Jon E Brommer

• Ph.D.
• Professor at University of Turku

Climate warming is driving changes in species distribution, but habitat characteristics can interact with warming temperatures to affect populations in unexpected ways. We investigated wintering waterbird responses to climate warming depending on habitat characteristics, with a focus on the northern boundary of their non‐breeding distributions wher...

Wetlands are important habitats for insectivorous bats, as the presence of water promotes insect abundance and provides drinking water for wildlife, and therefore could promote bat conservation. Research on bats and wetlands has mainly focused on constructed wetlands, and with a geographical emphasis on eastern United States and central Europe, whe...

Although the associations between climate, food conditions and reproduction in the wild has been the focus of numerous studies in recent years, we still know little about population level responses to climate and fluctuating food conditions in long-lived species and during longer periods of time. Here, we assessed the relative importance of the abu...

Hydrology LIFE (LIFE16/NAT/FI/000583) Action D4: Monitoring protected bats Final report: Restoration of boreal wetlands increases bat activity but not species richness

Climate warming is driving species to shift their geographical distribution poleward to track suitable climatic conditions. Two strategies have been suggested to help species respond to climate warming: facilitating distribution change or improving persistence. We questioned whether habitat management in favour of duck hunting activities interacted...

The role of an alien predator in the community depends on its interaction with native predators. The absence of apex predators may facilitate outbreaks of invasive mesopredators, but the effect of apex predators may vary between species and environments. We analysed the occurrence of a common invasive mesopredator in Europe, the raccoon dog ( Nycte...

Protected area networks help species respond to climate warming. However, the contribution of a site's environmental and conservation‐relevant characteristics to these responses is not well understood. We investigated how composition of nonbreeding waterbird communities (97 species) in the European Union Natura 2000 (N2K) network (3018 sites) chang...

Dispersal is a key process with crucial implications in spatial distribution, density, and genetic structure of species’ populations. Dispersal strategies can vary according to both individual and environmental features, but putative phenotype-by-environment interactions have rarely been accounted for. Melanin-based color polymorphism is a phenotyp...

Adult sex ratio and fecundity (juveniles per female) are key population parameters in sustainable wildlife management, but inferring these requires abundance estimates of at least three age/sex classes of the population (male and female adults and juveniles). Prior to harvest, we used an array of 36 wildlife camera traps during 2 and 3 weeks in the...

Animal populations at northern latitudes may have cyclical dynamics that are degraded by climate change leading to trophic cascade. Hare populations at more southerly latitudes are characterized by dramatic declines in abundance associated with agricultural intensification. We focus on the impact of historical climatic and agricultural change on a...

Climate warming is driving changes in species distributions, although many species show a so-called climatic debt, where their range shifts lag behind the fast shift in temperature isoclines. Protected areas (PAs) may impact the rate of distribution changes both positively and negatively. At the cold edges of species distributions, PAs can facilita...

Habitat use studies provide invaluable information for the conservation of species that suffer from habitat loss or degradation. We used satellite telemetry to study the habitat use of white-tailed eagles ( Haliaeetus albicilla ) in relation to six habitat classes (artificial surfaces, agricultural areas, forests, semi-natural areas, wetlands and w...

Adult sex ratio and fecundity are key population parameters in sustainable wildlife management, but inferring these requires estimates of the density of at least three age/sex classes of the population (male and female adults and juveniles). We used an array of 36 wildlife camera traps during 2–3 weeks in autumn prior to harvest during two consecut...

Climate warming is driving changes in species distributions and community composition. Many species have a so‐called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm‐dwelling spec...

Birds, among various other taxa, construct nests. Nests form an extended phenotype of the individual building it. Nests are used to extend control over the conditions in which offspring develop, and are therefore commonly considered to be shaped by selection. Nevertheless, scarcely any scientific evidence exist that nest composition is under select...

Many species throughout the animal kingdom construct nests for reproduction. A nest is an extended phenotype—a non-bodily attribute—of the individual building it. In some bird species, including our study population of blue tits (Cyanistes caeruleus), conspicuous feathers or other material are placed on top of the nest. These so-called nest ornamen...

Although labeled as environmentally friendly, wind power can have negative impacts on the environment, such as habitat destruction or wildlife fatalities. Considering the distribution and migratory characteristics of European bats, the negative effects of wind power should be addressed on an appropriate scale. This review summarizes the current sta...

Early-life conditions may have long-lasting effects on life history. In color polymorphic species, morph-specific sensitivity to environmental conditions may lead to differential fitness. In tawny owls (Strix aluco), pheomelanin-based color polymorphism is expected to be maintained because the brown morph has higher adult fitness in warmer environm...

Accurately estimating genetic variance components is important for studying evolution in the wild. Empirical work on domesticated and wild outbred populations suggests that dominance genetic variance represents a substantial part of genetic variance, and theoretical work predicts that ignoring dominance can inflate estimates of additive genetic var...

Bats utilize forests as roosting sites and feeding areas. However, it has not been documented how bats utilize these habitats in the boreal zone with methods afforded by recent technological advances. Forest structure and management practices can create a variety of three‐dimensional habitats for organisms capable of flight, such as bats. Here, we...

Repeatable behaviors (i.e., animal personality) are pervasive in the animal kingdom and various mechanisms have been proposed to explain their existence. Genetic and nongenetic mechanisms, which can be equally important, predict correlations between behavior and body mass on different levels (e.g., genetic and environmental) of variation. We invest...

Joint model of offspring colour as function of parental colour for each year in almost 40-year dataset. Recruitment of offspring based on their colour also inferred

Multivariate mixed models (MMM) are generalized linear models with both fixed and random effect having multiple response variables. MMM allow partitioning of total (phenotypic) (co)variances for multiple traits into (co)variances on hierarchically lower levels. We outline why ecologists and evolutionary biologists should be interested in such parti...

Animal personality traits are often heritable and plastic at the same time. Indeed, behaviors that reflect an individual's personality can respond to environmental factors or change with age. To date, little is known regarding personality changes during a wild animals' lifetime and even less about stability in heritability of behavior across ages....

Indirect sexual selection arises when reproductive individuals choose their mates based on heritable ornaments that are genetically correlated to fitness. Evidence for genetic associations between ornamental coloration and fitness remain scarce. In this study we investigate the quantitative genetic relationship between different aspects of tail str...

Among all environmental factors, food supply is thought to be the most important cause of variation in phenotype, for it is the fuel for development. During 10 years, we collected data on caterpillar biomass in birches (Betula sp.) and on 752 broods of blue tits (Cyanistes caeruleus) in a boreal forest of Southwest Finland. The aim was to investiga...

Recent global warming and other anthropogenic changes have caused well-documented range shifts and population declines in many species over a large spatial extent. Most large-scale studies focus on birds, large mammals, and threatened species, whereas large-scale population trends of small to medium-sized mammals and species that are currently of l...

Assortative mating is pervasive in wild populations and commonly described as a positive correlation between the phenotypes of males and females across mated pairs. This correlation is often assumed to reflect non-random mate choice based on phenotypic similarity. However, phenotypic resemblance between mates can also arise when their traits respon...

The expansion of wind energy over large areas may be accompanied by major conflicts with birds, including birds of prey. Hence, it is desirable that the space use of species known to be vulnerable to wind energy be assessed in light of current and future developments. Here, we report on the large-scale dispersal movements of pre-breeding white-tail...

Comparative analyses have demonstrated the existence of a ”pace-of-life” (POL) continuum of life-history strategies, from fast-reproducing short-lived species to slow-reproducing long-lived species. This idea has been extended to the concept of a ”pace-of-life syndrome” (POLS), an axis of phenotypic covariation among individuals within species, con...

In birds and other taxa, nest construction varies considerably between and within populations. Such variation is hypothesized to have an adaptive (i.e. genetic) basis, but estimates of heritability in nest construction are largely lacking. Here, we demonstrate with data collected over 10 years from 1010 nests built by blue tits in nest-boxes that n...

A species' distribution and abundance in both space and time play a pivotal role in ecology and wildlife management. Collection of such large-scale information typically requires engagement of volunteer citizens and tends to consist of non-repeated surveys made with a survey effort varying over space and time. We here used a hierarchical single-cen...

Behavioral ecologists consider behaviors that show significant between-individual variation as aspects of personality. When multiple aspects of personality covary, these are viewed as a behavioral syndrome. Meta-analyses have demonstrated that behaviors typically are repeatable and that behavioral syndromes are common across a wide variety of taxa....

Birds show immense variation in nest sizes within species. At least six different hypotheses have been forwarded to explain intraspecific variation in nest size in cavity nesting species, but very few of those hypotheses have been tested experimentally. In our study, when nestlings were 2 days old, we manipulated the height of 182 Blue Tit (Cyanist...

1. Assortative mating in wild populations is commonly reported as the correlation between males’ and females’ phenotypes across mated pairs. Theories of partner selection and quantitative genetics assume that phenotypic resemblance of partners captures associations in “intrinsically determined” trait values. However, when considering traits with a...

The presence of variation in behavior on the between-individual level is considered the hallmark of personality. In contrast, behavioral syndromes are commonly recognized when documented on the phenotypic level, which is a mix of between-individual and residual (within-individual) correlations. Phenotypic and between-individual correlations need no...

Linking dispersal to population growth remains a challenging task and is a major knowledge gap, for example, for conservation management. We studied relative roles of different demographic rates behind population growth in Siberian flying squirrels in two nest-box breeding populations in western Finland. Adults and offspring were captured and indiv...

There is large interspecific variation in the magnitude of population fluctuations, even among closely related species. The factors generating this variation are not well understood, primarily because of the challenges of separating the relative impact of variation in population size from fluctuations in the environment. Here, we show using demogra...

Supplementary Figures 1-4, Supplementary Table 1 and Supplementary Note 1

Despite a growing body of literature reporting developmental changes in personality, few studies have adopted a lifetime perspective to study age-related changes in personality traits. Since most personality traits are heritable and linked with fitness, ontogenetic changes can have evolutionary implications. In this paper, we explore age-related ch...

White-Tailed deer were introduced to Finland in 1934 from Minnesota, North America. The population has expanded and is now an important wildlife species, managed through hunting. We determined the age of 451 individuals harvested in the 2012 hunting season. Hunters measured their body mass after slaughter and we measured the dimensions of the lower...

Large-scale studies on population-level sex ratios are few, even though sex ratio is an important determinant of population viability and dynamics. Mechanisms driving large-scale sex ratio variation include spatially autocorrelated resources and scale differences in local versus global Fisherian feedback of the operational sex ratio. In this study,...

Birds host several ectoparasitic fly species with negative effects on nestling health and reproductive output, and with the capability of transmitting avian blood parasites. Information on the abundance and distribution of the ectoparasitic fly genera Ornithomya (Hippoboscidae) and Protocalliphora (Calliphoridae) in northern Europe is still general...

As a clean and renewable energy source, wind power is expected to play a major role in climate change mitigation. Despite its benefits, the construction of large-scale wind farms in many parts of the world is a cause of concern for wildlife, including the often vulnerable raptor populations. Here, we examined the influence of distance to wind-power...

Translocations, especially assisted colonizations, of animals are increasingly used as a conservation management tool. In many cases, however, limited funding and other logistic challenges limit the number of individuals available for translocation. In conservation genetics, small populations are predicted to rapidly lose genetic diversity which ca...

Overview of literature estimates of the correlation of behavioral traits across age classes

R script for producing the simulations in this paper

Overview of the literature considering changes in the correlation between two or more behavioral traits across ages

Glossary of terms used in this paper

Schematic illustration of how changes in the age-specific expression of behavior by an individual are modelled as deviations from the age-specific mean

Behaviors are highly plastic and one aspect of this plasticity is behavioral changes over age. The presence of age-related plasticity in behavior opens up the possibility of between-individual variation in age-related plasticity (Individual-Age interaction, IxA) and genotype-age interaction (GxA). We outline the available approaches for quantifying...

In animal populations, as in humans, behavioural differences between individuals that are consistent over time and across contexts are considered to reflect personality, and suites of correlated behaviours expressed by individuals are known as behavioural syndromes. Lifelong stability of behavioural syndromes is often assumed, either implicitly or...

The latitudinal gradient in body mass, which many organisms show (Bergmann’s rule), is thought to be a response to local environmental conditions varying across latitude. Hence, temporal changes in environmental conditions are expected to lead to a shift in Bergmann’s rule. We compared house sparrow Passer domesticus body mass measures taken in 198...

Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the pied flycatcher Ficedula hypoleuca is explained by...

Translocation of individuals across a barrier which hampers natural colonisation is a potentially important, but debated, conservation tool for a variety of organisms in a world altered by anthropogenic influences. The apollo Parnassius apollo is an endangered butterfly whose distribution retracted dramatically during the 1900s across Europe. In Fi...

Males can through their behavior (e.g., courtship feeding) exert an indirect effect on their partner’s reproductive traits, such as the seasonal timing and size of her clutch. Evidence for such indirect (male) effect on reproduction is starting to accumulate. We quantify female and male effects on reproduction in the tawny owl Strix aluco using a h...

A heterozygosity–fitness correlations (HFCs) may reflect inbreeding depression, but the extent to which they do so is debated. HFCs are particularly likely to occur after demographic disturbances such as population bottleneck or admixture. We here study HFC in an introduced and isolated ungulate population of white-tailed deer Odocoileus virginianu...

A shift from nomadic foraging to sedentary agriculture was a major turning point in human evolutionary history, increasing our population size and eventually leading to the development of modern societies. We however lack understanding of the changes in life histories that contributed to the increased population growth rate of agriculturalists, bec...

Different behavioral traits often covary, forming a behavioral syndrome. It is poorly known whether this covariance occurs on the between-individual level and what its selective consequences are. We used repeated measures (N = 562 observation events) of individual tawny owl Strix aluco females (N = 237) to study the integrated effects of seasonal t...

This book gathers the expertise of thirty evolutionary biologists from around the globe to highlight how applying the field of quantitative genetics (the analysis of the genetic basis of complex traits) to wild populations has provided major advancements in evolutionary ecology. It offers insights into the relevant methods and major discoveries in...

This book gathers the expertise of thirty evolutionary biologists from around the globe to highlight how applying the field of quantitative genetics (the analysis of the genetic basis of complex traits) to wild populations has provided major advancements in evolutionary ecology. It offers insights into the relevant methods and major discoveries in...

Genetic correlations between behaviors underlying a behavioral syndrome may constrain the capacity of a population to respond to selection on these behaviors. Average autonomy quantifies the extent in which estimated genetic (co)variances constrain the rate of evolutionary change of behavioral traits forming a syndrome when these traits are under s...

The evolution of a senescent decline in the performance of organisms as they grow old is thought to be an unavoidable aspect of life. A genotype-age interaction in performance is the 'fingerprint' of evolved senescence, which has now for the first time been detected in a plant.

The direction of covariation in behavioral traits (a behavioral syndrome) is typically the same in males and females, although intersexual differences in life history could lead to intersexual heterogeneity in syndrome structure. We explored whether a behavioral syndrome was the same in both sexes. We recorded 2 metrics of nest defense in wild blue...

Bergmann's rule predicts that individuals are larger in more poleward populations and that this size gradient has an adaptive basis. Hence, phenotypic divergence in size traits between populations (PST ) is expected to exceed the level of divergence by drift alone (FST ). We measured 16 skeletal traits, body mass and wing length in 409 male and 296...

Behavioral differences between individuals that are consistent over time characterize animal personality. The existence of such consistency contrasts to the expectation based on classical behavioral theory that facultative behavior maximizes individual fitness. Here, we study two personality traits (aggression and breath rate during handling) in a...

Understanding how survival is affected by the environment is essential to gain insight into population dynamics and the evolution of life‐history traits as well as to identify environmental selection pressures. However, we still have little understanding of the relative effect of different environmental factors and their interactions on demographic...

Studies increasingly explore whether there is variation between individuals in how they adjust their behavior to different environmental contexts using random regression analysis (RR). RR estimates the between-individual variance in elevation (expected behavior in the mean environment) and variance in plasticity (individual-specific adjustment of b...

Recently, integration of personality traits into a ‘pace-of-life syndrome’ (POLS) context has been advocated. To be able to understand how an individual’s behavioural, physiological and life history traits may coevolve, we need to jointly quantify these traits in order to study their covariance. Few studies have established links between personalit...

Negative density dependence of clutch size is a ubiquitous characteristic of avian populations and is partly due to within-individual phenotypic plasticity. Yet, very little is known about the extent to which individuals differ in their degree of phenotypic plasticity, whether such variation has a genetic basis and whether level of plasticity can t...

Different components of heritability, including genetic variance (V G), are influenced by environmental conditions. Here, we assessed phenotypic responses of life-history traits to two different developmental conditions, temperature and food limitation. The former represents an environment that defines seasonal polyphenism in our study organism, th...

Individual-based studies allow quantification of phenotypic plasticity in behavioural, life-history and other labile traits. The study of phenotypic plasticity in the wild can shed new light on the ultimate objectives (1) whether plasticity itself can evolve or is constrained by its genetic architecture, and (2) whether plasticity is associated to...

A recent discussion in this journal (Dingemanse et al. Behav Ecol Sociobiol 66: 1543–1548, 2012; Garamszegi and Herczeg Behav Ecol Socibiol 66:1651–1658, 2012) deals with a core issue in animal personality research: Can animal personality research quantify correlated behaviors on the between-individual level, or is this too demanding in terms of de...

The mechanisms by which melanin‐based colour polymorphism can evolve and be maintained in wild populations are poorly known. Theory predicts that colour morphs have differential sensitivity to environmental conditions. Recently it has been proposed that colour polymorphism covaries genetically with intrinsic and behavioural properties. Plumage moul...

Cycling in Unison Many small mammals, especially voles, display semi-regular cycles of population boom and bust. Given the fundamental importance of small mammals as basal consumers and prey, such cycles can have cascading effects in trophic food webs. Cornulier et al. (p. 63 ) collated raw data from vole populations across Europe collected over th...

Animal personality is defined as behavior that is consistent across time and context. We here applied a reaction-norm perspective implemented as a random regression phenotypic model (RRPM) to behaviors measured on blue tits Cyanistes caeruleus. During 3 consecutive breeding and winter seasons (2007–2009), a total of 508 wild-caught blue tits were a...

Global climate warming is predicted to lead to global and regional changes in the distribution of organisms. One influential approach to test this prediction using temporally repeated mapping surveys of organisms was suggested in a seminal paper by Thomas & Lennon (1999, Nature). The Thomas & Lennon approach corrects observed changes in the range m...

When several personality traits covary, they form a behavioral syndrome. Understanding the evolutionary dynamics of a behavioral syndrome requires knowledge of its genetic underpinning. At present, our understanding of the genetic basis of behavioral syndromes is largely restricted to domestic and laboratory animals. Wild behavioral syndromes are m...

Table S1. Model ranking for capture probability (p) assuming full model structure for apparent survival. Table S2. Coefficients for the CMR estimated apparent survival (Phi) and capture probability (p). Table S3. Recruitment probability of nestlings as a function of the breath rate of foster and genetic parents. Fig. S1. Plot of the effects of the...

To understand the biology of organisms it is important to take into account the evolutionary forces that have acted on their constituent populations. Neutral genetic variation is often assumed to reflect variation in quantitative traits under selection, though with even low neutral divergence there can be substantial differentiation in quantitative...

Within-population genetic diversity is expected to be dramatically reduced if a population is founded by a low number of individuals. Three females and one male white-tailed deer Odocoileus virginianus, a North American species, were successfully introduced in Finland in 1934 and the population has since been growing rapidly, but remained in comple...

Climatic warming predicts that species move their entire distribution poleward. Poleward movement of the 'cold' side of the distribution of species is empirically supported, but evidence of poleward movement at the 'warm' distributional side is relatively scarce. Finland has, as the first country in the world, completed three national atlas surveys...

Reproduction and survival values, as implemented in the individual-based genetic model. (DOCX)

The species names (in alphabetical order), range size (RS) and weighted mean latitude (WML) of southern species in the three atlases of Finnish breeding birds (A1, A2, A3, respectively). (DOCX)

Extended tabulated summary of available information on the development of the population of white-tailed deer in Finland. (DOCX)

White-tailed population development and application of classic population genetic theory ( eq. (1) in the main text). (DOCX)

Zipped archive with MATLAB M-files forming the individual-based population genetics model used in this study to simulate the introduction of the white-tailed deer in Finland. (ZIP)

Difference in the number of atlas grid cells surveyed for each latitudinal row between atlas 1 and atlas 3 (in blue) and between atlas 2 and atlas 3 (in green). Atlas 3 is the best surveyed atlas and the red line indicates equal number of cells surveyed as in atlas 3. (TIF)

Locus-specific allele frequencies of the Finnish population, presented for both the 72 individuals of this study and for the maximal number of individuals available per locus. (DOCX)

Introduction of the white-tailed deer in Finland. Details of its introduction and further information on rationale behind model parameters. (DOCX)