Monitoring wild populations is crucial for their effective management. Noninvasive genetic methods provide robust data from individual free-ranging animals, which can be used in capture-mark-recapture (CMR) models to estimate demographic parameters without capturing or disturbing them. However, sex- and status-specific behaviour, which may lead to differences in detection probabilities, is rarely considered in monitoring. Here, we investigated population size, sex ratio, sex- and status-related behaviour in 19 Rhinolophus hipposideros maternity colonies (Northern France) with a noninvasive genetic CMR approach (using faeces) combined with parentage assignments. The use of the DDX3X/Y-Mam sexual marker designed in this study, which shows inter- and intrachromosomal length polymorphism across placental mammals, together with eight polymorphic microsatellite markers, produced high-quality genetic data with limited genotyping errors and allowed us to reliably distinguish different categories of individuals (males, reproductive and nonreproductive females) and to estimate population sizes. We showed that visual counts represent well-adult female numbers and that population composition in maternity colonies changes dynamically during the summer. Before parturition, colonies mainly harbour pregnant and nonpregnant females with a few visiting males, whereas after parturition, colonies are mainly composed of mothers and their offspring with a few visiting nonmothers and males. Our approach gives deeper insight into sex- and status-specific behaviour, a prerequisite for understanding population dynamics and developing effective monitoring and management strategies. Provided sufficient samples can be obtained, this approach can be readily applied to a wide range of species.
The speed and dynamics of range expansions shape species distributions and community composition. Despite the critical impact of population growth rates for range expansion, they are neglected in existing empirical studies, which focus on the investigation of selected life-history traits. Here, we present an approach based on non-invasive genetic capture–mark–recapture data for the estimation of adult survival, fecundity and juvenile survival, which determine population growth. We demonstrate the reliability of our method with simulated data, and use it to investigate life-history changes associated with range expansion in 35 colonies of the bat species Rhinolophus hipposideros . Comparing the demographic parameters inferred for 19 of those colonies which belong to an expanding population with those inferred for the remaining 16 colonies from a non-expanding population reveals that range expansion is associated with higher net reproduction. Juvenile survival was the main driver of the observed reproduction increase in this long-lived bat species with low per capita annual reproductive output. The higher average growth rate in the expanding population was not associated with a trade-off between increased reproduction and survival, suggesting that the observed increase in reproduction stems from a higher resource acquisition in the expanding population. Environmental conditions in the novel habitat hence seem to have an important influence on range expansion dynamics, and warrant further investigation for the management of range expansion in both native and invasive species.
Recognizing variation in human–nature relationships across different contexts, entities of nature and individual people is central to an equitable management of nature and its contributions to people, and to design effective strategies for encouraging and guiding more sustainable human behaviour. We complement the broader Intergovernmental Science‐Policy Platform on Biodiversity and Ecosystem Services (IPBES) conceptual framework by zooming in from relationships between people and nature to individual relationships with entities of nature (IREN), and introduce a new typology that categorizes those relationships based on individual attitude, behavioural preference and behaviour towards an entity. These three dimensions illustrate if an individual perceives the entity to provide mainly positive, negative or no contributions; prefers to have a mainly positive, negative or no impact on the entity; and performs mainly actions with positive, negative or no impacts on the entity. The IREN typology defines 17 overarching relationship types, including not only types where attitude, behavioural preference and behaviour are all negative (intolerance), all neutral (indifference) or all positive (stewardship), but also types where the valence of some dimensions diverges. Among those, we integrate and redefine established types like tolerance, and introduce new ones like ambivalent opposition, which is highly relevant for the management of overabundant or invasive species. Combining attitude, behavioural preference and behaviour to categorize different IREN types can help detect inequalities in the benefits and detriments individual people receive from different entities, and signal societal conflict potential or misalignment of behaviour with conservation goals. Combining those three dimensions also indicates the relative importance of goal‐oriented motives like the desire to optimize an entity's perceived contributions, moral motives like the desire to act righteously and implementation barriers preventing individuals from acting according to their preference. By adding an individual‐ and entity‐specific perspective, the IREN framework and typology can encourage more equitable approaches to managing the benefits and detriments people derive from nature, and assist the development of more effective strategies for aligning human behaviour with conservation and sustainability goals.
Policy mixes (i.e. the total structure of policy processes, strategies, and instruments) are complex constructs that can quickly become incoherent, inconsistent, and incomprehensive. This is amplified when the policy mix strives to meet multiple objectives simultaneously, such as in the case of large carnivore policy mixes. Building on Rogge and Reichardt's analytical framework for the analysis of policy mixes, we compare the policy mixes of Norway, Sweden, Finland, the Netherlands, Germany (specifically Saxony and Bavaria), and Spain (specifically Castilla y León).The study shows that the large carnivore policy mixes in the case countries show signs of lacking vertical and horizontal coherence in the design of policy processes, weak consistency between objectives and designated policy instruments, and, as a consequence, lacking comprehensiveness. We conclude that creating consistent, coherent, and comprehensive policy mixes that build on multiple objectives requires stepping away from sectorized policy development, toward a holistic, systemic approach, strong collaborative structures across policy boundaries and regions, the inclusion of diverse stakeholders, and constant care and attention to address all objectives simultaneously rather than in isolation.
Population sex ratios are of high ecological relevance, but are challenging to determine in species lacking conspicuous external cues indicating their sex. Acoustic sexing is an option if vocalizations differ between sexes, but is precluded by overlapping distributions of the values of male and female vocalizations in many species. A method allowing the inference of sex ratios despite such an overlap will therefore greatly increase the information extractable from acoustic data. To meet this demand, we developed a novel approach using Approximate Bayesian Computation (ABC) to infer the sex ratio of populations from acoustic data. Additionally, parameters characterizing the male and female distribution of acoustic values (mean and standard deviation) are inferred. This information is then used to probabilistically assign a sex to a single acoustic signal. We furthermore develop a simpler means of sex ratio estimation based on the exclusion of calls from the overlap zone. Applying our methods to simulated data demonstrates that sex ratio and acoustic parameter characteristics of males and females are reliably inferred by the ABC approach. Applying both the ABC and the exclusion method to empirical datasets (echolocation calls recorded in colonies of lesser horseshoe bats, Rhinolophus hipposideros) provides similar sex ratios as molecular sexing. Our methods aim to facilitate evidence-based conservation, and to benefit scientists investigating ecological or conservation questions related to sex- or group specific behaviour across a wide range of organisms emitting acoustic signals. The developed methodology is non-invasive, low-cost and time-efficient, thus allowing the study of many sites and individuals. We provide an R-script for the easy application of the method and discuss potential future extensions and fields of applications. The script can be easily adapted to account for numerous biological systems by adjusting the type and number of groups to be distinguished (e.g. age, social rank, cryptic species) and the acoustic parameters investigated.
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