Bert Thys

• PhD
• PhD at University of Antwerp

Personality (i.e., among-individual variation in average behavior) often covaries with fitness, but how such personality-fitness relationships come about is poorly understood. Here, we explore potential mechanisms by which two female personality traits (female-female aggression and female nest defense as manifested by hissing behavior) were linked...

Behaviour is often both repeatable among individuals (i.e. personality) and plastically adjusted within individuals according to environmental conditions or age. Yet, little is known about the repeatability and age-related plasticity in behavioural traits across the lifetime of free-living animals, which is, however, crucial for understanding the d...

There is increasing evidence that individuals are consistent in the timing of their daily activities, and that individual variation in temporal behavior is related to the timing of reproduction. However, it remains unclear whether observed patterns relate to the timing of the onset of activity or whether an early onset of activity extends the time...

Individual variation in the timing of activities is increasingly being reported for a wide variety of species, often measured as the timing of activity onset in the morning. However, so far, the adaptive significance of consistent variation in temporal phenotypes (i.e. the chronotype) remains largely elusive. Potentially, differences in timing of a...

Anthropogenic environmental change is introducing a suite of novel disturbance factors, which can have wide-ranging effects on mean behavior and behavioral repeatability. For example, exposure to sensory pollutants, such as anthropogenic noise and artificial light at night (ALAN), may affect consistent and repeatable individual-level timing of dail...

Birds have evolved a variety of antipredator strategies, which have been extensively studied during day-time. Yet, how diurnal birds directly respond to nocturnal predation threats remains largely elusive, despite that predation risk can be high during both night- and day-time. One form of antipredator behaviour found in several tit species when co...

Understanding underlying genetic variation can elucidate how diversity in behavioral phenotypes evolves and is maintained. Genes in the serotonergic signaling pathway, including the serotonin transporter gene ( SERT ), are candidates for affecting animal personality, cognition and fitness. In a model species, the great tit ( Parus major ), we reeva...

(1) Within animal populations, competition is often most intense among individuals of the same sex since such individuals require the same limited resources to maximize reproductive success. Although competition between females is widespread – including in species with traditional sex-roles – the functional significance of, and nature of selection...

Quantifying variation in behaviour-related genes provides insight into the evolutionary potential of repeatable among-individual variation in behaviour (i.e. personality). Yet, individuals typically also plastically adjust their behaviour in response to environmental conditions and/or age, thereby complicating the detection of genotype-phenotype as...

The evolution and function of female trait exaggeration in species with traditional sex roles are poorly understood. Competition for social and ecological resources, rather than mating opportunities, may be a key selection pressure in females of socially monogamous species. Moreover, such pre-existing resource competition-selected traits (armaments...

Predation is the primary source of reproductive failure in many avian taxa and nest defence behaviour against predators is hence an important aspect of parental investment. Nest defence is a complex trait that might consistently differ among individuals (personality), while simultaneously vary within individuals (plasticity) according to the reprod...

Light pollution or artificial light at night (ALAN) is an increasing, worldwide challenge that affects many aspects of animal behaviour. Interestingly, the response to ALAN varies widely among individuals within a population and variation in personality (consistent individual differences in behaviour) may be an important factor explaining this vari...

Anthropogenic contaminants could alter traits central to animal behavioral types, or personalities, including aggressiveness, boldness and activity level. Lead and other toxic metals are persistent inorganic pollutants that affect organisms worldwide. Metal exposure can alter behavior by affecting neurology, endocrinology, and health. However, the...

Males often express traits that improve competitive ability, such as aggressiveness. Females also express such traits but our understanding about why is limited. Intraspecific aggression between females might be used to gain access to reproductive resources but simultaneously incurs costs in terms of energy and time available for reproductive activ...

Personality traits and behavioural syndromes are often assumed to relate to life history strategies and lifetime fitness variation and hence may be generally under selection. Key in this regard is the, often untested, assumption that individual differences in (correlated) behaviours are maintained across contexts and over an individual's lifetime....