Ecologie comportementale

Samuel CARO

Chargé de recherche au CNRSCaro ID fieldwork2 sm rotated

Campus du CNRS
1919, route de Mende
34293 Montpellier cedex 5

Tél : +33/0 4 67 61 33 08
Fax : +33/0 4 67 61 33 36
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Bureau 208

Short CV

2017         Habilitation à Diriger des Recherches (HDR)
2014-...      CNRS Researcher (CR1)

2010-2014  Postdoc (NWO-VENI Fellow), Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, NL. 
2008-2010  Postdoc (BAEF Fellow), University of North Carolina at Chapel Hill (UNC), USA.
2007-2008  Postdoc (NWO-Rubicon Fellow), Netherlands Institute of Ecology (NIOO-KNAW), Heteren, NL.
2001-2006  PhD (FRIA-FNRS Fellow), University of Liège (ULg), Liège, B.

Research interests

In my research I adopt an interdisciplinary approach mixing evolutionary and behavioural ecology with endocrinology, neurobiology and quantitative genetics, in order to understand how animals perceive and interact with their living environment. Integrative biology is currently advocated worldwide as a way of understanding complex phenomena such as the interactions between genotypes and phenotypes in changing environments. One of my major projects aims at 1) identifying the environmental cues (e.g. photoperiod, temperature, vegetation phenology, etc.) that birds use to time and organize their breeding cycles, 2) understanding how these cues are integrated at the physiological level, and 3) how this affects the individual fitness. A second major project focuses more on behavioural ecology per se and aims at testing the role that some phenotypic traits (e.g. plumage colour) plays in sexual selection. I am also interested in decomposing the large variance that characterizes many of the physiological parameters (e.g. hormone concentrations, etc.) commonly measured in breeding birds: what are the ecological, evolutionary and proximate causes of this inter- and intra-individual variation? See below for more information regarding the ongoing projects.        

Ongoing research projects

2015-2016 Self-referent phenotype matching in blue tit mate choice. Funded by a Fyssen-Foundation research grant.

2016-2020 Should birds use plants as a remedy for climate change? Funded by an ANR Jeune Chercheur research grant.


Lambrechts M.M., Caizergues A.E., Perrier C., Charmantier A., Caro S.P. 2020 Surface temperatures of non-incubated eggs in great tits (Parus major) are strongly associated with ambient temperature. International Journal of Biometeorology, in press

Salis L., Caro S.P., Hut R.A., Vernooij L., Visser M.E. 2019 Manipulation of photoperiod perception advances gonadal growth but not laying date in the great tit. Journal of Avian Biology, 50: e02197. 

Verhagen I., Laine V.N., Mateman C., Pijl A., de Wit R., van Lith B., Kamphuis W., Viitaniemi H.M., Williams T.D., Caro S.P., Meddle S.M., Gienapp P., van Oers M., Visser M.E. 2019 Fine-tuning of seasonal timing of breeding is regulated downstream in the underlying neuro-endocrine system in a small song bird. Journal of Experimental Biology, 222: jeb202481.

Caro, S.P., Cornil, C.A., van Oers, K., Visser, M.E. 2019 Personality and gonadal development as sources of individual variation in response to GnRH challenge in female great tits. Proceedings of the Royal Society B, 286: 20190142.

Dubuc-Messier, G., Caro, S.P., Perrier, C., van Oers, K., Réale, D., Charmantier, A. 2018 Gene flow does not prevent personality and morphological differentiation between two blue tit populations. Journal of Evolutionary Biology, 31: 1127-1137.

Lambrechts, M.M., Caro, S.P. 2018 Experimental manipulation of photoperiod and temperature does not influence nest size in blue and great tits. The Auk, 135: 218-227.

de Jong, M., Caro, S.P., Gienapp, P., Spoelstra, K., Visser, M.E. 2017 Early birds by light at night: effects of light color and intensity on daily activity patterns in blue tits. Journal of Biological Rhythms, 32: 323-333.

Lambrechts, M.M., Blondel, J., Bernard, C., Caro, S.P., Charmantier, A., Demeyrier, V., Doutrelant, C., Dubuc-Messier, G., Fargevieille, A., de Franceschi, C., Giovannini, P., Grégoire, A., Hurtrez-Boussès, S., Lucas, A., Mainwaring, M.C., 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.

Verhulst, E.C., Mateman, A.C., Zwier, M.V., Caro, S.P., Verhoeven, K.J.F., Van Oers, K. 2016 Evidence from pyrosequencing indicates that natural variation in animal personality is associated with DRD4 DNA methylation. Molecular Ecology, 25: 1801-1811.

Caro, S.P., Balthazart, J., Bonadonna, F. 2015 The perfume of reproducton in birds: chemosignalling in avian social life. Hormones and Behavior, 68: 25-42.

Reparaz, L.B., van Oers, K., Naguib, M., Doutrelant, C., Visser, M.E., Caro, S.P. 2014 Mate preference of female blue tits varies with experimental photoperiod. PLoS ONE, 9: e92527.

Caro, S.P., Schaper, S.V., Dawson, A., Sharp, P.J., Gienapp, P., Visser, M.E. 2013 Is microevolution the only emergency exit in a warming world? Temperature influences egg laying but not its underlying mechanisms in great tits. General and Comparative Endocrinology, 190: 164-169

Caro, S.P., Schaper, S.V., Hut, R.A., Ball, G.F., Visser, M.E. 2013 The case of the missing mechanism: how does temperature influence seasonal timing in homeotherms? PLoS Biology, 11: e1001517.

Sewall, K.B., Caro, S.P., Sockman, K.W. 2013 Song competition affects monoamine levels in sensory and motor forebrain regions of male Lincoln''s sparrows (Melospiza lincolnii). PLoS ONE, 8: e59857.

Schaper, S.V., Dawson, A., Sharp, P.J., Caro, S.P., Visser, M.E. 2012 Individual variation in avian reproductive physiology does not reliably predict variation in laying date. General and Comparative Endocrinology, 179: 53-62.

Caro, S.P. 2012 Avian Ecologists and Physiologists have different sexual preferences. General and Comparative Endocrinology, 176: 1-8.

Schaper, S.V., Dawson, A., Sharp, P.J., Gienapp, P., Caro, S.P., Visser, M.E. 2012 Increasing temperature, not mean temperature, is a cue for avian timing of reproduction. American Naturalist, 179: E55-E69.

Amo, L., Caro S.P., Visser, M.E. 2011 Sleeping birds do not respond to predator odour. PLoS ONE, 6 : e27576.

Visser, M.E, Schaper S.V., Dawson, A., Sharp, P.J., Gienapp, P., Caro, S.P. 2011 Genetic variation in the effect of temperature on the onset and termination of avian reproduction. Functional Ecology, 25 : 868-877.

Graham, E.B., Caro, S.P., Sockman, K.W. 2011 Change in offspring sex ratio over a very short season in Lincoln’s sparrows: the potential role of bill development. Journal of Field Ornithology, 82 : 44-51.

Caro, S.P., Balthazart, J. 2010 Pheromones in birds: myth or reality? Journal of Comparative Physiology A: Neuroethology Sensory Neural and Behavioral Physiology, 196 : 751-766.

Visser, M.E., Caro, S.P., van Oers, K., Schaper, S., Helm, B. 2010 Phenology, seasonal timing and circannual rhythms: towards a unified framework. Philosophical Transactions of the Royal Society of London, 365 : 3113-3127.

Caro, S.P., Sewall, K.B., Salvante K.G., Sockman, K.W. 2010 Female Lincoln’s sparrows modulate their behavior in response to variation in male song quality. Behavioral Ecology, 21 : 562-569.

Caro, S.P., Visser, M.E. 2009 Temperature induced elevation of basal metabolic rate does not affect testis growth in great tits. Journal of Experimental Biology, 212 : 1995-1999.

Caro, S.P., Keulen, C., Poncin, P. 2009 Song repertoires in a western population of Yellowhammers Emberiza citrinella. Acta Ornithologica, 44 : 9-16.

Visser, M.E., Holleman, L.J.M., Caro, S.P. 2009 Temperature has a causal effect on avian timing of reproduction. Proceedings of the Royal Society of London B, 276 : 2323-2331.

Caro, S.P., Charmantier, A., Lambrechts, M.M., Blondel, J., Balthazart J., Williams T.D. 2009 Local adaptation of timing of reproduction: females are in the driver’s seat. Functional Ecology, 23 : 172-179.

Bonadonna, F., Caro, S.P., Brooke, M.L. 2009 Olfactory sex recognition investigated in Antarctic prions. PLoS ONE, 4 : e4148.

Mennerat, A., Perret, P., Caro, S.P., Heeb, P., Lambrechts, M.M. 2008 Aromatic plants in blue tit (Cyanistes caeruleus) nests: no detectable negative effects on infestation rates of blood-sucking Protocalliphora larvae. Journal of Avian Biology, 39 : 127-132.

Müller C., Jenni-Eiermann S., Blondel J., Perret P., Caro S.P., Lambrechts M.M., Jenni L. 2007. Circulating corticosterone levels in breeding blue tit Parus caeruleus differ between island and mainland and between habitats. General and Comparative Endocrinology, 154 : 128-136.

Caro, S.P., Lambrechts, M.M., Balthazart, J., Perret, P. 2007. Non-photoperiodic factors and timing of breeding in blue tits: impact of environmental and social influences in semi-natural conditions. Behavioural Processes 75 : 1-7.

Bougault, P., Caro S.P., Perret, P. 2006. Do Blue Tits time their breeding based on cues obtained by consuming buds? Journal of Field Ornithology 77 : 399 - 404. 

Caro, S.P., Lambrechts, M.M., Chastel, O., Sharp, P.J., Thomas, D.W., Balthazart, J. 2006. Simultaneous pituitary-gonadal recrudescence in two Corsican populations of male blue tits with asynchronous breeding dates. Hormones and Behavior 50 : 347-360

Müller C., Jenni-Eiermann S., Blondel J., Perret P., Caro S.P., Lambrechts M.M., Jenni L. 2006. Effect of human presence and handling on corticosterone levels in breeding blue tits (Parus caeruleus). General and Comparative Endocrinology 148: 163-171.

Bonadonna F., Caro S.P., Jouventin P., Nevitt G.A. 2006. Evidence that blue petrel fledglings can detect and orient to dimethyl sulfide. Journal of Experimental Biology 209 : 2165-2169.

Caro, S.P., Lambrechts, M.M., Balthazart J. 2005. Early seasonal development of brain song control nuclei in male blue tits. Neuroscience Letters 386 : 139-144.

Caro, S.P., Balthazart, J., Thomas, D.W., Lacroix, A., Chastel, O., Lambrechts, M.M. 2005. Endocrine correlates of the breeding asynchrony in two Corsican populations of blue tits (Parus caeruleus). General and Comparative Endocrinology 140 : 52-60.

Lambrechts, M.M., Caro, S.P., Charmantier, A., Gross, N., Galan, M.-J., Perret, P., Cartan-Son, M., Dias, P.C., Blondel, J., Thomas, D.W. 2004. Habitat quality as a predictor of spatial variation in blue tit reproductive performance: a multi-plot analysis in a heterogeneous landscape. Oecologia 141 : 555-561.