WildFact
›
Premier Section
›
Edge of Extinction
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
|
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
|
Peter, the list is looking good but male #4 is from Nagarhole.
how about we throw in this guy?  *This image is copyright of its original author   (11-08-2014, 05:14 PM)'peter' Wrote: THE RELATION BETWEEN TIGER SIZE AND HERBIVORE SIZE as far as tigers in India are concerned the largest prey they can hunt are the wild buffs, gaurs, young elephants & rhinos, Kaziranga has all of em so it can be concluded that mebbe hunting these large animals has made the tigers here bigger but you'd find similar large herbivores even in Bandipur in southern India & the tigers there are no where near the size of even a central Indian tiger. Largest herbivore in Panna is I think a sambhar dear, how do you explain the size of Madla & even biggeer Hairyfoot? I think terrirtorial competitiveness could also be playing a part here, bigger male the better? generally we've seen larger males rule the roost. 
Heavy males (from the 270 kg specimens to the alleged 389 kg male) in history are almost always cattle killers and of the sort. The Panna males were confirmed cattle killers last I checked, and see how large they were.
Biologically speaking, size is a burden on its own. The rewards only outweigh the costs if either the size makes catching prey easier or outcompeting other predators (most exemplified in bears).
so are you implying Kazi tigers are cattle killers? [img]images/smilies/biggrin.gif[/img]
& no size cannot be a burden as size has helped some tigers establish their territories, can't agree with you on this. aren't the biggest wolf in most packs almost always are the alpha males? http://www.adfg.alaska.gov/index.cfm?adf...les_id=503
Kaziranga tigers are being reported to kill rhinos and elephants, I think cattle killer is now a feat of the past. Nevertheless, we've no data backing the Kaziranga sizes, unfortunately, so I'm implying nothing.
I'm talking size as a species, in evolutionary terms. One needs to look past the individual level, individuals are a moment in the evolutionary timeline of a species. If size was so beneficial, why'd the Ngandong tiger end up 1/3 of its size by the Holocene? Why do modern tigers struggle to get past 270 kg, even though it is so common for males to attain this size nowadays? Wouldn't we expect size increases to edge out competitors? Simple, environmental resources conquer all. Being bigger is a pro in some ways, like territory and competition, but the energy cost outweighs this pro if the resources simply are not there. By your theory, we should have 300 kg wolves by now as the bigger the better no matter what, but that energy cost can't be made up by the environment. Instead, everything has majorly downsized since the Pleistocene now due to lack of energy sources. (11-09-2014, 12:02 PM)'tigerluver' Wrote: ....Why do modern tigers struggle to get past 270 kg, even though it is so common for males to attain this size nowadays? Wouldn't we expect size increases to edge out competitors? Simple, environmental resources conquer all. Being bigger is a pro in some ways, like territory and competition, but the energy cost outweighs this pro if the resources simply are not there. By your theory, we should have 300 kg wolves by now as the bigger the better no matter what... Friend, how do you know tigers struggle to get past 270Kg.? you mebbe right but where's the data? all we have in the name of scientific data on Bengal tigers is that a tiger the size of Madla would weigh 250 kg. & this too is an educated guess & a tiger or two weighed & measured here & there thats it, rest is all bull**** from some Maharajah. about wolves size, well in the presence of some bigger predator the smaller predator will have to compromise on its size, there's a study available on this matter if you please, & pack/pride predators don't need individual big size to hunt & to defend territories, what matters here is head counts.
1. I am not getting what you're saying. We've some records, why deny the hunter weights accepted by science? There's plenty of data posted around here on weights. It isn't logical to expect a full population score. Regardless, the point still stands. Explain to me why the tiger downsized when greater size is advantage no matter what? I've already given you my reason twice. Also, we should leave the cursing off the forum.
2. You conflicted your own point. You first stated that size is better no matter what, using wolves as an example, and then stated that wolves don't get that big due to an environmental niche. That's what I've been saying, environmental niche will limit size. I am not saying that getting big is always a negative. I am saying that getting big needs reason to happen and need a foundation to support the calorie need. If an environment provides you with 2000 kcal, but you need 3000 kcal due to your size, you'd be weeded out of the population via starvation, and smaller specimens will carry on the next generation, and thus is the way of evolution. 
Tigerluver and Vinod, I partially agree with both of you, and also have disagreements, with both of you.
*This image is copyright of its original author 2. However I also agree that prey base is not always the principal driving factor. For example, tigers in Chitwan (Nepal) have a large prey base but the main prey is the Chital deer of between 50 to 90 kg, even then, they are the largest tigers recorded by scientists in the field (Assam tigers had been not captured.... yet). However, the prey base of Nepal is smaller than that of Nagarahole (India) in which there are not also more Sambar deer but there are Gaur at a large density and tigers regularly predate on them. However, the tigers in the area don't present exceptional sizes, as in more than 100 years, the heaviest specimen (empty belly) is a male of 227 kg. I don't know if this is the exception to the rule, but Nagarahole tigers should be giants, following the rule, but they are not. As we can see, I think that there are more factors than just prey base, maybe food intake (in the only two studies available, there are significant differences among tiger populations), or maybe genetic or even only prey density too. I don't try to draw a conclusion, only to show a few examples that can be used for your arguments. By the way, I have reach the page of the book "The Face of the tiger" where is mentioned the supposed record of 77 lb (35 kg) for the maximum food intake for a tiger (pg. 41). However, from my point of view, the account is really vague and I suspect this is an "estimation". Here is the scan of the page:  *This image is copyright of its original author What do you think guys? This look like an actual measurement or just an estimation, probably from a second hand source? Now, following the spirit of the topic, and like a gift to all of you, here are the images of the famous "Dakre" male (T-102) from Chitwan Nepal, the smallest adult male tiger in the range of Smith et al. (1983) and the young male of 200 kg that dominated the east area of the park until it was poisoned:  *This image is copyright of its original author From the book "The Face of the Tiger", going after a bait (lower right corner).  *This image is copyright of its original author From the book "Tiger moon", with our highly estimated Dr Sunquist and his wife Fiona. This is the first time that these pictures are presented in a forum, enjoy them and they will be useful to those that are making profile pictures from all the famous tigers.  *This image is copyright of its original author Peter (I think) posted this image before, but I scan it from my book in a clearer/larger version. Greetings to all.
wow, excellent find Guate.. this i believe is the first time we got to witness T102's photo. Also, how old was he when he was weighed?
 (11-08-2014, 06:15 AM)'peter' Wrote: 1 - ARTICLE "It is not known how tigers operate outside of protected reserves in india"??? I'm sorry, how do we think they operate? They operate the exact same way, search for territory, hunt for prey, mate and rest. Nothing changes, it is not easy to view them by human eyes, is what they should say. We already know tigers prey on wild boar, we already know they travel close to human settlements (they have no choice) and there is nothing they can do to "prevent human conflict" outside of teaching villagers to stop taking action in to their own hands when their cattle is lifted or a villager is attacked. Learn that we are invading their lands and they have no choice, expecting them not to take a animal that looks exactly like all other prey they take is ridicolous. And even so, cattle is actually lifted very rarely considering how much is available to them. This still seems like something that should be posted on the hands on or hands off thread and not on the extinction thread.
About prey size to tiger size,
I see a lot of talk about Kaziranga Tiger size and rightfully so, but lets no forget that Corbett is also assumed to have equally as large of Tigers as Kaziranga. But if you compare pictures, you can see that Kaziranga still has a more massively built tiger more often than not compared to corbett, but its not like Khali wasn't a massive tiger in his own right. Now that we know corbett has a large amount of elephants same with kaziranga, but kaziranga also has rhino, gaur and water buffalo. So all may contribute to the exceptional mass of the Kaziranga tiger, but the other thing that I really think makes a large difference is the terrain. Kaziranga has huge grass, wet plains and rough terrain that will all contribut to a larger cat that needs more power to take down this large prey all the while doing in a terrain that is extremely taxing on their body. Moving 250kg plus through high glass and 2' depth of water is going to take a lot of power. Like watching that massive kaziranga tiger run through the marsh to capture that cattle. You could just see the amount of power needed to move that fast, same with the tigress charging the FD on elephant grass through the tall grass. Both quite impressive displays of power.
Wonderful post Guate. It comes down to environment (past prey base obviously, but that's a major factor) and probably some genetic chance in determining size of a population. Albeit, Nagarhole houses larger tigers in my opinion, seeing that a young male far from prime was around 250 kg, an old, decomposing male was 230-240 kg, and Dhasa was 257 kg, un-adjusted yet not gorged. From a small size of only one prime male, these seem like larger tigers.
I believe via personal communication, Guate found out that all the males weights were adjusted by 30 kg, explaining why the Dr. Karanth's Nagarhole data was confused as more than 3 specimens. Gorged specimens these days don't get adjust by more than 20 kg, and Peter showed some good data to prove this point, so like I've stated numerous times, I feel the raw weights are better for comparison.
|
| Users browsing this thread: |
| 6 Guest(s) |