{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T22:23:16Z","timestamp":1777587796303,"version":"3.51.4"},"reference-count":35,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,5,19]],"date-time":"2023-05-19T00:00:00Z","timestamp":1684454400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"LIFE program of the European Commission","award":["UID\/BIA\/04004\/2020"],"award-info":[{"award-number":["UID\/BIA\/04004\/2020"]}]},{"name":"Azores Government","award":["UID\/BIA\/04004\/2020"],"award-info":[{"award-number":["UID\/BIA\/04004\/2020"]}]},{"name":"FCT","award":["UID\/BIA\/04004\/2020"],"award-info":[{"award-number":["UID\/BIA\/04004\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Diversity"],"abstract":"<jats:p>The Azores bullfinch (Pyrrhula murina Godman, 1866) is a rare Passeriformes endemic from the eastern part of S\u00e3o Miguel Island, Azores, Portugal. This bird was almost considered extinct in the first half of the 20th century, but due to recent conservation measures, it has experienced a recovery since the beginning of the 2000s. Despite the attention given to this bird, the size of its population is still controversial, and the most recent studies present significant divergences on this behalf. The purpose of the present study is to present data from the long-term monitoring and results of the third single-morning survey of the Azores bullfinch to update information about the population size and range of this species. In addition, we performed a literature review to highlight the limitations and advantages of the different approaches for monitoring this species. The Azores Bullfinch records during the single-morning survey indicated a reduction in the extent of occurrence and area of occupancy of this species in comparison with the previous studies, despite the increase in bird detection. However, we suggest that the distribution range of this species needs further analysis concerning its area to exclude non suitable habitats from this analysis. In this study, we conclude that the most likely size of the Azores bullfinch population is 500 to 800 couples, with a slow population growth tendency and an area of distribution of 136.5 km2.<\/jats:p>","DOI":"10.3390\/d15050685","type":"journal-article","created":{"date-parts":[[2023,5,19]],"date-time":"2023-05-19T10:08:55Z","timestamp":1684490935000},"page":"685","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["How Many Azores Bullfinches (Pyrrhula murina) Are There in the World? Case Study of a Threatened Species"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6065-9585","authenticated-orcid":false,"given":"Tarso de M. M.","family":"Costa","sequence":"first","affiliation":[{"name":"Sociedade Portuguesa para o Estudo das Aves, Rua Ant\u00f3nio Alves de Oliveira, 9630-147 Nordeste, Portugal"},{"name":"cE3c\u2014Centre for Ecology, Evolution and Environmental Changes & ABG\u2014Azorean Biodiversity Group, Faculty of Sciences and Technology, University of the Azores, 9500-321 Ponta Delgada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4450-8167","authenticated-orcid":false,"given":"Artur","family":"Gil","sequence":"additional","affiliation":[{"name":"IVAR\u2014Research Institute for Volcanology and Risks Assessment, University of the Azores, 9500-321 Ponta Delgada, Portugal"},{"name":"cE3c\u2014Centre for Ecology, Evolution and Environmental Changes & ABG\u2014Azorean Biodiversity Group, CHANGE\u2014Global Change and Sustainability Institute, Faculty of Sciences and Technology, University of the Azores, 9500-321 Ponta Delgada, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2417-3259","authenticated-orcid":false,"given":"Sergio","family":"Tim\u00f3teo","sequence":"additional","affiliation":[{"name":"Department of Life Sciences, Associate Laboratory TERRA, Centre for Functional Ecology, University of Coimbra, 3000-456 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7078-0178","authenticated-orcid":false,"given":"Ricardo S.","family":"Ceia","sequence":"additional","affiliation":[{"name":"CIBIO\/InBIO, Centro de Investiga\u00e7\u00e3o em Biodiversidade e Recursos Gen\u00e9ticos, Universidade do Porto, 4485-661 Vair\u00e3o, Portugal"},{"name":"CIBIO\/InBIO, Centro de Investiga\u00e7\u00e3o em Biodiversidade e Recursos Gen\u00e9ticos, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal"},{"name":"BIOPOLIS Program in Genomics, Biodiversity and Land Planning, Universidade do Porto, 4485-661 Vair\u00e3o, Portugal"}]},{"given":"R\u00faben","family":"Coelho","sequence":"additional","affiliation":[{"name":"Sociedade Portuguesa para o Estudo das Aves, Rua Ant\u00f3nio Alves de Oliveira, 9630-147 Nordeste, Portugal"},{"name":"Secretaria Regional do Ambiente e Altera\u00e7\u00f5es Clim\u00e1ticas, Rua do Galo, n\u00ba 118, 9700-091 Angra do Hero\u00edsmo, Portugal"}]},{"given":"Azucena","family":"de la Cruz Martin","sequence":"additional","affiliation":[{"name":"Sociedade Portuguesa para o Estudo das Aves, Rua Ant\u00f3nio Alves de Oliveira, 9630-147 Nordeste, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,19]]},"reference":[{"key":"ref_1","unstructured":"Ramos, J. (1993). Status and Ecology of the Priolo or Azores Bullfinch, Pyrrhula murina. [Doctoral Dissertation, University of Oxford]."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/0006-3207(94)00033-M","article-title":"The Diet of the Azores Bullfinch Pyrrhula murina and Floristic Variation within Its Range","volume":"71","author":"Ramos","year":"1995","journal-title":"Biol. Conserv."},{"key":"ref_3","first-page":"25","article-title":"Summer Abundance and Ecological Distribution of Passerines in Native and Exotic Forests in S\u00e3o Miguel, Azores","volume":"56","author":"Ceia","year":"2009","journal-title":"Ardeola"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"718169","DOI":"10.3389\/fevo.2021.718169","article-title":"Macaronesia as a Fruitful Arena for Ecology, Evolution, and Conservation Biology","volume":"9","author":"Florencio","year":"2021","journal-title":"Front. Ecol. Evol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1111\/j.1365-2699.2010.02427.x","article-title":"A Reconstruction of Palaeo-Macaronesia, with Particular Reference to the Long-Term Biogeography of the Atlantic Island Laurel Forests","volume":"38","author":"Otto","year":"2011","journal-title":"J. Biogeogr."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1016\/j.ppees.2009.10.001","article-title":"Conservation of Oceanic Island Floras: Present and Future Global Challenges","volume":"12","author":"Tye","year":"2010","journal-title":"Perspect. Plant Ecol. Evol. Syst."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1016\/j.ppees.2015.01.003","article-title":"Impacts of Global Climate Change on the Floras of Oceanic Islands\u2013Projections, Implications and Current Knowledge","volume":"17","author":"Harter","year":"2015","journal-title":"Perspect. Plant Ecol. Evol. Syst."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/j.jnc.2009.11.002","article-title":"Assessing the Areas under Risk of Invasion within Islands through Potential Distribution Modelling: The Case of Pittosporum undulatum in S\u00e3o Miguel, Azores","volume":"18","author":"Hortal","year":"2010","journal-title":"J. Nat. Conserv."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1111\/j.1365-2699.2011.02671.x","article-title":"The Ecological Impact of Oceanic Island Colonization\u2014A Palaeoecological Perspective from the Azores","volume":"39","author":"Connor","year":"2012","journal-title":"J. Biogeogr."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Foxcroft, L.C., Py\u0161ek, P., Richardson, D.M., and Genovesi, P. (2013). Plant Invasions in Protected Areas: Patterns, Problems and Challenges, Springer.","DOI":"10.1007\/978-94-007-7750-7"},{"key":"ref_11","unstructured":"Bannerman, D.A., and Bannerman, W.M. (1966). Birds of the Atlantic Islands, Vol. III. A History of the Birds of the Azores, Oliver & Boyd."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"344","DOI":"10.2307\/3677282","article-title":"Fern Frond Feeding by the Azores Bullfinch","volume":"25","author":"Ramos","year":"1994","journal-title":"J. Avian Biol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1111\/j.1469-7998.1996.tb05403.x","article-title":"The Influence of Size, Shape, and Phenolic Content on the Selection of Winter Foods by the Azores Bullfinch (Pyrrhula murina)","volume":"238","author":"Ramos","year":"1996","journal-title":"J. Zool."},{"key":"ref_14","first-page":"23","article-title":"The Azores Bullfinch\u2013Pyrrhula Murina GODMAN, 1866 The History of a Bird Species: Persecuted\u2013Missing\u2013Rediscovered\u2013Protected (?) (including a List of All Known Specimens and Syntypes)","volume":"102B","author":"Aubrecht","year":"2001","journal-title":"Ann. Naturhist. Mus. Wien"},{"key":"ref_15","first-page":"37","article-title":"Der Wiederentdeckte Azorengimpel","volume":"15","year":"1983","journal-title":"Wir Vogel"},{"key":"ref_16","first-page":"297","article-title":"Observations on the S\u00e3o Miguel Bullfinch","volume":"7","author":"Bibby","year":"1991","journal-title":"Acoreana"},{"key":"ref_17","first-page":"677","article-title":"Studies of West Paleartic Birds-Azores Bullfinch","volume":"85","author":"Bibby","year":"1992","journal-title":"Br. Birds"},{"key":"ref_18","unstructured":"European Commission (2022). European Red List of Birds 2021."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"477","DOI":"10.1017\/S0959270911000025","article-title":"Status Assessment of the Critically Endangered Azores Bullfinch Pyrrhula murina","volume":"21","author":"Ceia","year":"2011","journal-title":"Bird Conserv. Int."},{"key":"ref_20","unstructured":"Heredia, B., Rose, L., and Painter, M. (1996). ; BirdLife International. Globally Threatened Birds in Europe: Action Plans, Council of Europe."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"710","DOI":"10.2307\/2404942","article-title":"Introduction of Exotic Tree Species as a Threat to the Azores Bullfinch Population","volume":"33","author":"Ramos","year":"1996","journal-title":"J. Appl. Ecol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"627","DOI":"10.1007\/s10336-010-0501-4","article-title":"High Survival Rate of a Critically Endangered Species, the Azores Bullfinch Pyrrhula Murina, as a Contribution to Population Recovery","volume":"151","author":"Monticelli","year":"2010","journal-title":"J. Ornithol."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1111\/j.1095-8312.2012.02040.x","article-title":"The Azores Bullfinch (Pyrrhula murina) Has the Same Unusual and Size-Variable Sperm Morphology as the Eurasian Bullfinch (Pyrrhula pyrrhula)","volume":"108","author":"Lifjeld","year":"2013","journal-title":"Biol. J. Linn. Soc. Lond."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"125869","DOI":"10.1016\/j.jnc.2020.125869","article-title":"Downside in Habitat Restoration: Predation of Artificial Nests by Invasive Rodents in Macaronesian Laurel Forest","volume":"56","author":"Santos","year":"2020","journal-title":"J. Nat. Conserv."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1080\/03078698.1998.9674157","article-title":"Biometrics, Weights, Breeding and Moulting Seasons of Passerines in an Azores Cloud Forest","volume":"19","author":"Ramos","year":"1998","journal-title":"Ringing Migr."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1016\/j.ecoleng.2015.10.028","article-title":"The Priolo Atlas: A Citizen Science-Based Census Initiative for Supporting Pyrrhula murina Habitat Conservation and Restoration Policies in S\u00e3o Miguel Island (Azores, Portugal)","volume":"86","author":"Gil","year":"2016","journal-title":"Ecol. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"309","DOI":"10.2307\/1367399","article-title":"A Variable Circular-Plot Method for Estimating Bird Numbers","volume":"82","author":"Reynolds","year":"1980","journal-title":"Condor"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Buckland, S.T., Anderson, D.R., Burnham, K.P., Laake, J.L., Borchers, D.L., and Thomas, L. (2001). Introduction to Distance Sampling: Estimating Abundance of Biological Populations, Oxford University Press.","DOI":"10.1093\/oso\/9780198506492.001.0001"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1111\/j.1365-2664.2009.01737.x","article-title":"Distance Software: Design and Analysis of Distance Sampling Surveys for Estimating Population Size","volume":"47","author":"Thomas","year":"2010","journal-title":"J. Appl. Ecol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"716","DOI":"10.1109\/TAC.1974.1100705","article-title":"A New Look at the Statistical Model Identification","volume":"19","author":"Akaike","year":"1974","journal-title":"IEEE Trans. Automat. Contr."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Burnham, K.P., and Anderson, D.R. (1998). Model Selection and Inference: A Practical Information\u2013Theoretic Approach, Springer.","DOI":"10.1007\/978-1-4757-2917-7"},{"key":"ref_32","unstructured":"Lloyd, H., Cahill, A., Jones, M., and Marsden, S.J. (1998). Expedition Field Techniques: Bird Surveys, Royal Geographic Society."},{"key":"ref_33","first-page":"101","article-title":"The Annual Cycle of the Azores Bullfinch, Pyrrhula murina Goldman, 1866 (Aves: Passeriformes)","volume":"12A","author":"Ramos","year":"1994","journal-title":"Arquipelago"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1016\/j.biocon.2012.01.009","article-title":"Testing a Novel Spatially-Explicit Dynamic Modelling Approach in the Scope of the Laurel Forest Management for the Endangered Azores Bullfinch (Pyrrhula murina) Conservation","volume":"147","author":"Bastos","year":"2012","journal-title":"Biol. Conserv."},{"key":"ref_35","unstructured":"(2023, May 04). BirdLife International Species Factsheet: Pyrrhula murina. Available online: www.birdlife.org."}],"container-title":["Diversity"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-2818\/15\/5\/685\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:38:26Z","timestamp":1760125106000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-2818\/15\/5\/685"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,5,19]]},"references-count":35,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2023,5]]}},"alternative-id":["d15050685"],"URL":"https:\/\/doi.org\/10.3390\/d15050685","relation":{},"ISSN":["1424-2818"],"issn-type":[{"value":"1424-2818","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,5,19]]}}}