Estimating the Andean Condor Vultur gryphus population at the northern edge of its geographical range: a citizen science-based approach

Bird Conservation International, Год журнала: 2025, Номер 35

Опубликована: Янв. 1, 2025

Summary Andean Condor Vultur gryphus populations are particularly low in the northern Andes. The species is considered nearly eradicated from Venezuela and listed as “Endangered” Ecuador “Critically Endangered” Colombia. Even though it severely endangered, size of Colombian condor population remains unknown. Using a citizen science-based approach, we conducted first count for Colombia with help 207 observers at 84 simultaneous observation points. We used N-mixture models spatially replicated counts to estimate population. total number condors recorded simultaneously was 63 individuals, estimated 175–269 individuals using maximum likelihood approach 165–222 172–229 two best Bayesian approach. Adults were observed more frequently than juveniles (1:0.43), common pattern among raptors related higher mortality rates immature birds, which prominent conservation concern due status threats currently faces throughout Our study made possible gather, time Colombia, consolidated information on standardised methodology provide reference future actions, both national level geographical range species.

Язык: Английский

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Assessing the outcome of reintroduction efforts: Trends in population size and drivers of breeding success in alpine bearded vultures

Conservation Science and Practice, Год журнала: 2025, Номер unknown

Опубликована: Апрель 7, 2025

Abstract Vulture populations have dramatically declined worldwide over the past few decades. In Europe, various programs been implemented to reintroduce or restock these birds. Alps, Bearded ( Gypaetus barbatus ) was eradicated in early 20th century, prompting launch of an international reintroduction program 1986. Through intensive monitoring breeding territories 26 years (1995–2021), we observed spatial and temporal changes population size assessed environmental individual factors influencing performance across four countries Alpine arc. The number pairs increased steadily from 1 1995 65 2021, fledglings 0 42 although significant differences areas, with slower growth Eastern Alps. success (proportion clutches leading a fledgling) entire 68%, higher than that other European populations. Our analysis, which included variables, revealed nest elevation positively influenced success, while proportion open habitat territory had negative effect. Additionally, significantly coverage not strictly protected areas around nest. terms factors, longer pair bonds affected composed wild‐hatched individuals compared those including released individuals. results confirm overall positive trend reintroduced but also highlight vulnerability our findings suggest effective network can support establishment We identified directions for further research better understand drivers

Язык: Английский

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Linking favourability models with breeding output: a modelling approach to improve management and conservation actions for a threatened avian scavenger

Biological Conservation, Год журнала: 2025, Номер 307, С. 111165 - 111165

Опубликована: Апрель 22, 2025

Язык: Английский

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A predictive flight-altitude model for avoiding future conflicts between an emblematic raptor and wind energy development in the Swiss Alps

Royal Society Open Science, Год журнала: 2022, Номер 9(2)

Опубликована: Фев. 1, 2022

Deployment of wind energy is proposed as a mechanism to reduce greenhouse gas emissions. Yet, and large birds, notably soaring raptors, both depend on suitable conditions. Conflicts in airspace use may thus arise due the risks collisions birds with blades turbines. Using locations GPS-tagged bearded vultures, rare scavenging raptor reintroduced into Alps, we built spatially explicit model predict potential areas conflict future turbine deployments Swiss Alps. We modelled probability vultures flying within or below rotor-swept zone turbines function environmental conditions, including food supply. Seventy-four per cent GPS positions were collected 200 m above ground level, i.e. where could occur if present. Flight activity at risk collision concentrated south-exposed mountainsides, especially ibex carcasses have high occurrence probability, critical covering vast expanses throughout Our provides decision tool that will guide authorities companies for planning deployment farms proactive manner emblematic Alpine wildlife.

Язык: Английский

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Translocation in relict shy-selected animal populations: Program success versus prevention of wildlife-human conflict

Biological Conservation, Год журнала: 2022, Номер 268, С. 109519 - 109519

Опубликована: Март 11, 2022

Past human persecution of wildlife has acted as a major selection agent shaping many animal features including behaviour. A component behaviour with diverse consequences for conservation is the shyness/boldness continuum. Shyer individuals are often geographically restricted, less prone to wander out their ecological refuges but, on contrary, likely experience human-induced mortality and lead human-wildlife conflict. In this essay we discuss how success translocations may interact both positively negatively personalities, based several case studies re-introductions reinforcements involving remnant mammal bird populations. Although shyness be inconvenient conservationists when dealing raptor in which eventual dispersal desired trait long run, trade-off emerge between boldness prevention conflict large carnivores. Some other trade-offs also occur, such that philopatry at initial stage re-introductions.

Язык: Английский

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Long-term size and range changes of the Griffon Vulture Gyps fulvus population in the Balkans: a review

Bird Conservation International, Год журнала: 2021, Номер 32(2), С. 206 - 221

Опубликована: Июль 7, 2021

Summary The Eurasian Griffon Vulture Gyps fulvus is a large Palearctic, Indohimalayan and Afrotropical Old-World vulture. species’ range vast, encompassing territories from the Pyrenees to Himalayas. We reviewed analysed long-term data set for in Balkans estimate change its population size between 1980 2019. After historical decline, slightly increased last 39 years (λ = 1.02) reached 445–565 pairs recorded gradual increase of subpopulations Serbia 1.08 ± 0.003), Bulgaria 0.003) Croatia 1.05 0.005) steep moderate decline species Greece 0.88 North Macedonia 0.94 0.01). However, contracted half former same period. It occurred 42 UTM squares 1980–1990 period only 20 2011 2019 concentrated into three source Bulgaria, Serbia, Croatia. Following reintroductions new colonies were formed at novel localities after 2010. Regular movements individuals different exist nowadays. Therefore, preservation both current core areas used breeding roosting essential conservation region. still faces severe threats risk local extinction. Various hazards such as poisoning, collision with energy infrastructure, disturbance habitat alteration are depleting status Balkan full recovery. Further studies should analyse age-specific survival mortality, recruitment, genetic relatedness, spatial use inform viability this future.

Язык: Английский

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Demographic assessment of reintroduced bearded vultures in the Alps: Success in the core, challenges in the periphery

Ecological Solutions and Evidence, Год журнала: 2024, Номер 5(2)

Опубликована: Апрель 1, 2024

Abstract Regular assessment of reintroduced populations is essential to guide management and provide lessons for other reintroduction projects. Bearded vulture Gypaetus barbatus in the Alps began 1986 with release first fledglings, successful reproduction was recorded 1997, population has grown steadily since. A previous suggested that no further releases would be required establish a self‐sustaining from demographic point view. However, this conclusion based on small sample size spatially homogeneous rates released individuals, which may differ variable among wild‐hatched individuals. Using longitudinal data breeding site survey data, we constructed an integrated model examine demography entire Alpine population, stratified into core periphery. We performed retrospective analyses identify reasons spatial differences growth conducted viability assess impact future threats options. In 2021, estimated 172 (CRI: 147–198) females were present Alps, 65 63–67) breeders. Adult survival productivity higher than periphery, so grew more strongly Differences adult contributed most between two areas. The analysis predicts will double 10 years but increase mortality hazard above 0.055 lead decline. Unlike core, periphery dependent at stage. reintroductions have succeeded creating reproductive success similar probabilities autochthonous Pyrenean population. general, should focus preventing risks. reducing current increasing are make independent releases.

Язык: Английский

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Life and death in a dynamic environment: Invasive trout, floods, and intraspecific drivers of translocated populations

Ecological Applications, Год журнала: 2022, Номер 32(6)

Опубликована: Апрель 11, 2022

Understanding the relative strengths of intrinsic and extrinsic factors regulating populations is a long-standing focus ecology critical to advancing conservation programs for imperiled species. Conservation could benefit from an increased understanding influencing vital rates (somatic growth, recruitment, survival) in small, translocated populations, which lacking owing difficulties long-term monitoring rare Translocations, here defined as transfer wild-captured individuals source new habitats, are widely used species conservation, but outcomes often minimally monitored, translocations that monitored fail. To improve our how respond environmental variation, we developed tested hypotheses related (density dependent) (introduced rainbow trout Oncorhynchus mykiss, stream flow temperature regime) causes rate variation endangered humpback chub (Gila cypha) Colorado River tributaries Grand Canyon (GC), USA. Using biannual recapture data over 10 years, seasonal somatic recruitment population growth with linear mixed-effects models temporal symmetry mark-recapture models. We combined recaptures resights dispersed fish (both physical captures continuously recorded antenna detections) throughout GC test survival hypotheses, while accounting site fidelity, using joint live-recapture/live-resight While only occurred one site, also drove (relative survival), evidence supported density dependence survival, were further limited by introduced trout. Mixed-effects explained between 67% 86% showed greater flood-pulse frequency during monsoon season. Monthly was 0.56-0.99 0.80-0.99 two lower periods higher intraspecific abundance low flood frequency. Our results suggest can contribute toward recovery large-river fishes, continued suppression invasive fishes enhance may be required ensure resilience. Furthermore, demonstrate importance flooding demographics food-depauperate, dynamic, invaded systems.

Язык: Английский

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Consequences of violating assumptions of integrated population models on parameter estimates

Environmental and Ecological Statistics, Год журнала: 2021, Номер 28(3), С. 667 - 695

Опубликована: Июль 1, 2021

Abstract While ecologists know that models require assumptions, the consequences of their violation become vague as model complexity increases. Integrated population (IPMs) combine several datasets to inform a and estimate survival reproduction parameters jointly with higher precision than is possible using independent models. However, accuracy actually depends on an adequate fit datasets. We first investigated bias obtained from integrated when specific assumptions are violated. For instance, may assume all females reproduce although there non-breeding in population. Our second goal was identify which diagnostic tests sensitive detect violations IPMs. simulated data mimicking short- long-lived species under five scenarios assumption each scenario, we fitted IPM violates (simple IPM) does not violate assumption. estimated uncertainty performed seven assess data. results show simple quite robust many only resulted small parameter estimates. Yet, applied were such bias. The some absence immigrants larger more sensitive. informed by least amount most biased scenarios. provide guidelines misspecified diagnose being Simple should often be sufficient describe dynamics, abundant, complex accounting for processes will able shed light biological questions.

Язык: Английский

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High long‐term survival and asymmetric movements in a reintroduced metapopulation of Cinereous vultures

Ecosphere, Год журнала: 2022, Номер 13(2)

Опубликована: Фев. 1, 2022

Abstract Post‐release mortality and movements are critical factors of translocation failure. Yet, survival movement reflect different demographic behavioral processes may therefore have contrasted responses to management, although they often very difficult disentangle in animal populations. To provide guidance translocations, we discriminated the respective roles long‐term dynamic a translocated metapopulation Cinereous vultures ( Aegypius monachus ) France using multievent capture–recapture analyses reintroduced n = 119) wild‐born individual 163) observations. Annual apparent rates were high structured age (>0.8 for young >0.9 adults) did not differ between origin (wild‐born or released), release methods (aviary hacking) nor regions (Alps Causses), except those released Alps experiencing reduced one year after release. In contrast, structure differed populations status. Wild‐born from Causses more erratic than older individuals, whereas demonstrated restricted during their first Despite such asymmetric movements, overall highlight strong tropism individuals whatever region origin. Since respectively higher lower compared with adults, recommend adults primary stage translocations increasing establishment success at site. Further releasing securing successful breeding into wild would increase growth between‐population connections.

Язык: Английский

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