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

[Pckts]

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

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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):

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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.

Add to that the issues with Scat sampling.
Most likely you will not know the actual age, sex or weight of the prey taken from scat.
You will also probably be monitoring a limited number of Cats since finding scat samples is generally very difficult unless you know where the cats territory is. 
I'd also wager heavily that Bandhavgarh now has far more Cattle present as well as the reintroduction of Gaur, both would contribute quite a bit to those numbers. Reply