Comparing Cats: A Discussion of Similarities & Differences

[Pckts]

(03-13-2021, 03:03 AM)tigerluver Wrote: The leopard and jaguar debate has brought some nice sources and information but please do not attack on another.

In trying to figure out if that large Persian leopard skull is of that weighed specimen, I noticed that can't be the case as the skull is from 1990 and the weighed specimen from 1997 going by the figure captions.

*This image is copyright of its original author

*This image is copyright of its original author

The excerpt is written unclearly but the figure captions seem to clarify.


Interspecific comparison of skull lengths to estimate weights is also filled with error and should not be used to determine which species is heavier. For instance, lions have proportionately longer skulls for their weight. Here is some data from Mazak et al. (see attachment) we can look at nonetheless to compare the jaguar and leopard:

  BM     CBL      Species
  47.3   219.8   Panthera onca CN5659 (♀)
  67.4   229.7   Panthera onca CN5660 (♂)
  51.5   222.4   Panthera onca CN5707 (♀)
  71.0   246.6   Panthera onca CN6221 (♂)
  56.7   188.2   Panthera pardus CN5661 (♀)
  57.9   210.1   Panthera pardus CN5662 (♂)
  44.5   199.7   Panthera pardus CN8462 (♂)


We should probably compare male to male and female to female, separately.

Average male jaguar has CBL of 238.15 mm and weight of 69.2 kg. Average male leopard has CBL of 204.9 mm and weight of 51.2 kg. We can now test by isometry which animal has a longer skull for its weight. If the below equation overestimates the larger skull, the shorter skulled animal has a proportionately shorter skull for mass (higher mass to skull length ratio) and vice versa.:

Jaguar predicted weight = (Jaguar skull length/Leopard skull length)^3 * Leopard weight
Jaguar predicted weight = (238.15 mm/204.9 mm)^3 * 51.2 kg
Jaguar predicted weight = 80.4 kg

Actual weight of the jaguars we had was 69.2 kg, so 16% overestimation. By this, the male leopard actually has a smaller skull for its weight and thus at equal skull lengths would actually be heavier than the male jaguar. 

For females, this math isn't necessary as the female jaguars have an average CBL of 221.1 mm and average weight of 49.4 kg while the single female leopard has a CBL 188.2 mm with weight of 56.7 kg. 

Just because the sample is so small here is a calculation pooling both genders:
Avg. jaguar CBL: 229.63 mm; Avg. weight: 59.3 kg
Avg. leopard CBL: 199.33 mm; Avg. weight: 53.3 kg

Jaguar predicted weight = (Jaguar skull length/Leopard skull length)^3 * Leopard weight
Jaguar predicted weight = (229.63 mm/199.33 mm)^3 * 53.3 kg
Jaguar predicted weight = 81.5 kg

The actual averaged weight of the jaguars we had was 59.3 kg, so 37% overestimation. By this extremely small sample size, the leopard actually has a smaller skull for its weight and thus at equal skull lengths would actually be heavier than the jaguar by quite a bit. The oddly heavy female leopard is the reason why the discrepancy jumps so much here.

Again the sample is extremely small and the specimens are captive, so I'm not confident in the results. I'd love to see if people have more body dimension to skull length data.

Condylobasal Length can be inaccurate compared to Total Length. Sometimes larger or smaller skulls can have equal or different CBL's in comparison that you wouldn't expect. 
And like you said, such a limited sample size from captive cats isn't going to shed much light. Especially when no distinction between cats age, health or subspecies is specified. 
I can present plenty of Jaguars total skull length to body mass though if that helps? Reply