Hi all,

we are seeking candidates for our subject in evolutionary biodemography in birds at the doctoral school E2M2 in Lyon.


Identifying the demographic and ecological correlates of extinction risk in a context of environmental changes is a major task devoted to conservation biologists in order to dampen the current loss of biodiversity. Detailed information regarding demographic parameters and life-history traits are critically needed in this context to identify species at risk and design efficient conservation planning, yet they are available only for a small fraction of tetrapods. The PhD project aims to fill this gap in birds by providing a comprehensive database to both researchers and conservationists and to address key-question in evolutionary biodemography and conservation. Nearly a quarter of the ca. 11,000 extant bird species are currently threatened with extinction and even more show strong population declines and range contractions2. A comprehensive review of their demography is therefore badly needed for informing efficient conservation planning. The PhD project will update and improve BIDDABA, a biodemography database built at the population level and last updated in 2007, with an exhaustive survey of the literature over the past fifteen years, a period particularly rich in terms of bird demographic studies. Age-dependent variation in survival and fecundity parameters strongly influence the evolution of life history traits (morphology, behaviour, etc.) and their resulting variation among species. They are essential metrics to tackle evolutionary questions and determine the vulnerability of wild populations to increasing anthropogenic pressures in the context of global change. Gaps in data (i.e. for species lacking demographic information) will be filled using an up-to-date modelling approach including allometric relationships, life-history traits and phylogeny, in order to provide a comprehensive database for the ca. 11,000 bird species. Based on this rigorous imputation, we will estimate species-specific generation length, population growth rate and its sensitivity to variation of the main demographic parameters (survival and fecundity), two key metrics for deriving a genuine assessment of extinction risk and inform conservation strategies. Overall, the PhD project seeks to provide detailed answers to the following major questions: 1) What are the demographic and life-history species attributes that best explain the variation of extinction risk in birds and the ability of species to cope with major anthropogenic threats, such as harvesting and 2) How species showing different demographic strategies will respond to ongoing climate change in the next decades? Finally, we will pay attention to the effective transfer of these results to managers and conservationists.

More specifically, the PhD will be achieved according to the following structure:
Axis 1: Building BIDDABA 2.0, a detailed and updated database on avian biodemography
The PhD student will update the existing BIDDABA database taking advantage of its new MySQL design through an intensive literature search, including results from recently published reviews. The PhD project will gather new data to record fully age- and sex-dependent survival and fecundity at the population level. In addition, the PhD project will develop a comprehensive, and thoroughly discussed, list of information on species life history and ecology (e.g. body mass and other size metrics, diet, migratory behaviour, distribution range & size, mating system, invasiveness…) and environmental context (e.g. hunting pressure, habitat degradation). The goal is to provide a generic and multi-purpose database to both researchers and conservationists, including age-dependent average estimates together with their standard errors, sample size, and estimation methods. Uniquely, BIDDABA 2.0 will also compile population-specific time series of demographic parameters, when available, thus providing a unique opportunity for investigating population responses to changing environments.

Axis 2: Improving BIDDABA 2.0 by imputing missing values as a function of species traits and phylogeny, and developing an umbrella demographic model for all bird species
Proper estimates for sex- and age-specific demographic parameters exist for only a minority of the species5. An important step therefore consists in imputing missing estimates using allometric scaling, accounting for phylogenetic relationships and life history traits tightly related to avian demography. Then, a demographic umbrella model based on a stage/age-structured matrix model will be developed. From this model, we will estimate generation time length, asymptotic growth rate and its sensitivity to change in any of the demographic parameter. These metrics are critical to inform conservation strategies and the assessment of species conservation status (using generation length to properly scale population trends and extinction risk over time). For species with data on temporal variation in demographic parameters, we will further compute transient life table response experiments to decompose realized population growth rates into contributions from specific vital rates and components of population structure (see axis 4).

Axis 3: Exploring BIDDABA 2.0 to investigate the contribution of species attributes and environmental factors to global conservation status
The PhD project will use BIDDABA 2.0 to investigate the relationship between generation length and IUCN Red-List categories (i.e. global conservation status). Long-lived species are indeed over-represented among threatened species and are more extinction-prone than short-lived species. Then, in order to decipher pathways to extinction, the PhD student will investigate the relationships of life history traits and ecology with demographic sensitivity to identify particular sets of traits making species more vulnerable to a particular anthropogenic threat as assessed by IUCN (e.g. habitat destruction, hunting, climate change, invasive species). Accurate estimates of generation length also allow one for the calculation of the maximal annual growth rate and thus the maximum sustainable level of additional –human-related– mortality for each species. A specific review will be conducted to assess the level of sustainability of birds’ hunting worldwide.

Axis 4: Using BIDDABA 2.0 to assess the expected fate of bird populations in the face of global change and its consequences for forecasted extinction risk
Climatic projections consistently state that both average temperature and the frequency of extreme events will increase in the coming decades inducing rapid environmental changes. Under such new selective pressures, we expect some species-specific tactics to be counter-selected while other will be selected for. Taking advantage of available population time series of vital rates in >50 species covering a large range of bird groups, we will assess the species-specific functional relationships linking the frequency of extreme events and temperatures during critical life stages to demographic estimates and will forecast species demography using available climatic projections at 50-100 year horizons. Then, we will use stochastic life table response experiments to quantify the net effect of global warming on species-specific long-run population growth and identify changes in vital rates responsible for changes in growth rates. Finally, we will look for ecological and life history correlates of the amount of change in population growth. This approach will provide crucial information for determining the species with the highest extinction risk, and thus for defining priorities of conservation.

Putative candidates are asked to send an email contact with a motivation letter and a CV to Sébastien Devillard (sebastien.devillard@univ-lyon1.fr) and Alexandre Millon (alexandre.millon@imbe.fr). Expected skills include a genuine interest in conservation biology, population demography and reading efficiency. Skills in population modelling and database management are also welcome.

Le contenu de cette offre est la responsabilité de ses auteurs. Pour toute question relative à cette offre en particulier (date, lieu, mode de candidature, etc.), merci de les contacter directement. Un email de contact est disponible: sebastien.devillard@univ-lyon1.fr

Pout toute autre question, vous pouvez contacter sfecodiff@sfecologie.org.