Maned Wolf - Energy Requirements

Amazingly so, there is unfortunately not a lot of information on the energy requirements of maned wolves but I did end up finding one study which was quite useful. This study, conducted by Barboza et al., estimated the basal metabolic rate (BMR) to be 501-674 kJ/kg-0.75 per day. This is very similar to the maintenance requirement of domestic dogs, which is 525 kJ/kg per day (3). Based off this BMR, I was able to calculate a very general approximation range of the maned wolf’s possible daily energy expenditure (DEE) as well as the pregnancy and growth energy requirements below:

BMR:

BMRmin = 501 kJ/kg per day = 119.7 kcal/kg-0.75 per day

BMRmax = 674 kJ/kg per day = 161.1 kcal/kg-0.75 per day

DEE = 2.3 x BMR

DEEmin = 119.7 x 2.3 = 275.31 kcal/kg-0.75 per day

DEEmax = 161.1 x 2.3 = 370.53 kcal/kg-0.75 per day

The range of BMR would be 275.31-370.53 kcal/kg-0.75 per day

Pregnant:

DEE(Pregnant) = 2.7 to 3.1 x BMR

DEEmin(Pregnant) = 2.7 x 275.31 = 743.3 kcal/kg-0.75 per day

DEEmax(Pregnant) = 3.1 x 370.53 = 1148.6 kcal/kg-0.75 per day

The range of the DEE for pregnant maned wolves would be 743.3-1148.6 kcal/kg-0.75 per day.

For growth requirements, I was also unable to find an exact value, but usually a rapidly growing mammal will have approximately 2 times the adult DEE. This would mean that for a growing maned wolf they would require 550.62-741.06 kcal/kg-0.75 per day.

Unfortunately, the Barboza et al. study was conducted on captive maned wolves who were fed a more meat-based diet than they would eat in nature. Therefore, this DEE (pregnant and nonpregnant) and the BMR could be slightly different from the actual values in the wild maned wolf population.

I also could not find the metabolizable energy of Solanum lycocarpum but they are closely related to tomatoes that have an apparent metabolizable energy of 8.59 MJ/kg or 2053 kcal/kg (15). With one wolf fruit being around 0.08 kg, the maned wolf would have to eat around 52 Solanum lycocarpum fruits a day. Therefore, it is a very good thing that they have animal sources in their diet to provide the necessary energy they need every day.