Michael Schaub

• PhD
• Head of Department at Swiss Ornithological Institute

Bayesian statistics has exploded into biology and its sub-disciplines, such as ecology, over the past decade. The free software program WinBUGS and its open-source sister OpenBugs is currently the only flexible and general-purpose program available with which the average ecologist can conduct standard and non-standard Bayesian statistics. Bayesian...

Survival is often estimated from capture–recapture data using Cormack–Jolly–Seber ( CJS ) models, where mortality and emigration cannot be distinguished, and the estimated apparent survival probability is the product of the probabilities of true survival and of study area fidelity. Consequently, apparent survival is lower than true survival unless...

A mechanistic understanding of the dynamics of populations requires knowledge about the variation of the underlying demographic rates and about the reasons for their variability. In geographically open populations, immigration is often necessary to prevent declines, but little is known about whether immigration can contribute to its regulation. We...

Integrated population models (IPMs) represent the single, unified analysis of population count data and demographic data. This modelling framework is quite novel and can be implemented within the classical or the Bayesian mode of statistical inference. Here, we briefly show the basic steps that need to be taken when an integrated population model i...

The polygyny in Pied Flycatchers has been studied for almost 40 years in two nest box networks in western Switzerland. 577 nests were monitored in Baulmes between 1980 and 2016, and 663 nests were monitored near Grandson and Concise between 1989 and 2016. The overall rate of polygyny was relatively high in Baulmes, with 27.4 % of nests, but only 7....

Population dynamics are driven by stochastic and density‐dependent processes acting on demographic rates. Individuals differ demographically, and to capture these differences, models of population dynamics are usually structured by age and stage, rarely by sex. An effect of sex on population dynamics is expected if the dynamics of males and females...

Regular assessment of reintroduced populations is essential to guide management and provide lessons for other reintroduction projects. Bearded vulture Gypaetus barbatus reintroduction in the Alps began in 1986 with the release of the first fledglings, the first successful reproduction was recorded in 1997, and the population has grown steadily sinc...

Gathering demographic information on rare species is critical to understanding their population dynamics and implementing efficient conservation measures. Using integrated models, we jointly analyzed multiple data sets, including capture–recapture, GPS tracking and nest monitoring data collected over the last 10 years, to provide the first demograp...

The Magellanic sub-Antarctic Forest is home to the world's southernmost avian community and is the only Southern Hemisphere analogue to Northern Hemisphere temperate forests at this latitude. This region is considered among the few remaining pristine areas of the world, and shifts in environmental conditions are predominantly driven by climate vari...

Climate change affects timing of reproduction in many bird species, but few studies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average...

Evaluating the effectiveness of conservation actions is challenging for migratory species because a population can be impacted anywhere along its route. Conservation actions for the critically endangered Fennoscandian lesser white-fronted goose population include culling of red foxes in the breeding area and habitat improvements and reduction of il...

An understanding of the drivers of individual fitness is a fundamental component of evolutionary ecology and life‐history theory. Reproductive senescence, mate and mating tactic choice and latent heterogeneity in individual quality interact to affect individual fitness. We sought to disentangle the effects of these fitness drivers, where longitudin...

Local population dynamics are driven by local processes such as temporal variation of productivity, survival, emigration and population stage structure, and by processes originating from outside the local population, such as immigration. Populations may operate as sources that contribute more individuals than have died or as sinks that depend on ne...

Harvest of wild organisms is an important component of human culture, economy, and recreation, but can also put species at risk of extinction. Decisions that guide successful management actions therefore rely on the ability of researchers to link changes in demographic processes to the anthropogenic actions or environmental changes that underlie va...

The estimation of demographic parameters is a key component of evolutionary demography and conservation biology. Capture-mark-recapture methods have served as a fundamental tool for estimating demographic parameters. The accurate estimation of demographic parameters in capture-mark-recapture studies depends on accurate modeling of the observation p...

The management of sustainable harvest of animal populations is of great ecological and conservation importance. Development of formal quantitative tools to estimate and mitigate the impacts of harvest on animal populations has positively impacted conservation efforts. The vast majority of existing harvest models, however, do not simultaneously esti...

The estimation of demographic parameters is a key component of evolutionary demography and conservation biology. Capture-mark-recapture methods have served as a fundamental tool for estimating demographic parameters. The accurate estimation of demographic parameters in capture-mark-recapture studies depends on accurate modeling of the observation p...

Misidentification of marked individuals is unavoidable in most studies of wild animal populations. Models commonly used for the estimation of survival from such capture–recapture data ignore misidentification errors potentially resulting in biased parameter estimates. With a simulation study, we show that ignoring misidentification in Cormack–Jolly...

In many animal species, sexually mature individuals may skip breeding opportunities despite a likely negative impact on fitness. In spatio‐temporally heterogeneous environments, habitat selection theory predicts that individuals select habitats where fitness prospects are maximized. Individuals are attracted to high‐quality habitat patches where th...

We develop an IPM for a small population of woodchat shrikes (Lanius senator) that combines three types of data: capture-recapture data, and counts of the number of fledglings and of breeding pairs (the latter being interpreted as the population counts). The model accounts for environmental variability and demographic stochasticity, and adopts a Po...

Density dependence is a crucial regulation mechanism in population dynamics but is challenging to study empirically. We illustrate the use of integrated population models (IPMs) to study density dependence while offering a number of interesting possibilities to overcome some of these challenges. As IPMs include both individual and population levels...

We develop an individual-based spatial integrated population model (IPM) to jointly analyze spatial capture-recapture and occupancy data of black bears (Ursus americanus luteolus) collected from 2007 to 2012 in Louisiana, USA. The process model of this IPM does not aggregate individuals into stage or age classes as do traditional IPMs, but instead,...

The focus of this chapter is the presentation of demographic population analyses that look backward in time and attempt to understand why a population has shown the observed trajectory. Such analyses are called retrospective population analyses and allow a fundamental understanding about demographic drivers of population dynamics. There are several...

The core of most integrated population models is a stage-structured (or matrix) population model, which provides the linkage between the demography of individuals and the trajectory of a population. We give a concise summary of the traditional analysis of matrix population models and emphasize the connection between matrix and integrated population...

We develop an integrated population model on greater horseshoe bats (Rhinolophus ferrumequinum) to estimate demographic rates and population composition. We combine three different data sets from a nursery colony of this bat in a small church in the Swiss Alps: counts of free-flying adults emerging from the colony at dusk, counts of newborns, and c...

We introduce integrated population models (IPMs) in two different ways. First, we start from a matrix population model and progressively add more data sets along with likelihoods for estimating certain parameters from them as part of a single model fit with the JAGS program. We emphasize that the inclusion of population count (or similarly, populat...

As with any statistical model, an integrated population model (IPM) makes simplifying assumptions about Nature. Accurate parameter estimates are only obtained when these assumptions have been sufficiently met. The main assumptions of an IPM are classified as two types. The first comprises the assumptions made by each component model; the second is...

In this chapter, we extend the previous case study to a continuous representation of space. Rather than dividing up a large region into a few discrete strata, we model spatial variation in the initial abundance, apparent survival, and recruitment rate of kestrels (Falco tinnunculus) in the northwestern corner of Switzerland in an essentially contin...

The joint analysis of data sets from population and individual levels through an integrated population model provides a number of benefits highlighted here. Key benefits of integrated population models (IPMs) are the increased precision of parameter estimates and the ability to estimate parameters without explicit data—the so-called hidden paramete...

We develop an integrated population model (IPM) for the hoopoe (Upupa epops) data set consisting of the classical combination of population count, capture-recapture, and individual productivity data to estimate latent individual quality. In the model for productivity, we use a finite-mixture model with two latent groups to define individual quality...

In this case study, we develop a seasonal, two-sex integrated population model (IPM) for a population of black grouse (Lyrurus tetrix) in the Italian Alps. Three different data sets are entered in this model: a lek survey in spring to count displaying males, a survey in late summer to count males, females, and chicks, and radio tracking data. The m...

A population viability analysis (PVA) is an important technique in the population assessment applied to rare, harvested, and pest species alike. In a broad sense, it aims to project the future size of a population and possibly incorporate the effects of predicted changes in the environment or in some management action. We illustrate the use of an i...

We provide a largely nonmathematical introduction to the using of probability in statistical modeling and parametric statistical inference by the two dominant estimation methods, maximum likelihood and Bayesian posterior inference. We explain and illustrate the simulation method concepts collectively known as Markov chain Monte Carlo (MCMC), which...

We develop a multisite integrated population model (IPM) for great cormorants (Phalacrocorax carbo) to analyze count and capture-recapture data sampled in three Danish breeding colonies. The goal is the estimation of colony-specific survival and productivity as well as natal and breeding dispersal among the three colonies. The population model beco...

In this case study, we fit two integrated population models to population counts, productivity counts, and dead-recovery data in a population of the Peregrine Falcon (Falco peregrinus) in the Jura mountains over 43 years (1965–2007). The main objectives are to investigate whether the much-publicized population crash caused by the effects of pestici...

We give an overview of the data types and associated models typically combined in an integrated population model (IPM). These models are the components or “ingredients” of an IPM. We focus on key models for surveys of population counts, productivity, and capture-recapture. We start with an overview of the main features of these data types that focu...

We develop an integrated population model (IPM) to study the demographic causes of synchrony in population dynamics, i.e., coincidence in the changes in demographic rates and of population growth in multiple populations. The model requires that component data sets are sampled at different sites and during time periods that must overlap at least par...

We develop an integrated population model based on data collected over large spatial scales for monitoring populations and demography. Specifically, we analyze data from the North American Breeding Bird Survey and Monitoring Avian Productivity and Survivorship programs for gray catbirds (Dumetella carolinensis) in the New England/Mid-Atlantic regio...

Small thermal roofs in building attics might be a promising option to maintain and support nursery colonies of bats, but little empirical evidence is available. In a controlled study conducted from 2014 to 2021 on the northern side of the Swiss Alps, we investigated the effects of a thermal roof within an attic on the establishment and size of a nu...

Species- and population-specific responses to their environment may depend to a large extent on the spatial variation in life-history traits and in demographic processes of local population dynamics. Yet, those parameters and their variability remain largely unknown for many cold-adapted species, which are exposed to particularly rapid rates of env...

Abstract Estimating demographic parameters of interest is a critical component of applied conservation biology and evolutionary ecology, where demographic models and demographic data have become increasingly complex over the last several decades. These advances have been spurred by the development and use of information theoretic approaches, progra...

• The estimation of abundance and distribution and factors governing patterns in these parameters is central to the field of ecology. The continued development of hierarchical models that best utilize available information to inform these processes is a key goal of quantitative ecologists. However, much remains to be learned about simultaneously mo...

Alpine black grouse populations are generally declining, but the underlying demographic drivers are largely unknown. We studied the dynamics of two adjacent black grouse populations over a 20 years period in the Italian Alps that differ in hunting pressure to identify the main demographic process affecting these populations and to study the impact...

Age-related variation in reproductive performance is central for the understanding of population dynamics and evolutionary processes. Our understanding of age trajectories in vital rates has long been limited by the lack of distinction between patterns occurring within- and among-individuals, and by the lack of comparative studies of age trajectori...

While ecologists know that models require assumptions, the consequences of their violation become vague as model complexity increases. Integrated population models (IPMs) combine several datasets to inform a population model and to estimate survival and reproduction parameters jointly with higher precision than is possible using independent models....

Predation can affect prey behavior, demography, abundance, and distribution, particularly in lentic freshwater ecosystems. Fish are predators known to reduce the abundance of their prey and to restrict the distribution of species. Using time series which spanned 43 and 22 yr, respectively, we analyzed the effect of a change in the fish predator com...

Relevance of breeding season fecundity as a driver of population dynamics has been highlighted by many studies. Despite that, knowledge about how brood type specific (i.e. first, second or replacement) fecundity affects demography of multiple‐brooded species is limited. In fact, estimation of brood type specific fecundity is often challenging due t...

Animal reintroductions are important tools for conservation but often fail for reasons poorly understood. Biological and methodological factors can affect reintroduction success in complex manners. Investigating dispersal after release often relies on the use of biologging devices but individuals cope differently with these devices. They can detrim...

Integrated population models (IPMs) are widely used to combine disparate data sets in joint analysis to better understand population dynamics and provide guidance for conservation activities. An often‐cited assumption of IPMs is independence among component data sets within the combined likelihood. Dependency among data sets should lead to underest...

Population size of species with birth-pulse life-cycles varies both within and between seasons, but most population dynamics models assume that a population can be characterised adequately by a single number within a season. However, within-season dynamics can sometimes be too substantial to be ignored when modelling dynamics between seasons. Typic...

The demographic reasons of local population extinctions are rarely known which hampers learning for preventing extinction of other populations. Here we study the demography of a population of the endangered woodchat shrike Lanius senator at the edge of its distribution range from 1966 to 1992. We recorded the number of breeding pairs and collected...

The difficulties in understanding the underlying reasons of a population decline lie in the typical short duration of field studies, the often too small size already reached by a declining population or the multitude of environmental factors that may influence population trend. In this difficult context, useful demographic tools such as integrated...

Migratory species form an important component of biodiversity; they link ecosystems across the globe, but are increasingly threatened by global environmental change. Understanding and mitigating threats requires knowledge of how demographic processes operate throughout the annual cycle, but this can be difficult to achieve when breeding and non‐bre...

European farmland birds show massive large‐scale population declines due to agricultural intensification. Long‐distance migrants are particularly affected as their populations appear to undergo larger declines than those of residents and short‐distance migrants, raising the question about the impact of non‐breeding environmental conditions and thei...

Senescence has been studied since a long time by theoreticians in ecology and evolution, but empirical support in natural population has only recently been accumulating. One of the current challenges is the investigation of senescence of multiple fitness components and the study of differences between sexes. Until now, studies have been more freque...

Abstract Theoretical studies suggest that temporal covariation among and temporal autocorrelation within demographic rates are important features of population dynamics. Yet, empirical studies have rarely focused on temporal covariation and autocorrelation limiting our understanding of these patterns in natural populations. This lack of knowledge r...

Rodents are classical model species to investigate spatial synchrony in population fluctuation. Yet, previous studies have been strongly biased geographically toward high latitude (boreal ecosystem) and limited in their spatial scale, i.e., few sampling sites separated by a few tens of kilometers. Both aspects currently limit our understanding of r...

Database gathering the results of the systematic litterature review associated to the paper entitled: Quantifying the contribution of immigration to population dynamics: a review of methods, evidence and perspectives in birds and mammals by Millon, Lambin, Devillard & Schaub, published in Biological Reviews 94, 2049-2067.

The identification of the source–sink status of a population is critical for the establishment of conservation plans and enacting smart management decisions. We developed an integrated population model to formally assess the source status of a kestrel Falco tinnunculus population breeding in nest boxes in Switzerland. We estimated juvenile and adul...

Despite the protective measures that have been implemented to increase the productivity of meadow birds, populations are still declining in most breeding and wintering areas. We therefore still do not know how large the protective efforts need to be to curb the decline of the meadow bird populations. By taking advantage of monitoring data from the...

The demography of a population is often reduced to the apparent (or local) survival of individuals and their realised fecundity within a study area defined according to logistical constraints rather than landscape features. Such demographics are then used to infer whether a local population contributes positively to population dynamics across a wid...

Conservation action aims at halting the erosion of biodiversity. Assessing the outcome of a conservation intervention is thus key to improving its efficiency. This is often done by comparing an intervention to a control. Comparative effectiveness studies, on the other hand, compare multiple conservation interventions among each other. In doing so,...

Population dynamics models have long assumed that populations are composed of a restricted number of groups, where individuals in each group have identical demographic rates and where all groups are similarly affected by density‐dependent and ‐independent effects. However, individuals usually vary tremendously in performance and in their sensitivit...

Dynamic population models typically aim to predict demography and the resulting population dynamics in relation to environmental variation. However, they rarely include the diversity of individual responses to environmental changes, thus hampering our understanding of demographic mechanisms. We develop an integrated integral projection model (IPM²)...

Non-random gene flow is a widely neglected force in evolution and ecology. This genotype-dependent dispersal is difficult to assess, yet can impact the genetic variation of natural populations and their fitness. In this work, we demonstrate a high immigration rate of barn owls (Tyto alba) inside a Swiss population surveyed during 15 years. Using te...

The annual cycle of migrating birds is shaped by their seasonal movements between breeding and non-breeding sites. Studying how migratory populations are linked throughout the annual cycle—migratory connectivity, is crucial to understanding the population dynamics of migrating bird species. This requires the consideration not only of spatial scales...

Reproductive and survival costs due to reproductive investment are a central element for the evolution of life histories. Both intra- (reduction of reproductive performance of second brood due to investment in first brood) and inter-seasonal costs (reduction of reproductive performance or annual survival due to reproductive investment in preceding...

Comparative studies about the relationships between vital rates and ecological traits at the community level are conspicuously lacking for most taxa because estimating vital rates requires detailed demographic data. Identifying relationships between vital rates and ecological traits could help to better understand ecological and evolutionary demogr...

Integrated population models (IPMs) represent a formal statistical methodology for combining multiple data sets such as population counts, band recoveries, and fecundity estimates into a single unified analysis with dual objectives: better estimating population size, trajectory, and vital rates; and formally describing the ecological processes that...

Dispersal is considered to be a species-specific trait, but intraspecific variation can be high. However, when and how this complex trait starts to differentiate during the divergence of species/lineages is unknown. Here, we studied the differentiation of movement behavior in a large salamander population (Salamandra salamandra), in which individua...

Growth is a fundamental life history trait in all organisms and is closely related to individual fitness. In altricial birds, growth of many traits is restricted to the short period between hatching and fledging and strongly depends on the amount of food that parents deliver and the extent of hatching asynchrony. However, empirical studies of energ...

Theoretical work has emphasized the important role of individual traits on population dynamics, but empirical models are often based on average or stage-dependent demographic rates. In this study on a monogamous bird, the Eurasian hoopoe (Upupa epops), we show how the interactions between male and female fixed and dynamic heterogeneity influence de...

Identifying the demographic parameters (e.g., reproduction, survival, dispersal) that most influence population dynamics can increase conservation effectiveness and enhance ecological understanding. Life table response experiments (LTRE) aim to decompose the effects of change in parameters on past demographic outcomes (e.g., population growth rates...

The recent arrival of Batrachochytrium salamandrivorans in Europe was followed by rapid expansion of its geographical distribution and host range, confirming the unprecedented threat that this chytrid fungus poses to western Palaearctic amphibians. Mitigating this hazard requires a thorough understanding of the pathogen's disease ecology that is dr...

Migrating birds have to incorporate migration into their annual cycle, next to breeding and moult. This presents the challenge to arrive at the right place at the right time at any given moment during the year to maximize fitness. Although many studies have investigated the timing of specific (life-history) activities of migrating birds, it is poor...

Understanding the factors that limit and regulate wildlife populations requires insight into demographic and environmental processes acting throughout the annual cycle. Here, we combine multi-year tracking data of individual birds with a 26-year demographic study of a migratory songbird to evaluate the relative effects of density and weather at the...

Supplementary Figures, Supplementary Methods and Supplementary References

Life-history theory predicts trade-offs between reproductive and survival traits such that different strategies or environmental constraints may yield comparable lifetime reproductive success among conspecifics. Food availability is one of the most important environmental factors shaping developmental processes. It notably affects key life-history...

Dispersal is considered to be a species-specific trait, but intraspecific variation can be high. However, when and how this complex trait starts to differentiate during the divergence of species/lineages is unknown. Here, we studied the differentiation of movement behaviour in a large salamander population (Salamandra salamandra), in which individu...

Migratory birds are often faithful to wintering (nonbreeding) sites, and also migration timing is usually remarkably consistent, that is, highly repeatable. Spatiotemporal re-peatability can be of advantage for multiple reasons, including familiarity with local resources and predators as well as avoiding the costs of finding a new place, for exampl...

Understanding effects of harvest on population dynamics is of major interest, especially for declining species. European lapwing Vanellus vanellus populations increased from the 1960s until the 1980s and declined strongly thereafter. About 400,000 lapwings are harvested annually and it is thus of high conservation relevance to assess whether huntin...

Implementation of the multievent cause-specific mortality model in E-SURGE. We provided the full procedure to implement this model in program E-SURGE. (PDF)

On the use of recoveries with unknown source of death in the standard cause-specific mortality model. Comparison of mean and standard errors survival and proportion of death due to hunting between the multievent cause-specific mortality model and the standard cause-specific mortality model [16] where recoveries with unknown cause of death where eit...

Comparison of parameter estimates obtained from the multievent cause-specific mortality model and a multievent Seber model. (PDF)

List of ringing schemes that provided the ringing and recovery data. Includes a table summarizing origin of ringing data and a figure illustrating locations of recoveries by area of ringing. (PDF)

Multievent Seber model. Brief description of the model used to estimate survival and recovery probabilities while taking into account uncertainty in the recovery process. (PDF)

Comparison of kill rates computed from different values of reporting and retrieval rates. (PDF)

Dataset. Encounter histories of ringed lapwings formatted for the multievent cause-specific mortality model adopted in our study. Lapwings were ringed from 1960 to 2010 in Denmark, Finland, Germany, Great-Britain, Netherlands, Norway and Sweden. (TXT)

Review of reporting rates and crippling loss rates of Mourning doves. Tables summarizing reporting rates and crippling loss rates of Mourning doves from the literature. (PDF)