Showing posts with label Giant Trevally. Show all posts
Showing posts with label Giant Trevally. Show all posts

Monday, August 31, 2020

GTs vs Sharksuckers - Paper!

 
Remember this post?
 
That was not the only observation by far.
This never before described novel hunting technique probably started as an attempt by a single innovative Giant Trevally, only to be quickly adopted by the the whole gang of miscreants. At its apex in late 2011, the 15m Take-out had become a veritable gauntlet, with dozens of GTs targeting the Sharksuckers whenever a Bull would come in for a feed. The Trevallies would wait in front of the feeder and then follow the Shark throughout the feeding area, only to then return to the starting point in order to intercept the next approaching Bull.
Of interest, not all caught Sharksuckers would perish as some would manage to latch on to the attacker,  only to then jump back onto a passing Bull Shark - click on the the pic at the top.
 
It however all ended at year end.
When the Bulls get ready for pupping and mating and are less interested in our bait, we relocate the feed to 25m where the topography is completely different and the trajectory of the feeding Bulls is much less predictable. And then most of the Bulls leave for 4-5 weeks, and the few who remain feed way less, thus further greatly reducing the predation opportunities of the GTs.
Whether it was the above and the Trevallies lost interest, or whether the individual Sharksucker-hunting GTs moved away or were fished: the fact is that we've never witnessed that behavior again.

But we had plenty of footage.
Here's a quick-&-dirty little iMovie edit of some memorable moments. Yeah I know the slo-mo kinda sucks - but you get the gist and I promise that I'll post something better later on.


And now Juerg has also written the paper - finally!
On top of the above story, it also describes other really interesting observations of Sharksuckers at Shark Reef and other Shark provisioning sites in Fiji.
Press release here, additional clips here.

Enjoy Juerg's paper!  

Friday, October 27, 2017

Bird-eating GTs - Video!

Source.

This is beyond awesome.
Latest since that paper, I knew that those GTs are totally badass - but seeing this, along with the unbelievably spectacular footage and the awesome editing simply leaves me in total awe!
And yes this would obviously be the BBC - who else!

H/T Serena - enjoy!



Saturday, August 18, 2012

Giant Trevally - lethal!

Giant Trevally at Shark Reef - pic by Daniel.

Ever wondered why the GTs have that big head?
No, probably not for dominance fights like the Bumphead Parrots.

This may be one possible reason.
At least in Palau, they have been observed to attack and kill Sharks all the way to good-sized Tigers (!) by repeatedly, and incredibly persistently head-butting them on the area right behind the pectoral fins.

Paper here
Read it, it describes in minute detail how a GT attacked and killed two Blacktips, and then one hour-long lethal attack on a 3m Tiger Shark.
Absolutely fascinating stuff!

Monday, March 14, 2011

More Shenanigans by the GTs!

We got ourselves a thief!

As you know we collect discarded Bull Shark teeth.
We had high hopes that they would shed light on the Sharks' exposure to fresh water but the results have been inconclusive and we've abandoned collecting them for science, the more as we continue to collect proper tissue samples for Mahmood's DNA forensics. Still, the Shark teeth remain a very hot commodity among our staff who hand them to selected customers, a rather clever strategy that may possibly translate into better tips but above all, into radiant smiles from the grateful pretty tahines.

Thing is, as of recent, the teeth supply has been disappointing.
Having suspected some kind of thievery, we've decided to install video surveillance - and BINGO : we've been finally able to capture the perpetrator in flagrante - yes it's none other than the murderer of those poor Sharksuckers, or possibly one of his equally sleazy cousins!
Check it out - click for detail.

TOTALLY busted!

A friend, incidentally one of the above mentioned tooth-owning tahines writes Why they would eat a shark tooth? Can they digest the tooth? The tooth is really sharp as well, I was playing with one and I still have the cut on my finger. Does it not cut the trevally's intestines?
Yes it probably will, especially one of those upper serrated teeth as the one depicted!
Talk about instant retribution!

Serves them right for f... with the BAD boys!

Tuesday, March 08, 2011

Predation!


From today's Shark diving footage.
In case you didn't know it: Giant Trevally are very much awesome predators in their own right that will jump at any opportunity - which is why all of our clients have to wear dark gloves lest the ever greedy Fish will nail their hands!
As Wikipedia tells us, the species has some quite novel hunting strategies including following monk seals and stealing prey that is stirred up, as well as using sharks to ambush prey - q.e.d.!!!
Is this cool, or what!!!

Click for detail.