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Comparing big cats - differences/changes with time
Comparing big cats - differences/changes with time
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Comparing big cats - differences/changes with time
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@BlakeW39
Quote:Well, the study we've both reviewed takes into consideration over 3,000 jaguar kills; of this >3,000, it is found that all species of tapir were significantly avoided, with lowland tapir being very rarely predated on and the baird's tapid not being hunted one single time (out of 3,000).First you must take into account how these "Kills" are monitored. "We searched Google Scholar and Web of Science for literature on the diet of jaguars, as well as gray literature (dissertations, theses) and the reference lists of any publications found. Keyword searches were for “jaguar” OR “Panthera onca” OR “onça” OR “onça-pintada” OR “onza” OR “yaguar” OR “yaguareté” OR “tigre Americano” AND “diet” OR “fezes” OR “presas” OR “heces” OR “disponibilidad” OR “alimentación” OR “dieta” OR “hábitos alimentarios” OR “depredación” OR “ecología alimentar." In literature, kills are monitored by numerous ways but in terms of the most common, it's scat samples. Scat Samples are anything but conclusive and are very limited. There is no way to ID the animal via scat and you are only getting a limited amount of data from that scat. Meaning, you're getting only what the animal recently ate and nothing else. The Pantanal is a massive place, impossible to monitor most cats, let alone get scat samples and investigate kill sites. It's also no surprise that there is a direct correlation to Cat size and prey size taken "Hoogesteijn and Mondolfi (1996) found that floodplain jaguars were significantly larger [body mass: Llanos = 104.5 kg (males), 66.9 kg (females) and Pantanal = 99.5 kg (males), 76.7 kg (females)] than forest jaguars [body mass: Amazon = 83.6 kg (males), no data for females and Central American = 56.1 kg (males), 41.4 kg (females)]. This variability was also reflected in the diet of the populations, with the forest jaguars having a significantly lower mean weight of vertebrate prey at 5.8 kg, compared to 89 kg (including livestock) for floodplain jaguars (Hoogesteijn and Mondolfi, 1996)." We also know that Jaguars do take Tapir, 3 in the study Posted and a few others below Tapir skull killed by Jaguar  *This image is copyright of its original author  *This image is copyright of its original author But yes, these are rare but it again depends on the location. Where they are abundant, they will be killed more often imo. Quote:Also, while livestock are large, they lack defenaive capabilities similar to their wild counterparts, not even just physically, but that they lack the appropriate response to predators which a wild prey animal would have.I'm not sure about that, I've seen Cattle Run off bears, they've ran off Pumas and Wolves as well. Even a young Lion has been killed by Cattle While a domestic breed isn't as attune to the threats around it, it wont take long to learn and become more aware. Quote:Jaguars were able to adapt to the Holocene because they didn't rely so much on the prey that was lost. I don't think it's at all misleading to say this.You cant say that "they didn't rely on it" now that there's none available. What apex big cat doesn't rely on larger prey when it's available?  (03-01-2020, 12:27 AM)Pckts Wrote: Even a young Lion has been killed by CattleA cattle managed to kill a young lion? Wow, I didn't knew that was possible. And I like how the cow was rewarded because of killing the lion hahaha.  (02-18-2020, 10:59 PM)Ashutosh Wrote: True, @Pckts. But, Jaguars are the absolute apex predator in their landscape. On the other hand, tigers in Sunderbans have to deal with saltwater crocodiles and highly venomous sea snakes and both of those are better in water than the tiger, and no other animal is worrying the jaguar on such levels. Patrolling a territory is so much harder with such dangers lurking around. So, should the criteria for a more aquatic cat be based only on the prey? Personally, I think the fishing cat is the most aquatic cat around, but there is so little known about them. Similarly, jaguars in los Llanos have to deal with Orinoco crocodiles (bigger than the salties in the Sudarbans) and giant green anacondas in the water, and they seem to be just as aquatic as Pantanal ones in the water. In the Amazon, they deal with black caiman too, but I'm not sure how much jaguars there rely on rivers and marsh areas to hunt in comparison with Llanos/Pantanal ones. (07-27-2020, 12:22 AM)Ashutosh Wrote: Where exactly is the evidence of Saltwater crocodiles of Sundarbans being smaller than Orinoco Crocodiles? They grow slightly bigger at absolute measurements, crocodiles from the Sundarbans are smaller than other salt-water populations. Most importantly the claim that jaguars do not interact with other top carnivores in comparison to Sundarbans tigers was incorrect.
Still no evidence, just your opinion. If you have some measurements, then let us see it. Plus, Sundarbans is not the only mangrove system that tigers inhabited in the past. They were found in Bhitarkanika where they shared habitat with saltwater crocodiles (you can claim orinoco crocodiles are larger than the ones found in Bhitarkanika but that would be a waste of time). In fact all along the Bay of Bengal they interacted with saltwater crocodile which are much bigger than orinoco crocodile.
(07-27-2020, 12:46 AM)Ashutosh Wrote: Still no evidence, just your opinion. If you have some measurements, then let us see it. Plus, Sundarbans is not the only mangrove system that tigers inhabited in the past. They were found in Bhitarkanika where they shared habitat with saltwater crocodiles (you can claim orinoco crocodiles are larger than the ones found in Bhitarkanika but that would be a waste of time). In fact all along the Bay of Bengal they interacted with saltwater crocodile which are much bigger than orinoco crocodile. You're right that I lack the data regarding Sudarnbans salties because studies on them haven't been performed to determine average body mass or length, but based on my discussions with crocodile enthusiasts I have had in the past I was left under the impression that Sundarbans salties have been thought to be smaller than other populations. Now, if you disagree with that then perhaps we could see your data on them and the burden of proof would fall on you. I'm also exclusively referring to the claim regarding the Sundarbans because that's the biome you mentioned, and even if those crocodiles aren't necessarily smaller (which I highly doubt), it doesn't take away from the fact that the claim that floodplains jaguars don't have to deal with comparable aquatic competitors to Sundarbans tigers is false. (07-27-2020, 01:03 AM)Balam Wrote:(07-27-2020, 12:46 AM)Ashutosh Wrote: Still no evidence, just your opinion. If you have some measurements, then let us see it. Plus, Sundarbans is not the only mangrove system that tigers inhabited in the past. They were found in Bhitarkanika where they shared habitat with saltwater crocodiles (you can claim orinoco crocodiles are larger than the ones found in Bhitarkanika but that would be a waste of time). In fact all along the Bay of Bengal they interacted with saltwater crocodile which are much bigger than orinoco crocodile. I think it would be better if you think you can bring saltwater crocodiles size data from Sunderbans since you said they were small. Also It would be better to see interspecific interactions between floodplain jaguars and Anaconda, Orinoco crocs and black caimans. (08-01-2020, 10:21 PM)Bitishannah Wrote:(07-27-2020, 01:03 AM)Balam Wrote:(07-27-2020, 12:46 AM)Ashutosh Wrote: Still no evidence, just your opinion. If you have some measurements, then let us see it. Plus, Sundarbans is not the only mangrove system that tigers inhabited in the past. They were found in Bhitarkanika where they shared habitat with saltwater crocodiles (you can claim orinoco crocodiles are larger than the ones found in Bhitarkanika but that would be a waste of time). In fact all along the Bay of Bengal they interacted with saltwater crocodile which are much bigger than orinoco crocodile. I didn't say they were small, I said *smaller* than salties from other regions, don't twist my words. Not only that but the initial claim was that jaguar didn't interact with comparable crocodilians to which I brought up Orinoco crocodiles and black caiman (I forgot to add American crocodiles to that mix as well), it was never to compare how both felids interacted in general with the crocodiles, just to show that jaguars too face similar threats in the water in certain regions. Interactions between jaguars and black caiman as well as anacondas have been posted in this forum before. (08-01-2020, 11:14 PM)Balam Wrote:(08-01-2020, 10:21 PM)Bitishannah Wrote:(07-27-2020, 01:03 AM)Balam Wrote:(07-27-2020, 12:46 AM)Ashutosh Wrote: Still no evidence, just your opinion. If you have some measurements, then let us see it. Plus, Sundarbans is not the only mangrove system that tigers inhabited in the past. They were found in Bhitarkanika where they shared habitat with saltwater crocodiles (you can claim orinoco crocodiles are larger than the ones found in Bhitarkanika but that would be a waste of time). In fact all along the Bay of Bengal they interacted with saltwater crocodile which are much bigger than orinoco crocodile. Here is a quote from Mainak Ray, who is a photographer at the Sundarbans, involving saltwater crocodiles there: "A saltwater crocodile carrying its deer kill on its back waiting for another round of death roll to tear the prey. A common sight in Africa during the migration but in the canals of the mangroves in Sunderbans the deer is not so desperate to cross the river and even when they do so they cross very cautiously after a long check for any danger whatsoever. And the size of the swamp crocs here are much smaller. This is rare sight in the mangroves where the crocodile is hardly as big as the male deer " Source: https://hive.natureinfocus.in/photo_sharing/death-roll/ He's comparing the crocodiles to the Nile ones who feed on ungulates, as well as the ungulates themselves, clearly stating these crocodiles are smaller than the Niles he's seen. Furthermore, while the data on Sundarbans salties sizes is scarce, we do have one measurement of a crocodile who was responsible for killing a tigress, and it measured close to 14 ft or 4.2 meters in length:  *This image is copyright of its original author Source: https://pdfs.semanticscholar.org/b9d0/4bb0907914b0bfe39595e9a5a45beab13d70.pdf Based on the information above my initial statement regarding the size comparisons between Orinoco and Sundarbans saltwater crocodiles has validity to it. I believe there is some overlap in size, but the big Orinoco crocodiles are definitely the largest out of the two, salties from other areas such as Australasia would come up on top tho. And this also clarifies that jaguars also deal with large crocodilians in water, contrary to what was stated before.
There are no orinoco crocs recorded in modern times over 5.2 metres and the one which you highlighted from Sundarbans is bigger than the biggest orinoco croc recently because when Guiness measured them, they couldn’t find one over 4.2 metres. It has been claimed they can reach lengths of 5.2 metres, but unless, one measures that big these days, it’s all speculation. Historical figures of Orinoco crocs reaching 20 feet are in the same category of claims as Amur tigers weighing 300 kilos on average (gross exaggeration).
Secondly, Sundarbans is 120 kilometres away from Bhitarkanika which houses some of the largest crocodilians on the planet with at least 4 measuring over 20 feet. There might not be any research on crocs from Sundarbans owing to their small number, but, Bhitarkanika has been watched over extensively. That is a 3 day swim for any saltwater croc. Are the saltwater crocs in Sundarbans smaller than ones in Bhitarkanika? Sure. But, they aren’t smaller than orinoco crocs who barely even reach 4.5 metres in length these days. Even exceptional mugger crocs are bigger than that.
It doesn't matter because I am not using recent weights to determine their size, the current population estimation of Orinoco crocodiles in the wild is at around 250 individuals only, they have been heavily hunted and their genetic pool and therefore size has suffered as a result. To determine their regular interactions with jaguars then one has to study their historical sizes and size potential, where they surpass anything registered by a Sudarbans saltwater crocodile with ease. Actually, recent measurements for Orinoco crocodiles in captivity and those released into the wild haven't been performed, but I wouldn't be surprised if those are already surpassing 5 meters in length, even @epaiva recorded this video of an Orinoco crocodiles of about 5 meters in length, he can reiterate that himself:
No mugger, regardless of how much of an outlier it might be, is going to outsize a large Orinoco crocodile. And I'm not speaking of other crocodile populations, in specifically mentioning Sundarbans, the sizes of the crocodiles in surrounding regions is irrelevant. 
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(08-09-2020, 11:11 AM)Ashutosh Wrote: There are no orinoco crocs recorded in modern times over 5.2 metres and the one which you highlighted from Sundarbans is bigger than the biggest orinoco croc recently because when Guiness measured them, they couldn’t find one over 4.2 metres. It has been claimed they can reach lengths of 5.2 metres, but unless, one measures that big these days, it’s all speculation. Historical figures of Orinoco crocs reaching 20 feet are in the same category of claims as Amur tigers weighing 300 kilos on average (gross exaggeration).Larger individuals Orinoco Crocodiles today reach 5 meters long, on a breeding facility they have two very close to 5 meters long and I saw a wild one larger than the ones I saw in the facility, in the good old times a few of them grew a lot larger with the largest one over 6 meters long. Their numbers today a very low about 2000 in Venezuela and 200 in Colombia. Saltwater crocodiles in the Sinderbans are larger for sure. I didn't think Guinness came here to measure them because you can find many over 4,2 meters long and bigger females measure very close to 4 meters long.
@Balam, and that exactly is the issue. You are comparing the historical size of orinoco crocs to present size of Sundarbans saltwater crocs . As for hunting, saltwater crocs in India were hunted just as brutally as orinoco crocs (they were once found all along the eastern coast, but once the mangroves disappeared so did the crocs). They numbered 96 in 1976 in mainland India (except Andamans). Use the same barometer for both.
And, historically the Sundarbans crocs were part of the same contiguous population as the ones from Bhitarkanika and like I said the distance is only 120 kilometre between these two landscapes and there have been specimens of skulls of 100 cm found here historically. 10% of all adult saltwater crocs in Bhitarkanika exceed 6 metres. In fact, if you put GPS collar on a few of them today, you will see a few migrating to Sundarbans (they have been migrating as Bhitarkanika is reaching it’s carrying capacity). So, instead of using two different standards, use the same historical sizes argument for the saltwater crocs from Sundarbans. Unless you want to argue that orinoco crocs are bigger than saltwater crocs (not just any saltwater crocs as Bhitarkanika houses couple of croc skull bigger than any skull found in Australia), it is all part of wild speculation with very little basis in merit. |
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