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Molina M, Mota M, Ramos A. Mathematical modeling in semelparous biological species through two-sex branching processes. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2024; 21:6407-6424. [PMID: 39176432 DOI: 10.3934/mbe.2024280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
This research focused its interest on the mathematical modeling of the demographic dynamics of semelparous biological species through branching processes. We continued the research line started in previous papers, providing new methodological contributions of biological and ecological interest. We determined the probability distribution associated with the number of generations elapsed before the possible extinction of the population in its natural habitat. We mathematically modeled the phenomenon of populating or repopulating habitats with semelparous species. We also proposed estimates for the offspring parameters governing the reproductive strategies of the species. To this purpose, we used the maximum likelihood and Bayesian estimation methodologies. The statistical results are illustrated through a simulated example contextualized with Labord chameleon (Furcifer labordi) species.
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Affiliation(s)
- Manuel Molina
- Department of Mathematics, University of Extremadura, Badajoz 06006, Spain
- Institute of Advanced Scientific Computation, University of Extremadura, Badajoz 06006, Spain
| | - Manuel Mota
- Department of Mathematics, University of Extremadura, Badajoz 06006, Spain
- Institute of Advanced Scientific Computation, University of Extremadura, Badajoz 06006, Spain
| | - Alfonso Ramos
- Department of Mathematics, University of Extremadura, Badajoz 06006, Spain
- Institute in Livestock and Cynegetic, University of Extremadura, Badajoz 06006, Spain
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2
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Rose JP, Kim R, Schoenig EJ, Lien PC, Halstead BJ. Comparing reintroduction strategies for the endangered San Francisco gartersnake (Thamnophis sirtalis tetrataenia) using demographic models. PLoS One 2023; 18:e0292379. [PMID: 37796777 PMCID: PMC10553336 DOI: 10.1371/journal.pone.0292379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 09/19/2023] [Indexed: 10/07/2023] Open
Abstract
For endangered species persisting in a few populations, reintroductions to unoccupied habitat are a popular conservation action to increase viability in the long term. Identifying the reintroduction strategy that is most likely to result in viable founder and donor populations is essential to optimally use resources available for conservation. The San Francisco gartersnake (Thamnophis sirtalis tetrataenia) is an endangered sub-species that persists in a small number of populations in a highly urbanized region of California. Most of the extant populations of San Francisco gartersnakes have low adult abundance and effective population size, heightening the need for establishment of more populations for insurance against the risk of extinction. We used simulations from demographic models to project the probability of quasi-extinction for reintroduced populations of San Francisco gartersnakes based on the release of neonate, juvenile, adult, or mixed-age propagules. Our simulation results indicated that the release of head-started juveniles resulted in the greatest viability of reintroduced populations, and that releases would need to continue for at least 15 years to ensure a low probability of quasi-extinction. Releasing captive-bred juvenile snakes would also have less effect on the viability of the donor population, compared to strategies that require more adult snakes to be removed from the donor population for translocation. Our models focus on snake demography, but the genetic makeup of donor, captive, and reintroduced populations will also be a major concern for any proposed reintroduction plan. This study demonstrates how modeling can be used to inform reintroduction strategies for highly imperiled species.
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Affiliation(s)
- Jonathan P. Rose
- U.S. Geological Survey, Western Ecological Research Center, Santa Cruz, California, United States of America
| | - Richard Kim
- U.S. Geological Survey, Western Ecological Research Center, Dixon, California, United States of America
| | - Elliot J. Schoenig
- U.S. Geological Survey, Western Ecological Research Center, Dixon, California, United States of America
| | - Patrick C. Lien
- U.S. Geological Survey, Western Ecological Research Center, Dixon, California, United States of America
| | - Brian J. Halstead
- U.S. Geological Survey, Western Ecological Research Center, Dixon, California, United States of America
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Torres-Blas I, Migura-García L, Cerdà-Cuéllar M, Carbajal A, Lopez-Bejar M, Mateo R, Herrero-Villar M, Llopis A, Marco I. HEALTH ASSESSMENT OF CAPTIVE BEARDED VULTURES ( GYPAETUS BARBATUS) IN CATALONIA (SPAIN). J Zoo Wildl Med 2023; 54:464-472. [PMID: 37817612 DOI: 10.1638/2022-0057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2023] [Indexed: 10/12/2023] Open
Abstract
Bearded vulture (Gypaetus barbatus) populations are declining worldwide primarily due to anthropogenic factors. A captive breeding program has been established in Spain, a country with one of the largest free-living populations in Europe, to further enhance the conservation efforts of this emblematic species. However, captive vulture populations can be exposed to different risks through food, such as drug residues and antimicrobial-resistant (AMR) bacteria. Health surveillance of species involved in captive breeding programs is important to face introduction of healthy animals in situ and to obtain baseline clinical data. The objective of this study was to assess the general health status of bearded vultures held in captivity in Catalonia (northeastern Spain) by carrying out hematologic, biochemical, toxicologic, and bacteriologic analyses. A total of 16 bearded vultures were sampled; the data obtained from one vulture, with a chronic tibiotarsal fracture, were excluded from the statistical analysis. Hematologic and biochemical parameters of the bearded vultures were mostly within the range of standard values as stated in previous studies. Basal feather and serum corticosterone levels were analyzed and described for the first time in this species. A total of 15 Escherichia coli isolates were obtained that were resistant to fluoroquinolones (80%), tetracycline (60%), trimethoprim and ampicillin (40%), sulfamethoxazole (33%), and colistin (20%), with 40% of them being multidrug resistant. Three of 15 isolates were carriers of the mcr-1 gene. Only the injured bird previously treated with enrofloxacin was positive for fluoroquinolone residues. Periodic monitoring for the presence of AMR bacteria would be recommended in captive breeding programs as a preventive action to establish future therapies.
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Affiliation(s)
- Irene Torres-Blas
- Wildlife Conservation Medicine Research Group, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Travessera dels Turons s/n, 08193 Bellaterra, Catalonia, Spain
| | - Lourdes Migura-García
- Unitat mixta d'Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
- IRTA, Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
| | - Marta Cerdà-Cuéllar
- Unitat mixta d'Investigació IRTA-UAB en Sanitat Animal, Centre de Recerca en Sanitat Animal, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
- IRTA, Programa de Sanitat Animal, Centre de Recerca en Sanitat Animal, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Catalonia, Spain
| | - Anaïs Carbajal
- Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Manuel Lopez-Bejar
- Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
- College of Veterinary Medicine, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Rafael Mateo
- Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, 13005 Ciudad Real, Spain
| | - Marta Herrero-Villar
- Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC-UCLM-JCCM, 13005 Ciudad Real, Spain
| | - Alex Llopis
- VCF Vultures Captive Breeding Manager, Bearded Vulture EEP Coordinator, Centre de Fauna Vallcalent 63, 25199 Lleida, Spain
| | - Ignasi Marco
- Wildlife Conservation Medicine Research Group, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Travessera dels Turons s/n, 08193 Bellaterra, Catalonia, Spain,
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Mitchell WF, Boulton RL, Sunnucks P, Clarke RH. Are we adequately assessing the demographic impacts of harvesting for wild‐sourced conservation translocations? CONSERVATION SCIENCE AND PRACTICE 2021. [DOI: 10.1111/csp2.569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
| | - Rebecca L. Boulton
- School of Biological Sciences The University of Adelaide Adelaide South Australia Australia
| | - Paul Sunnucks
- School of Biological Sciences Monash University Clayton Victoria Australia
| | - Rohan H. Clarke
- School of Biological Sciences Monash University Clayton Victoria Australia
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De la Cruz A, Bastos R, Silva E, Cabral JA, Santos M. What to expect from alternative management strategies to conserve seabirds? Hints from a dynamic modelling framework applied to an endangered population. Anim Conserv 2021. [DOI: 10.1111/acv.12751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A. De la Cruz
- Marine Research University Institute (INMAR) Campus of International Excellence of the Sea (CEIMAR) University of Cádiz Cádiz Spain
| | - R. Bastos
- Laboratory of Applied Ecology CITAB – Centre for the Research and Technology of Agro‐Environment and Biological Services Institute for Innovation Capacity Building and Sustainability of Agri‐food Production (Inov4Agro) University of Trás‐os‐Montes e Alto Douro Vila Real Portugal
| | - E. Silva
- Portuguese Society for the Study of Birds (SPEA) Lisboa Portugal
| | - J. A. Cabral
- Laboratory of Applied Ecology CITAB – Centre for the Research and Technology of Agro‐Environment and Biological Services Institute for Innovation Capacity Building and Sustainability of Agri‐food Production (Inov4Agro) University of Trás‐os‐Montes e Alto Douro Vila Real Portugal
| | - M. Santos
- Laboratory of Applied Ecology CITAB – Centre for the Research and Technology of Agro‐Environment and Biological Services Institute for Innovation Capacity Building and Sustainability of Agri‐food Production (Inov4Agro) University of Trás‐os‐Montes e Alto Douro Vila Real Portugal
- Laboratory of Ecology and Conservation Federal Institute of Education Science and Technology of Maranhão, R. Dep. Gastão Vieira Buriticupu MA Brazil
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Rayner K, Lohr CA, Garretson S, Speldewinde P. Two species, one island: Retrospective analysis of threatened fauna translocations with divergent outcomes. PLoS One 2021; 16:e0253962. [PMID: 34252101 PMCID: PMC8274872 DOI: 10.1371/journal.pone.0253962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 06/16/2021] [Indexed: 11/23/2022] Open
Abstract
Translocations are globally a popular tool used with the intention of improving threatened species conservation and re-establishing ecosystem function. While practitioners strive for successful outcomes the failure rate of translocations continues to be high. We demonstrate how predictive modelling can contribute to more informed decision making and hence potentially improve the success rate of translocation programs. Two species, the Djoongari (Shark Bay mouse) Pseudomys fieldi and the golden bandicoot Isoodon auratus barrowensis, were introduced independently to Doole Island in the Exmouth Gulf of Western Australia. We used population viability analysis to critique the outcomes of these translocations and provide an example of how this tool can be incorporated with expert knowledge to predict likely outcomes of translocations. Djoongari did not establish on the island after seven translocations over nine years, while golden bandicoots established a population after just one release event. Retrospective population viability analysis (of data that was unavailable prior to the translocations) predicted and clarified the reasons behind the outcomes of both translocations. Golden bandicoots have considerably higher demographic plasticity than Djoongari, which were never likely to establish on the island. We conclude that the failure of the Djoongari translocation was due to interactions between sparse habitat, native predators and cyclonic storm surges, whereas golden bandicoots have demonstrated habitat flexibility and an ability to recover from multiple natural disasters. As a result we (1) remind conservation planners of the importance of quantifying likely refuges and habitat availability at release sites, (2) suggest practitioners consider how different threats (including natural disasters) may interact at potential release sites and (3) advocate for the incorporation of predictive modelling during the planning stages of translocations, particularly for conservation introductions where no precedent exists for the species’ survival at a particular location.
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Affiliation(s)
- Kelly Rayner
- Biodiversity and Conservation Science Division, Western Australia Department of Biodiversity, Conservation and Attractions, Perth, Western Australia, Australia
- * E-mail:
| | - Cheryl A. Lohr
- Biodiversity and Conservation Science Division, Western Australia Department of Biodiversity, Conservation and Attractions, Perth, Western Australia, Australia
| | - Sean Garretson
- Biodiversity and Conservation Science Division, Western Australia Department of Biodiversity, Conservation and Attractions, Perth, Western Australia, Australia
| | - Peter Speldewinde
- Centre of Excellence in Natural Resource Management, The University of Western Australia, Perth, Western Australia, Australia
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Rodriguez de Rivera O, McCrea R. Removal modelling in ecology: A systematic review. PLoS One 2021; 16:e0229965. [PMID: 33661897 PMCID: PMC7932160 DOI: 10.1371/journal.pone.0229965] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 01/15/2021] [Indexed: 11/18/2022] Open
Abstract
Removal models were proposed over 80 years ago as a tool to estimate unknown population size. More recently, they are used as an effective tool for management actions for the control of non desirable species, or for the evaluation of translocation management actions. Although the models have evolved over time, in essence, the protocol for data collection has remained similar: at each sampling occasion attempts are made to capture and remove individuals from the study area. Within this paper we review the literature of removal modelling and highlight the methodological developments for the analysis of removal data, in order to provide a unified resource for ecologists wishing to implement these approaches. Models for removal data have developed to better accommodate important features of the data and we discuss the shift in the required assumptions for the implementation of the models. The relative simplicity of this type of data and associated models mean that the method remains attractive and we discuss the potential future role of this technique.
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Affiliation(s)
- Oscar Rodriguez de Rivera
- Statistical Ecology @ Kent, National Centre for Statistical Ecology, School of Mathematics, Statistics and Actuarial Science, University of Kent, Canterbury, United Kingdom
- * E-mail:
| | - Rachel McCrea
- Statistical Ecology @ Kent, National Centre for Statistical Ecology, School of Mathematics, Statistics and Actuarial Science, University of Kent, Canterbury, United Kingdom
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Margalida A, Jiménez J, Martínez JM, Sesé JA, García‐Ferré D, Llamas A, Razin M, Colomer M, Arroyo B. An assessment of population size and demographic drivers of the Bearded Vulture using integrated population models. ECOL MONOGR 2020. [DOI: 10.1002/ecm.1414] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Antoni Margalida
- Instituto de Investigación en Recursos Cinegéticos (IREC, CSIC‐UCLM‐JCCM) E‐13005 Ciudad Real Spain
- Division of Conservation Biology Institute of Ecology and Evolution University of Bern Baltzerstrasse 6 CH‐3012 Bern Switzerland
| | - José Jiménez
- Instituto de Investigación en Recursos Cinegéticos (IREC, CSIC‐UCLM‐JCCM) E‐13005 Ciudad Real Spain
| | - José M. Martínez
- Gobierno de Aragón Subdirección General de Desarrollo Rural y Sostenibilidad Departamento Medio Ambiente C/ General Lasheras 8 E‐22003 Huesca Spain
| | - José A. Sesé
- Gobierno de Aragón Subdirección General de Desarrollo Rural y Sostenibilidad Departamento Medio Ambiente C/ General Lasheras 8 E‐22003 Huesca Spain
| | - Diego García‐Ferré
- Generalitat de Catalunya Departament de Territori i Sostenibilitat Servei de Fauna i Flora. C/Provença 204 08036 Barcelona Spain
| | - Alfonso Llamas
- Gestión Ambiental de Navarra C/ Padre Adoain 219 E‐31015 Pamplona Spain
| | - Martine Razin
- Ligue pour la Protection des Oiseaux (LPO/BirdLife) Fonderies Royales 8/10 rue du Dr Pujos F‐17305 Rochefort Cedex France
| | - MªÀngels Colomer
- Department of Mathematics Faculty of Life Sciences and Engineering University of Lleida E‐25198 Lleida Spain
| | - Beatriz Arroyo
- Instituto de Investigación en Recursos Cinegéticos (IREC, CSIC‐UCLM‐JCCM) E‐13005 Ciudad Real Spain
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9
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Colomer MÀ, Oliva‐Vidal P, Jiménez J, Martínez JM, Margalida A. Prioritizing among removal scenarios for the reintroduction of endangered species: insights from bearded vulture simulation modeling. Anim Conserv 2019. [DOI: 10.1111/acv.12549] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. À. Colomer
- Department of Mathematics Faculty of Life Sciences and Engineering University of Lleida Lleida Spain
| | - P. Oliva‐Vidal
- Department of Animal Science (Division of Wildlife) Faculty of Life Sciences and Engineering University of Lleida Lleida Spain
| | - J. Jiménez
- Institute for Game and Wildlife Research IREC (CSIC‐UCLM‐JCCM) Ciudad Real Spain
| | - J. M. Martínez
- Subdirección General de Desarrollo Rural y Sostenibilidad Departamento Medio Ambiente Gobierno de Aragón Huesca Spain
| | - A. Margalida
- Institute for Game and Wildlife Research IREC (CSIC‐UCLM‐JCCM) Ciudad Real Spain
- Division of Conservation Biology Institute of Ecology and Evolution University of Bern Bern Switzerland
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Colomer MÀ, Margalida A, Fraile L. Improving the management procedures in farms infected with the Porcine Reproductive and Respiratory Syndrome virus using PDP models. Sci Rep 2019; 9:9959. [PMID: 31292473 PMCID: PMC6620323 DOI: 10.1038/s41598-019-46339-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 06/27/2019] [Indexed: 02/04/2023] Open
Abstract
Pig meat production need to be built up in the future due to the increase of the human population worldwide. To address this challenge, there is plenty of room for improvement in terms of pig production efficiency that could be severely hampered by the presence of diseases. In this sense, Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is one of the most costly disease present in industrial pork production in Europe and North America. We have developed a model to analyze the effect of different management procedures to control this important virus in different epidemiological scenarios. Our results clearly suggest that no cross-fostering during lactation and the maintaining of litter integrity significantly decrease the number of sick and dead animals during the rearing period compared to scenarios where cross-fostering and no litter integrity are practiced. These results highlight the relevance of different management strategies to control PRRSV and quantify the effect of limiting cross-fostering and avoiding mixing animals from different litters in PRRSV positive farms to optimize animal production. Our findings will allow pig farmers to apply these management procedures to control this disease under field conditions in a very cost-effective way.
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Affiliation(s)
- Ma Àngels Colomer
- Department of Mathematics ETSEA, University of Lleida, 25198, Lleida, Spain
| | - Antoni Margalida
- Department of Mathematics ETSEA, University of Lleida, 25198, Lleida, Spain. .,Department of Animal Science, ETSEA, University of Lleida, 25198, Lleida, Spain. .,Institute for Game and Wildlife Research, IREC (CSIC-UCLM-JCCM), 13005, Ciudad Real, Spain.
| | - Lorenzo Fraile
- Department of Animal Science, ETSEA, University of Lleida, 25198, Lleida, Spain.,Agrotecnio, University of Lleida, 25198, Lleida, Spain
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A mathematical model to describe the demographic dynamics of long-lived raptor species. Biosystems 2019; 180:54-62. [PMID: 30885688 DOI: 10.1016/j.biosystems.2019.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 10/29/2018] [Accepted: 01/23/2019] [Indexed: 11/22/2022]
Abstract
Population viability analysis of threatened large and long-lived raptor species has strong limitations due to the restricted demographic information available for these species. In this work, we mathematically model the demographic dynamics of these raptor species through time-indexed branching processes. By assuming the more general non-parametric statistical setting, we determine accurate estimates for the most relevant reproductive parameters involved in the model. To this end, we propose an algorithm based on approximate Bayesian computations methods. As illustration, by using real data of counts of the number of pairs in the population, we apply the proposed statistical and computational methods to describe the demographic dynamics of the Eurasian black vulture colony located at National Park of Monfragüe (Spain), which appears to be both the largest and densest breeding colony worldwide. In the scenario of these data-poor species, the class of time-indexed branching processes introduced appears to be appropriate and a more cost-effective method to evaluate dynamics and viability of the populations, applicable to the conservation of these taxa.
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Morandini V, Dietz S, Newton I, Ferrer M. The role of age of first breeding in modeling raptor reintroductions. Ecol Evol 2019; 9:2978-2985. [PMID: 30891230 PMCID: PMC6405524 DOI: 10.1002/ece3.4979] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 12/14/2018] [Accepted: 12/14/2018] [Indexed: 11/16/2022] Open
Abstract
The present biodiversity crisis has led to an increasing number of reintroduction programs, and this conservation method is likely to be increasingly used in the future, especially in the face of climate change. Many fundamental questions in population ecology are focused on the mechanisms through which populations escape extinction.Population viability analysis (PVA) is the most common procedure for analyzing extinction risk. In the use of PVA to model the trajectories of reintroduced populations, demographic values are sometimes taken from other existing wild populations or even from individuals in captivity.Density dependence in productivity is usually considered in viability models, but density-dependent variation in age of first breeding is usually ignored. Nevertheless, age of first breeding has a buffering effect on population fluctuations and in consequence on population persistence.We simulated the viability of Spanish Imperial Eagle (Aquila adalberti) and Osprey (Pandion haliaetus) populations using data from established and reintroduced populations in southern Spain.Our results show that reduction in the age of first breeding is critical in the success of reintroductions of such long-lived birds. Additionally, increases in productivity allow populations to growth at maximum rate. However, without considering variation in age of breeding, and the associated increasing overall productivity, reintroduced populations seem nonviable.To ignore density dependence in age of breeding in PVA means that we are seriously limiting the potential of the model population to respond to fluctuations in density, thereby reducing its resilience and viability. Variation in age of first breeding is an important factor that must be considered and included in any simulation model involving long-lived birds with deferred maturity.
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Affiliation(s)
- Virginia Morandini
- Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and WildlifeOregon State UniversityCorvallisOregon
| | - Sabrina Dietz
- Applied Ecology GroupEstación Biológica de Doñana (EBD‐CSIC)SevilleSpain
| | - Ian Newton
- Centre for Ecology & HydrologyWallingfordUK
| | - Miguel Ferrer
- Applied Ecology GroupEstación Biológica de Doñana (EBD‐CSIC)SevilleSpain
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Hernández M, Colomer MÀ, Pizarro M, Margalida A. Changes in eggshell thickness and ultrastructure in the Bearded Vulture (Gypaetus barbatus) Pyrenean population: A long-term analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 624:713-721. [PMID: 29272840 DOI: 10.1016/j.scitotenv.2017.12.150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Revised: 12/12/2017] [Accepted: 12/13/2017] [Indexed: 06/07/2023]
Abstract
The Spanish Bearded Vulture (Gypaetus barbatus) population has suffered from negative trends in a number of reproductive parameters that could jeopardize its long-term viability. From 1989 to 2012, 27 entire eggs and 63 eggshell fragments were collected from nests after breeding failure and/or fledging. Longer-term changes in eggshell thickness were made by examining 69 eggs collected in Spain from 1858 to 1911, and now held in European museums. Low levels of contamination with organochlorine pesticides and polychlorinated biphenyls were found in whole eggs and in conjunction with the high fertility rates observed in the field (66.7%) do not indicate a population suffering from the effects of organochlorine contamination. However, a decrease in the Ratcliffe Index and eggshell thickness were observed in eggs collected since 2001, increasingly so in samples post-2004, indicating an abrupt loss of egg quality. We found no significant relationship between organochlorine residues and eggshell in any of the variables measured. In contrast, we found a positive relationship between food availability and the Ratcliffe Index, eggshell thickness and eggshell surface area. A density-dependent explanation of reduced egg quality could arise from ecological constraints as the decrease of food resources. The impact of sudden changes in food availability due to sanitary regulations between 2006 and 2011 could be related with the loss of Bearded Vulture egg quality.
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Affiliation(s)
| | - Ma Àngels Colomer
- Department of Mathematics, Faculty of Life Sciences and Engineering, University of Lleida, Lleida, Spain
| | - Manuel Pizarro
- Department of Animal Medicine and Surgery, Veterinary Faculty, University Complutense of Madrid, Madrid, Spain
| | - Antoni Margalida
- Department of Animal Science (Division of Wildlife), Faculty of Life Sciences and Engineering, University of Lleida, Lleida, Spain; Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.
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Abstract
Obligate scavengers such as vultures provide critical ecosystem services and their populations have undergone severe declines in Asia and Africa. Intentional poisoning is a major threat to vultures in Africa, yet the impact on vulture populations of where poisoned carcasses are positioned is not known. We used re-sightings of 183 African white-backed vultures captured and tagged in two regions of South Africa, some 200 km apart, to estimate spatial differences in relative survival rates across life stages. Juvenile survival rates were similar in the two regions, whilst subadult and adult survival rates differed significantly. Using agent-based modelling, we show that this pattern of relative survival rates is consistent between regions that differ in intensity of poisoning, despite the proximity of the two regions. This may have important consequences for vulture conservation and the targeting of conservation efforts, particularly with regard to the efficacy of “vulture safe zones” around vulture breeding populations.
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Green RE, Donázar JA, Sánchez-Zapata JA, Margalida A. Potential threat to Eurasian griffon vultures in Spain from veterinary use of the drug diclofenac. J Appl Ecol 2016. [DOI: 10.1111/1365-2664.12663] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Rhys E. Green
- Conservation Science Group; Department of Zoology; University of Cambridge; Downing Street Cambridge CB2 3EJ UK
- RSPB Centre for Conservation Science; Royal Society for the Protection of Birds; The Lodge Sandy SG19 2DL UK
| | - José A. Donázar
- Department of Conservation Biology; Estación Biológica de Doñana - CSIC; Avenida de Américo Vespucio s/n Seville E-41092 Spain
| | - José A. Sánchez-Zapata
- Department of Applied Biology; Universidad Miguel Hernández; Ctra Beniel km 3·2 Alicante E-03312 Spain
| | - Antoni Margalida
- Faculty of Life Sciences and Engineering; University of Lleida; Lleida E-25003 Spain
- Division of Conservation Biology; Institute of Ecology and Evolution; University of Bern; Bern 3012 Switzerland
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