The largest recorded Orca

[GuateGojira]

(02-25-2015, 11:27 PM)'Pckts' Wrote: You can never say what a wild animal can weigh at their maximum. There are 1000s that will never be measured or even seen. In captivity you can monitor the animal for its entire life, you know how old it is, you can compare it to others, weigh it with relative ease, etc. In the wild you can't just capture the biggest orca in the sea and weigh it, its impossible. A captive animal will never be as larger as a wild counterpart. As heavy, maybe, but obese for sure. A wild animal will always be more physically fit, stronger, faster and most likely larger. That goes for big cats as well, look how close the averages are between captive and wild animals. Yet the captive are fat, at least most of them compared to the wild animals. Its always going to be like that, and the same rule applies. You cant just capture and weigh the largest big cat in the wild at the prime of his life, it just doesn't happen but you can with a captive animal.


 

Pckts, I appreciate your comment, but you are mixing things here.

You are using the "old" excuse of the Cryptozoologist about the sea. Yes, the sea is huge, but from many, "many" killed animals in centuries, the largest orca recorded "reliably" was of less than 10 meters and between 8-9 tons (one scientific sources quote a weight of 10.5 tons, but no reference is presented). Most of the largest ecoptypes of orcas average about 7 meters, with the largest specimens reaching 8 to 9 m (Pitman et al. 2007). There are smaller ecotypes, but like I mentioned in my first posts, we are discussing on the largest orcas, so only the largest specimens should be investigated.

Also, the logic about the "wild vs captive" is incorrect. Captive animals are normally heavier than wild counterparts. For example, the largest wild tigers and lions are not as heavy than they largest captive brothers. The same goes with elephants, giraffes, gorillas, etc. etc. etc, check Wood (1977) about the differences. This apply to land animals, and as far I know, there is no scientific document suggesting that the contrary is the "rule" in the marine mammals. I don't discard the possibility on sea, but qualified it as a "rule" is simply incorrect at this point. 

In the wild, a large agile orca will have more possibilities to survive than a fat one like Tilikum. An interesting fact about the orcas hunting large prey, when the pod attack a large whale, the smaller females, not the males, are the one that makes most of the kill and only, in the final stage, when they are finishing the prey, the males enter and with they weight, drown the large cetaceans.

Clauset (2012) created a document where he observed body masses for all extant cetacean species and are predicted, with no tunable parameters, by a macroevolutionary tradeoff between short-term selective advantages and long-term extinction risks from increased species body size. In table one, he presented some weights for orcas, check it out:

Species mass  (kg)     primary source (reference)
Orcinus orca    4300   Smith et al. (2003) .
Orcinus orca    8750   Jefferson, Leatherwood, Webber (1993) .
Orcinus orca    4685   Culik (2004) .
Orcinus orca    7050   Perrin, Zubtsova, Kuzmin (2004) - reported mass mean of 2 specimens

I guess these are real weights from wild specimens, and if this is correct, we could guess that wild orcas, in fact, DO weight more than the captive specimens. This seems to be supported by my comparison between "Old Tom" and Tilikum, which at the same length, the heavier was the wild one (sadly, some poster ignored this comparison for unknown reasons). However, I most ask again if these weights are from wild specimens or if they are real weights and not estimations. I think is fair to ask about it.
 

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