Browsing by Author "Azat, Claudio"

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    50 years of cetacean strandings reveal a concerning rise in Chilean patagonia
    (2020) Alvarado-Rybak, Mario; Toro, Frederick; Escobar-Dodero, Joaquín; Kinsley, Amy C.; Sepúlveda, Maximiliano A.; Capella, Juan; Azat, Claudio; Cortés Hinojosa, Galaxia Andrea; Zimin Veselkoff, Natalia; Mardones, Fernando O.
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    A flagship for Austral temperate forest conservation: an action plan for Darwin's frogs brings key stakeholders together
    (2021) Azat, Claudio; Valenzuela-Sanchez, Andres; Delgado, Soledad; Cunningham, Andrew A.; Alvarado-Rybak, Mario; Bourke, Johara; Briones, Raul; Cabeza, Osvaldo; Castro-Carrasco, Camila; Charrier, Andres; Correa, Claudio; Crump, Martha L.; Cuevas, Cesar C.; de la Maza, Mariano; Diaz-Vidal, Sandra; Flores, Edgardo; Harding, Gemma; Lavilla, Esteban O.; Mendez, Marco A.; Oberwemmer, Frank; Carlos Ortiz, Juan; Pastore, Hernan; Penafiel-Ricaurte, Alexandra; Rojas-Salinas, Leonora; Manuel Serrano, Jose; Sepulveda, Maximiliano A.; Toledo, Veronica; Ubeda, Carmen; Uribe-Rivera, David E.; Valdivia, Catalina; Wren, Sally; Angulo, Ariadne
    Darwin's frogs Rhinoderma darwinii and Rhinoderma rufum are the only known species of amphibians in which males brood their offspring in their vocal sacs. We propose these frogs as flagship species for the conservation of the Austral temperate forests of Chile and Argentina. This recommendation forms part of the vision of the Binational Conservation Strategy for Darwin's Frogs, which was launched in 2018. The strategy is a conservation initiative led by the IUCN SSC Amphibian Specialist Group, which in 2017 convened 30 governmental, non-profit and private organizations from Chile, Argentina and elsewhere. Darwin's frogs are iconic examples of the global amphibian conservation crisis: R. rufum is categorized as Critically Endangered (Possibly Extinct) on the IUCN Red List, and R. darwinii as Endangered. Here we articulate the conservation planning process that led to the development of the conservation strategy for these species and present its main findings and recommendations. Using an evidence-based approach, the Binational Conservation Strategy for Darwin's Frogs contains a comprehensive status review of Rhinoderma spp., including critical threat analyses, and proposes 39 prioritized conservation actions. Its goal is that by 2028, key information gaps on Rhinoderma spp. will be filled, the main threats to these species will be reduced, and financial, legal and societal support will have been achieved. The strategy is a multi-disciplinary, transnational endeavour aimed at ensuring the long-term viability of these unique frogs and their particular habitat.
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    Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity
    (2019) Scheele, Ben C.; Pasmans, Frank; Skerratt, Lee F.; Berger, Lee; Martel, An; Beukema, Wouter; Acevedo, Aldemar; Burrowes, Patricia A.; Carvalho, Tamilie; Catenazzi, Alessandro; De la Riva, Ignacio; Fisher, Matthew C.; Flechas, Sandra Victoria; Foster, Claire N.; Frías Álvarez, Patricia; Garner, Trenton W. J.; Gratwicke, Brian; Guayasamin, M.; Hirschfeld, M.; Kolby, Jonathan E.; Kosch, Tiffany A.; La Marca, Enrique; Lindenmayer, David B.; Lips, Karen R.; Longo, Ana V.; Maneyro, Raúl; McDonald, Cait A.; Mendelson Ill., Joseph R.; Palacios Rodríguez, Pablo; Parra Olea, Gabriela; Richards Zawacki, Corinne L.; Rödel, Mark O.; Rovito, Sean M.; Azat, Claudio; Toledo, Luis Felipe; Voyles, Jamie; Weldon, Ché; Whitfield, Steven M.; Wilkinson, Mark; Zamudio, Kelly R.; Canessa, Stefano
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    Bioclimatic and anthropogenic variables shape the occurrence of Batrachochytrium dendrobatidis over a large latitudinal gradient
    (NATURE PORTFOLIO, 2021) Alvarado Rybak, Mario; Lepe Lopez, Manuel; Penafiel Ricaurte, Alexandra; Valenzuela Sanchez, Andres; Valdivia, Catalina; Mardones, Fernando O.; Bacigalupe, Leonardo D.; Puschendorf, Robert; Cunningham, Andrew A.; Azat, Claudio
    Amphibian chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has caused the greatest known loss of biodiversity due to an infectious disease. We used Bd infection data from quantitative real-time PCR (qPCR) assays of amphibian skin swabs collected across Chile during 2008-2018 to model Bd occurrence with the aim to determine bioclimatic and anthropogenic variables associated with Bd infection. Also, we used Bd presence/absence records to identify geographical Bd high-risk areas and compare Bd prevalence and infection loads between amphibian families, ecoregions, and host ecology. Data comprised 4155 Bd-specific qPCR assays from 162 locations across a latitudinal gradient of 3700 km (18 degrees to 51 degrees S). Results showed a significant clustering of Bd associated with urban centres and anthropogenically highly disturbed ecosystems in central-south Chile. Both Bd prevalence and Bd infection loads were higher in aquatic than terrestrial amphibian species. Our model indicated positive associations of Bd prevalence with altitude, temperature, precipitation and human-modified landscapes. Also, we found that macroscale drivers, such as land use change and climate, shape the occurrence of Bd at the landscape level. Our study provides with new evidence that can improve the effectiveness of strategies to mitigate biodiversity loss due to amphibian chytridiomycosis.
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    Current threats faced by amphibian populations in the southern cone of South America
    (2022) Pablo Kacoliris, Federico; Berkunsky, Igor; Carlos Acosta, Juan; Acosta, Rodrigo; Gabriela Agostini, Maria; Sebastian Akmentins, Mauricio; Luz Arellano, Maria; Azat, Claudio; Carla Bach, Nadia; Mirta Blanco, Graciela; Calvo, Rodrigo; Charrier, Andres; Corbalan, Valeria; Correa, Claudio; Elena Cuello, Maria; Deutsch, Camila; Di-Pietro, Diego; Soledad Gaston, Maria; Gomez-Ales, Rodrigo; Kass, Camila; Kass, Nicolas; Lobos, Gabriel; Agustin Martinez, Tomas; Martinez-Aguirre, Tomas; Mora, Marta; Nieva-Cocilio, Rodrigo; Pastore, Hernan; Manuel Perez-Iglesias, Juan; Piaggio-Kokot, Lia; Rabanal, Felipe; Jesus Rodriguez-Munoz, Melina; Cecilia Sanchez, Laura; Tala, Charif; Ubeda, Carmen; Vaira, Marcos; Alicia Velasco, Melina; Vidal, Marcela; Daniel Williams, Jorge
    In this work, we update and increase knowledge on the severity and extent of threats affecting 57 populations of 46 amphibian species from Chile and Argentina in southern South America. We analyzed the intrinsic conser-vation problems that directly impact these populations. We shared a questionnaire among specialists on threats affecting target amphibian populations with information on i) range, ii) historical occurrence and abundance, iii) population trends, iv) local extinctions, v) threats, and vi) ongoing and necessary conservation/research. We assessed association patterns between reported threats and population trends using multiple correspondence analysis. Since 2010, 25 of 57 populations have declined, while 16 experienced local extinctions. These pop-ulations were affected by 81% of the threat categories analyzed, with those related to agricultural activities and/ or habitat modifications being the most frequently reported. Invasive species, emerging diseases, and activities related to grazing, ranching, or farming were the threats most associated with population declines. Low con-nectivity was the most frequent intrinsic conservation problem affecting 68% of the target populations, followed by low population numbers, affecting 60%. Ongoing monitoring activity was conducted in 32 (56%) populations and was the most frequent research activity. Threat mitigation was reported in 27 (47%) populations and was the most frequent ongoing management activity. We found that habitat management is ongoing in 5 (9%) pop-ulations. At least 44% of the amphibian populations surveyed in Chile and Argentina are declining. More in-formation related to the effect of management actions to restore habitats, recover populations, and eliminate threats such as invasive species is urgently needed to reverse the conservation crisis facing amphibians in this Neotropical region.