There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
(01-08-2015, 06:28 AM)'brotherbear' Wrote: Are these averages accurate?
Nagarhole tiger - 217 kg.
Chitwan tiger - 223 kg.
Pama tiger - 245 kg.
More or less:
1. Nagarahole - males average 217 kg, based in 3 males, all adjusted for stomach content (c.30 kg), none of them was a territorial male at the moment of the capture.
2. Chitwan - males average 221 kg, based in 7 males, now adjusted for stomach content (c.14 kg), although with the new two males reported by Tigerluver, the average seems to be higher.
3. Panna - males average 245 kg, based in 2 males. There is a third, larger male (Hairy foot), but it was not weighed. All were territorial males.
(01-08-2015, 06:28 AM)'brotherbear' Wrote: Are these averages accurate?
Nagarhole tiger - 217 kg.
Chitwan tiger - 223 kg.
Pama tiger - 245 kg.
More or less:
1. Nagarahole - males average 217 kg, based in 3 males, all adjusted for stomach content (c.30 kg), none of them was a territorial male at the moment of the capture.
2. Chitwan - males average 221 kg, based in 7 males, now adjusted for stomach content (c.14 kg), although with the new two males reported by Tigerluver, the average seems to be higher.
3. Panna - males average 245 kg, based in 2 males. There is a third, larger male (Hairy foot), but it was not weighed. All were territorial males.
Isn't it better not to adjust yourself?
Madla was 250kg +
We have no clue how much more, its better just to keep the 250kg + number as its the only accurate mark. He could of been 300kg or 255kg, but no way to know. Same with the 221kg number, correct. They were all bottomed out scales aswell?
Adjust yourself? I don't get it. What do you mean?
About Madla, yes, he was over 250 kg, I use that weight with the old male of 240 kg and the resulting average was of 245 kg. The figure is obviously not accurate as it only have two animals, but is suggestive of how an average dominant male should weight.
The figure of 221 kg is the same average of 235 kg, but adjusted by 14 kg, which is the average food intake in 24 hours, according with Sunquist. So, again, this figure is also suggestive, as the other two new males and another adult of 180 kg captured by Dr McDougal, would change that figure, again. Like I say, the real figure is probably higher.
I just think to adjust an animal that we don't know the exact weight for seems incorrect. Maybe just a * next to the weight to show the "scale bottomed out" or a g next to the weight to show "gorged"
I dont know, I just think its way to hard to try and determine what a animal actually weighed when a scale is bottomed out.
02-03-2015, 05:33 AM( This post was last modified: 02-03-2015, 05:39 AM by WaveRiders )
The estimate of 221 kg suggested by GuateGojira as average weight of Chitawan NP adult male tigers coming from the figure of 235 kg (and the one for adult females of 140 kg) provided in the study of Smith et al. (1983) can in my opinion be refined on the basis of the following consideration.
Sunquist (1981) provides average food intake of tigers (unsexed) in the first 24 hours after a kill as 14,0 kg. His study basically included 2 adult males, 5 adult females (1 died at day of capture) and 1 subadult male with number of observations different from animal to animal.
I propose to use the very much known Kleiber’s Law to estimate the specific adult male and female average food intakes in the first 24 hours after a kill from the overall biased average 14,0 kg figure for males and females in the first 24 hours.
Without going into the validity of this law, a topic much debated in biology with countless number of studies, Kleiber’s Law states that the metabolic rate of all organisms scales to the 0,75 power of the body mass.
To strengthen the reasonable validity of my assumption I highlight that Sunquist (1981) suggests males tend (obviously) to eat more then females and that he observed 2 males eat 56 kg and 57 kg of meat respectively in 3 days of undisturbed feeding (18,7 kg/day and 19,0 kg /day) while a female 41 kg (13,7 kg/day).
“Magically” the ratio 18,75 kg to 13,7 kg computed from Sunquist’s examples (I neglect the extreme case reported of a female eating 30 kg in 24 hours) is close to the ratio expected by two cospecific animals weighing 235 kg (adult male average body mass including stomach contents) and 140 kg (adult female average body mass including stomach contents) respectively if the metabolic rate and the consequent energy needs would exactly follow Kleiber’s Law.
With a few mathematical iterations to calculate ratios from empty stomach weights and not from total body masses and assuming the average food intake of the first 24 hours refers to all individuals captured and radiocollared (2 adult males. 1 subadult male, 3 adult females and 1 subadult / then adult female) I got the following.
Adult males : average body mass at empty stomach 217,3 kg (heaviest 241,9 kg again following Kleiber’s Law)
Average food intake in the first 24 hours 18,3 kg
Adult females : average body mass at empty stomach 128,1 kg (heaviest pregnant 150,5 kg / non-pregnant 140,2 kg adult female again following Kleiber’s Law)
Average food intake in the first 24 hours 11,9 kg
Please note that the heaviest weight of adult Female 101 measured at 164 kg occurred while she was pregnant and relatively close to give birth to a litter (approximately 4 weeks if I do recall well as I read the report a long time ago). Therefore this weight was not a natural weight for the animal (apart from the stomach contents issue).
I've stated this before and is something to keep in mind, and this is from the veterinary side, but food intake is not actually equal to mass in belly at weighing unless the weighing was very close to the feeding.
Also some other things to note, is the "alleged" gorging that occurs can't be measured. How would they get their # of X kg of meat being consumed?
They would have to weight the carcass before feeding then after each feeding. They they don't take in to account (Blood loss which can be significant, scavengers contributing to the feeding, even maggots or other flesh consuming bugs)
Then the metobolic rate that Waverider discussed etc. There are to many variables to try and use a exact number IMO. Its easier to use the actual weight as the official record and estimate the gorging amount if any after.
02-04-2015, 10:10 AM( This post was last modified: 02-04-2015, 10:17 AM by GuateGojira )
So, the consensus here, right now, is not to adjust for stomach content.
However, what you are going to answer to people like Dr Yamaguchi or hard-core-lion-fans (you already know who), that constantly get this issue on the dish???
Are we going to ignore the issue or are we going to give at least one logical answer?
Posts 172 and 173 sum up the reasoning well, in my opinion. Other than the Nagarhole oddity, all other weights were unadjusted by top scientists, from Sunquist to Berry, which in a way is a vouch to the concensus. Gorged specimens should always be noted nonetheless, but your average, not really visible belly distention intake probably is not significant as realistically one would expect most organisms to have some content in the tracts at all times, and those contents are essentially part of the functional weight. In the morphological studies of other species (many who eat constantly throughout the day as well, so a high expected weight of contents in the tract), I've not really heard of issues with food intake either.
02-04-2015, 10:32 AM( This post was last modified: 02-04-2015, 10:33 AM by GuateGojira )
Ok, I agree, that is logic and I have saw this mostly in the herbivores, which always have some stomach content in they bellies.
Even then, it is disturbing to read about Yamaguchi using the "gorged" issued to estimate the famous Sauraha male of 272 kg at only 218 kg, which is ridiculous.
I think we most discuss a little more on this issue of the food intake, of tigers at least.
(02-04-2015, 10:32 AM)'GuateGojira' Wrote: Ok, I agree, that is logic and I have saw this mostly in the herbivores, which always have some stomach content in they bellies.
Even then, it is disturbing to read about Yamaguchi using the "gorged" issued to estimate the famous Sauraha male of 272 kg at only 218 kg, which is ridiculous.
I think we most discuss a little more on this issue of the food intake, of tigers at least.
I think if science is based off of exacts than the best way to compare is to use exacts. If something weighs X then that is the # we should use. If somebody wants to note that it was baited or gorged, etc. That is up to the scientist but we can only compare the exact # used. Where I get urked is when the scales are bottomed out. Cause that leaves far to many variables, not only do you deal with the "gorged" issue but then you are left trying to guess how much over the scale the animal weighed. Which we all have seen, is extremely hard even to the most trained eyes.
That is absolutely true but I did not want to complicate the matter too much. I remember in 2004 in AVA I estimated similar figures speculating also on faecal rate, average faecal mass, fluid mass flow (water in and urine out) and so on arriving at figures of 215 kg and 128 kg for adult males and females respectively, but there were included also some different assumptions. It has past a long time since then and I am getting old for those kind of elaborated speculations. My purpose was to refine empty stomach body mass differentiating the data from Sunquist (1981) and Smith et al. (1983) for adult males and adult females.
BTW
Errata-Corrige: Average food intake in the first 24 hours 17,7 kg
As a further mathematical exercise I considered the body mass of each individual instead of the sex/age class weigh to get collectively the average 14,0 kg of food intake in the first 24 hours and I obtained slightly different results as follows
Adult males : average body mass at empty stomach 217,0 kg (heaviest 241,5 kg again following Kleiber’s Law)
Average food intake in the first 24 hours 18,0 kg
Adult females : average body mass at empty stomach 127,9 kg (heaviest pregnant 150,4 kg / non-pregnant 140,1 kg adult female again following Kleiber’s Law)
Average food intake in the first 24 hours 12,1 kg
Pckts
How can you compare the Smuts sample of Kruger lion weights all corrected for stomach contents with Chitawan tiger weight sample where the capturing technique implicated an almost certain 12/18 hours of feeding in the very most if not all cases before the weighing operation and no estimated stomach contents was accounted? Mine is therefore an attempt to account for the statistical impact of any likely stomach contents in the sample based on info on capturing technique, ecology data and any biology consideration that can help to refine the estimates. It is up to each one to use actual data or data modified in the most sensible way. It depends from the contest and from the consistency with other data when doing comparisons and other statistical analyses.
That is absolutely true but I did not want to complicate the matter too much. I remember in 2004 in AVA I estimated similar figures speculating also on faecal rate, average faecal mass, fluid mass flow (water in and urine out) and so on arriving at figures of 215 kg and 128 kg for adult males and females respectively, but there were included also some different assumptions. It has past a long time since then and I am getting old for those kind of elaborated speculations. My purpose was to refine empty stomach body mass differentiating the data from Sunquist (1981) and Smith et al. (1983) for adult males and adult females.
BTW
Errata-Corrige: Average food intake in the first 24 hours 17,7 kg
As a further mathematical exercise I considered the body mass of each individual instead of the sex/age class weigh to get collectively the average 14,0 kg of food intake in the first 24 hours and I obtained slightly different results as follows
Adult males : average body mass at empty stomach 217,0 kg (heaviest 241,5 kg again following Kleiber’s Law)
Average food intake in the first 24 hours 18,0 kg
Adult females : average body mass at empty stomach 127,9 kg (heaviest pregnant 150,4 kg / non-pregnant 140,1 kg adult female again following Kleiber’s Law)
Average food intake in the first 24 hours 12,1 kg
Pckts
How can you compare the Smuts sample of Kruger lion weights all corrected for stomach contents with Chitawan tiger weight sample where the capturing technique implicated an almost certain 12/18 hours of feeding in the very most if not all cases before the weighing operation and no estimated stomach contents was accounted? Mine is therefore an attempt to account for the statistical impact of any likely stomach contents in the sample based on info on capturing technique, ecology data and any biology consideration that can help to refine the estimates. It is up to each one to use actual data or data modified in the most sensible way. It depends from the contest and from the consistency with other data when doing comparisons and other statistical analyses.
WaveRiders
Chitwan tigers were bottomed out. So the alleged weight is the barest minimum. Without knowing the exact weight over the 272kg and 227kg scale that was bottomed out, its impossible to put a number on it. So if you are adjusting 17kg for "gorged" but only subtracting it to the weight estimated weight you won't necessarily get a correct average. I think the "gorged" idea should be noted but not used in finding the average weight. Since there are many factors that play a role in what a big cat will consume compared to what it has actually consumed.
Here are the weights I see for smuts
*This image is copyright of its original author
and another (not sure if this is smuts or not)
*This image is copyright of its original author
So if smuts lions were "gorged" I would rather use the actual weight measured and just note that they were gorged. But when using the Chitwan tigers the # could still be higher even with the gorged factor subtracted due to the bottomed out scale. So subtracting an estimated "gorge weight" to a minimum total will still give you smaller weight than what most likely it actually is.
In regards to your Tigress weights, here are a few that are larger than what you have listed
Also, for the adjustment of Sauraha's weight that is being focused on too much in my view. Reading through recent literature that started employing chest girth for body mass estimation, including the Sauraha estimate equation, there is one major flaw, the lack of logarithmic scaling. A straight trendline is being used to estimate a relation which in reality increases by a power greater than 1 will underestimate values at the high end, with the extent of the underestimate increasing proportionately with how much greater the high value is than the average values. I can provide a visual explanation of needed. Assuming Sauraha's girth is at the high end and he was not a light framed tiger, the 261 kg number would be an underestimate.
Who is the "king" of tigers? - Bengal or Amur
