This article was downloaded by: [ETH Zurich] On: 23 September 2013, At: 04:58 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Historical Biology: An International Journal of Paleobiology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/ghbi20 Added credence for a late Dodo extinction date Andrew Jackson a a Institute for Geophysics , Sonneggstr. 5, Zurich , Switzerland Published online: 23 Sep 2013. To cite this article: Andrew Jackson , Historical Biology (2013): Added credence for a late Dodo extinction date, Historical Biology: An International Journal of Paleobiology To link to this article: http://dx.doi.org/10.1080/08912963.2013.838231 PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. 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Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions Historical Biology, 2013 http://dx.doi.org/10.1080/08912963.2013.838231 Added credence for a late Dodo extinction date Andrew Jackson* Institute for Geophysics, Sonneggstr. 5, Zurich, Switzerland (Received 14 August 2013; accepted 22 August 2013) Considerable controversy surrounds the extinction date for the dodo (Raphus cucullatus), and the last uncontrovertibly confirmed sighting is ascribed to Volkert Evertsz on an islet off Mauritius in 1662. Nevertheless, both Roberts and Solow (2003), using a statistical technique, and Hume et al. (2004), drawing on Lamotius’ hunting diaries (1685–1688), place the extinction date as late as 1690 and 1693, respectively. A well-known account of Benjamin Harry from 1681 seems to have been frequently dismissed as unreliable or anecdotal. Our purpose here is to provide new background information on Harry’s scientific credentials that adds considerable credence to his 1681 report and thus adds to the likelihood of a late date for the dodo’s demise, in agreement with the 1690 lower bound. Keywords: Benjamin Harry; history of geomagnetism; extinction of the Dodo; Great Comet of 1680; Kirsch’s Comet; earliest inclination measurement The scientific content of Benjamin Harry’s manuscript provide previously unknown background information The date for the demise of the dodo is a question that concerning Harry that adds immense weight to the veracity continues to cause debate. Although written accounts of of his observation: Harry was not just a casual observer but a sightings exist, various reasons have been given to discredit synoptic recorder par excellence. these accounts as unsubstantiated or anecdotal. One such Little is known about Benjamin Harry, despite the fact important account that is subject to scrutiny is that of that he made the first known measurement of magnetic Benjamin Harry in 1681, the details of which we will inclination south of the equator when he was chief mate on discuss in detail below. Detractors from Harry’s account the ship, the Berkeley Castle, en route from England to India suggest that he was erroneously ascribing the name ‘dodo’ under the captaincy of Wm. Talbot. Inclination measures the (or dodaarsen in Dutch) to a different species of bird, the angle between the Earth’s magnetic field and the horizontal, Red Rail or Hen (e.g. Cheke 1987, 2006); Pitot (1905) and observed values of inclination in Europe played a pivotal simply finds Harry’s dodo reference ‘most improbable’. We role in supporting the theory of William Gilbert, espoused in put these doubts into context by airing, for the first time, the his publication De Magnete in 1600, that the Earth has a scientific credentials of Harry based on his other writings. magnetic field of internal origin similar to that of one of the It is the case that the last written record of dodo being spherical lodestones (terrella) he experimented with. On 7 8 0 , 8 hunted was on 25 November 1688 in the Daghregister of June 1680, OS at a latitude of 35 28 S and longitude of 40 Isaac Joan Lamotius (1685–1688) when he was Governor of East, Harry recorded an accompaniment to his more regular Downloaded by [ETH Zurich] at 04:58 23 September 2013 Mauritius. The actual record is reproduced in Den Hengst declination measurements, namely ‘poynt diped about 63’, (2009). The day books for subsequent years appear to be now the first southern hemisphere measurement still extant (see lost, so this provides a bound on the extinction date. But this Figure 1). We do not know the circumstances under which date is not universally accepted: Cheke (2006) argues that he made this measurement, nor with which instrument, as Lamotius had transferred the name ‘dodaersen’ to another there are no surviving records pertaining to the equipping of species of flightless bird once common on the island called the ship. Harry made a further four measurements in late June, still south of the equator (and with a reported accuracy the Red Hen or Aphanapteryx bonasia. Den Hengst (2009) 0 counters that the context of the listing of the hunt, naming the of 30 of arc), before his ship passed the Great Basses, dodo alongside deer, goats, pigs and manatees, is more modern-day Sri Lanka, and finally reached Fort St George, consistent with the presence of a large bird than that of a red Madras, India. These observations form the only inclinations rail, whose weight would be c. 0.5 kg. A very readable ever measured by an East Indiaman in the seventeenth account of the evidence can be found in Hume (2006).1 The century and are, as such, quite remarkable. observation of Benjamin Harry in 1681 adds credence to the So much for this intriguing set of observations on the 1688 report of Lamotius, and it is the purpose of this piece to outward journey. On the return journey, the Berkeley Castle *Email: [email protected] q 2013 Taylor & Francis 2 A. Jackson 14 November 1680 NS and which was also observed by Edmond Halley himself. Harry’s figures show the development of the comet, and in particular the length of its tail, reaching some 70–908 across the sky. Having delved into geophysics and astronomy, more was to come from this remarkable observer. On 5 July 1681, Harry’s ship moored in Mauritius, and Harry wrote extensively about the place and its products and inhabitants. At this time, Harry put to ink the famous observation ‘of winged and feathered ffowle the less passant are Dodos, whose fflesh is very hard’ (Figure 4). This observation has been the subject of considerable controversy as a result of its ambiguity: did Harry indeed taste the dodo? Harry’s words have been noted to be very similar to those used by the navigator Marshall in the 1660s, who appeared to be describing red rails (e.g. Cheke 2006). In defence of Harry, Den Hengst (2009) notes that ‘contrary to other authors, Harry had no reason to quote Figure 1. The first measurement of inclination or dip in the southern hemisphere that is still in existence, made by Benjamin from a previous account as his report was not destined for Harry on 7 June 1680 OS. q British Library Board, Sloane 3668. public information’. Nevertheless, we can perhaps suspect that Harry was compiling a list based on his own and his was moored in the Bay of Bengal between 21 November crew’s experiences and observations, or was recounting 1680 and 25 January 1681. During this time, we can read a local knowledge regarding the local victuals. In the latter most impressive set of scientific observations, the second case, likely this was derived from the Governor or from strand of evidence that Harry was a skilled and careful local stockmen, since he lists their prices for goats and observer. Beginning on the 21 November 1680 (OS) and on cattle. As noted by J. P. Hume in his review of this until 7 February, Harry made a series of observations and manuscript (personal communication, 2013), detailed drawings of a comet that was unmissable in the ¼ heavens. His initial entry for 21 November 1680 (Figure 2) Harry also mentions “curleues” [ curlews] in his list, 8 which may have represented migrant curlews, but just as reads ‘In y Morning I see y Commett dist from S md 7 5S likely to have been referable to red rails. On Mauritius, perpendicular under him or her allmost in a line with S8 migrant curlews are wary and difficult to approach, and so Ballasore ...’ and continues on 23 November ‘The Comett in the 1600s, they could have only been taken by stalking appeared at first as bigg as a Star of y 2 Mag: butt his Luminus and shooting (a time-consuming and expensive parts, bigger tn? a * of y first mgg’.