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02-19-2021, 09:29 PM( This post was last modified: 07-23-2021, 10:18 PM by Balam )
FULL COMPILATION OF MODERN WEIGHTS FOR JAGUARS IN FOUR POPULATIONS
Over the past months, we have gathered a total of 184 weights of jaguars that have been published over the past years. We've compiled the weights of four populations: the Pantanal which has by far the most data on captures of any jaguar population, and three other populations that did not have public data released on their weights (except for one published paper on Cerrado jaguars by IOP). Other populations such as the Llanos, Central and North America, and the Amazon have had a great body of work released in the past concerning jaguar captures and weights, while recent captures have been few or null, thus lacking the required data to compile enough information on them.
In terms of jaguars from the Cerrado, data on females is greatly lacking, so the data on males was the only one able to be comprised into a table at the moment.
I'm sure we will continue to receive new information as captures are performed continuously and the tables will be adjusted accordingly, but this should suffice for now a good compilation of data for anyone interested in jaguar morphology and size variations in recent times. PANTANAL (n:123)
I've made this comparative image as a guideline of jaguar morphology and groupings based on the biome they inhabit. I've seen many people confusing biomes and jaguars from different places, or grouping populations in size classes with other populations that don't belong together, hopefully this will help.
Comments:
The SH of jaguars from tier B is taken from one male of 110 kg captured in Porto Primavera, a seasonally flooded area between the Cerrado and At Forest that doesn't belong to either eco-region. In theory, this area would be placed in tier A but since it is so small and by now it has been completely lost due to anthropogenic factors I'm basing the maximum SH recorded in this area for jaguars from tier B who are the closest in proximity and similar maximum weight (P. Crawshaw).
Jaguars from the Yungas do not have any recorded weight so far, they are placed under tier C due to them belonging to a similar biome as the other eco-regions, but based on estimates from the team of Red Yaguarete, these jaguars could likely be slightly larger than those form tier C in averages and maximums thanks to the preservation of their habitat.
Maximum SH estimates for tiers C to E follow the same statistical trend as those from tier A.
From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
(05-19-2021, 06:03 PM)Balam Wrote: From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
(05-19-2021, 06:03 PM)Balam Wrote: From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
I have a hard time believing that prey base could produce larger Jags than the wetlands.
I'm not sure if they meant fossil records pertaining to Holocene jaguars or Pleistocene ones, we know the Pleistocene Patagonian forms were much larger than extant jaguars. Before the European settlements in Argentina and Chile there were millions of guanacos prowling the steppes of the Patagonia, I think prey like that is large enough to sustain really big cats. Guanacos extended all the way through the dry Chaco but most of the Chacoan guanacos have gone extinct, this is also another one of the reasons why Chacoan jaguars grew so big, we know they average around 95 kg today but I think they were even larger a few centuries ago
(05-19-2021, 06:03 PM)Balam Wrote: From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
I have a hard time believing that prey base could produce larger Jags than the wetlands.
I'm not sure if they meant fossil records pertaining to Holocene jaguars or Pleistocene ones, we know the Pleistocene Patagonian forms were much larger than extant jaguars. Before the European settlements in Argentina and Chile there were millions of guanacos prowling the steppes of the Patagonia, I think prey like that is large enough to sustain really big cats. Guanacos extended all the way through the dry Chaco but most of the Chacoan guanacos have gone extinct, this is also another one of the reasons why Chacoan jaguars grew so big, we know they average around 95 kg today but I think they were even larger a few centuries ago
My doubt comes from the hunting styles. I think the marshland style of hunting is going to give Jaguars their best specimens. They don’t seem to produce as impressive sizes when elevated terrains come into play. Their morphology isn’t as suited for the rocky terrain in comparison to explosive bursts of power from the waters edge.
(05-19-2021, 06:03 PM)Balam Wrote: From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
I have a hard time believing that prey base could produce larger Jags than the wetlands.
I'm not sure if they meant fossil records pertaining to Holocene jaguars or Pleistocene ones, we know the Pleistocene Patagonian forms were much larger than extant jaguars. Before the European settlements in Argentina and Chile there were millions of guanacos prowling the steppes of the Patagonia, I think prey like that is large enough to sustain really big cats. Guanacos extended all the way through the dry Chaco but most of the Chacoan guanacos have gone extinct, this is also another one of the reasons why Chacoan jaguars grew so big, we know they average around 95 kg today but I think they were even larger a few centuries ago
My doubt comes from the hunting styles. I think the marshland style of hunting is going to give Jaguars their best specimens. They don’t seem to produce as impressive sizes when elevated terrains come into play. Their morphology isn’t as suited for the rocky terrain in comparison to explosive bursts of power from the waters edge.
At elevated terrains jaguars definitely appear just as stocky, in this case, the Yungas is the only eco-region left where jaguars inhabit high altitudes albeit still lower than the Andes, both jaguars and cougars from this area appear particularly stocky to me:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
This trend seems to be consistent among felids in general, Barbary lions were thought to have been lower at the shoulder and more robust than their Sub-Sharan savanna counterparts, northern Indian and Nepalese tigers are probably the most robust tiger eco-types, and Persian leopards appear more stocky than their savanna counterparts as well. Usually, big cats become less robust in the environments where they live a more cursorial lifestyle, IMO in this case Llanos jaguars appear to show a lighter build but with a larger body frame, akin to a lion:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
It's all speculative but they do give me that impression. In regards to the morphology of the now-extinct Patagonian jaguars, my guess is that they would've been very stocky like the Yungas specimens but greater in size. It's such a shame we've almost lost all information concerning these jaguars as they were hunted very rapidly during the initial European settlements, it would've been super interesting to see what that jaguar eco-type would've looked like, but I don't doubt it was big.
(05-19-2021, 06:03 PM)Balam Wrote: From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
I have a hard time believing that prey base could produce larger Jags than the wetlands.
I'm not sure if they meant fossil records pertaining to Holocene jaguars or Pleistocene ones, we know the Pleistocene Patagonian forms were much larger than extant jaguars. Before the European settlements in Argentina and Chile there were millions of guanacos prowling the steppes of the Patagonia, I think prey like that is large enough to sustain really big cats. Guanacos extended all the way through the dry Chaco but most of the Chacoan guanacos have gone extinct, this is also another one of the reasons why Chacoan jaguars grew so big, we know they average around 95 kg today but I think they were even larger a few centuries ago
My doubt comes from the hunting styles. I think the marshland style of hunting is going to give Jaguars their best specimens. They don’t seem to produce as impressive sizes when elevated terrains come into play. Their morphology isn’t as suited for the rocky terrain in comparison to explosive bursts of power from the waters edge.
At elevated terrains jaguars definitely appear just as stocky, in this case, the Yungas is the only eco-region left where jaguars inhabit high altitudes albeit still lower than the Andes, both jaguars and cougars from this area appear particularly stocky to me:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
This trend seems to be consistent among felids in general, Barbary lions were thought to have been lower at the shoulder and more robust than their Sub-Sharan savanna counterparts, northern Indian and Nepalese tigers are probably the most robust tiger eco-types, and Persian leopards appear more stocky than their savanna counterparts as well. Usually, big cats become less robust in the environments where they live a more cursorial lifestyle, IMO in this case Llanos jaguars appear to show a lighter build but with a larger body frame, akin to a lion:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
It's all speculative but they do give me that impression. In regards to the morphology of the now-extinct Patagonian jaguars, my guess is that they would've been very stocky like the Yungas specimens but greater in size. It's such a shame we've almost lost all information concerning these jaguars as they were hunted very rapidly during the initial European settlements, it would've been super interesting to see what that jaguar eco-type would've looked like, but I don't doubt it was big.
Camera trap photo's are difficult to determine but we know that these Jaguars shown aren't in the Pantanal/Llanos weight class.
Cougars are a different case, they should thrive in elevated terrain since their morphology contributes to a better suited cat for that habitat. Long legs with a lighter frame allows them to chase prey in deep snow or uneven ground while a Jaguar being very stocky with short limbs and a long body doesn't seem as suited for that. Not to mention the hunting style of land mammals vs semi aquatic animals. I think the marshland is just the perfect habitat for Jaguars and it shows in their size, they've always been quoted as being the largest in these areas no matter how far back we go when eye witness accounts are involved.
In regards to other felines, as of now Barbary Lions have shown no difference in morphology, at least off the minimum data we have and N. Indian Tigers may or may not be larger than their C. or S. Indian counter parts but the weights and measurements we have now all overlap considerably. In fact, possibly the largest Lions and Tigers alive today come from wet habitats. (Delta and Kaziranga) with notable mentions from the Crater and Terai Arc.
Like you said, it's all speculative and Bergmans law contributes to larger cats but it's not the only landscape that does.
The following 1 user Likes Pckts's post:1 user Likes Pckts's post • peter
(05-19-2021, 06:03 PM)Balam Wrote: From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
I have a hard time believing that prey base could produce larger Jags than the wetlands.
I'm not sure if they meant fossil records pertaining to Holocene jaguars or Pleistocene ones, we know the Pleistocene Patagonian forms were much larger than extant jaguars. Before the European settlements in Argentina and Chile there were millions of guanacos prowling the steppes of the Patagonia, I think prey like that is large enough to sustain really big cats. Guanacos extended all the way through the dry Chaco but most of the Chacoan guanacos have gone extinct, this is also another one of the reasons why Chacoan jaguars grew so big, we know they average around 95 kg today but I think they were even larger a few centuries ago
My doubt comes from the hunting styles. I think the marshland style of hunting is going to give Jaguars their best specimens. They don’t seem to produce as impressive sizes when elevated terrains come into play. Their morphology isn’t as suited for the rocky terrain in comparison to explosive bursts of power from the waters edge.
At elevated terrains jaguars definitely appear just as stocky, in this case, the Yungas is the only eco-region left where jaguars inhabit high altitudes albeit still lower than the Andes, both jaguars and cougars from this area appear particularly stocky to me:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
This trend seems to be consistent among felids in general, Barbary lions were thought to have been lower at the shoulder and more robust than their Sub-Sharan savanna counterparts, northern Indian and Nepalese tigers are probably the most robust tiger eco-types, and Persian leopards appear more stocky than their savanna counterparts as well. Usually, big cats become less robust in the environments where they live a more cursorial lifestyle, IMO in this case Llanos jaguars appear to show a lighter build but with a larger body frame, akin to a lion:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
It's all speculative but they do give me that impression. In regards to the morphology of the now-extinct Patagonian jaguars, my guess is that they would've been very stocky like the Yungas specimens but greater in size. It's such a shame we've almost lost all information concerning these jaguars as they were hunted very rapidly during the initial European settlements, it would've been super interesting to see what that jaguar eco-type would've looked like, but I don't doubt it was big.
Camera trap photo's are difficult to determine but we know that these Jaguars shown aren't in the Pantanal/Llanos weight class.
Cougars are a different case, they should thrive in elevated terrain since their morphology contributes to a better suited cat for that habitat. Long legs with a lighter frame allows them to chase prey in deep snow or uneven ground while a Jaguar being very stocky with short limbs and a long body doesn't seem as suited for that. Not to mention the hunting style of land mammals vs semi aquatic animals. I think the marshland is just the perfect habitat for Jaguars and it shows in their size, they've always been quoted as being the largest in these areas no matter how far back we go when eye witness accounts are involved.
In regards to other felines, as of now Barbary Lions have shown no difference in morphology, at least off the minimum data we have and N. Indian Tigers may or may not be larger than their C. or S. Indian counter parts but the weights and measurements we have now all overlap considerably. In fact, possibly the largest Lions and Tigers alive today come from wet habitats. (Delta and Kaziranga) with notable mentions from the Crater and Terai Arc.
Like you said, it's all speculative and Bergmans law contributes to larger cats but it's not the only landscape that does.
That's not my point, jaguars from the Yungas are likely smaller than Pantanal/Llanos ones, I was referring to what their morphology entails in terms of robusticity, they're just as robust IMO. Jaguar weights we know are completely dependant on the prey biomass of the biomes they live in which is why they grow so big in the flooded savannas, but in certain higher terrain areas where they used to inhabit and had access to very large and plentiful ungulate prey like Patagonia and the certain parts of the US (post-Pleistocene), jaguars could've grown very large as well, as detailed by writings from centuries ago. My comparison with other species is also related to this area of stockiness, I actually don't subscribe to Bergmann's rule because it is not consistent throughout, to me it's clear that genetic diversity and proper nutrition during developmental years are the key factors in the overall body mass of different felid populations.
For example, jaguar from northern Mexico and southern Arizona are among the smallest as their main prey are coatis and collared peccaries, the moment these jaguars get reintroduced in areas of central or northern Arizona where elk are found, they will progressively increase in size with each generation and become more robust as well.
The following 1 user Likes Balam's post:1 user Likes Balam's post • peter
(05-19-2021, 06:03 PM)Balam Wrote: From my subreddit r/jaguarland, a really nice poster gave more background on the past distribution of jaguars in Argentina during the Holocene, going as far as places in the high Andes such as Nahuel Huapi.
It is known that the jaguar inhabited the pampas and even the Patagonian steppe canyons, there are also mentions in the Limay river in the Nahuel Huapi National Park, in fact the name Nahuel Huapi translates as Isla Jaguar, the sightings of jaguars in Patagonia by part del European settlers reach the Magellan Channel, unfortunately there are not so many records pertaining to the campaigns of Argentina and Chile further south of the Chubut River. According to descriptions, the jaguars in this region were quite large and the fossil record supports this idea It is estimated that the Patagonian Jaguars were larger than those of the Pantanal . The prey that the Jaguar could find in Patagonia are Rheas, Guanacos, Andean Deer, also the Deer of the Pampas that came to inhabit the north of Santa Cruz in the past and the Patagonian Mara that although it is smaller and faster than the Capybara It is still a good appetizer. Otters, Armadillos, Penguins, Land Turtles, Sea Lions and Seals could also be a good prey and it is known that collared peccaries inhabited northern Patagonia. Of course, you should share these prey with the Puma and the Culpeo Fox, although with the Puma they are generally nice and the Culpeo is not a direct competitor.
I have a hard time believing that prey base could produce larger Jags than the wetlands.
I'm not sure if they meant fossil records pertaining to Holocene jaguars or Pleistocene ones, we know the Pleistocene Patagonian forms were much larger than extant jaguars. Before the European settlements in Argentina and Chile there were millions of guanacos prowling the steppes of the Patagonia, I think prey like that is large enough to sustain really big cats. Guanacos extended all the way through the dry Chaco but most of the Chacoan guanacos have gone extinct, this is also another one of the reasons why Chacoan jaguars grew so big, we know they average around 95 kg today but I think they were even larger a few centuries ago
My doubt comes from the hunting styles. I think the marshland style of hunting is going to give Jaguars their best specimens. They don’t seem to produce as impressive sizes when elevated terrains come into play. Their morphology isn’t as suited for the rocky terrain in comparison to explosive bursts of power from the waters edge.
At elevated terrains jaguars definitely appear just as stocky, in this case, the Yungas is the only eco-region left where jaguars inhabit high altitudes albeit still lower than the Andes, both jaguars and cougars from this area appear particularly stocky to me:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
This trend seems to be consistent among felids in general, Barbary lions were thought to have been lower at the shoulder and more robust than their Sub-Sharan savanna counterparts, northern Indian and Nepalese tigers are probably the most robust tiger eco-types, and Persian leopards appear more stocky than their savanna counterparts as well. Usually, big cats become less robust in the environments where they live a more cursorial lifestyle, IMO in this case Llanos jaguars appear to show a lighter build but with a larger body frame, akin to a lion:
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
*This image is copyright of its original author
It's all speculative but they do give me that impression. In regards to the morphology of the now-extinct Patagonian jaguars, my guess is that they would've been very stocky like the Yungas specimens but greater in size. It's such a shame we've almost lost all information concerning these jaguars as they were hunted very rapidly during the initial European settlements, it would've been super interesting to see what that jaguar eco-type would've looked like, but I don't doubt it was big.
Camera trap photo's are difficult to determine but we know that these Jaguars shown aren't in the Pantanal/Llanos weight class.
Cougars are a different case, they should thrive in elevated terrain since their morphology contributes to a better suited cat for that habitat. Long legs with a lighter frame allows them to chase prey in deep snow or uneven ground while a Jaguar being very stocky with short limbs and a long body doesn't seem as suited for that. Not to mention the hunting style of land mammals vs semi aquatic animals. I think the marshland is just the perfect habitat for Jaguars and it shows in their size, they've always been quoted as being the largest in these areas no matter how far back we go when eye witness accounts are involved.
In regards to other felines, as of now Barbary Lions have shown no difference in morphology, at least off the minimum data we have and N. Indian Tigers may or may not be larger than their C. or S. Indian counter parts but the weights and measurements we have now all overlap considerably. In fact, possibly the largest Lions and Tigers alive today come from wet habitats. (Delta and Kaziranga) with notable mentions from the Crater and Terai Arc.
Like you said, it's all speculative and Bergmans law contributes to larger cats but it's not the only landscape that does.
That's not my point, jaguars from the Yungas are likely smaller than Pantanal/Llanos ones, I was referring to what their morphology entails in terms of robusticity, they're just as robust IMO. Jaguar weights we know are completely dependant on the prey biomass of the biomes they live in which is why they grow so big in the flooded savannas, but in certain higher terrain areas where they used to inhabit and had access to very large and plentiful ungulate prey like Patagonia and the certain parts of the US (post-Pleistocene), jaguars could've grown very large as well, as detailed by writings from centuries ago. My comparison with other species is also related to this area of stockiness, I actually don't subscribe to Bergmann's rule because it is not consistent throughout, to me it's clear that genetic diversity and proper nutrition during developmental years are the key factors in the overall body mass of different felid populations.
For example, jaguar from northern Mexico and southern Arizona are among the smallest as their main prey are coatis and collared peccaries, the moment these jaguars get reintroduced in areas of central or northern Arizona where elk are found, they will progressively increase in size with each generation and become more robust as well.
I'm no disagreeing that given the addition of a proper prey base in elevated terrain that these Jaguars wouldn't grow large. But all things being equal, both would have an abundance of prey but my opinion is that the marshland habitat is going to contribute to the largest Jaguars. Their bodies are built to succeed there where as they don't seem as suited for chasing mammals through mountainous terrain.
All animals, including carnivores, adapt their daily activity duration and distribution to satisfy food demands, breed, or avoid mortality risk. We used the kernel density method to estimate daily movement activity levels and movement activity patterns of jaguars in Hato Piñero, in Venezuelan Western Llanos, based on 3,656 jaguar detection time records from two and a half years of camera trapping. Jaguars were active for 11.7 h per day on average and exhibited mostly nocturnal and crepuscular activity pattern, however, with marked differences between sex/age/reproductive groups. Reproductive females had the highest daily activity level (13.2 h/day), followed by adult males (10.9 h/day), non-reproductive females (10.5 h/day), and cubs (8.7 h/day). Activity patterns also differed, with males and reproductive females having activity peaks at the same hours after sunset and before sunrise, cubs in the night and after sunrise, while non-reproductive females were most active during night hours. This study was the first to document the effect of sex, age, and reproductive status on daily level and activity pattern in the jaguar.
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An unlikely safari in Brazil is helping save the Pantanal’s jaguars
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A pioneer in wildlife safaris in Brazil, the Onçafari Project combines jaguar sightseeing with conservation of the species and its reintroduction into nature.
Thanks to the strategy of getting jaguars habituated to safari vehicles, the Pantanal has become the best place in Brazil to spot the feline; the number of tourists at the project’s host farm has tripled in a decade.
The presence of tourists has changed farmers’ mentality, from previously seeing jaguars as a pest to kill, to now even working as Onçafari tour guides.
In 2015, Onçafari recorded the world’s first successful case of reintroduction of captive jaguars into nature; the two females have since given birth to five offspring and even four grandcubs.
Watching the largest feline in the Americas in the wild has always been a rare and remarkable experience. In Brazil’s Pantanal, the world’s largest continental floodplain and one of the main jaguar refuges, such encounters have become increasingly frequent. In the municipality of Miranda, in the state of Mato Grosso do Sul, 95% of the guests of the Caiman Farm, which is open to tourists, have seen at least one jaguar on each visit.
During a reddish sunset in August 2021, I had the opportunity to see my first wild jaguars and understand that this is not just a beautiful ecotourism experience. The sight of the mother jaguar, devouring with her cub a recently slaughtered carcass just 5 meters (16 feet) from our four-wheel-drive vehicle adapted for safaris, was special. Fera (“Furious Beast” in Portuguese), as the jaguar was nicknamed, is part of conservation history, along with her sister, Isa, as part of the world’s first successful case of captive jaguar reintroduction into nature.
The first Brazilian safari
The only member of the big cat genus Panthera not yet listed as threatened with extinction, jaguars (Panthera onca) have a strong ally in their fight for survival in the Pantanal. This is the Onçafari Project, which turned 10 years old in 2021 and has already registered sightings of more than 200 individuals on the Caiman Farm. This is the result of combining the pioneering African safari-like experience of observing animals with a conservation project that conducts scientific studies and reintroduces rehabilitated animals back to the wild.
Since former Formula 1 test driver and conservationist Mario Haberfeld teamed up with farm owner, entrepreneur and environmentalist Roberto Klabin to implement the project at the Caiman Farm to habituate local jaguars to safari vehicles, the territory has become the best place to watch these felines in Brazil. Within a decade, the number of guests has tripled. It’s a win-win for all involved: the tourists get to see the star of the area’s Big Five — a list that also includes tapirs (Tapirus terrestris), giant anteaters (Myrmecophaga tridactyla), yacare caimans (Caiman yacare) and marsh deer (Blastocerus dichotomus). And the jaguars win as the species gains protection and an increasing number of advocates.
Worth more alive than dead
An example of this change in awareness is another Mario — Mario Nélson Cleto, my safari field guide, who comes from a family of jaguar hunters. “My grandfather said he was ashamed of me when I took this job, but now my family understands why I protect jaguars,” he says.
In the not-so-distant past, a good jaguar used to be a dead jaguar, as far as the local population was concerned. At the top of the food chain, the species was an enemy to be shot when it entered farms in search of the easiest prey: cattle. Killing jaguars was part of the culture in the Pantanal, home to more than 3.8 million head of cattle in just the Brazilian part of the wetland.
“The development of tourism to watch jaguars has changed that culture,” says Haberfeld, who tried out the best safaris available before developing the Onçafari Project at the Caiman Farm in 2011. “With more farms dedicated to ecotourism, people from the Pantanal have become aware that jaguars bring money and jobs,” he says.
Quote:Both the Llanos and the Pantanal are exceptionally rich wetlands. Caimans, capybaras, turtles and fish thrive in the water, while other prey such as peccaries and livestock abound on land. That abundance leads to female jaguars having small and overlapping territories. Therefore, by banding together, males may increase their chances of taking over these areas and defending their access to mating with resident females. In other areas of the jaguar’s range, those conditions — the concentration of prey and subsequently females — don’t generally occur, so coalitions may not form.
“Our research shows that while the genetic factor and evolutionary histories are certainly important, under certain environmental conditions other species can also develop more complex social interactions,” Jędrzejewski said.
Study co-author Allison Devlin, deputy director of the jaguar program at Panthera, the global wild cat conservation organization, said the discovery points to the benefits of having long-term studies with multiple types of data, and adequate protection so that species can thrive.
“It shows the value of having long-term camera tracking, movement ecology data and direct observations through citizen science,” she said. “And from that we’re able to see that if you have a relatively stable jaguar population, healthy prey base, and protection for the species, we can start seeing these more natural behaviors, and start understanding some of the interactions that a solitary species might have.”
Here's an amazing interactive visualization made by a Jaguarland contributor of the weights of jaguars across their range in Brazil, Argentina, and Paraguay based on our data collection. Highly recommend taking a look at it:
ON THE EDGE OF EXTINCTION - C - THE JAGUAR (Panthera onca)
