Are you what you eat? Patterns in primate feeding

Goals for today... Body size and Basal Metabolic rate Body size and diet (Kay’s Threshold) Anatomy and diet Dietary patterns

Basal Metabolic rate (BMR) Amount of energy an animal expends in a resting state. (measured in amount of oxygen consumed). Table 4.2 (handout) Mouse to elephant graph (Figure 6.1- handout)

Irony of BMR Relative to their body size, larger animals do not expend as much energy as smaller ones.

Body size and diet Dietary intake increases with body weight (figure 9.8, handout) Dietary patterns and diet quality fall out with body size generally. (Kay’s Threshold handout)

Jarman-Bell Principle nutrient requirement Body Weight Total nutrient requirement Large animal Large (abundent food) Small (poor quality foods) Small (rare foods) Large (high quality) small animal See Strier pg 40

Tradeoff in brain and gut Brain and gut are big users of metabolic energy See tradeoff in primate order between the two (see humans in particular) Aeillo and Wheeler 1995

Expensive tissue Hypothesis More complex foraging behavior Higher Diet Quality Larger Brain Increased energy available Reduced bulk Rapid assimilation Smaller Gut Increased Energy available Selection pressure Relaxed constraints Aeillo and Wheeler 1995

Gut Morphology Foregut or Forestomach fermentor- food broken down in stomach e.g. colobus monkey. Hindgut or ceaco-colic fermenter- food broken down in large intestine (Wooly monkey). See handouts in coursepak

Body size and transit time. Figure 3 showing log body mass and log transit time (handout in coursepak) While it takes longer to process food the larger you are, not all variation explained.

Examples….. Brown lemurs Gut transit = 0.5 hrs Bamboo lemur