Bryde’s Whales forever in the bay
While most people excitedly anticipate the arrival of the humpback and southern right whales sometime during June or July their migration from sub-antarctic waters, many may forget or overlook our near shore resident species, the Bryde’s whale Balaenoptera brydei. Both the humpback and southern right whales are bigger in size, personality, approachability, and visibility than the shy and elusive Bryde’s whale, even for the few short months they are here. Bryde’s whales are a complicated species, listed as Data Deficient by the IUCN, and the identity and number of how many species there are in the Bryde’s whale complex is uncertain. The South African near shore Bryde’s whale population, recognized as the South African Inshore Stock by the International Whaling Commission, are the Bryde’s whales that we will find in our beautiful Plettenberg Bay. Although not officially recognized as a subspecies, or separate species, they are a little different from the “ordinary” Bryde’s whales. These Bryde’s whales are found over the continental shelf, south of 30°S, and remain near shore, with very little migratory movement beyond slightly along the west coast in winter. Bryde’s whales are dark grey on top and white underneath, with a very pointed jaw and three longitudinal ridges on the upper jaw. They have a clearly defined dorsal fin, which is noticeably hooked. The near shore population grow to between 12-13 m in length which is slightly smaller than the “ordinary” Bryde’s whale length of 14 m. Another big difference between the inshore and offshore Bryde’s whales is the presence of crater-like wounds, now known to be caused by the cookie-cutter shark Isistius spp. Inshore Bryde’s whales have not been found to have any of these wounds, either fresh or healed, while the offshore Bryde’s whales have! It would seem it is definitely safer to stay close to shore!
Written by: Minke Witteveen
For further reading:
- Best, P.B. 2001. Distribution and population separation of Bryde’s whale Balaenoptera edenii off southern Africa. Marine Ecological Progress Series 220: 277-289.
- Best, P.B. and Photopoulou, T. 2016. Identifying the “demon whale-biter”: Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius PLoS ONE 11: e0152643.
- Branch, G.M., Griffiths, C.L., Branch, M.L. and Beckley, L.E. 2010. Two Oceans: A guide to the marine life of southern Africa. Pp. 364. Random House Struik Publishers, Cape Town.
- Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. and Zerbini, A.N. 2008. Balaenoptera edeni. The IUCN Red List of Threatened Species 2008. Accessed: 2016-08-01. URL: http://www.iucnredlist.org/details/full/2476/0