MAMMAL COMMUNICATIONS Volume 6 ISSN 2056-872X (online)
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MAMMAL COMMUNICATIONS Volume 6 ISSN 2056-872X (online) 29 page number Hedgehog road casualties in Great Britain © Dylan Walker / World Cetacean Alliance Andrew C. Kitchener, Georg Hantke, Jeremy S. Herman, Mariel ten Doeschate & Andrew C. Brownlow
Record of True’s beaked whale in Britain Mammal Communications First record of True’s beaked whale, Mesoplodon mirus, in Britain Andrew C. Kitchener1*, Georg Hantke1, Jeremy S. Herman1, Mariel ten Doeschate2 and Andrew C. Brownlow2, ABSTRACT A female beaked whale, Family Ziphiidae, was reported as stranded on 29th January 2020 at Kearvaig Bay, Sutherland, Scotland. Examination of its skull confirms that this is the first recorded stranding of True’s beaked whale, Mesoplodon mirus, in Britain. INTRODUCTION True’s beaked whale, Mesoplodon mirus, has a disjunct Ziphius cavirostris, strand most frequently off the British distribution, occurring in the North Atlantic mainly coast (Crawley et al. 2020), but until now there have been between 25o and 50o north and in the southern oceans, no strandings of True’s beaked whale. A previous record principally off the coasts of eastern southern Africa and in January 1931 from Geirinish, South Uist, Western Isles the southern coast of Australia, but with a presumed was later re-identified as a female Cuvier’s beaked whale circumglobal range (Jefferson et al. 2015). It is one of six (Fraser, 1934; McCann, 1964; Kitchener & Herman, species of beaked whale, Family Ziphiidae, recorded 1995). However, there have been strandings and regularly from European seas (Still et al. 2019; Crawley et sightings of this species in Ireland and elsewhere in al. 2020), although a single Gray’s beaked whale, M. Europe (Weir et al. 2004; Evans et al. 2007; Crawley et grayi, from the southern hemisphere was stranded in al. 2020). For example, there were 13 strandings in 1927 in the Netherlands (MacLeod, 2000). Beaked Ireland between 1899 and 2014 (Evans et al. 2007; whales feed primarily on squid, which they hunt at depth McGovern et al. 2014; Coombs et al. 2019). Most off the continental shelf, so that strandings are usually strandings of this species occur in the eastern coast of rare in comparison with other cetaceans. Sowerby’s North America (MacLeod, 2000). beaked whale, M. bidens, and Cuvier’s beaked whale, SPECIMEN On 29th January 2020 a stranded beaked whale was Blubber thicknesses just anterior to the dorsal fin were 50 recorded on a rocky shore at Kearvaig Bay, near Cape millimetres (dorsal), 41 mm (lateral) and 46 mm (ventral). Wrath, Sutherland, Scotland (58.611317o N -4.9428770o The carcase was in a moderate state of decomposition, W; UK CSIP Strandings no. SW2020/66) (Figure 1). On with widespread loss of epidermis and autolysis of 7th February 2020 the Scottish Marine Animal Strandings visceral organs. The animal was otherwise in moderate to Scheme carried out a post-mortem examination on site thin condition and had not fed recently prior to death. following protocols as described in Ijsseldijk, Brownlow & There was no indication of ingestion or entanglement in Mazzariol (2019). The genital and anal openings were in marine debris and the parasite burden was negligible. the same ventral slit, confirming its identification as a Necropsy examination revealed multiple fractures to ribs, female and it was 490 centimetres long with a maximum vertebral column and skull. The cranial vault was intact, girth, just posterior to the pectoral fins, of 264 cm and but significant intracranial and intraventricular cerebral girth immediately anterior to the dorsal fin of 245 cm. haemorrhage was noted in conjunction with focal 1 Department of Natural Sciences, National Museums Scotland, Chambers Street, Edinburgh EH1 1JF, UK 2 Scottish Marine Animal Stranding Scheme, SRUC Northern Faculty, An Lòchran, Inverness Campus, IV2 5NA, UK * corresponding author a.kitchener@nms.ac.uk Key words: Mesoplodon mirus, Ziphiidae, stranding, skull, pathology Full citation: Kitchener, A.C., Hantke, G., Herman, J.S., ten Doeschate, M. & Brownlow, A.C. (2020) First record of True’s beaked whale, Mesoplodon mirus, in Britain. Mammal Communications 6: 29-33, London. 30
Record of True’s beaked whale in Britain Mammal Communications subdural bruising. This indicated severe ante-mortem vertebrae, a right scapula, both flippers and some trauma to the skull and the proximal cause of death was fragments of ribs. diagnosed to be trauma associated with live stranding, The teeth were missing, and the distal mandible is most likely as a result of a severe storm, possibly Storm damaged, but the alveolus for a mandibular tooth is Brendan on 13th January 2020, because the carcase was situated at the extreme distal end as is typical for this found about 10 m above the high water mark and no species. The morphology of the synvertex (Figure 2a), other traumatic causes of death could be discerned at where the nasals, frontals and premaxillae converge on post mortem. The head was recovered following post the dorsal side of the skull, is identical to that for a male mortem, with the rest of what remained of the skeleton True’s beaked whale figured in Best (2007; USNM being collected on 1st March 2020. The partial skeleton is 571357) (Figure 2b), which was found in New Jersey, registered in the collections of National Museums USA in 1989. Although the morphology of the synvertex Scotland (NMS.Z.2020.24) and comprises the skull with a of Gervais’ beaked whale, M. europaeus, is somewhat broken rostrum, mandible and part post-cranial skeleton, similar in appearance, the mandibular tooth is not situated including all caudal vertebrae, chevrons, most lumbar at the distal end of the mandible (Best et al. 2007). Figure 1: A female True’s beaked whale, Mesoplodon mirus, found stranded on 29th January 2020 at Kearvaig Bay, Sutherland. a. Antero-dorsal view. b. Posterior view. a) b) 31
Record of True’s beaked whale in Britain Mammal Communications Figure 2: Dorsal views of synvertices of (a) female True’s beaked whale, M. mirus, from Kearvaig Bay, Sutherland (NMS.Z.2020.30) (© National Museums Scotland) and (b) male from New Jersey, USA (USNM 571357) (© National Museum of Natural History, Smithsonian Institution). Anterior is at the top. a) b) 32
Record of True’s beaked whale in Britain Mammal Communications DISCUSSION This specimen is the first confirmed record of M. mirus mobile phone technology have increased strandings from Britain and the fourth new cetacean species to reporting rates over the past decade. Increases in strand in Britain since strandings schemes began in 1991. strandings of beaked whales, Family Ziphiidae, in recent These records of Fraser’s dolphin, Lagenodelphis hosei, years, culminating in 2018 in the Unusual Mortality Event dwarf sperm whale, Kogia sima, and Blainville’s beaked involving more than 90 mostly Cuvier’s beaked whales on whale, Mesoplodon densirostris, and other warm-water the west coasts of Scotland and Ireland show that deep- species may in part reflect increased public reporting water habitats, mostly outside territorial waters, need effort coupled with changing climate and sea better research and protection. Although this record of a temperatures. Improved public awareness, citizen science new cetacean species to Britain is welcome, it may be an monitoring and sampling initiatives and almost universal indicator of wider problems in marine ecosystems. ACKNOWLEDGEMENTS We are most grateful to Roberta Mackay, Christopher Anderson and Ian Patterson for their considerable help in allowing us access to the whale and helping to transport the skeleton to the shore. National Museums Scotland thanks the SeaWorld and Busch Gardens Conservation Fund for its generous support of the collecting of beaked whale and killer whale specimens. We thank the National Museum of Natural History, Smithsonian Institution for permission to reproduce Figure 2a. REFERENCES Best, P.B. (2007). Whales and dolphins of the southern Jefferson, T.A., Webber, M.A., Pitman, R.L. & Gorter, U. African subregion. Cambridge University Press, (2015) Marine mammals of the world - 2nd edition. Cambridge. Academic Press, London. Coombs, E.J., Deaville, R., Sabin, R.C., Allan, L., Kitchener, A.C. & Herman, J.S. (1995) Re‐identification of O'Connell, M., Berrow, S., Smith, B., Brownlow, A., the supposed True's beaked whale Mesoplodon mirus Doeschate, M.T., Penrose, R. & Williams, R. (2019) What from Scotland. Journal of Zoology 236(2): 353-357. can cetacean stranding records tell us? A study of UK MacLeod, C.D. (2000) Review of the distribution of and Irish cetacean diversity over the past 100 years. Mesoplodon species (Order Cetacea, Family Ziphiidae) in Marine Mammal Science 35(4): 1527-1555. the North Atlantic. Mammal Review 30(1): 1-8. Crawley, D., Coomber, F., Kubasiewicz, L. M., Harrower, McCann, C. (1964) The supposed occurrence of True’s C. A., Evans, P., Waggitt, J., Smith, B. & Mathews, F. beaked whale (Mesoplodon mirus) on the Scottish coast– (2020) Atlas of the Mammals of Great Britain and a correction. Scottish Naturalist 71: 78-80. Northern Ireland. Pelagic Publishing, Exeter. 192 pp. McGovern, B., Culloch, R.M., O'Connell, M. & Berrow, S. Evans, P.G.H., Herman, J.S. & Kitchener, A.C. (2008). (2018) Temporal and spatial trends in stranding records True’s beaked whale Mesoplodon mirus. In: Harris, S. of cetaceans on the Irish coast, 2002–2014. Journal of and Yalden, D.W. (eds.). Mammals of the British Isles - the Marine Biological Association of the United Kingdom 4th edition, pp. 694-696. The Mammal Society, 98(5): 977-989. Southampton. Still, R., Harrop, H., Stenton, T. & Dias, L. (2019) Fraser, F.C. (1934). Report on Cetacea stranded on the Europe’s sea mammals. Princeton: Princeton University British coast. British Museum of Natural History, London. Press. IJsseldijk, L.L., Brownlow, A.C. & Mazzariol, S. (eds.) Weir, C. R., Stokes, J., Martin, C., & Cermeño, P. (2004) (2019) European best practice on cetacean post-mortem Three sightings of Mesoplodon species in the Bay of investigation and tissue sampling. Joint Biscay: First confirmed True's beaked whales (M. mirus) ACCOBAMS/ASCOBANS Document. for the north-east Atlantic? Journal of the Marine DOI10.31219/osf.io/zh4ra Biological Association of the United Kingdom 84(5), 1095- 1099. 33
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