Lec: Food and Feeding

digestive tract review

Insectivory

basic/primary mammals (insects were the first major food source), wide range/diversity of mammals, aerial, aquatic, and terrestrial insectivores, incisors procumbent in many, consume minimal amounts of fiber, which affects morphology of digestive tract

Insectivore digestive tract

stomach is big and muscular, short intestine, no cecum (don’t need to ferment)

Carnivory

different types (arboreal, terrestrial, marine), sharp cutting teeth w/ some homodont dentition, some specials (sanguinivorous and piscivorous)

Sanguinivorous

blood suckers (vampire bats)

Carnivore digestive tract

big stomach, simple gut, short intestine and colon, have cecum

Kinds of Herbivores

browsers and grazers (hooved mammals and aquatic grazers)

gnawing mammals (rodents and lagomorphs, coprophagy)

• don’t get as much energy from vegetation as a carnivore would get from their prey, so they have to constantly graze

Herbivore characteristics and digestive tract

selenodont dentition, canines reduced of absent, broad molars (crushing, shredding, and grinding), fermentation (hindgut and foregut), enlarged cecum

Nonruminant herbivore

large incisors to crop foliage

Ruminant herbivore

lost their upper incisors (callous pad on their upper gum)

Coprophagy

hindgut fermenters, consumption of cecotropes (nutrient dense droppings)

compare and contrast hind and foregut fermenters

specific dynamic action

the energy expenditure required by the body to digest, absorb, and assimilate food

types of herbivores

folivory (leaf eaters), frugivory (fruit eaters), nectarivory (nectar eaters), gummivory (gum-eating), mycophagy (fungus-eating), granivory (seed eating)

omnivory

everything eater w/ versatile dentition

optimal foraging strategies

decisions used by animals to obtain optimal cost-benefit for foraging, have to consider amount of energy to expend and amount of time to spend

marginal value theorem

details of when an animal will decide to leave a food patch, energy spent moving between patches, when is it more productive to move on?

food hoarding and caching

animals that cache (rodents, pikas, carnivores, etc.), store food for later when they are more safe or for when food isn’t as readily available