Have you ever seen black and white wolves hunt in the sea?
Wolves of the sea – Killer Whale/Orca (Orcinus orca)
It has been noted that in regions of ice, orcas (Orcinus orca) were observed to spyhop for seals and sometimes hit the ice from below to knock pinnipeds or penguins (Spheniscidae) into the water (Fraser, 1949).
Figure 1: 2 Orcas spot a potential meal
Figure 2: “Spyhopping”
Figure 3: “Wave” creation
Figure 4: “Waves” approaching the targeted Weddell seal (Leptonychotes weddellii)
The above figures show an interesting cooperative behavior known as the “Wave Wash”. They show how orcas combine forces to hunt a weddell seal (Leptonychotes weddellii). Communicating with the pod through infrasound and echolocation clicks (Breed and Moore,2011), they devise a game plan to “wave wash” the weddell seal off the ice floe. They execute this plan by swimming in perfect synchrony at a high speed, creating very forceful “waves” to sweep the hapless seal off the ice floe. Depending on the magnitude of the “waves”, the seal is pushed off or close to the edge of the ice floe.
Figure 5: Exhausted Weddell seal (Leptonychotes weddellii) dragged into the sea
Figure 5 shows an exhausted weddell seal dragged into the sea for consumption after numerous “wave washes”. To better understand this technique, refer to videos 1 and 2:
Video 1:
http://www.youtube.com/watch?v=hPge_0lea3o
Video 2:
Further to this, seven orcas were spotted washing a crabeater seal (Lobodon carcinophagus) off an ice floe in the Antarctic (Smith et al, 1981). Other harmonized feeding events have involved attacks on baleen whales where the prey was harassed from all sides (Hoelzel, 1991). These two observations show orcas hunting cooperatively. In fact, orcas live in matrilineal social groups known as pods (Breed and Moore, 2011) and these observations are examples of improved foraging, a benefit that they gain from living and hunting together.
This complex technique therefore showcases the orcas’ ability to solve problems and band together to hunt like a pack of wolves and this is why they are dubbed the “Wolves of the Sea” (Zimen, 1976).
In relation to the module content, the foraging behaviors of orcas can be said to be dependent on the type, number and size of prey (Heyning and Dalheim, 1988) as these intelligent mammals also adopt different strategies:
Video 3:
http://www.youtube.com/watch?NR=1&v=96yynCGST8U&feature=endscreen
Video 4:
Video 5:
http://www.youtube.com/watch?v=K9I_DcSbZjI
Video 6:
Sources and Citations:
A. Rus Hoelzel, 1991. Killer Whale Predation on Marine Mammals at Punta Norte, Argentina; Food Sharing, Provisioning and Foraging Strategy in Behavioral Ecology and Sociobiology, Vol. 29, No. 3, pp. 197-204. Springer
Fraser F,. C. 1949. Whales and dolphins in Field book of giant fishes (by J. R. Norman and F. C. Fraser), Pp. 201-349
John E. Heyning and Marilyn E. Dahlheim, 1988. Orcinus orca in Mammalian Species, No. 304, pp. 1-9. American Society of Mammalogists.
Michael D. Breed and Janice Moore, 2011. Communication in Animal Behaviour. Chapter 7, pp. 196
Smith TG, Siniff DB, Reichle R, Stone S, 1981. Coordinated behavior of killer whales (Orcinus orca) hunting a crabeater seal (Lobodon carcinphagus). Can J Zool 59: 1185-1189.
Zimen E, 1976. On the regulation of pack size in wolves. Z Tierpsy-chol 40: 300-341
Photo sources (in chronological order):
http://www.sailfeed.com/orca-uber-alles
http://www.telegraph.co.uk/earth/wildlife/8828768/Killer-whales-hunt-seals-by-creating-waves.html
http://www.sailfeed.com/orca-uber-alles
http://www.thesun.co.uk/sol/homepage/news/3876729/Fishing-for-killer-footage-br-on-our-frozen-planet.html
http://www.bbc.co.uk/nature/15308790
Video Sources (in chronological order):
http://www.youtube.com/watch?v=hPge_0lea3o
http://www.youtube.com/watch?v=AwbNRNCxhFg
http://www.youtube.com/watch?NR=1&v=96yynCGST8U&feature=endscreen
http://www.youtube.com/watch?NR=1&v=Z_n604BHvBQ&feature=fvwp
http://www.youtube.com/watch?v=K9I_DcSbZjI
http://www.youtube.com/watch?NR=1&v=DWsN63PRCW8&feature=endscreen
Video Sources (in chronological order):
“Killer Whales “Wave Wash” Seal” by Frozen Planet, 16 Mar 2012 URL: http://dsc.discovery.com/tv-shows/frozen-planet/videos/killer-whales-wave-wash-seal.htm (accessed on 5/4/2013)
“Orcas hunting seal on ice floe in Antarctica” by manfredthimme, 14 Dec 2009. (accessed on 5/4/2013)
“Wild Kingdom – Orcas Hunt King Penguins” by Animal Planet, 13 Dec 2010. URL: http://animal.discovery.com/tv-shows/wild-kingdom/videos/orcas-hunt-king-penguins.htm (accessed on 5/4/2013)
“Killer Whales vs. Minke Whales” by National Geographic, 29 Aug 2011. (accessed on 5/4/2013)
“Killer Whales vs. Great White Shark” by National Geographic, 4 Feb 2012. Posted by TropicVenom. (accessed on 5/4/2013)
“Killer Whales vs. Sea Lions” by National Geographic, 1 Oct 2007. (accessed on 5/4/2013)