Introduction: Timing of birth is a major determinant of individuals reproductive success and survival, and is driven by multiple internal and external factors. However, there is currently no quantitative assessment of the extent and support received by the drivers of the phenology of births in mammals. Due to their diverse phenology of births, large herbivores represent an ideal case study to quantify this. Aims: our objective was to identify the different drivers tested for their effect on the phenology of births in large herbivores and how much empirical support they received, as well as determine thematic, taxonomic and spatial gaps in the literature. Methods: We conducted a systematic review focusing on the drivers of the phenology of births in wild large herbivores. We extracted the outcomes of 124 relevant articles and assessed the reliability of their findings using a general index based on the quality of the data and methods used. Results and Discussion: As expected, the two dominant hypotheses (seasonality and predation) received strong support regarding their effect on birth timing and synchrony, respectively. The effect of female, offspring and population characteristics remained marginally accounted for, even though there was evidence of their importance in the determination of the phenology of births. We identified a major research gap in Asian and South and Central American species. Conclusions: We encourage research in these understudied domains, as well as large scale multi-species comparative analyses to fill in the gaps and improve our understanding of reproductive phenology. ### Competing Interest Statement The authors have declared no competing interest. Ministère de l’Enseignement Supérieur et de la Recherche, https://ror.org/03sjk9a61 Nelson Mandela University, https://ror.org/03r1jm528

Population Projection Matrices (PPM) are discrete mathematical formulations of population growth that are key tools in demographic population studies, enabling the prediction of growth for populations structured with age, size, or other life stages. However, several studies have identified errors stemming from misconceptions related to survival and reproduction parameters, as well as confusion between post-breeding and pre-breeding in the case of Leslie matrices. The present work aims to propose a simple and robust method called Matrices Alternated Products (MAP) for reliably constructing PPM directly from life tables and empirical data. The MAP approach provides a systematic framework for defining both survival and reproductive parameters and producing pre-breeding and post-breeding matrices. The method we propose allows reducing errors and improving the accuracy of demographic population models, and the code we provide will allow population ecologists and wildlife managers to apply this method to any case study in practice.

Advance in the phenology of plants and animals is a widely observed response to climate change. The magnitude of the changes is, however, very variable across species. Several biological factors could influence the strength of the phenological advances, including lifestyle. Hibernation has evolved in response to harsh environmental conditions and could, hence, potentially buffer organisms against changing climatic conditions. In the Alps, the Alpine marmot hibernates for almost 6 months. Owing to its slow pace-of-life, we expected Alpine marmots to be more responsive to earlier springs than non-hibernating species. Here we investigate temporal variation in the date at which pups emerge from their natal burrow for the first time. Using quantile regressions, we provide clear evidence of an earlier pup emergence between 1990 and 2023. Over the study period, the predicted change is 4.7 days. In particular, late emergence dates are becoming especially rare over time. Our findings are in line with previous works on other Alpine species, which suggest a general advance in reproductive phenology. The rate of change of pup emergence dates over years is, however, weaker in the Alpine marmot than in most other mammalian species studied so far.

The island of Mindoro, Philippines, is a biodiversity hotspot with numerous endemic and threatened species, including mammals like the tamaraw Bubalus mindorensis and Oliver's warty pig Sus oliveri. Unfortunately, mammals in Mindoro are threatened by poaching, habitat loss, and expanding infrastructure. To develop effective conservation plans to protect these species, it is important to have up-to-date information on their population status in key areas. From December 2020 to May 2022, we conducted semi-structured camera-trapping in the Aruyan-Malati region, a forest area located in the Municipality of Sablayan, in Occidental Mindoro. Total camera-trapping effort was 1889 camera-trap nights from 73 stations. We identified a total of 6 mammal species, including tamaraw, Oliver's warty pig, common palm civet Paradoxurus hermaphroditus, long-tailed macaque Macaca fascicularis, and domestic dogs and cats, but we failed to record Philippine deer Rusa marianna, despite indications that the species was previously present in the area. To inform future camera-trapping in future surveys in other parts of Mindoro, we estimated detection probability for the mammal species and scaled this by camera-trapping effort. The fact that we recorded a relatively intact mammal community, including both tamaraw and Oliver's warty pig, suggests that Aruyan-Malati harbors globally important mammalian biodiversity. Future conservation efforts should focus on strengthening site security and minimizing the potential adverse effects of domestic dogs and cats.

In large herbivores, the timing of births often matches the seasonal peak of availability of food resources, likely to improve juvenile survival and reduce reproduction costs. Some species however breed year round, even in seasonal environments. To what extent being born during the lean season reduces juveniles and reproductive females survival remains mostly unknown. This holds particularly true in tropical ecosystems where the demographic processes underlying population dynamics are often poorly studied. We investigate the variability of survival for plains zebras ( Equus quagga ) in Hwange National Park (Zimbabwe), a highly seasonal savanna ecosystem. We used capture-recapture models to analyse long-term demographic data (2008-2019). We investigated the effect of seasonality as a categorical (wet versus dry season) and continuous (duration of the dry season) variable on survival. We found little variability in the survival of younger foals (< 6 m.o.), whereas older foals and yearlings’ survival, which was higher on average, decreased with the length of the dry season. Female survival was high but decreased with increasing exposure to the dry season for the non-reproductive ones only. The probability of females becoming reproductive the next year was not affected by the length of the dry season. Together, our results highlight the importance of individual quality in reproductive performance, as reproductive females seem to buffer the effect of environmental variability on their own survival and that of their foal. Timing of birth in this population might be the result of a trade off between minimising mother’s reproductive costs and maximising juvenile survival.

Context The current rate of biodiversity loss increasingly motivates population reinforcement efforts. If reinforcement aims at increasing population abundance, the factors that influence the success of such operations remain poorly understood. Moreover, unintended side effects may lead to the opposite outcome such as a decrease in abundance following reinforcement. The abundance of European hare (Lepus europaeus) in France has been repeatedly reported to be in decline since the 1960s, especially in grassland landscapes. Although past studies have investigated the effects of hare translocation operations (i.e. reintroduction and re-stocking) on post-release survival rates, whether these wildlife management actions have led to an increase in the population abundance of European hare remains unclear.Aims Our objectives were to assess the impact of re-stocking operations on the population dynamics of European hare in a grassland landscape in the Jura Mountains (France), where hare populations are declining in numbers, and to determine whether these actions effectively enhance local abundance.Methods We investigated here the effects of hare re-stocking on (1) the rate and causes of mortality of 103 released individuals (51 in 2021 and 52 in 2022) and (2) the overall spatial and temporal impact of releases on local population dynamics by analysing the variation of hare abundance estimated from nocturnal point counts.Key results Despite the large number of released individuals, we report a limited short-term temporal impact of re-stocking on local population abundance of European hare. Overall survival rates of released hares were low (<10% after 1 year) owing to predation (57%), roadkill (20%), and diseases (12%), although the relative contribution of each cause varied over time after release.Conclusion Our results suggest that re-stockings had limited benefits for the mitigation of European hare decline, primarily owing to high post-release mortality, which is likely being driven by predator attraction to released individuals, especially in the days following release.Implications Reinforcement operations, especially for prey species, should perhaps consider strategies such as acclimatisation, soft-release, and anti-predator training, to reduce predation risk and improve the success of these interventions.

Road networks have major ecological impacts on living organisms consequent to habitat loss and fragmentation, chemical and acoustic pollution, and direct mortality when wildlife-vehicle collisions are involved (WVC). The many past empirical studies revealed major variables accounting for WVC incidence (e.g., population density). Similarly, spatial locations of WVC hot-spots are associated to landscape features at large spatial scales, and to road characteristics at small spatial scales. Yet, we currently lack a comprehensive theoretical framework for WVC. Animal movement in relation to habitats is likely an essential driver of encounters with roads, but this remains largely ignored in most studies. Movement ecology now provides the necessary tools to investigate the impact of animal movement on WVC. We built a general individual-based model incorporating recent knowledge in movement ecology (movement typology: roaming, migratory route crossing a road, active attraction and active repulsion of roads) to estimate WVC risks. We explored the relative effects of animal and vehicle movement parameters (speed, abundance, road sinuosity and animal movement pattern) on collision probability. We show that animal behavior toward roads has major impacts on the number and risks of WVC, but also modulate the effects of other factors (animal speed, species local abundance, road traffic volume) on WVC. Sensitivity analyses show that the movement and behavior of the animal has more influence on WVC risks than any of the characteristics of roads and vehicles we tested. Our results suggest that empirical studies of WVC should incorporate knowledge about the behavioral habits of the focal species in relation to roads.

The rapidly expanding road network threatens the persistence of many terrestrial species through habitat loss, fragmentation, chemical, light and noise pollution and mortality associated with wildlife-vehicle collisions. Roadkill monitoring under-estimate actual collision numbers as the time during which roadkill carcasses remain visible on the road is often shorter than the frequency of road monitoring. By placing passerines (< 20 g) and amphibian carcasses on stretches of roads we surveyed every 2 hours, we fine-tuned existing persistence estimates for these species. We found median disappearance times (time for half of the carcasses to disappear) of less than 30 minutes for birds and 1-18 hours for amphibians depending on the volume of traffic, which is much shorter than previous estimates. Rainfall did not impact carcass persistence. We show the implications of these results by (1) correcting the results of roadkill surveys performed on common toads in reproductive migration for the number of removed carcasses and (2) estimating the number of passerine-vehicle collisions in the Auvergne-Rhône-Alpes (AuRA) region of France using the citizen-science database Faune-AuRA. We estimate that a road survey conducted 3 hours after amphibian road crossing under-estimates the number of roadkill by half, and that about 6800 passerine collisions were missed in 2022 by contributors because of short carcass persistence on the road. Small-bodied carcasses are hard to detect for drivers, and for a collision-report rate of 1%, total collision numbers for passerines could be as high as 700 000 individuals from 21 reported passerine species in 2022 in AuRA.

Caring for newborn offspring hampers resource acquisition of mammalian females, curbing their ability to meet the high energy expenditure of early lactation. Newborns are particularly vulnerable, and, among the large herbivores, ungulates have evolved a continuum of neonatal antipredator tactics, ranging from immobile hider (such as roe deer fawns or impala calves) to highly mobile follower offspring (such as reindeer calves or chamois kids). How these tactics constrain female movements around parturition is unknown, particularly within the current context of increasing habitat fragmentation and earlier plant phenology caused by global warming. Here, using a comparative analysis across 54 populations of 23 species of large herbivores from 5 ungulate families (Bovidae, Cervidae, Equidae, Antilocapridae and Giraffidae), we show that mothers adjust their movements to variation in resource productivity and heterogeneity according to their offspring’s neonatal tactic. Mothers with hider offspring are unable to exploit environments where the variability of resources occurs at a broad scale, which might alter resource allocation compared with mothers with follower offspring. Our findings reveal that the overlooked neonatal tactic plays a key role for predicting how species are coping with environmental variation. Combining a large-scale dataset of 23 ungulate species (in which newborns follow contrasting tactics of predator avoidance) with continuous-time stochastic movement models, the authors reveal that there are multiple dimensions of maternal movement behaviour and space use.

Road networks have major ecological impacts on living organisms consequent to habitat loss and fragmentation, chemical and acoustic pollution, and direct mortality when wildlife-vehicle collisions are involved (WVC). The many past empirical studies revealed biological traits shared by species most vulnerable to roadkills (e.g. population density). Similarly, spatial locations of WVC hot-spots are associated to landscape features at large spatial scales, and to road characteristics at small spatial scale. We currently lack a comprehensive theoretical framework for WVC. Animal movement in relation to habitats is an essential driver of encounters with roads, but this remains largely ignored in studies, even when movement ecology provides the necessary tools to investigate the impact of animal movement on WVC. We built a general individual-based model incorporating recent knowledge in movement ecology (movement typology: roaming, migratory route crossing a road, active attraction and active repulsion of roads) to estimate WVC risks. We explored the relative effects of animal and vehicle movement parameters (speed, abundance, road sinuosity and animal movement pattern) on collision probability. We show that animal behaviour toward roads has major impacts on the number and risks of WVC, but also modulate the effects of other factors (animal traveling speed, species local abundance, road traffic volume) on WVC. Sensitivity analyses show that the movement and behaviour of the animal has more influence on WVC risks than any of the characteristics of roads and vehicles we tested. Our results suggest that (1) effective roadkill mitigation should be species-specific and could vary in efficiency depending on the target’s movement pattern (mating and migratory seasons, foraging habits…) and (2) empirical studies of WVC should incorporate knowledge about the behavioural habits of the focal species in relation to roads.

Camera-traps are a versatile and widely adopted tool for collecting biological data for wildlife conservation and management. While estimating population abundance from camera-trap data is the primarily goal of many projects, the question of which population estimator is suitable for analysing these data needs to be investigated. We took advantage of a 21 day camera-trap monitoring period of giraffes (Giraffa camelopardalis angolensis) on the Ongava Game Reserve (Namibia) to compare capture-recapture (CR), rarefaction curves and N-mixture estimators of population abundance. A marked variation in detection probability of giraffes was observed both in time and between individuals. Giraffes were also less likely to be detected after they were seen at a waterhole (mean daily visit frequency of f = 0.25). We estimated the population size to be 119 giraffes (C-v = 0.10) using the most robust reference estimator (CR). All other estimators deviated from the CR population size by ca. -20 to > +80%. This was due the fact that these models did not account for the temporal and individual variations in detection probability. We found that modelling choice was much less forgiving for N-mixture models than CR estimators because it leads to very variable and inconsistent estimations of abundance. Double counts were problematic for N-mixture models, challenging the use of raw counts (i.e. when individuals are not identified) at waterholes, to monitor the abundance of giraffe or of other species without idiosyncratic coat patterns.

Endangered species, despite often living at low population densities, may undergo unexpected density-dependent feedbacks in the case of successful recovery or marked reduction in range. Because density-dependence dynamics can increase risk of extinction, these effects can hamper conservation efforts. In this study, we analyse the dynamics of the largest population of the tamaraw ( Bubalus mindorensis ), a critically endangered ungulate species endemic to Mindoro island, Philippines. The population is located within a < 3,000 ha area in Mounts Iglit-Baco Natural Park, with limited expansion possibilities. We took advantage of a 21 year time series of tamaraw counts to estimate annual population growth rate and possible density-dependence, accounting for sampling errors in the counts. The tamaraw population has been increasing at an average rate of +5% per year, as would be expected given its protected status by law. Population growth showed strong spatial structuring, with a population growth close to +10% in the core area of protection, and a reduction of abundance of −5% at the periphery of its range, inside the protected area. This range constriction is concerning because our best population dynamics model suggests significant negative density-dependence (Bayes factor = 0.9). The contraction of tamaraw range is likely caused by anthropogenic pressures forcing the species to live at relatively high densities in the core zone where protection is most effective, creating source-sink dynamics. Our study highlights the fact that, despite the continuous population growth over the last two decades, the long-term viability of the Mounts Iglit-Baco Natural Park tamaraw population remains uncertain.

Browsing damage in forests relies on a complex interaction between herbivore density and both forest understory composition and relative availability. Although variation in the amount of browsed twigs is sometimes used to assess abundance of large herbivores, the potential confounding effect of resource availability on this relationship has not yet been investigated. To fill the gap, we measured how browsing intensity of the woody plants varied in response to changes in both roe deer ( Capreolus capreolus ) abundance and vegetation availability from an intensive long-term monitoring. We estimated plant availability and consumption by roe deer from a modified Aldous method throughout a 14 yearlong period during which we experimentally manipulated population density. The functional response was strongly non-linear and density-dependent. When plant availability was low (< 12.5%), browsing intensity strongly increased with plant availability with an increasing rate with roe deer density, whereas beyond this threshold, browsing intensity slightly increased with both plant availability and population density in an additive way. Thus, forest susceptibility to browsing increases with increasing competition for food, especially when plant availability is low. Moreover, the interplay between browsing intensity and population density at low plant availability prevents the use of browsing intensity to monitor roe deer abundance when plant availability is low. Our findings provide clear evidence that relying on key ecological concepts such as functional responses improves the accuracy of management tools when monitoring changes of the herbivore-plant system over time.

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 latent correlations among different demographic parameters occurring within individuals. Despite the frequent use of multivariate mixed models, we lack an assessment of their reliability when applied to Bernoulli variables. Using simulations, we estimated the reliability of multivariate mixed effect models for estimating correlated fixed individual heterogeneity in demographic parameters modelled with a Bernoulli distribution. We evaluated both bias and precision of the estimates across a range of scenarios that investigate the effects of life‐history strategy, levels of individual heterogeneity and presence of temporal variation and state dependence. We also compared estimates across different sampling designs to assess the importance of study duration, number of individuals monitored and detection probability. In many simulated scenarios, the estimates for the correlated random effects were biased and imprecise, which highlight the challenge in estimating correlated random effects for Bernoulli variables. The amount of fixed among‐individual heterogeneity was frequently overestimated, and the absolute value of the correlation between random effects was almost always underestimated. Simulations also showed contrasting performances of mixed models depending on the scenario considered. Generally, estimation bias decreases and precision increases with slower pace of life, large fixed individual heterogeneity and large sample size. We provide guidelines for the empirical investigation of individual heterogeneity using correlated random effects according to the life‐history strategy of the species, as well as, the volume and structure of the data available to the researcher. Caution is warranted when interpreting results regarding correlated individual random effects in demographic parameters modelled with a Bernoulli distribution. Because bias varies with sampling design and life history, comparisons of individual heterogeneity among species is challenging. The issue addressed here is not specific to demography, making this warning relevant for all research areas, including behavioural and evolutionary studies.

The cost of reproduction on demographic rates is often assumed to operate through changing body condition. Several studies have found that reproduction depresses body mass more if the current conditions are severe, such as high population densities or adverse weather, than under benign environmental conditions. However, few studies have investigated the association between the fitness and body mass costs of reproduction. Using 25 years of individual-based capture-recapture data from Svalbard reindeer (Rangifer tarandus platyrhynchus), we built a novel Bayesian state-space model that jointly estimated inter-annual change in mass, annual reproductive success, and survival, while accounting for incomplete observations. The model allowed us to partition the differential effects of intrinsic and extrinsic factors on both non-reproductive mass change and the body mass cost of reproduction and to quantify their consequences on demographic rates. Contrary to our expectation, the body mass cost of reproduction (mean = 5.8 kg) varied little between years (CV = 0.08) whereas the between-year variation in body mass changes, that were independent of the previous year's reproductive state, varied substantially (CV = 0.4) in relation to autumn temperature and the amount of rain-on-snow in winter. This mass loss led to a cost of reproduction on the next reproduction, which was amplified by the same environmental covariates, from a 10% reduction in reproductive success in benign years, to a 50% reduction in harsh years. The reproductive mass loss also resulted in a small reduction in survival. Our results show how demographic costs of reproduction, driven by inter-annual fluctuations in individual body condition, result from the balance between body mass costs of reproduction and body mass changes that are independent of previous reproductive state. We illustrate how a strong context dependent fitness cost of reproduction can occur, despite a relatively fixed body mass cost of reproduction. This suggests that female reindeer display a very conservative energy allocation strategy, either aborting their reproductive attempt at an early stage or weaning at a relatively constant cost. Such a strategy might be common in species living in a highly stochastic food limited environment.

Proposed in 1849 by Charles Morren to depict periodical phenomena governed by seasons, the term 'phenology' has spread in many fields of biology. With the wide adoption of the concept of phenology flourished a large number of metrics with different meaning and interpretation. Here, we first a priori classified 52 previously published metrics used to characterise the phenology of births in large herbivores according to four biological characteristics of interest: timing, synchrony, rhythmicity and regularity of births. We then applied each metric retrieved on simulation data, considering normal and non-normal distributions of births, and varying distributions of births in time. We then evaluated the ability of each metric to capture the variation of the four phenology characteristics via a sensitivity analysis. Finally, we scored each metric according to eight criteria we considered important to describe phenology correctly. The high correlation we found among the many metrics we retrieved suggests that such diversity of metrics is unnecessary. We further show that the best metrics are not the most commonly used, and that simpler is often better. Circular statistics with the mean vector orientation and mean vector length seems, respectively, particularly suitable to describe the timing and synchrony of births in a wide range of phenology patterns. Tests designed to compare statistical distributions, like Mood and Kolmogorov-Smirnov tests, allow a first and easy quantification of rhythmicity and regularity of birth phenology respectively. By identifying the most relevant metrics our study should facilitate comparative studies of phenology of births or of any other life-history event. For instance, comparative studies of the phenology of mating or migration dates are particularly important in the context of climate change.

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 species with contrasting pace of life to quantify correlation patterns among five key demographic parameters: juvenile and adult survival, reproductive probability, reproductive success and productivity. Correlations among demographic parameters were ubiquitous, more frequently positive than negative, but strongly differed across species. Correlations did not markedly change along the slow-fast continuum of life histories, suggesting that they were more strongly driven by ecological than evolutionary factors. As positive temporal demographic correlations decrease the mean of the long-run population growth rate, the common practice of ignoring temporal correlations in population models could lead to the underestimation of extinction risks in most species.

An increasing number of ecological monitoring programmes rely on photographic capture–recapture of individuals to study distribution, demography and abundance of species. Photo‐identification of individuals can sometimes be done using idiosyncratic coat or skin patterns, instead of using tags or loggers. However, when performed manually, the task of going through photographs is tedious and rapidly becomes too time‐consuming as the number of pictures grows. Computer vision techniques are an appealing and unavoidable help to tackle this apparently simple task in the big‐data era. In this context, we propose to revisit animal re‐identification using image similarity networks and metric learning with convolutional neural networks (CNNs), taking the giraffe as a working example. We first developed an end‐to‐end pipeline to retrieve a comprehensive set of re‐identified giraffes from about 4,000 raw photographs. To do so, we combined CNN‐based object detection, SIFT pattern matching and image similarity networks. We then quantified the performance of deep metric learning to retrieve the identity of known individuals, and to detect unknown individuals never seen in the previous years of monitoring. After a data augmentation procedure, the re‐identification performance of the CNN reached a Top‐1 accuracy of about 90%, despite the very small number of images per individual in the training dataset. While the complete pipeline succeeded in re‐identifying known individuals, it slightly under‐performed with unknown individuals. Fully based on open‐source software packages, our work paves the way for further attempts to build automatic pipelines for re‐identification of individual animals, not only in giraffes but also in other species.

In the Lesser Antilles, the Ringed Kingfisher (Megaceryle torquata stictipennis) is only found in Martinique, Dominica, and Guadeloupe. In Martinique and Guadeloupe, farmers growing bananas used the insecticide chlordecone extensively from 1973 until 1993. Chlordecone is a remnant organochlorine insecticide that bioaccumulates in organisms easily. In 2009, we conducted a survey of the Ringed Kingfisher on Basse-Terre, Guadeloupe, traveling 270 km along 44 rivers to assess the effects of chlordecone on habitat selection behavior. During our survey, we encountered 47 Ringed Kingfishers, which we estimated to be 16 different individuals. A habitat selection analysis revealed that the Ringed Kingfishers were located mainly in sections of rivers flowing through the ombrophilous forest but were absent on the ocean shoreline and in the lower parts of rivers. The Ringed Kingfisher’s distribution in Guadeloupe could be negatively associated with areas heavily polluted by chlordecone. We propose that the widespread use of chlordecone in banana plantations in Guadeloupe had adverse ecological consequences and may be responsible for the absence of Ringed Kingfishers in lowland habitats on the island.

Comparative demographic analyses aim to identify axes of variation in vital rates and the factors that determine the position of species along these axes. These analyses can be performed using different primary data sets, with marked heterogeneity in data quality and structure. Whether the outcome of demographic comparative analyses depends on the database used because theoretical predictions of evolutionary ecology are not that robust and depend on the set of species analysed or because data limitation prevents the identification of the expected patterns has never been investigated. This chapter fills this knowledge gap by performing a comparative demographic analysis across mammalian species from two distinct databases (Comadre and Malddaba) that were built for different purposes. The chapter first estimates some demographic metrics for each database, analyses their allometric relationships, and compares the estimates with theoretical expectations by performing phylogenetic regressions. Using Malddaba led to stronger allometric relationships closer to the expectation than Comadre. Moreover, the contribution of dimensionless demographic metrics to axes of variation in the shape of demographic trajectories was different between databases. The findings in the chapter demonstrate the key role of age dependence in vital rates for shaping demographic tactics across mammalian species and highlight the need for carefully choosing the database and the metrics to use depending on the question asked. Instead of opposing databases, the authors’ analysis nicely illustrates that different databases could be used to address different questions about life history variation.