Heaviside's dolphin

Heaviside's dolphin (Cephalorhynchus heavisidii), sometimes called Haviside's dolphin after its discoverer, is a small dolphin found from the southern coasts of Angola to the Cape of Good Hope. It is one of four dolphins in the genus Cephalorhynchus — the others being the Chilean dolphin, Hector's dolphin, and Commerson's dolphin.

Heaviside's dolphin
Heaviside's dolphin off Lüderitz
Size compared to an average human

Near Threatened  (IUCN 3.1)[1]
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: Delphinidae
Genus: Cephalorhynchus
Species:
C. heavisidii
Binomial name
Cephalorhynchus heavisidii
Gray, 1828
Heaviside's dolphin range

Name

Early in the 19th century, a specimen was caught off the Cape of Good Hope and brought to the United Kingdom by a Captain Haviside of the British East India Company. Zoologist John Edward Gray, who described the species in his Spicilegia Zoologica, misidentified Haviside as the surgeon John Heaviside, whose collection was acquired roughly contemporaneously.[2][3][4][5] "Heaviside's Dolphin" is most common in the literature, though some authorities use the originally intended name "Haviside's dolphin".

Population and distribution

Although sightings of the species are not uncommon off the Skeleton Coast of Namibia, Heaviside's dolphins have not been systematically studied by scientists. They have been recorded off the coast of northern Namibia at 17°S and as far south as the southern tip of South Africa. Sightings are often recorded from major population centres such as Cape Town and towns such as Walvis Bay. Sightings are likely from Lambert's Bay either from the shore or from boat trips run from the harbour. No estimates of abundance exist.

Physical description
Heaviside's dolphins off Walvis Bay, Namibia

Heaviside's dolphin is a fairly small dolphin, growing to about 1.8 m (5 ft 11 in) in length and weighing up to 75 kg (165 lb). Their size and the bluntness of their heads lead these dolphins to often be mistaken for porpoises. The head is coloured a dark grey. The front half of the upper side and the flanks are a much lighter grey.[6] The dorsal fin, fluke and back half of the back are again a darker grey colour. The underbelly is white, with flashes of white on the flanks below the dorsal fin.

Males reach sexual maturity around 7 to 9 years old. Females reach breeding age at the same time. The gestation period is probably 10 months. Mating occurs in spring and summer. Females are believed to calve on average once every three years. The maximum known age of a Heaviside's dolphin is 20 years. This relatively short lifespan, coupled with the long calving period, causes a naturally low population growth rate. Therefore, the species is particularly sensitive to being hunted.

Heaviside's dolphins are active and social animals. They typically congregate in groups of about five to 10 in number, but sometimes in larger groups. They are able to swim fast. Part of their play and social activity is to jump vertically clear of the water, turn in the air, and fall back into the sea with virtually no splashing or noise.

Conservation

Heaviside's dolphin is listed on Appendix II[7] of the Convention on the Conservation of Migratory Species of Wild Animals. It is listed on Appendix II[7] as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.[8]

Heaviside's dolphin is covered by the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia.[9]

gollark: Also, Python libraries generally seem to be imperative stuff with a thin OOP veneer which makes it slightly more irritating to use.
gollark: ```Internet Protocols and Support webbrowser — Convenient Web-browser controller cgi — Common Gateway Interface support cgitb — Traceback manager for CGI scripts wsgiref — WSGI Utilities and Reference Implementation urllib — URL handling modules urllib.request — Extensible library for opening URLs urllib.response — Response classes used by urllib urllib.parse — Parse URLs into components urllib.error — Exception classes raised by urllib.request urllib.robotparser — Parser for robots.txt http — HTTP modules http.client — HTTP protocol client ftplib — FTP protocol client poplib — POP3 protocol client imaplib — IMAP4 protocol client nntplib — NNTP protocol client smtplib — SMTP protocol client smtpd — SMTP Server telnetlib — Telnet client uuid — UUID objects according to RFC 4122 socketserver — A framework for network servers http.server — HTTP servers http.cookies — HTTP state management http.cookiejar — Cookie handling for HTTP clients xmlrpc — XMLRPC server and client modules xmlrpc.client — XML-RPC client access xmlrpc.server — Basic XML-RPC servers ipaddress — IPv4/IPv6 manipulation library```Why is there, *specifically*, **in the standard library**, a traceback manager for CGI scripts?
gollark: ```Structured Markup Processing Tools html — HyperText Markup Language support html.parser — Simple HTML and XHTML parser html.entities — Definitions of HTML general entities XML Processing Modules xml.etree.ElementTree — The ElementTree XML API xml.dom — The Document Object Model API xml.dom.minidom — Minimal DOM implementation xml.dom.pulldom — Support for building partial DOM trees xml.sax — Support for SAX2 parsers xml.sax.handler — Base classes for SAX handlers xml.sax.saxutils — SAX Utilities xml.sax.xmlreader — Interface for XML parsers xml.parsers.expat — Fast XML parsing using Expat```... why.
gollark: There is no perfect language.
gollark: ```Internet Data Handling email — An email and MIME handling package json — JSON encoder and decoder mailcap — Mailcap file handling mailbox — Manipulate mailboxes in various formats mimetypes — Map filenames to MIME types base64 — Base16, Base32, Base64, Base85 Data Encodings binhex — Encode and decode binhex4 files binascii — Convert between binary and ASCII quopri — Encode and decode MIME quoted-printable data uu — Encode and decode uuencode files```Mostly should be libraries outside of the python core, and why are they not under file formats?

See also

References
  1. Elwen, S.; Gopal, K. (2018), "Heaviside's Dolphin, Cephalorhynchus heavisidii", The IUCN Red List of Threatened Species 2018: e.T4161A50352086, doi:10.2305/IUCN.UK.2018-2.RLTS.T4161A50352086.en, retrieved 18 December 2018
  2. National Audubon Society Guide to Marine Mammals of the World. A.A. Knopf. 2002. p. 337. ISBN 978-0-375-41141-0.
  3. Platt, John R. (9 May 2014). "First Major Genetic Study of Elusive South African Dolphin Reveals a Species in Peril". Scientific American. Retrieved 10 December 2015.
  4. Gray, John Edward (1828). Spicilegia Zoologica, , or original figures and short systematic descriptions of new and unfigured animals Pt 1. London: Treuttel, Würtz & Co. p. 2.
  5. Norris, Kenneth Stafford (1966). Whales, Dolphins, and Porpoises. p. 17. ISBN 9780520032835.
  6. Perrin, W. F. (2002). Encyclopedia of Marine Mammals. Gulf Professional Publishing. p. 265. ISBN 978-0-12-551340-1.
  7. "Appendices I and II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS)" (PDF). 5 March 2009. p. 6. Archived from the original (PDF) on 21 February 2012.
  8. "Cephalorhynchus heavisidii (Gray, 1828)". Convention on Migratory Species. Archived from the original on 2 April 2012. Retrieved 31 August 2011.
  9. "Cephalorhynchus heavisidii". Convention on the Conservation of Migratory Species of Wild Animals. Retrieved 13 January 2020.
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