Research

We currently work on the following topics:

Development of individuality in social traits: influence of the early-life environment

Social interactions are a pervasive component of an individual’s environment and their absence is associated with aging and morbidity in vertebrates. Surprisingly, however, we know little about why there is consistent individual variation in sociability within populations. Thus, we are interested in how newborn animals develop adaptive cost-effective social behaviours, and in how important early life experiences are (e.g. with siblings and parents) in shaping sociability.

There is ample evidence that mothers can modify the developmental trajectory of their offspring, even before birth, by transferring non-genetic material via their placenta or eggs to the offspring (the so-called “prenatal maternal effects”). Yet, it is still debated whether such trans-generational phenotypic plasticity is adaptive. Thus, we are currently exploring whether mothers prepare their offspring for the social environment they might encounter via maternal effects (e.g. by hormone transference or epigenetic marks), focusing on the blue tit Cyanistes caeruleus, as a model species.

Signals in social conflicts: plasticity of behavioural response rules

In animal societies, including humans, information exchange forms a central component of the interactions among group members. Learning how individuals use social information to adjust their decision rules is one of the key questions in evolutionary biology, such as the origin of sociality and cooperation. A key social factor that facilitates information exchange is the expression of signals. For instance, badges of status inform rivals about the probability of winning a contest and can reduce the costs of competitive interactions

We use animal family life as a model social environment to explore how the expression of signals shapes individual decision rules and the resolution of conflicts. For example, at the intra-specific level, in the blue tit (Cyanistes caeruleus), we have observed that a signal (ultraviolet plumage colouration) expressed by the offspring determines the position in the social network early in life (García-Antón et al. 2023 Anim Behav, pdf download), and modulates costly interactions with multiple family members (e.g. García-Campa et al. 2021 Behav Ecol, pdf download). In gulls, we have found that parental decision rules can shift from flexible to fixed according to signals expressed by other family members (Morales et al. 2009 Proceedings B, pdf download). Also, across bird species, the presence of conspicuous feathers in the offspring is more common in lineages with larger families, that is, in those with a higher potential for intra-family conflict (Morales et al. 2019 Behav Ecol, pdf download).

Signals of quality and life-history tradeoffs

The evolution of quality signals is among our favourite themes. We have experimentally demonstrated the long-standing idea that fecundity costs constrain the degree of ornamentation in females and explains sexual dimorphism  (Morales, Velando & Torres Behav Ecol 2009; pdf download).

Moreover, females can express ornaments that are unique to their sex. This is the case of egg colouration, which has been proposed to function as a signal of female quality to induce male investment in parental care. We have studied this interesting aspect of sexual selection in avian species with different life histories like seabirds and songbirds.

At present, we are interested in whether signals expressed both by male and female parents play a role beyond sexual selection, for example, in parent-offspring interactions. This has been little studied in different taxa (Morales & Velando 2013 Anim Behav; pdf download) and we are now exploring this question at the intra-specific level, in blue tit families.