ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)

[GuateGojira]

(04-29-2020, 12:30 AM)tigerluver Wrote: A new study on the prey habits of Bandhavgarh tigers. Here is their key table:

*This image is copyright of its original author

The weight of prey eaten per scat is another interesting point that could be of use for those "empty belly" estimations. It is based on this equation from Ackerman et al. (1984):

*This image is copyright of its original author

From my understanding (which may be off the mark), the equation was derived by comparing prey mass and how much of the prey was consumed by 3 captive cougars. Navaneethan et al. (2020) apply this equation to tigers. If this equation holds true, tigers don't seem to eat as much per kill perhaps. The limitation of this method is that it as a calculated estimate and not actually weighing what is left of consumed prey.

Digging deeper into the Ackerman et al. (1984), the test cougars produced 9 kg of scat total (average scat of 203 g x n of 45) and consumed about 40 kg of prey (summing from the graph above) throughout the study. This would be about 75% of intake is digested and assimilated and 25% is defecated. Therefore, when correcting body mass for food intake, simply subtracting the entire mass of prey consumed from the measured body weight of the cat is inaccurate as such does not account for absorption and assimilation of intake. If we assume tigers have similar efficiency of digestion as cougars, we could infer that 14 kg of consumed prey would need a mass correction of 3.5 kg (25% of consumed biomass).

I have attached both papers. Please let me know your thoughts.

You done it, you hit the nail!!! This is what I tried to explain but I did not manage to do it. That part of the amount ingested by the tiger is absorved, so it is incorrect to "adjust" the body weight of an animal taking in count the entire amount ate, as part of that is going to be absorbed. Also we must take in count the time of the digestion, which in cats is very fast, in fact they can be empty-belly is less than 6 hours after a large meal.

Also, again, we must remember that the estimation at simple sight for the stomach content is not accurate, as Dr Chundawat (2018) proved with the tiger M-91: the field team members estimated that the tigers could eat between 25 - 30 kg in one sitting, but when the large male M-91 vomited and emptied his belly after a full meal the last night, the amount was actually "just" 19 kg, a big diference from the estimated figures.

Thank you for sharing this information @tigerluver. Reply