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Leucism has been reported in at least 14 cetacean species, including Risso’s dolphin (Grampus griseus). Risso’s dolphins with abnormal pigmentation were sighted and photographed north of Faial Island, Azores Archipelago, in 6 separate events between 2020 and 2023. In 2020, a calf and a juvenile/subadult were observed within a group of over 100 individuals. A leucistic calf with pale skin and dark eyes was observed in 2021, 2022, and 2023 in the same area followed by the same adult within a pod of about 12 individuals, including 3 juveniles, all with normal coloration. This is the first report of wild leucistic Risso’s dolphins in the Atlantic, which could be of interest in future local population and hypopigmentation studies on a dolphin species known to become completely white with age.
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Alves F, Ferreira R, Dias L, Nicolau C, Sousa D, Moura C, Gomes C, Dinis A. 2017. Rare records of hypo- and hyper-pigmented individuals in two delphinid species off Madeira island. Hystrix It J Mamm. 28(1):116-118. https://doi.org/10.4404/hystrix-28.1-11888
De Boer MN, Clark J, Leopold MF, Simmonds MP, Reijnders PJH. 2013. Photo-identification methods reveal seasonal and long-term site-fidelity of Risso’s dolphins (Grampus griseus) in shallow waters (Cardigan Bay, Wales). OJMS. 3:66-75. https://doi.org/10.4236/ojms.2013.32A007 DOI: https://doi.org/10.4236/ojms.2013.32A007
Dos Santos RP, Simião S, Madruga P, Mendonça AS, Seitre R, Gomes-Pereira JN. 2016. Anomalously white Atlantic spotted dolphins (Stenella frontalis, Cuvier, 1892) off the Azores. Aquat Mamm. 42(2):245-252. http://doi.org/10.1578/AM.42.2.2016.244 DOI: https://doi.org/10.1578/AM.42.2.2016.245
Fertl D, Barros NB, Rowlett RA, Estes S, Richlen M. 2004. An update on anomalously white cetaceans, including the first account for the pantropical spotted dolphin (Stenella attenuata graffmani). Lat Am J Aquat Mamm. 3(2):163-166. https://doi.org/10.5597/lajam00061 DOI: https://doi.org/10.5597/lajam00061
Fertl D, Pusser LT, Long JJ. 1999. First record of an albino bottlenose dolphin (Tursiops truncatus) in the Gulf of Mexico, with a review of anomalously white cetaceans. Mar Mammal Sci. 15(1):227-234. https://doi.org/10.1111/j.1748-7692.1999.tb00794.x DOI: https://doi.org/10.1111/j.1748-7692.1999.tb00794.x
Fertl D, Rosel PE. 2009. Albinism. In: Wursig B, Perrin W, Wursig B, Thewissen J (eds.), Encyclopedia of Marine Mammals. 2nd ed. Cambridge (MA): Academic Press. p. 24-26. https://doi.org/10.1016/B978-0-12-373553-9.00006-7 DOI: https://doi.org/10.1016/B978-0-12-373553-9.00006-7
Funasaka N, Kirihata T, Hosono M, Kato H, Ohsumi S. 2017. Three cases of anomalously white Risso’s dolphins Grampus griseus in Japan. Mammal Study. 42(3):173-178. https://doi.org/10.3106/041.042.0307 DOI: https://doi.org/10.3106/041.042.0307
Gaspari S, Airoldi S, Hoelzel AR. 2007. Risso’s dolphins (Grampus griseus) in UK waters are differentiated from a population in the Mediterranean Sea and genetically less diverse. Conserv Genet. 8:727-732. https://doi.org/10.1007/s10592-006-9205-y DOI: https://doi.org/10.1007/s10592-006-9205-y
Hartman KL, Fernandez M, Azevedo JMN. 2014. Spatial segregation of calving and nursing Risso’s dolphins (Grampus griseus) in the Azores, and its conservation implications. Mar Biol. 161:1419-1428. https://doi.org/10.1007/s00227-014-2430-x DOI: https://doi.org/10.1007/s00227-014-2430-x
Hartman KL, Visser F, Hendriks AJE. 2008. Social structure of Risso’s dolphins (Grampus griseus) at the Azores: a stratified community based on highly associated social units. Can J Zool. 86(4):294-306. https://doi.org/10.1139/Z07-138 DOI: https://doi.org/10.1139/Z07-138
Hartman KL, Wittich A, Azevedo JMN. 2013. Show me your body and I tell you how old you are: A noninvasive method to define 6 life history - classes in Risso’s dolphins (Grampus griseus) using an identified trial population in the Atlantic. In: Chen I, Hartman KL, Simmonds M, Wittich A, Wright AJ (eds.), Report from the European Cetacean Society Conference Workshop: Grampus griseus 200th anniversary: Risso’s dolphins in the contemporary world, 26–28 March 2012. Galway (Ireland): [ECS] European Cetacean Society. p. 69-88.
Hartman KL, Wittich A, Cai JJ, van der Meulen FH, Azevedo JMN. 2016. Estimating the age of Risso’s dolphins (Grampus griseus) based on skin appearance. J Mammal. 97(2):490-502.https://doi.org/10.1093/jmammal/gyv193 DOI: https://doi.org/10.1093/jmammal/gyv193
Hauser-Davis RA, Lemos LS, Moreira SC, Siciliano S. 2020. A scientometric review on leucism in wild dolphins. Bol Lab Hidrobiol. 30(2):1-9. https://doi.org/10.18764/1981-6421e2020.9 DOI: https://doi.org/10.18764/1981-6421e2020.9
Koper RP, Drost E, Plön S. 2017. First sighting of a leucistic humpback whale (Megaptera novaeangliae) in South African coastal waters. Aquat Mamm. 43(3):331-334. https://doi.org/10.1578/AM.43.3.2017.331 DOI: https://doi.org/10.1578/AM.43.3.2017.331
Pereira JNDSG. 2008. Field notes on Risso’s dolphin (Grampus griseus) distribution, social ecology, behaviour, and occurrence in the Azores. Aquat Mamm. 34(4):426-435. https://doi.org/10.1578/AM.34.4.2008.426 DOI: https://doi.org/10.1578/AM.34.4.2008.426
Pereira JN, Gonçalves JM. 2009. Scientific literature on cetaceans in the Azores region: an historical overview. In: Brito C, Evans PGH (eds.), Proceedings of the ECS Workshop Marine Mammal History, 21 April 2007. San Sebástian, (Spain): [ECS] European Cetacean Society. p. 29-33.
Perrin WF. 2009. Coloration. In: Wursig B, Perrin W, Wursig B, Thewissen J (eds.), Encyclopedia of Marine Mammals. 2nd ed. Cambridge (MA): Academic Press. p. 243-249. https://doi.org/10.1016/B978-0-12-373553-9.00061-4 DOI: https://doi.org/10.1016/B978-0-12-373553-9.00061-4
Silva MA, Prieto R, Cascão I, Seabra MI, Machete M, Baumgartner MF, Santos RS. 2014. Spatial and temporal distribution of cetaceans in the mid-Atlantic waters around the Azores. Mar Biol Res. 10(2):123-137. https://doi.org/10.1080/17451000.2013.793814 DOI: https://doi.org/10.1080/17451000.2013.793814
Sprogis KR, Pollock KH, Raudino HC, Allen SJ, Kopps AM, Manlink O, Tyne JA, Bejder L. 2016. Sex-specific patterns in abundance, temporary emigration and survival of Indo-Pacific bottlenose dolphins (Tursiops aduncus) in coastal and estuarine waters. Front Mar Sci. 3:1-15. https://doi.org/10.3389/fmars.2016.00012 DOI: https://doi.org/10.3389/fmars.2016.00012
Stevens A. 2014. A photo-ID study of the Risso’s dolphin (Grampus griseus) in Welsh coastal waters and the use of Maxent modelling to examine the environmental determinants of spatial and temporal distribution in the Irish Sea [MSc thesis]. [Menai Bridge (UK)]: School of Ocean Sciences, Bangor University. 97 p.
Tyson RB, Nowacek SM, Nowacek DP. 2011. Community structure and abundance of bottlenose dolphins Tursiops truncatus in coastal waters of the northeast Gulf of Mexico. Mar Ecol Prog Ser. 438:253-265. https://doi.org/10.3354/meps09292 DOI: https://doi.org/10.3354/meps09292
Van Grouw H. 2013. What colour is that bird? The causes and recognition of common colour aberrations in birds. Br Birds. 106(1–56):17-29.