The strongest bites in the animal kingdom

[Balam]

I'm seeing people constantly misrepresenting what BFQ means, alluding that the well-established and scientifically agreed-upon notion that jaguars have the strongest bite force among the big cats p4p is a "myth". People are using Wroe's second 2007 paper on bite force equations discussed here before: BITE FORCES AND EVOLUTIONARY ADAPTATIONS TO FEEDINGECOLOGY IN CARNIVORES, and completely misrepresenting what the data means and the nuance that comes with it.

As was pointed out here before, Wroe's 2007 paper did NOT use any proper estimation model to gauge the body mass of the specimens utilized for his table based on their skulls, he used literature weights that may or may have not been the accurate body mass of the animals involved in this study during their lives:

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In the case of jaguars, the body mass assumed for their calculations was 95.5 kg, and the BFQ was one of the lowest among the pantherines when factoring for the biteforce assumed in Newtons, despite the fact that jaguar skull anatomy is specialized in areas that are crucial to eject large amounts of pressure when biting, especially at the carnassials as I'll show in a second:

*This image is copyright of its original author

We actually have more data on similar calculations for the estimated bite force in jaguars, but this time divided by population which would offer us a better and more detailed look. From the study: Bite force and jaw stress in the jaguar (Panthera onca) during predation of the peccaries (Artiodactyla: Tayassuidae) by fracture of its skulls, by Del Moral et al. (2011).


Abstract:

One of the most effective ways of the jaguar’s predation (Panthera onca) is the application of bite force at the neurocranium of peccaries, one of its main natural preys, causing highly compressive stress that becomes fracture with its back a quick killing. In the present study were analyzed by the method of dry skull, 15 adult jaguar’s skulls moreover completing craniometrical measures with reported data in the literature belonging to different subspecies or phenotypes of this species’ distributional range, to obtain its maximum bite’s force canines and carnassials moreover of the cutting efforts and maximum flexor moments along the jaw. The resolution of these variables in a hiperestaticity structure is achieved through the Moment Distribution Method by Cross. After correlated the maximum bite forces of the jaguar and its action in the cross section of the neurocranium of Pecari tajacu, Tayassu pecari and Catagonus wagneri by Cremona method to obtain the internal stress for before skull fracture. It was found that jaguar’s maximum canine bite force is of 681.56 Newton and in the carnassials line is still 3 times most compressive. These forces are sufficiently high to cause fracture of a rigid structure as is the neurocranium’s triangular section of the peccaries. Moreover the jaguar’s robust canines resist the bending forces applied by struggling prey and a wider muzzle helps to stabilize grip and distribute bite forces more evenly during the killing bite.

*This image is copyright of its original author

If we compare the above table which divides jaguars by populations and just like Wroe use literature weight to infer their body mass to biteforce correlation in Newtons, we find out that the strength in the bite of jaguars at the carnassials in this comprehensive study is significantly greater than the value deducted by Wroe in his 2007 paper. 

Wroe calculated a BF of 1361.2 at the carnassials for a jaguar with a (literature average) body mass of 95.5 kg, in contrast, if we use Hoogesteijn and Mondolfi's average of 99.5 kg for the nominal population of Pantanal jaguars (P. onca palustris), we see that the discrepancy in biteforce is major despite the minuscule difference in average weight: 2360,96 vs 1361,2. This is in fact higher than both the lion and tiger's BF calculations at the carnassials according to Wroe's study as well.

The discrepancy grows even larger when we factor in the bite force of the jaguars from northeastern Mexico (P. onca veraecrucis) who have a body mass that seldomly surpasses 60 kg, and where we can assume an average of 55 kg per literature data as well. The bite force at the carnassials for this population was 2320, nearly as strong as those from the Pantanal and once again stronger than lions and tigers and significantly greater than that of leopards, who for Wroe's study had a similar assumed body mass of 55 kg and BFcarn of 964.4. Meaning that at similar assumed body masses, the jaguar had a BFcarn more than twice as strong compared to the leopard.

The only area where Del Moran and Wroe data aligns is in the BFca, which is to be expected as the jaguar's short rostrum and wide zygomatic arches would transfer most of the biting pressure to the back of the skull rather than the front. Other than that, the bite forces of jaguars significantly surpass that of other big cats on a p4p and often times absolute basis. The myth that they have the weakest bite force among the pantherines which some fanboys on other sites are spreading can end right now. Reply