Navigation Links
Great white sharks
Date:4/10/2013

MIAMI April 9, 2013 Many terrestrial animals are frequently observed scavenging on other animals whether it is a hyena stealing a lion kill in the Serengeti or a buzzard swooping down on a dead animal. However, documenting this sort of activity in the oceans is especially difficult, and often overlooked in marine food web studies.

In a new study published in PLOS ONE titled, "White sharks (Carcharodon carcharias) scavenging on whales and its potential role in further shaping the ecology of an apex predator," Captain Chris Fallows from Apex Expeditions collaborated with University of Miami (UM) scientists Dr. Neil Hammerschlag and Austin Gallagher, to explore the behaviors of Great white sharks scavenging on dead whales in South Africa. The team documented as many as 40 different sharks scavenging on a carcass over the course of a single day, revealing unique social interactions among sharks.

The study summarized observations based on four scavenging events opportunistically observed over a 10 year period. In each multi-day observation, the team recorded daily evidence of social, aggregative and feeding behaviors observed in the waters off South Africa. They suggest that although the occurrence of coming upon a whale carcass may be sporadic, the shark populations are likely prepared to scavenge on them, and may even rely on their scavenging activities to supplement their regular feeding activities.

"Although rarely seen, we suspect that as white sharks mature, scavenging on whales becomes more prevalent and significant to these species than previously thought," said Hammerschlag, who is director of the R.J. Dunlap Marine Conservation Program at UM.

The team found that sharks showed a clear preference for scavenging on the blubber, probably because these high calorie meals can sustain the sharks for longer periods of time. Interestingly, though, the study also found that sharks showed an initial preference for feeding on the whale's fluke before moving on to feed on the rest of the carcass. The team also found that while scavenging on whales, they ceased hunting and feeding on seals, one of their primary natural prey.

"While scavenging on the whale, the sharks clearly showed a size-based pecking order," said Fallows. "The biggest sharks came right in, targeting areas of highest blubber content, while smaller sharks fed on areas with less blubber or kept their distance from the whale, mostly scavenging on pieces of blubber that drifted away from the carcass."

The paper reveals how the social and size structure of sharks at the carcass appeared to be influenced by environmental patterns. "The cues, such as the oils, emanating from this pulse of food are likely attracting much larger sharks over 4.5 meters from long distances to scavenge," said Gallagher. "These data provide some credence to the hypothesis that large white sharks may be swimming known ocean corridors looking for dead, dying, or vulnerable whales."

"By attracting many large white sharks together to scavenge, we suspect that the appearance of a whale carcass can play a role in shaping the behaviors, movements, and the ecosystem impacts of white sharks" said Hammerschlag. "These patterns may shed some light into the ecology of this often studied - yet still highly enigmatic - marine predator."


'/>"/>

Contact: Alexandra Bassil
a.bassil@miami.edu
305-284-1092
University of Miami
Source:Eurekalert

Related biology news :

1. Asian carp DNA not widespread in the Great Lakes
2. Notre Dame study finds Asian carp DNA not widespread in the Great Lakes
3. Obama calls Ben-Gurion U. brain research a great idea
4. Are survivors of childhood leukemia and lymphoma at greater risk of chronic fatigue as adults?
5. Paving the way for greater use of ancient medical knowledge
6. Speech emerges in children with autism and severe language delay at greater rate than thought
7. Environmental threat map highlights Great Lakes restoration challenges
8. Mapping effort charts restoration tack for Great Lakes
9. Grant furthers Mercyhurst research for human pathogens in Great Lakes
10. Notre Dame research reveals migrating Great Lakes salmon carry contaminants upstream
11. University of Michigan, Michigan State University award grants for Great Lakes climate change research
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/11/2016)... LIVERMORE, Calif. , Feb. 11, 2016  Vigilant Solutions ... commercial LPR data are being used by Lee,s ... residents, including the recent location and arrest of a homicide ... Lee,s Summit covers around 65 square miles and ... Police Department has a single mobile license plate ...
(Date:2/9/2016)... Aware, Inc. (NASDAQ: AWRE ), a leading supplier of biometrics ... and year ended December 31, 2015.  --> ... was $6.9 million, an increase of 61% compared to $4.3 million ... quarter of 2015 was $2.6 million compared to $0.2 million in ... --> Higher revenue and operating income in the fourth ...
(Date:2/8/2016)... 2016 Worldcore is ... innovation for clients, comfort and unbeatable security, with ... --> Worldcore is the first EU-regulated ... comfort and unbeatable security, with a Voice Biometrics ... Worldcore is the first EU-regulated global payment ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... Florida , February 11, 2016 ... PositiveID Corporation ("PositiveID" or "Company") (OTCQB: PSID), a ... announced today that its Thermomedics subsidiary, which markets ... on its growth plan in January 2016, including ... distributors, increasing sequential monthly sales growth, and establishing ...
(Date:2/11/2016)... MIAMI (PRWEB) , ... February 11, 2016 , ... ... in regenerative medicine, has announced a new agreement with Bankok,Thailand-based Global Stem Cells ... researchers and phsyicians in 15 Latin American countries, including Mexico, Costa Rica, Dominican ...
(Date:2/10/2016)... , February 10, 2016 Early-career researchers ... , Peru , Uganda and ... life-enhancing work in health and nutrition   Indonesia ... Uganda and Yemen are being ... and epidemiology. They are also celebrated for mentoring young women scientists who ...
(Date:2/10/2016)... ASAE is introducing a hybrid membership model which will ... of joining or renewing through an organizational purchasing model. ... every employee in any size association or AMC office ... member benefits.   John H. Graham, IV ... allow organizations of any size and their employees to ...
Breaking Biology Technology: