Stéphanie Jenouvrier

• PhD
• Woods Hole Oceanographic Institution at Woods Hole Oceanographic Institution

Dispersal is a ubiquitous phenomenon that affects the dynamics of the population and the evolution of natural populations; however, it is challenging to measure in most species. Furthermore, the influence of informed dispersal behaviors, referring to the nonrandom selection of breeding habitats by individuals, on species' responses to rapid global...

Population ecology and biogeography applications often necessitate the transfer of models across spatial and/or temporal dimensions to make predictions outside the bounds of the data used for model fitting. However, ecological data are often spatiotemporally unbalanced such that the spatial or the temporal dimension tends to contain more data than...

Subtropical anticyclones are semi-permanent high-pressure systems present in all major ocean basins, shaping large-scale wind patterns and weather conditions. These systems play a crucial role in structuring physical environments that influence ecosystem productivity, yet their demographic impacts on wildlife remain largely unexplored. Understandin...

Population dynamics are shaped by individual differences. With a good understanding of the relationships between individual differences and vital rates, population models can be improved to yield more realistic and detailed demographic projections. Personality, i.e., consistent individual differences in behaviour, is expected to shape individual di...

Climate change can influence populations of monogamous species by affecting pair‐bond dynamics. This study examined the impact of climate on widowhood and divorce, and the subsequent effects on individual vital rates and life‐history outcomes over 54 years in a snow petrel (Pagodroma nivea) population. We found that environmental conditions can aff...

Responses of natural populations to climate change are driven by how multiple climatic and biotic factors affect survival and reproduction, and ultimately shape population dynamics. Yet, we lack a general understanding of the role of such mechanisms in moderating climate-change impacts across different species. Here, we synthesize how the joint eff...

Climate change has marked effects on global weather patterns and oceanic systems, impacting animal behaviour and fitness in potentially profound ways. Despite this, we lack detailed information about species' responses to climatic variation. Using an 11‐year tracking dataset of over 300 individual birds, we explore the consequences of variation in...

Many ecological systems dominated by stochastic dynamics can produce complex time series that inherently limit forecast accuracy. The ‘intrinsic predictability’ of these systems can be approximated by a time series complexity metric called weighted permutation entropy (WPE). While WPE is a useful metric to gauge forecast performance prior to model...

Differences among individuals within a population are ubiquitous. Those differences are known to affect the entire life cycle with important consequences for all demographic rates and outcomes. One source of among‐individual phenotypic variation that has received little attention from a demographic perspective is animal personality, which is define...

Like many polar animals, emperor penguin populations are challenging to monitor because of the species' life history and remoteness. Consequently, it has been difficult to establish its global status, a subject important to resolve as polar environments change. To advance our understanding of emperor penguins, we combined remote sensing, validation...

Emperor penguins are tough birds that breed on sea ice, which is the frozen surface of the ocean. They are famous for walking across the sea ice, to and from the open ocean, to get food for their chicks. Their bodies and behaviors help them live in the cold, dark winters of Antarctica. However, though they live far away from people, human actions a...

Predicting species survival in the face of climate change requires understanding the drivers that influence their distribution. Emperor penguins ( Aptenodytes forsteri ) incubate and rear chicks on landfast sea ice, whose extent, dynamics, and quality are expected to vary substantially due to climate change. Until recently, this species’ continent-...

This study investigates winter polynyas in the southern Ross Sea, Antarctica where several polynyas are known to form. Coastal polynyas are areas of lower sea ice concentration and/or thickness along the coast that are otherwise surrounded by more extensive, thicker sea ice pack. Polynyas are also locations where organisms can exploit both the ice...

Threats to species under climate change can be understood as a time at which the signal of climate change in ecological processes emerges from the noise of ecosystem variability, defined as ‘time of emergence’ (ToE). Here we show that ToE for the great tit (Parus major) will occur earlier at the level of population size than trait (laying date) and...

The slow-fast continuum is a commonly used framework to describe variation in life-history strategies across species. Individual life histories have also been assumed to follow a similar pattern, especially in the pace-of-life syndrome literature. However, whether a slow-fast continuum commonly explains life-history variation among individuals with...

Ecological predictions are necessary for testing whether processes hypothesized to regulate species population dynamics are generalizable across time and space. In order to demonstrate generalizability, model predictions should be transferable in one or more dimensions, where transferability is the successful prediction of responses outside of the...

This study investigates winter polynyas in the southern Ross Sea, Antarctica where several polynyas are known to form. Coastal polynyas are areas of lower sea ice concentration and/or thickness along the coast that are otherwise surrounded by the thicker ice pack, and polynyas are locations where organisms can exploit both the ice substrate and pel...

Antarctic terrestrial biodiversity faces multiple threats, from invasive species to climate change. Yet no large-scale assessments of threat management strategies exist. Applying a structured participatory approach, we demonstrate that existing conservation efforts are insufficient in a changing world, estimating that 65% (at best 37%, at worst 97%...

Personality predicts divorce rates in humans, yet how personality traits affect divorce in wild animals remains largely unknown. In a male-skewed population of wandering albatross ( Diomedea exulans ), we showed that personality predicts divorce; shyer males exhibited higher divorce rates than bolder males but no such relationship was found in fema...

Individuals differ in many ways. Most produce few offspring; a handful produce many. Some die early; others live to old age. It is tempting to attribute these differences in outcomes to differences in individual traits, and thus in the demographic rates experienced. However, there is more to individual variation than meets the eye of the biologist....

Temporal correlations among demographic parameters can strongly influence population dynamics. Our empirical knowledge, however, is very limited regarding the direction and the magnitude of these correlations and how they vary among demographic parameters and species’ life histories. Here, we use long‐term demographic data from 15 bird and mammal s...

Many animals form long‐term monogamous pair bonds, and the disruption of a pair bond (through either divorce or widowhood) can have significant consequences for individual vital rates (survival, breeding, and breeding success probabilities) and life‐history outcomes (lifetime reproductive success [LRS], life expectancy). Here, we investigated the c...

Climate impacts are not always easily discerned in wild populations as detecting climate change signals in populations is challenged by stochastic noise associated with natural climate variability, variability in biotic and abiotic processes, and observation error in demographic rates. Detection of the impact of climate change on populations requir...

An increasing number of empirical studies aim to quantify individual variation in demographic parameters because these patterns are key for evolutionary and ecological processes. Advanced approaches to estimate individual heterogeneity are now using a multivariate normal distribution with correlated individual random effects to account for the late...

Climate change has led to phenological shifts in many species, but with large variation in magnitude among species and trophic levels. The poster child example of the resulting phenological mismatches between the phenology of predators and their prey is the great tit ( Parus major ), where this mismatch led to directional selection for earlier seas...

For species inhabiting areas at the limit of their environmental tolerance, extreme events often drive population persistence. However, because extreme events are uncommon, their effects on population dynamics of expanding species are poorly known. We examined how extreme climate events in winter and summer affected three populations of wild turkey...

Synchrony in ecological systems, the degree to which elements respond similarly over time or space, can inform our understanding of how ecosystems function and how they are responding to global change. While studies of ecological synchrony are often focused on within-species dynamics, synchrony among species may provide important insights into how...

Very high‐resolution satellite (VHR) imagery is a promising tool for estimating the abundance of wildlife populations, especially in remote regions where traditional surveys are limited by logistical challenges. Emperor penguins Aptenodytes forsteri were the first species to have a circumpolar population estimate derived via VHR imagery. Here we ad...

Species extinction risk is accelerating due to anthropogenic climate change, making it urgent to protect vulnerable species through legal frameworks in order to facilitate conservation actions that help mitigate risk. Here, we discuss fundamental concepts for assessing climate change risks to species using the example of the emperor penguin (Apteno...

In a fast-changing world, polar ecosystems are threatened by climate variability. Understanding the roles of fine-scale processes, and linear and nonlinear effects of climate factors on the demography of polar species is crucial for anticipating the future state of these fragile ecosystems. While the effects of sea ice on polar marine top predators...

Harvest, through its intensity and regulation, often results in selection on female reproductive traits. Changes in female traits can have demographic consequences, as they are fundamental in shaping population dynamics. It is thus imperative to understand and quantify the demographic consequences of changes in female reproductive traits to better...

Climate impacts are not always easily discerned in wild populations as climate change occurs in the context of natural variability. Furthermore, species responses to climate change and variability differ among life histories. The time of emergence (ToE) identifies when the signal of anthropogenic climate change can be quantitatively distinguished f...

Declines in reproductive performance among older age classes have been reported in many bird and mammal species, and are commonly presented as demonstrating reproductive senescence. However, no declines in performance could be demonstrated in studies of several bird species. We measured reproductive performance in Common Terns (Sterna hirundo) of k...

Understanding the scales at which environmental variability affects populations is critical for projecting population dynamics and species distributions in rapidly changing environments. Here, we used a multi‐level Bayesian analysis of range‐wide survey data for Adélie penguins to characterize multi‐decadal‐ and annual effects of sea ice on populat...

The Paris Agreement is a multinational initiative to combat climate change by keeping a global temperature increase in this century to 2°C above preindustrial levels while pursuing efforts to limit the increase to 1.5°C. Until recently, ensembles of coupled climate simulations producing temporal dynamics of climate en route to stable global mean te...

Plain Language Summary Polar ecosystems are threatened by future loss of sea ice. The availability of satellite sea ice products has facilitated a better assessment of the impact of sea ice on polar species. Yet most studies have focused on coarse spatial scale sea ice products hampering an understanding of the mechanisms by which sea ice affects s...

Individuals differ in many ways. Most produce few offspring; a handful produce many. Some die early; others live to old age. It is tempting to attribute these differences in outcomes to differences in individual traits, and thus in the demographic rates experienced. However, there is more to individual variation than meets the eye of the biologist....

We argue the need to improve climate change forecasting for ecology, and importantly, how to relate long-term projections to conservation. As an example, we discuss the need for effective management of one species, the emperor penguin, Aptenodytes forsteri. This species is unique amongst birds in that its breeding habit is critically dependent upon...

Ecologists widely acknowledge that a complex interplay of endogenous (density‐dependent) and exogenous (density‐independent) factors impact demographic processes. Individuals respond differently to those forces, ultimately shaping the dynamics of wild populations. Most comprehensive studies disentangling simultaneously the effects of density depend...

Penguins face a wide range of threats. Most observed population changes have been negative and have happened over the last 60 years. Today, populations of 11 penguin species are decreasing. Here we present a review that synthesizes details of threats faced by the world’s 18 species of penguins. We discuss alterations to their environment at both br...

Adult emperor penguins Aptenodytes forsteri breed on fast ice and forage within sea ice in winter. However, it remains unknown whether juveniles exhibit similar foraging behavior during their early life at-sea movements, and how it links with the oceanographic conditions. We investigated the first at-sea odyssey of 15 juvenile emperor penguins from...

Recent studies unravelled the effect of climate changes on populations through their impact on functional traits and demographic rates in terrestrial and freshwater ecosystems, but such understanding in marine ecosystems remains incomplete. Here, we evaluate the impact of the combined effects of climate and functional traits on population dynamics...

Studies of the mechanisms underlying climate‐induced population changes are critically needed to better understand and accurately predict population responses to climate change. Long‐lived migratory species might be particularly vulnerable to climate change as they are constrained by different climate conditions and energetic requirements during th...

Despite concerted international effort to track and interpret shifts in the abundance and distribution of Adélie penguins, large populations continue to be identified. Here we report on a major hotspot of Adélie penguin abundance identified in the Danger Islands off the northern tip of the Antarctic Peninsula (AP). We present the first complete cen...

Phenological changes have been observed in a variety of systems over the past century. There is concern that, as a consequence, ecological interactions are becoming increasingly mismatched in time, with negative consequences for ecological function. Significant spatial heterogeneity (inter‐site) and temporal variability (inter‐annual) can make it d...

Colonially-breeding seabirds have long served as indicator species for the health of the oceans on which they depend. Abundance and breeding data are repeatedly collected at fixed study sites in the hopes that changes in abundance and productivity may be useful for adaptive management of marine resources, but their suitability for this purpose is o...

Individuals are heterogeneous in many ways. Some of these differences are incorporated as individual states (e.g. age, size, breeding status) in population models. However, substantial amounts of heterogeneity may remain unaccounted for, due to unmeasurable genetic, maternal or environmental factors. Such unobserved heterogeneity (UH) affects the b...

Species endangered by rapid climate change may persist by tracking their optimal habitat; this depends on their dispersal characteristics. The Emperor penguin (EP) is an Antarctic seabird threatened by future sea ice change, currently under consideration for listing under the US Endangered Species Act. Indeed, a climate-dependent-demographic model...

Climate changes include concurrent changes in environmental mean, variance and extremes, and it is challenging to understand their respective impact on wild populations, especially when contrasted age-dependent responses to climate occur. We assessed how changes in mean and standard deviation of sea surface temperature (SST), frequency and magnitud...

More extreme climatic events (ECEs) are among the most prominent consequences of climate change. Despite a long-standing recognition of the importance of ECEs by paleo-ecologists and macro-evolutionary biologists, ECEs have only recently received a strong interest in the wider ecological and evolutionary community. However, as with many rapidly exp...

One of the predicted consequences of climate change is a shift in body mass distributions within animal populations. Yet body mass, an important component of the physiological state of an organism, can affect key life-history traits and consequently population dynamics. Over the past decades, the wandering albatross—a pelagic seabird providing bi-p...

Evidence of climate change-driven shifts in plant and animal phenology have raised concerns that certain trophic interactions may be increasingly mismatched in time, resulting in declines in reproductive success. Given the constraints imposed by extreme seasonality at high latitudes and the rapid shifts in phenology seen in the Arctic, we would als...

Sea ice variability within the marginal ice zone (MIZ) and polynyas plays an important role for phytoplankton productivity and krill abundance. Therefore, mapping their spatial extent as well as seasonal and interannual variability is essential for understanding how current and future changes in these biologically active regions may impact the Anta...

Sea ice variability within the marginal ice zone (MIZ) and polynyas plays an important role for phytoplankton productivity and krill abundance. Therefore mapping their spatial extent, seasonal and interannual variability is essential for understanding how current and future changes in these biological active regions may impact the Antarctic marine...

Phytoplankton in Antarctic coastal polynyas has a temporally short yet spatially variant growth window constrained by ice cover and day length. Using 18-year satellite measurements (1997–2015) of sea ice and chlorophyll concentrations, we assessed the synchronicity between the spring phytoplankton bloom and light availability, taking into account t...

Extreme climatic conditions and their ecological impacts are currently emerging as critical features of climate change. We studied extreme sea ice condition (ESIC) and found it impacts both life‐history traits and population dynamics of an Antarctic seabird well beyond ordinary variability. The Southern Fulmar ( Fulmarus glacialoides ) is an ice‐de...

The Southern Fulmar, Fulmarus glacialoides, is an ice-dependentseabird, and individuals forage near the ice edge. During an extremeunfavorable sea ice year (ESIC), foraging trips were greater in distanceand duration, adults brought less food to their chicks, which fledgedin the poorest body condition. During such ESICs, breeding successwas extremel...

The Galápagos is a flourishing yet fragile ecosystem whose health is particularly sensitive to regional and global climate variations. The distribution of several species, including the Galápagos Penguin, is intimately tied to upwelling of cold, nutrient-rich water along the western shores of the archipelago. Here we show, using reliable, high-reso...

Atmosphere-Ocean General Circulation Models (AOGCMs) predict changes in the sea ice environment and in atmospheric precipitations over larger areas of Antarctica. These changes are expected to affect the population dynamics of seabirds and marine mammals, but the extent of this influence is not clear. We investigated the future population trajector...

Le vaste continent antarctique d’une superficievoisine de celle de l’Europe et de la péninsuleArabique réunies, est entouré d’un immenseocéan ininterrompu, l’océan Austral.Celui-ci englobe les eaux des océans Pacifique,Indien et Atlantique situées au sud du frontocéanique subtropical (environ 40° S). Trèspeu d’espèces ont pu coloniser et s’adaptera...

Climate change has been projected to affect species distribution(1) and future trends of local populations(2,3), but projections of global population trends are rare. We analyse global population trends of the emperor penguin (Aptenodytes forsteri), an iconic Antarctic top predator, under the influence of sea ice conditions projected by coupled cli...

Broad-scale environmental changes are altering patterns of natural selection in the wild, but few empirical studies have quantified the demographic cost of sustained directional selection in response to these changes. We tested whether population growth in a wild bird is negatively affected by climate change–induced phenological mismatch, using alm...

This review focuses on the impacts of climate change on population dynamics. I introduce the MUP (Measuring, Understanding, and Predicting) approach, which provides a general framework where an enhanced understanding of climate‐population processes, along with improved long‐term data, are merged into coherent projections of future population respon...

Sea ice conditions in the Antarctic affect the life cycle of the emperor penguin (Aptenodytes forsteri). We present a population projection for the emperor penguin population of Terre Adélie, Antarctica, by linking demographic models (stage-structured, seasonal, nonlinear, two-sex matrix population models) to sea ice forecasts from an ensemble of I...

Background/Question/Methods Individuals within a population are different (e.g. age or breeding experience). Taking into account individual differences in responses to climatic fluctuations can change our understanding of how populations may cope with a warming climate. In this study, we examined the effect of climate fluctuations over a 47-yea...

Background/Question/Methods There is now ample evidence of the ecological impacts of recent climate change in marine ecosystems. Seabirds are good bio-indicator species of the ecological consequences of climate change on marine ecosystems. In polar ecosystems, the sea ice environment is a critical habitat for many seabirds because it influences...

Populations are shifting their phenology in response to climate change, but these shifts are often asynchronous among interacting species. Resulting phenological mismatches can drive simultaneous changes in natural selection and population demography, but the links between these interacting processes are poorly understood. Here we analyse 37 years...

Over the last century, major climate changes and intense human exploitation of natural living resources have occurred in the Southern Ocean, potentially affecting its ecosystems up to top marine predators. Fisheries may also directly affect seabirds through bycatch and additional food resources provided by discards. The past 20 yr of research has s...

Evidence that infectious diseases cause wildlife population extirpation or extinction remains anecdotal and it is unclear whether the impacts of a pathogen at the individual level can scale up to population level so drastically. Here, we quantify the response of a Common eider colony to emerging epidemics of avian cholera, one of the most important...

Survival modelling of adult and juvenile female common eiders breeding at the East Bay colony, Southampton Island, Nunavut, Canada. (DOC)

Estimation of vital rates for common eiders breeding at the East Bay colony, Southampton Island, Nunavut, Canada. (DOC)

The debate on emission targets of greenhouse gasses designed to limit global climate change has to take into account the ecological consequences. One of the clearest ecological consequences is shifts in phenology. Linking these shifts to changes in population viability under various greenhouse gasses emission scenarios requires a unifying framework...

We present a new approach to modeling two-sex populations, using periodic, nonlinear two-sex matrix models. The models project the population growth rate, the population structure, and any ratio of interest (e.g., operational sex ratio). The periodic formulation permits inclusion of highly seasonal behavioral events. A periodic product of the seaso...