Short-finned pilot whale
| Short-finned pilot whale | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Short-finned pilot whale off La Gomera (Canary Islands) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Globicephala macrorhynchus | ||||||||||||
| Gray , 1846 |
The short-finned pilot whale or Indian pilot whale ( Globicephala macrorhynchus ) is a species of whale from the dolphin family (Delphinidae). Together with the common pilot whale , it forms the genus of the pilot whale ( Globicephala ).
features
Short-finned pilot whales are stocky, pitch black or dark gray animals from 3.6 to 7.2 meters in length and one to four tons in weight, with the males usually up to 6.8 meters being much larger than the average 5.5 meters long females are. The head is almost or completely beakless and has a spherical melon , which is particularly pronounced in the males. The shape of the fin is very variable, depending on gender and age, its tip is rounded. The fluke has a clear notch in the middle and sits on a strongly developed tail root. The flippers sit close behind the head and are slim and short. There are several light gray patterns on the dark basic color, but these can be quite variable between individuals. A diagonal stripe runs from behind the eye towards the fin, a w-shaped spot is on the neck and a gray or off-white spot on the abdomen is present. There may be a gray or white indistinct cape behind the fin.
The short-finned pilot whale is very similar to the common pilot whale. In the few areas where both species are found, it is nearly impossible to tell apart from sightings at sea. In the short-finned pilot whale, however, the flippers are significantly shorter, the abdominal spot is less strong and the number of teeth is seven to nine per half of the jaw than in the common pilot whale (8 to 13 per half of the jaw).
distribution
Short-finned pilot whales are found in all tropical and subtropical seas between latitude 50 degrees north and latitude 40 degrees south worldwide. The species is also found in the Red Sea , but not in the Persian Gulf and the Mediterranean .
In contrast to the common pilot whale, which prefers cooler waters, this species is restricted to warmer areas. Therefore, only in relatively small areas (for example the central Atlantic ) does the range of the two species overlap.
Way of life
Short-finned pilot whales usually stay in the open sea, but they can also come to shallow waters to look for food. They live in schools of mostly 10 to 30 animals, and when there is too much food, several hundred whales can be observed together. There are on average eight females for each male in the group. They are often in the company of bottlenose dolphins or other small whales . Short-finned pilot whales are leisurely animals that only swim quickly when threatened and almost never jump out of the water. Their dives are usually around 10, but also up to 27 minutes long, they reach a depth of 800 to 900 meters and eat their food there, mainly cephalopods . They make their forays to forage mainly at night, when their prey animals ascend to higher ocean regions.
Systematics
The short-finned pilot whale is classified as an independent species within the genus of the pilot whale ( Globicephala ), which currently consists of two species and in addition to this species also contains the long-finned pilot whale ( Globicephala melas ). The first scientific description comes from the English zoologist John Edward Gray from 1846, who described the species using individuals from the "southern seas".
In addition to the nominate form, no subspecies are currently differentiated within the species , but molecular biological and morphological analyzes suggest that animals south and north of Japan could be different species and that this species could accordingly be two or more species.
Status, threat and protection
.jpg)
Due to the unclear taxonomy, the International Union for Conservation of Nature and Natural Resources (IUCN) does not classify it in a hazard category, but classifies it as unclear (data deficient). In order to enable a clear classification, further data should clarify whether it is one or more species and how these are related. The organization does not rule out the possibility that some of these potential species are endangered, primarily due to intensive fishing with longlines and the high level of noise in the whale habitats. According to the current state of affairs, fishing has only a minor influence on the species as a whole, as it is regional and the whales are not affected in large parts of the range. For individual populations that may receive species status, on the other hand, a reduction in stocks of more than 30% within the last three generations and thus a threat within the realm of the possible.
No estimates are available for the total population, but there are estimates for the population figures for numerous marine regions. The populations north of Japan are estimated at 4,000 to 5,000 animals, the populations south of Japan at around 14,000 animals. For the Philippines estimates are the Sulu Sea at about 7,500 animals, while in the Tanon Strait is only about 180 animals are estimated (according to Wang et al 2014. The Philippines only 2,200 animals). About 590,000 animals are estimated for the eastern tropical Pacific (according to Wang et al. 2014 this number is about 45,400 animals). In the area around Hawaii the estimates are around 8,900 animals (according to Wang et al. 2014 2,947 animals) and around 300 animals are said to live off the North American coast. In the Gulf of Mexico , the estimates are at least around 2,400 animals (according to Wang et al. 2014 3,450 animals) and around 31,100 animals of both pilot whale species are estimated for the western North Atlantic. According to the IUCN, the figures for the Pacific increased significantly in 1998 to 2000 compared to 1986 to 1990.
supporting documents
- ↑ a b c d e f J.Y. Wang, KN Riehl, SZDungan: Family Delphinidae (Ocean Dolphins); Short-finned Pilot Whale In: Don E. Wilson, Russell A. Mittermeier: Handbook of the Mammals of the World. 4. Sea Mammals. Lynx Edicions, Barcelona 2014; Pp. 517-518. ISBN 978-84-96553-93-4 .
- ↑ Globicephala macrorhynchus ( Memento of the original from February 25, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . In: Don E. Wilson , DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
- ↑ a b c d e f Globicephala macrorhynchus in the Red List of Threatened Species of the IUCN 2013.2. Posted by: BL: Taylor, R. Baird, J. Barlow, SM Dawson, J. Ford, JG Mead, G. Notarbartolo di Sciara, P. Wade, RL Pitman, 2008. Retrieved December 17, 2016.
literature
- JY Wang, KN Riehl, SZDungan: Family Delphinidae (Ocean Dolphins); Short-finned Pilot Whale In: Don E. Wilson, Russell A. Mittermeier: Handbook of the Mammals of the World. 4. Sea Mammals. Lynx Edicions, Barcelona 2014; Pp. 517-518. ISBN 978-84-96553-93-4 .
- Hadoram Shirihai, Brett Jarrett: Marine Mammals . Franckh-Kosmos, Stuttgart 2008, ISBN 978-3-440-11277-9 , pp. 78-81 .
- Mark Carwardine : Whales and Dolphins . Delius Klasing, Bielefeld 2008, ISBN 978-3-7688-2473-6 , p. 148-149 .
Web links
- Short-finned pilot whale in the FAO Species Identification guide: Marine Mammals of the World
- Globicephala macrorhynchus in the Red List of Threatened Species of the IUCN 2013.2. Posted by: BL: Taylor, R. Baird, J. Barlow, SM Dawson, J. Ford, JG Mead, G. Notarbartolo di Sciara, P. Wade, RL Pitman, 2008. Retrieved December 17, 2016.