Crab-eating Fox - Energy Requirements

I found a couple studies on the BMR of crab-eating foxes and they were all very similar. The BMR value was around 0.275 cm3 O2 g-1 h-1 (10). This is the same as 721.5 kJ/day (28) for a 5444g fox. This is only about 65-75% of what is expected from their body mass (10). Researchers presume that the low BMR is due to their diet consisting largely of fruit and invertebrates (10).

Unfortunately, I was unable to find the daily expenditure value for pregnant and nonpregnant crab-eating foxes or the growth energy requirements, but I was able to calculate an approximate value below:

BMR = 721.5 kJ/day = 172.4 kcal/day

DEE = 2.3 x BMR = 2.3 x 172.4 = 396.52 kcal/day

DEE(Pregnant) range = 2.7-3.1 x BMR

= 465.5 to 534.5 kcal/day

DEE(growth) = 2 x DEE(adult) = 2 x 396.52 = 793.04 kcal/day

With grasshoppers providing 363 kcal/100g (with one grasshopper weighing approximately 0.54 g), an adult crab eating fox would have to consume around 203 grasshoppers per day to just consume enough to meet the daily energy expenditure. With pregnancy and growth, the crab-eating fox would have to consume even higher amounts of food (more than 203 grasshoppers per day) to be able to function properly.

For those of you who don't know, basal metabolic rate is the minimal rate of oxygen consumption of post-absorptive animals in their rest phase at thermoneutral temperatures (28).