Report on cetacea stranded on the British coasts during 1913 / by S.F. Harmer.

  • Harmer, S. F. (Sidney Frederic), 1862-1950.
Date:
1914
Catalogue details

Licence: In copyright

Credit: Report on cetacea stranded on the British coasts during 1913 / by S.F. Harmer. Source: Wellcome Collection.

    13/24 (page 9)
    The two curves have very marked characters, although the small number of specimens recorded during the first half of the year may have been due partly to the fact that the Coast Guards did not at first grasp fully the nature of their new responsibilities. But taking the facts as they stand, the larger curve shows a sudden rise from 2 specimens in July to 15 in August. The curve continues to ascend to 18 in September, and reaches a maximum of 21 in the first half of October. From this point it sinks suddenly to 4 in the second half of October, and remains at a low level during the remainder of the year. It will be interesting to ascertain how far the curves of future years agree with this one ; and thus to what extent the 21 special frequency of the records during 20 August, September and the first half of October has a definite significance It may ° J 17 — well have some relation to migration ; but it is obvious that the curve of frequency 15 is really a composite one, made up of u the individual curves of several species. i3 These species may not all have iden- 12 tical periods of migration, and in any 11 case the form of the curve must be 10 specially influenced by the number of 9 records of the commonest species. In a Report received from the Coast 7 Guard at Coatham (Yorkshire) it was 0 suggested that the frequency of the occurrence of stranded “ Porpoises ” at certain seasons of the year was due to the fact that they were individuals which, 1 after being caught by fishermen in 0 Herring-nets, had been killed and thrown overboard, and had subsequently drifted ashore. In order to estimate, to some extent, the correctness of this suggestion, another curve was constructed to show the frequency of the records of the smaller Cetacea (possibly including a few Sharks) in the North Sea, as far South as the Straits of Dover, during July to November. It is obvious from the figure that these records have had a marked effect on the larger curve, though it is also true that if they were subtracted from the total, the form of that curve would not be materially affected. It thus appears legitimate to conclude that a larger number of Cetacea which have not been captured by fishing boats are stranded during August, September and the first half of October than at other times of the year.