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Conceptual and methodological advances in population and evolutionary ecology are often pursued with the ambition that they will help identify demographic, ecological and genetic constraints on population growth rate (λ), and ultimately facilitate evidence‐based conservation. However, such advances are often decoupled from conservation practice, impeding translation of scientific understanding into effective conservation and of conservation‐motivated research into wider conceptual understanding.We summarise key outcomes from long‐term studies of a red‐billed chough Pyrrhocorax pyrrhocorax population of conservation concern, where we proactively aimed to achieve the dual and interacting objectives of advancing population and evolutionary ecology and advancing effective conservation.Estimation of means, variances and covariances in key vital rates from individual‐based demographic data identified temporal and spatial variation in subadult survival as key constraints on λ, and simultaneously provided new insights into how vital rates can vary as functions of demographic structure, natal conditions and parental life history.Targeted analyses showed that first‐year survival increased with prey abundance, implying that food limitation may constrain λ. First‐year survival then decreased dramatically, threatening population viability and prompting emergency supplementary feeding interventions. Detailed evaluations suggested that the interventions successfully increased first‐year survival in some years and additionally increased adult survival and successful reproduction, thereby feeding back to inform intervention refinements and understanding of complex ecological constraints on λ.Genetic analyses revealed novel evidence of expression of a lethal recessive allele, and demonstrated how critically small effective population size can arise, thereby increasing inbreeding and loss of genetic variation. Population viability analyses parameterised with all available demographic and genetic data showed how ecological and genetic constraints can interact to limit population viability, and identified ecological management as of primacy over genetic management to ensure short‐term persistence of the focal population.This case study demonstrates a full iteration through the sequence of primary science, evidence‐based intervention, quantitative evaluation and feedback that is advocated in conservation science but still infrequently achieved. It thereby illustrates how pure science advances informed conservation actions to ensure the (short‐term) stability of the target population, and how conservation‐motivated analyses fed back to advance fundamental understanding of population processes. [ABSTRACT FROM AUTHOR]

Overall impacts of targeted conservation interventions on population growth rate (λ) will depend on within‐year and among‐year variation in exposure of target individuals to interventions, and in intervention efficacy in increasing vital rates of exposed individuals. Juvenile survival is one key vital rate that commonly varies substantially within and among years, and consequently drives variation in λ. However, within‐year, among‐year and overall impacts of targeted interventions on population‐wide survival probabilities of potentially mobile juveniles are rarely quantified, precluding full evaluation and evidence‐based refinement of interventions.We applied multi‐state mark–recapture models to 8 years of ring–resighting data from a threatened red‐billed chough Pyrrhocorax pyrrhocorax population to quantify within‐year and among‐year variation in juvenile exposure to a targeted intervention of supplementary feeding and parasite treatment, and to estimate efficacy in increasing juvenile survival probability. We then combined and up‐scaled these estimated effects to evaluate the impact of the 8‐year intervention on overall population‐wide survival probability and resulting population size.High proportions of surviving juveniles (>70%) were exposed to the intervention across the annual biological cycle in all years. Exposure was associated with higher short‐term survival probabilities through the full annual cycle. Consequently, management increased estimated population‐wide annual juvenile survival by approximately 0.14. However, such effects were only evident in cohorts with low overall annual survival.Population models projected that these impacts on annual juvenile survival substantially reduced population decline, such that population size at the end of the 8‐year intervention was approximately double that without management.Synthesis and applications. Our results show how complex patterns of within‐year and among‐year variation in exposure and efficacy of targeted conservation interventions can arise and scale up to affect population‐level outcomes. We demonstrate overall positive effects of a joint supplementary feeding and parasite treatment intervention on the focal chough population, but also highlight potential routes to improve efficacy, for example, through more precise targeting of interventions and agricultural management actions in the context of among‐year variation in environmental conditions. [ABSTRACT FROM AUTHOR]

Effective evidence‐based conservation requires full quantification of the impacts of targeted management interventions on focal populations. Such impacts may extend beyond target individuals to also affect demographic rates of non‐target conspecifics (e.g. different age classes). However, such collateral (i.e. unplanned) impacts are rarely evaluated despite their potential to substantially alter conservation outcomes. Subsequent management decisions may then be poorly informed or erroneous.We used 15 years of individual‐based demographic data in a 'before‐after control‐impact' (BACI) analysis to quantify collateral demographic impacts of a targeted multi‐year supplementary feeding programme designed to increase sub‐adult survival and hence viability of a small, threatened red‐billed chough Pyrrhocorax pyrrhocorax population. Specifically, we assessed whether the intervention also affected adult survival and reproductive success, and whether such collateral effects were themselves sufficient to stabilize population size and hence achieve short‐term conservation aims.The probabilities of adult survival and successful reproduction increased substantially between the 'before‐feeding' and 'during‐feeding' periods in those choughs associated with supplementary feeding, but not otherwise. Overall breeding success (i.e. number of chicks fledged per occupied territory) also tended to increase, even though brood sizes did not increase. These relationships, which were detectible only through BACI analyses, suggest that supplementary feeding targeted at sub‐adults had unplanned positive impacts on adult demographic rates.Deterministic matrix models designed to project population growth demonstrate that these estimated collateral effects were sufficient to make a substantial contribution to increasing population growth rate and achieving short‐term population stability.Synthesis and applications. Our results indicate substantial positive collateral impacts of a targeted supplementary feeding intervention on population viability, despite no a priori expectation that the non‐target adults were food‐limited. This casestudy illustrates how thorough assessment of collateral impacts of targeted interventions can affect assessment of short‐term efficacy and reveal new opportunities for future interventions, thereby informing subsequent management decisions. [ABSTRACT FROM AUTHOR]

Small, declining populations can face simultaneous, interacting, ecological and genetic threats to viability. Conservation management strategies designed to tackle such threats independently may then prove ineffective. Population viability analyses that evaluate the efficacy of management strategies implemented independently versus simultaneously are then essential to the design of effective management plans, yet such quantitative evaluations are typically lacking.We used stochastic individual‐based models, parameterised with high‐quality multi‐year demographic and genetic data, to evaluate the efficacy of independent or simultaneous ecological (supplementary feeding) and genetic (translocations to alleviate inbreeding) management strategies for a red‐billed chough (Pyrrhocorax pyrrhocorax) population of major conservation concern. This population is experiencing ecological threats from food limitation and genetic threats from escalating inbreeding. Conservation managers therefore face a dilemma: supplementary feeding may be ineffective if inbreeding is limiting stochastic population growth rate (λs), while translocations may be ineffective if food is limiting.Model simulations suggested that the focal population will decline to extinction relatively rapidly with no conservation management (mean λs ≈ 0.86) and with genetic management alone (λs ≈ 0.90). Ecological management alone reduced, but did not halt the population decline (λs ≈ 0.93). However, simultaneous genetic and ecological management yielded population stability (λs ≈ 1), with genetic rescue lasting ~25 years.These outcomes arose because the capacity for translocations to alleviate inbreeding depression is limited by food availability, while supplementary feeding cannot achieve population viability in the presence of accumulating inbreeding. However, supplementary feeding improved environmental quality enough to allow expression of variance in fitness and thus inbreeding depression, meaning that reductions in inbreeding following translocations can increase λs.Synthesis and applications. Our analyses suggest that simultaneous management of ecological and genetic threats will be critical to ensuring viability of Scotland's chough population; neither strategy independently is likely to achieve population persistence and may consequently waste conservation resources. Managers of other resource‐limited, inbred populations should consider that the efficacy of strategies designed to alleviate ecological and genetic threats may be interdependent, such that holistic management is essential to ensure population viability. Our analyses suggest that simultaneous management of ecological and genetic threats will be critical to ensuring viability of Scotland's chough population; neither strategy independently is likely to achieve population persistence and may consequently waste conservation resources. Managers of other resource‐limited, inbred populations should consider that the efficacy of strategies designed to alleviate ecological and genetic threats may be interdependent, such that holistic management is essential to ensure population viability. [ABSTRACT FROM AUTHOR]

1. A population's effective size (Ne) is a key parameter that shapes rates of inbreeding and loss of genetic diversity, thereby influencing evolutionary processes and population viability. However, estimating Ne and identifying key demographic mechanisms that underlie the Ne to census population size (N) ratio, remains challenging, especially for small populations with overlapping generations and substantial environmental and demographic stochasticity and hence dynamic age-structure. 2. A sophisticated demographic method of estimating Ne/N, which uses Fisher's reproductive value to account for dynamic age-structure, has been formulated. However, this method requires detailed individual and population-level data on sex and age-specific reproduction and survival and has rarely been implemented. 3. Here, we use the reproductive value method and detailed demographic data to estimate Ne/N for a small and apparently isolated red-billed chough (Pyrrhocorax pyrrhocorax) population of high conservation concern. We additionally calculated two single-sample molecular genetic estimates of Ne to corroborate the demographic estimate and examine evidence for unobserved immigration and gene flow. 4. The demographic estimate of Ne/N was 0.21, reflecting a high total demographic variance (σ 2 dg) of 0.71. Females and males made similar overall contributions to σ 2 dg. However, contributions varied among sex-age classes, with greater contributions from 3 year-old females than males, but greater contributions from ⩾5 year-old males than females. 5. The demographic estimate of Ne was ∼30, suggesting that rates of increase of inbreeding and loss of genetic variation per generation will be relatively high. Molecular genetic estimates of Ne computed from linkage disequilibrium and approximate Bayesian computation were approximately 50 and 30, respectively, providing no evidence of substantial unobserved immigration which could bias demographic estimates of Ne. 6. Our analyses identify key sex-age classes contributing to demographic variance and thus decreasing Ne/N in a small age-structured population inhabiting a variable environment. They thereby demonstrate how assessments of Ne can incorporate stochastic sex and age-specific demography and elucidate key demographic processes affecting a population's evolutionary trajectory and viability. Furthermore, our analyses show that Ne for the focal chough population is critically small, implying that management to re-establish genetic connectivity may be required to ensure population viability. [ABSTRACT FROM AUTHOR]

Deleterious recessive alleles that are masked in outbred populations are predicted to be expressed in small, inbred populations, reducing both individual fitness and population viability. However, there are few definitive examples of phenotypic expression of lethal recessive alleles under inbreeding conditions in wild populations. Studies that demonstrate the action of such alleles, and infer their distribution and dynamics, are required to understand their potential impact on population viability and inform management responses., The Scottish population of red-billed choughs ( Pyrrhocorax pyrrhocorax), which currently totals <60 breeding pairs and is of major conservation concern, has recently been affected by lethal blindness in nestlings. We used family data to show that the pattern of occurrence of blindness within and across affected families that produced blind nestlings was exactly 0·25, matching that expected given a single-locus autosomal lethal recessive allele. Furthermore, the observed distribution of blind nestlings within affected families did not differ from that expected given Mendelian inheritance of such an allele., Relatedness estimates showed that individuals from affected families were not more closely related to each other than they were to individuals from unaffected families that did not produce blind nestlings. Blind individuals tended to be less heterozygous than non-blind individuals, as expected if blindness was caused by the expression of a recessive allele under inbreeding. However, there was no difference in the variance in heterozygosity estimates, suggesting that some blind individuals were relatively outbred. These results suggest carriers of the blindness allele may be widely distributed across contemporary families rather than restricted to a single family lineage, implying that the allele has persisted across multiple generations., Blindness occurred at low frequency (affecting 1·6% of observed nestlings since 1981). However, affected families had larger initial brood sizes than unaffected families. Such high fecundity of carriers of a lethal recessive allele might reflect overdominance, potentially reducing purging and increasing allele persistence probability., We thereby demonstrate the phenotypic expression of a lethal recessive allele in a wild population of conservation concern, and provide a general framework for inferring allele distribution and persistence and informing management responses. [ABSTRACT FROM AUTHOR]

Summary: A changing climate will inevitably impact on the natural environment, including agriculture. Anticipatory adaptation is necessary to minimise the negative impacts of climate change, to take advantage of opportunities, and to ensure that food and fibre production is maintained. More detailed information is required as to which adaptation measures will yield relatively greater social rates of return. Such information would help define an efficient adaptation agenda in the agricultural sector. This article identifies key adaptation strategies across England's agricultural sector, and applies cost–benefit analysis to these to determine their net present values, highlighting where the greatest returns can be made, and the role for policy. The results span a wide range, with some soil management activities indicating a negative NPV of £122 million over the course of this century, to a positive NPV of £3,279 million in the case of some livestock adaptations to heat stress. Animal disease surveillance and peatland restoration also generated high NPVs of £1,850 million and £1,840 million, respectively. Adaptations addressing crop disease, water storage measures and managed coastal realignment generated more modest values ranging from £1 million to £61 million. Direct comparison of the numbers is misleading however as some refer to the national level while others are site‐specific. The analysis provides a basis for a discussion on priorities and planning for adaptation in the agricultural sector. Une modification du climat va inévitablement affecter l'environnement naturel et donc l'agriculture. Une adaptation anticipée permettra de minimiser les impacts négatifs du changement climatique, de profiter des opportunités et d'assurer le maintien de la production d'aliments et de fibres. Des informations plus détaillées seraient nécessaires pour savoir quelles mesures d'adaptation auront des retours sur investissement plus élevés au plan social. Ces informations permettraient de définir un programme d'adaptation efficace pour le secteur agricole. Cet article identifie les principales stratégies d'adaptation pour l'ensemble du secteur agricole anglais et analyse leurs coûts et avantages pour déterminer leur valeur nette actualisée (VNA), en soulignant les domaines les plus performants et le rôle des politiques. Les résultats couvrent une large gamme: certaines activités de gestion des sols présentent une VNA négative de 122 millions de livres au cours de ce siècle tandis que certaines adaptations du bétail au stress thermique obtiennent une VNA positive de 3279 millions de livres. La surveillance des maladies animales et la remise en état des tourbières obtiennent également de fortes NVA de 1850 et 1840 millions de livres, respectivement. Les adaptations concernant les maladies des plantes, les mesures de stockage de l'eau et le réalignement contrôlé des zones côtières ont des valeurs plus modestes allant de 1 million à 61 millions de livres. Il serait cependant trompeur de comparer directement ces chiffres car certains concernent le niveau national alors que d'autres sont spécifiques à un site. L'analyse peut servir pour discuter des priorités et prévoir des adaptations dans le secteur agricole. Ein sich wandelndes Klima wird sich unweigerlich auf die natürliche Umwelt einschließlich der Landwirtschaft auswirken. Eine antizipative Anpassung an den Klimawandel ist erforderlich, um die negativen Auswirkungen zu minimieren, Gelegenheiten zu nutzen und die Nahrungsmittel‐ und Rohstoffproduktion weiterhin sicherzustellen. Wir benötigen nähere Informationen darüber, welche Anpassungsmaßnahmen relativ hohe soziale Erträge bringen. Solche Angaben wären hilfreich beim Erstellen einer effizienten Agenda zur Anpassung an den Klimawandel im Agrarsektor. Dieser Beitrag identifiziert die wesentlichen Anpassungsstrategien im englischen Agrarsektor und unterzieht diese einer Kosten‐Nutzen‐Analyse, um deren Kapitalwert zu ermitteln. Wir zeigen auf, wo die höchsten Erträge erzielt werden können, und welche Rolle der Politik zukommt. Die Ergebnisse sind breit gestreut und beinhalten Aktivitäten aus dem Bereich der Bodenbewirtschaftung, die im Laufe dieses Jahrhunderts auf einen negativen Kapitalwert von £122 Mio. hinweisen, bis hin zu einem positiven Kapitalwert von £3.279 Mio. im Bereich der Viehwirtschaft für Anpassungen an extreme Hitze. Hohe Kapitalwerte waren ebenfalls in der Tierseuchenüberwachung (£1.850 Mio.) und in der Wiedervernässung von Mooren (£1.840 Mio.) zu erzielen. Anpassungen in den Bereichen Getreideseuchen, Maßnahmen zur Wasserspeicherung und Deichrückverlegung erzielten geringere Werte zwischen £1 Mio. und £61 Mio. Allerdings handelt es sich hier teils um länderbezogene und teils um flächenbezogene Angaben, daher wäre ein direkter Vergleich irreführend. Die Analyse stellt eine Diskussionsgrundlage für die Prioritäten und die Planung der Anpassungen im Agrarsektor zur Verfügung. A changing climate will inevitably impact on the natural environment, including agriculture. Anticipatory adaptation is necessary to minimise the negative impacts of climate change, to take advantage of opportunities, and to ensure that food and fibre production is maintained. More detailed information is required as to which adaptation measures will yield relatively greater social rates of return. Such information would help define an efficient adaptation agenda in the agricultural sector. This article identifies key adaptation strategies across England's agricultural sector, and applies cost–benefit analysis to these to determine their net present values, highlighting where the greatest returns can be made, and the role for policy. [ABSTRACT FROM AUTHOR]

Determining the precise timing and location of major demographic bottlenecks, such as periods of low survival, is key to identifying ecological causes of variation in population growth rate. Such understanding is key to designing efficient and effective mitigation. In a protected population of red-billed chough Pyrrhocorax pyrrhocorax on Islay, Scotland, variation in population growth rate largely reflects among-year variation in first-year survival. First-year survival was unprecedentedly low during 2007-2010, threatening population viability. We used colour-ring resightings to estimate monthly survival probabilities (Φ) throughout the first year from fledging for eight chough cohorts (totalling 519 individuals) representing the full observed range of variation in first-year survival. We thereby identify the time and location of recent low survival. On average across all cohorts, Φ varied among months, being low during the first month after ringing (May-June, accounting for c. 24% of all first-year mortality) and high during the last 4 months of the first year (January-May, accounting for c. 6% of all first-year mortality). Most mortality ( c. 70%) occurred after fledglings dispersed from natal territories. The 2007-2009 cohorts experienced low Φ during July-December. This represents an additional low survival period compared to previous cohorts rather than decreased Φ across all months or further decreases through periods when Φ was low across all cohorts. Synthesis and applications. These data have general relevance in showing that dramatically low annual survival, which needs to spark rapid management action, can reflect different and unanticipated periods of low survival rather than exaggeration of typical variation. With specific regard to conserving Islay's chough population, our data show that sub-adult survival has recently been low during July-December, probably reflecting conditions on key grassland foraging areas. Managers aiming to increase population viability should increase invertebrate diversity, abundance and availability at these times and locations, thereby increasing foraging options available to choughs. [ABSTRACT FROM AUTHOR]

1. Understanding the degree to which reproductive success varies with an individual’s age and lifespan, and the degree to which population-level variation mirrors individual-level variation, is central to understanding life-history evolution and the dynamics of age-structured populations. We quantified variation in the survival probability of offspring, one key component of reproductive success and fitness, in relation to parent age and lifespan in a wild population of red-billed choughs ( Pyrrhocorax pyrrhocorax). 2. On average across the study population, the first-year survival probability of offspring decreased with increasing parent age and lifespan; offspring of old parents were less likely to survive than offspring of young parents, and offspring of long-lived parents were less likely to survive than offspring of short-lived parents. 3. However, survival did not vary with parent age across offspring produced by groups of parents that ultimately had similar lifespans. 4. Rather, across offspring produced by young parents, offspring survival decreased with increasing parent lifespan; parents that ultimately had long lifespans produced offspring that survived poorly, even when these parents were breeding at young ages. 5. The average decrease in offspring survival with increasing parent age observed across the population therefore reflected the gradual disappearance of short-lived parents that produced offspring that survived well, not age-specific variation in offspring survival within individual parents. 6. The negative correlation between offspring survival and maternal lifespan was strongest when environmental conditions meant that offspring survival was low across the population. 7. These data suggest an environment-dependent trade-off between parent and offspring survival, show consistent individual variation in the resolution of this trade-off that is set early in a parent’s life, and demonstrate that such structured life-history variation can generate spurious evidence of senescence in key fitness components when measured across a population. [ABSTRACT FROM AUTHOR]