073/pnas.2112004119
Mennerat, A, Charmantier, A, Hurtrez-Bousses, S, Perret, P, and Lambrechts, M.M. 2021. Parasite intensity is driven by temperature in a wild bird. Peer Community Journal, 1:e60, https://doi.org/10.24072/pci. ecology.100012
Culina, A., Adriaensen, F., Bailey, L. D., Burgess, M. D., Charmantier, A., Cole, E. F., …, Mennerat, A., ..., Visser, M. E. 2021. Connecting the data landscape of long-term ecological studies: the SPI-Birds data hub. Journal of Animal Ecology 90 (9), 2147-2160 https://doi.org/10.1111/1365-2656.13388
Gabagambi, N.P., Skorping, A., Chacha, M., Kihedu, K.J., Mennerat, A. 2020. Life history shifts in an exploited African fish following invasion by a castrating parasite. Ecology and Evolution 10 (23), 13225-13235
Mennerat, A. 2020. Nåtidens evolusjon. Naturen 144 (03), 72-77
Mennerat, A., Frago, E. 2019. The response of interacting species to biotic seasonal cues. Peer Community in Ecology, 100022 [doi:10.24072/pci.ecology.100022]
Mennerat, A. 2019. Limited dispersal in a vector on territorial hosts. Peer Community in Ecology, 100013 [doi:10.24072/pci.ecology.100013]
Mennerat A, Charmantier A, Hurtrez-Boussès S, Perret P, Lambrechts MM. 2019. Parasite intensity is driven by temperature in a wild bird. BioRxiv 323311 (ver 4), peer-reviewed and recommended by Peer Community in Ecology [doi:10.1101/323311]
Mennerat, A, Charmantier, A, Jørgensen, C, Eliassen, S. 2018. Correlates of complete brood failure in blue tits: could extra-pair mating provide unexplored benefits to females? Journal of Avian Biology 49(5) [ doi:10.1111/jav.01701 ]
Mennerat A, Ugelvik MS, Håkonsrud Jensen C, Skorping A. 2017. Invest more and die faster: the life history of a parasite on intensive farms. Evolutionary Applications10(9): 890-896 [ doi:10.1111/eva.12488 ]
Ugelvik MS, Skorping A, Moberg O, Mennerat A.2017. Evolution of virulence under intensive farming: Salmon lice increase skin lesions and reduce host growth in salmon farms. Journal of Evolutionary Biology30(6):1136-1142. [ doi:10.1111/jeb.13082 ]
Mennerat A, Lefèvre T. 2017. Evidence of epistasis provides further support to the Red Queen theory of host-parasite coevolution. Peer Community in Evolutionary Biology. [ doi:10.24072/pci.evolbiol.100006 ] [ open access ]
Ugelvik MS, Mo T, Mennerat A, Skorping A. 2017. Atlantic salmon infected with salmon lice are more susceptible to new lice infections. Journal of Fish Diseases 40:311-317. [ doi:10.1111/jfd.12514 ] [ pdf ]
Ugelvik MS, Skorping A, Mennerat A. 2017. Parasite fecundity decreases with increasing parasite load in the salmon louse Lepeophtheirus salmonis infecting Atlantic salmon Salmo salar. Journal of Fish Diseases 40:671-678. [ doi:10.1111/jfd.12547 ] [ pdf ]
Lambrechts MM, Blondel J, Bernard C, Caro SP, Charmantier A, Demeyrier V, Doutrelant C, Dubuc-Messier G, Fargevieille A, de Franceschi C, Giovannini P, Grégoire A, Lucas A, Mainwaring MC, Marrot P, Mennerat A, Perret S, Perret P. 2016. Exploring biotic and abiotic determinants of nest size in Mediterranean great tits (Parus major) and blue tits (Cyanistes caeruleus). Ethology 122:492-501. [ doi:10.1111/eth.12494 ]
Doury G, Pottier J, Ameline A, Mennerat A, Dubois F, Rambaud C, Couty A. 2015. Bioenergy crops and natural enemies: host plant mediated effects of miscanthus on the aphid parasitoid Lysiphlebus testaceipes. Bioenergy Research 8:1275-1273. [ doi:10.1007/s12155-015-9589-y ] [ pdf ]
Mennerat, A., Eslin, P. 2014. À quoi servent les parasites? (What are the benefits of parasites?) in Faune sauvage, biodiversité et santé, QUAE, Morand S., Moutou F., Richomme C. and Gauthier-Clerc M. (eds), pp 51-58
Mennerat A, Hamre L, Ebert D, Nilsen F, Dávidová M, Skorping A. 2012. Life history and virulence are linked in the ectoparasitic salmon louse Lepeophtheirus salmonis. Journal of Evolutionary Biology 25:856-861. [ doi:10.1111/j.1420-9101.2012.02474.x ] [ pdf ]
Mennerat A, Mirleau P, Blondel J, Perret P, Lambrechts MM, Heeb P. 2009. Aromatic plants in nests of the blue tit Cyanistes caeruleus protect chicks from bacteria. Oecologia 161:849-855. [ doi:10.1007/s00442-009-1418-6 ] [ pdf ]
Mennerat A, Perret P, Bourgault P, Blondel J, Gimenez O, Thomas DW, Heeb P, Lambrechts MM. 2009. Aromatic plants in nests of blue tits: positive effects on nestlings. Animal Behaviour 77:569-574. [ doi:10.1016/j.anbehav.2008.11.008 ] [ pdf ]
Mennerat A. 2008. Blue tits (Cyanistes caeruleus) respond to an experimental change in the aromatic plant odour composition of their nest. Behavioural Processes 79:189-191. [ doi:10.1016/j.beproc.2008.07.003 ] [ pdf ]
Mennerat A, Perret P, Caro SP, Heeb P, Lambrechts MM. 2008. Aromatic plants in blue tit Cyanistes caeruleus nests: no negative effect on blood-sucking Protocalliphora blow fly larvae. Journal of Avian Biology 39:127-132. [ doi:10.1111/j.0908-8857.2008.04400.x ] [ pdf ]
Lambrechts MM, Bourgault P, Mennerat A, Galan MJ, Cartan-Son M, Perret P, Doutrelant C, Charmantier A. 2007. Cavity-nesting black rats in distinct Corsican oak habitats and their potential impact on breeding Paridae. Folia Zoologica 56:445-448. [ open access ] [ pdf ]
Mennerat A, Bonadonna F, Perret P, Lambrechts MM. 2005. Olfactory conditioning experiments in a food-searching passerine bird in semi-natural conditions. Behavioural Processes 70:264-270. [ doi:10.1016/j.beproc.2005.07.005 ] [ pdf ]
Ecology & Evolution of parasites
In the ParAnthropE project (NFR, FRIMEDBIO) we investigate how selection on parasites varies with environmental change, how parasites respond, and what trade-offs underlie these responses. To address these questions we use the salmon louse as a model of infectious organism facing rapid environmental change. Please get in touch if interested.
Students having worked with me on parasite ecology & evolution: Mathias Stølen Ugelvik (former PhD student), Camilla Håkonsrud Jensen (former MSc & PhD student), Steinar Trengereid (former MSc student).
Behavioural ecology of host-parasite interactions
Do free-living animals medicate themselves and how? This was the topic of my PhD.
In southern France and Corsica (CEFE, Montpellier) female blue tits Cyanistes caeruleus garnish their nests with aromatic plants. In a series of field experiments over 4 years, I have shown that by doing so they reduce bacterial loads on their offspring, who then grow and develop better. This behaviour thus appears as a special kind of maternal care taking the form of preventive medication. It was featured in a documentary movie by Jacques Mitsch: "Les animaux médecins" (2014) and on BBC Earth News.
I also study this behaviour in our local nestbox population in Bergen - get in touch if interested!
Effects of predation risk on behaviour and extra-pair mating
Theory suggests that extra-pair mating might create incentives for males to invest more into behaviours that are beneficial for the neighbourhood, because their potential reproductive success is spread out among several nearby nests. Using longitudinal data combined with field experiments in the blue tit Cyanistes caeruleus, I have investigated the links between predation risk, extra-pair mating and parental behaviour.
Students having worked with me on extra-pair mating and predation risk: Marie Stine Danielsen (former MSc student), Simon Miljeteig (former MSc student)
If you are looking for a master project and are interested in ecology & evolution, parasites, animal behaviour or a combination of these, please get in touch !
I have been using a wide range of organisms depending on the research question (bacteria, parasitoid wasps, Drosophila flies, parasitic blow flies, salmon lice, birds). Here is some more information on my two favourite study species.
The salmon louse Lepeophtheirus salmonis
What exactly are salmon lice? What is their biology and what do they do to their hosts? What do we know about them?
The Salmon Lice Research Centre (SLRC, Bergen) has prepared a little overview here: The Atlantic salmon louse, Lepeophtheirus salmonis
The blue tit Cyanistes caeruleus
Blue tits are my favourite study species; I have been watching their behaviour for about 30 years (yes, that long!) and they have been involved in my research since 2003. I have studied their olfactory abilities, their behavioural responses to parasitism, and more recently their extra-pair mating behaviour.
Blue tits are widely used as a model species in evolutionary ecology because they can be ringed and their reproduction can be monitored using nestboxes, which they readily adopt. This allows to collect large amounts of longitudinal data that can be used in many ways, and in particular to study processes of adaptive evolution in the wild.
The blue tit is a non migratory bird species, which means it can be seen throughout the year in Europe. It is a territorial, socially monogamous species where different pairs breed on different, adjacent territories. Copulations (including extra-pair copulations) occur in early spring. Females build a nest in a cavity (or a nestbox) and lay clutches of 6-12 eggs, which hatch after ca. 2 weeks and the chicks fledge ca. 3 weeks later. The young rely on food and protection provided by both parents.