Quantifying individual variation in reaction norms: Mind the residual.

Phenotypic plasticity is a central topic in ecology and evolution. Individuals may differ in the degree of plasticity (individual-by-environment interaction (I × E)), which has implications for the capacity of populations to respond to selection. Random regression models (RRMs) are a popular tool to study I × E in behavioural or life-history traits, yet evidence for I × E is mixed, differing between species, populations, and even between studies on the same population.

Comparing two measures of phenological synchrony in a predator-prey interaction: Simpler works better.

Global climate change has sparked a vast research effort into the demographic and evolutionary consequences of mismatches between consumer and resource phenology. Many studies have used the difference in peak dates to quantify phenological synchrony (match in dates, MD), but this approach has been suggested to be inconclusive, since it does not incorporate the temporal overlap between the phenological distributions (match in overlap, MO). We used 24 years of detailed data on the phenology of a predator-prey system, the great tit (Parus major) and the main food for its nestlings, caterpillars, to estimate MD and MO at the population and brood levels.

Phenological mismatch drives selection on elevation, but not on slope, of breeding time plasticity in a wild songbird.

Phenotypic plasticity is an important mechanism for populations to respond to fluctuating environments, yet may be insufficient to adapt to a directionally changing environment. To study whether plasticity can evolve under current climate change, we quantified selection and genetic variation in both the elevation (RN ) and slope (RN ) of the breeding time reaction norm in a long-term (1973-2016) study population of great tits (Parus major). The optimal RN (the caterpillar biomass peak date regressed against the temperature used as cue by great tits) changed over time, whereas the optimal RN did not.

Environmental coupling of heritability and selection is rare and of minor evolutionary significance in wild populations.

Predicting the rate of adaptation to environmental change in wild populations is important for understanding evolutionary change. However, predictions may be unreliable if the two key variables affecting the rate of evolutionary change-heritability and selection-are both affected by the same environmental variable. To determine how general such an environmentally induced coupling of heritability and selection is, and how this may influence the rate of adaptation, we made use of freely accessible, open data on pedigreed wild populations to answer this question at the broadest possible scale.

No effect of artificial light of different colors on commuting Daubenton's bats (Myotis daubentonii) in a choice experiment.

Progressive illumination at night poses an increasing threat to species worldwide. Light at night is particularly problematic for bats as most species are nocturnal and often cross relatively large distances when commuting between roosts and foraging grounds. Earlier studies have shown that illumination of linear structures in the landscape disturbs commuting bats, and that the response of bats to light may strongly depend on the light spectrum.

Maternal Effects in a Wild Songbird Are Environmentally Plastic but Only Marginally Alter the Rate of Adaptation.

Despite ample evidence for the presence of maternal effects (MEs) in a variety of traits and strong theoretical indications for their evolutionary consequences, empirical evidence to what extent MEs can influence evolutionary responses to selection remains ambiguous. We tested the degree to which MEs can alter the rate of adaptation of a key life-history trait, clutch size, using an individual-based model approach parameterized with experimental data from a long-term study of great tits (Parus major). We modeled two types of MEs: (i) an environmentally plastic ME, in which the relationship between maternal and offspring clutch size depended on the maternal environment via offspring condition, and (ii) a fixed ME, in which this relationship was constant.

Response of bats to light with different spectra: light-shy and agile bat presence is affected by white and green, but not red light.

Artificial light at night has shown a remarkable increase over the past decades. Effects are reported for many species groups, and include changes in presence, behaviour, physiology and life-history traits. Among these, bats are strongly affected, and how bat species react to light is likely to vary with light colour.