Size comparisons

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(08-25-2019, 09:23 PM)chui_ Wrote: Hello all, I’ve largely stayed away from the online world of zoological discussion for the past couple of years but I occasionally browse through the forums. Since there was some discussion on topics which interest me in the previous few pages I thought I would help clarify some things especially since I’m seeing a lot of stuff from my old posts from the Carnivora forum being posted here.

(07-16-2019, 04:58 AM)peter Wrote: Reliable data say adult male jaguars of large subspecies are a bit longer than adult male leopards of large subspecies in head and body. Seen from the perspective of leopards, jaguars seem to be about 10% longer. In weight, however, the difference is outspoken. Male jaguars of large subspecies average 95-105 kg., whereas male leopards of large subspecies average 60-65 kg., maybe a bit more in some regions. Seen from the perspective of male leopards of large subspecies, male jaguars of large subspecies are at least 50% heavier.

In the skull department, the differences between adult male leopards of large subspecies (about 240-245 mm.) and adult male jaguars or large subspecies (about 290 mm.) also is significant (about 20%). Using the info we have (see above), one could say male jaguars of large subspecies, compared to male leopards of large subspecies, have relatively long skulls for their head and body length and be right.

Some points to consider since you bring up perspective.
 
Male leopards of around 60-65kg are pretty standard for many parts of the species range - most of Southern Africa, many parts of East Africa, most of western Asia, most of India, and probably some other regions from where we don’t have much data. Higher mean weights can probably be expected from the best areas (Northern Iran, Coastal Gabon, North/East Congo, Rift Valley highlands etc).
 
On the other hand, a 95-105kg jaguar would be a pretty big one for most of that species range. It’s only in 2 specific locations where male jaguars average within this range, the Pantanal and the Llanos. Both these areas are especially prey rich and jaguars in both also frequently hunt domestic cattle which provide easy meals. These largest of jaguars have had lots and lots of data recorded on their size – we have much more data on the size of Pantanal jaguars than those from other regions – even though they are the exception not the rule. The same is not true of data on the size of leopards (little data on weights has been recorded for what are probably the biggest leopards based on skull size).
 
I am in no way suggesting that leopards can match or approach the biggest jaguars in size and of course even the more typical male jaguars of around 80-85kg from much of South America still considerably outweigh the average 60-65kg male leopards from many parts of Africa and Asia. But comparing fairly standard (widely occurring) leopards with the pinnacle Pantanal jaguar as people often do exaggerates the difference. To put things in perspective, we could go to various different parts of Africa and Asia and find plenty of 60kg+ leopards but you're going to struggle to find 100kg+ jaguars outside the swamps and cattle ranches of the Pantanal and the Llanos (according to Tony Almeida 100kg would be an extreme weight for a jaguar outside the swamps). 

Quote:b - Skull photographs - a large male leopard and an average-sized male jaguar side by side 
 
In 2012, I visited the Staatliches Museum für Naturkunde Stuttgart twice. On both occasions, I was there for a week to measure and photograph skulls of big cats. Poster 'Wanderfalke', living close to Stuttgart, assisted when he had time. He's the one who made the photographs.
 
The Staatliches Museum had 7 jaguar skulls. All skulls belonged to wild jaguars. The 3 male skulls were from Surinam, Argentina and Bolivia. The skull from Surinam, although short and not as heavy as the others, had the most massive upper canines. In this respect, it compared to many lion and tiger skulls. I selected the Bolivian skull for the photograph, because it is the longest (279,27 mm.). 
 
As a result of a lack of time, I wasn't able to measure all leopard skulls. Of the 34 skulls I measured, 24 were male skulls. Of these, 12 belonged to leopards shot in what was then German East Africa (Tanzania today). The longest is 221,47 mm. in greatest total length. Of the 12 others, the skull of a leopard from the western part of Central Africa is the largest. That skull, collected a long time ago, has a greatest total length of 243,94 mm.
 
Here's a photograph showing the longest male jaguar skull (right) and the longest male leopard skull next to each other:
 
The skull of the male jaguar, missing a part of the right arch, is wider (188,34 mm. versus 149,51 mm.) and more elevated at the orbit (147,20 mm. versus 110,02 mm.). The rostrum is significantly wider as well (81,24 mm. versus 59,81 mm.). As a result, the skull of the male jaguar is almost twice as heavy (0,970 kg. versus 0,585 kg.). The skull of the male jaguar was cleaned (cooked), whereas the skull of the leopard was not. The real difference in weight, therefore, is even more outspoken. Most of the canines of the leopard, on the other hand, are missing. 
 
I have to add that the skull of the male leopard was heavier than all other leopard skulls, whereas the skull of the male jaguar wasn't the heaviest I saw. The skull from Argentina, although a bit shorter, was 0,997 kg.
 
Based on what I have, I'd say that skulls of leopards from the western part of Central Africa are more robust than skulls of leopards from other parts of Africa. They're a bit lower at the orbit, but often have relatively large mandibulas and heavy teeth.
 
Most unfortunately, I never saw leopard skulls exceeding 250 mm. in greatest total length in European natural history museums. They seem to be few and far between.

Interesting comparison Peter but your leopard skull is hardly representative of big male leopards. You may not have seen any, but there are numerous male leopard skulls recorded by scientific sources measuring 250mm or more in total length. From a total of around 200 or so adult male skulls from across the leopard’s range whose measurements have been documented, around 60 exceed the size of the skull you’ve used for your comparison. Such big skulls seem pretty standard for some areas. 

Here is a list I composed some time ago of the 20 biggest scientifically recorded leopard skulls (of about 17" or more total score) I was aware of. There are 2 additional skulls from Per Christiansen's data from his 2012 paper on the sexual dimorphism in smilodon and pantherine skulls - skull BM1958.11.20 from the London Natural History Museum which had a CBL of 236.9mm and ZW of 174.5mm, and also skull ZMB56448 from the Berlin Museum with CBL of 243.2mm and ZW of 166.4mm - both of these would have greatest lengths well over 250mm and total scores above 17" but I don't know their full details.

*This image is copyright of its original author

Quote:Luipaard said there is some overlap in the department of skulls. More accurately, he said exceptional skulls of male leopards living in regions where leopards grow to a large size could compare to skulls of average-sized male jaguars living in regions where jaguars grow to a large size.
 
The question is if he has a point. The answer is it depends on the perspective.
 
If we use elevation (height at the orbit), weight, zygomatic width, rostrum width and the length and diameter of the upper canines as indicators, the answer is no. If we use condylobasal and total length as indicators, the answer is yes. Exceptional leopard skulls can be as long as average-sized skulls of male jaguars living in regions with good conditions.

Have to disagree here, a look at published data suggests yes they can be comparable in those measurements, although in terms of canines and the rostrum just barely. Again, I am talking about the biggest/most impressive leopard skulls compared to similar sized adult male jaguar skulls. The main point to remember is that the leopard is more variable than the jaguar in its skull and overall morphology. 
 
The biggest leopard skulls can certainly compare with average adult male Pantanal jaguar skulls in terms of zygomatic width. The broadest leopard skulls from scientific sources (see the chart above) are over 180mm in width, the broadest is 191mm from Iran and 2 others from the Congo at 186mm (and additional 4 others also over 180mm). For comparison, 6 adult male jaguar skulls from the Pantanal measured by George Schallar ranged from 181 to 200mm in zygmatic width, with a mean of 188mm. 
 
Zygomatic width measurements from George Schallar's paper, Jaguar predation on capybara 1978.

*This image is copyright of its original author

 
In terms of skull weight, data is pretty limited to provide any indepth comparison but we know leopard skulls certainly get well over 595g. Peter Turnbull-Kemp recorded a weight of 1lb 15.75oz (900g) for a huge leopard skull and considered anything over 1lb 10oz (737g) as heavy. His figures refer to properly dried skulls. A huge skull (282x 182mm) from Gabon measured by both RI Pocock and Rowland Ward weighed 1lb 12oz (794g). This skull according to Pocock’s assessment was from an adult but not old specimen as it had unworn teeth and some sutures still present (skulls tend to get heavier and more massive with age). Male jaguar skulls will probably be heavier at similar overall size (length+width) in most cases but the available data suggests the biggest male leopard skulls can be comparable at around 900 grams.
 
Some info on the measurements of leopards from Peter Turnbull-Kemp's book, "The Leopard" 1967. Info on skull weight in the last paragraph.

*This image is copyright of its original author

 

In terms of canine diameter, a quick look at Pocock’s and J.A. Allen’s papers shows male leopard skulls with anterior-posterior canine diameters of up to 21mm. The greatest canine anterior-posterior diameter recorded by Pocock was from a huge leopard skull from Kigezi Uganda at 21mm. Allen recorded measurements of 20.4mm and 20.8mm for two male leopard skulls from DR Congo. For comparison, 6 adult male South American jaguar skulls ranged from 20.7 to 22.8mm in canine diameter and 5 Central American adult male skulls ranged from 18.4 to 21.4mm (From Nelson and Goldman's 1933 paper, Revision of the Jaguars). 
 
In terms of rostrum width, Persian leopards have the greatest measurements for leopards even compared to Central African skulls of similar or larger size. The single greatest I know of is 73.6mm from Iran, from unpublished data on Persian leopards.  The greatest from Africa are around 66mm. For comparison the 6 adult male South American jaguar skulls paper ranged from 68.2 to 80mm and 5 from Central America from 63.8 to 74.5mm (again from Nelson and Goldman's paper).

Nice to see carefully written postings. You mentioned in a way one aspect which has been missing all the time in this skull discussion and you did it by mentioning weight. I find it a bit disturbing, that all the time only with and length are compared, when talking about animals, which look as different as jaguars and leopards, when putting side by side. Skull is 3-dimensional, not 2-dimensional. 

So what is height difference is one key factor in this comparison, imo. What is volume of these skulls. Jaguars head usually looks clearly more robust when comparing to leopard.

Anyway very good if something new comes up and/or some issues can be cleared a bit. Reply