Nutritional Ecology: Food Processing Systems PDF

NUTRITIONAL ECOLOGY: FOOD PROCESSING SYSTEMS  Typical mammalian digestive tract Finish Start I. MAMMALIAN DIGESTIVE SYSTEM A. ________ Cavity – lips (bills) – taste buds – teeth – tongue – ________ ________ Saliva lubricates food Swal...

NUTRITIONAL ECOLOGY: FOOD PROCESSING SYSTEMS  Typical mammalian digestive tract Finish Start I. MAMMALIAN DIGESTIVE SYSTEM A. ________ Cavity – lips (bills) – taste buds – teeth – tongue – ________ ________ Saliva lubricates food Swallowing Digestive prep for stomach Prominent in herbivores (dry fibrous diet) – Myrmecophagy (extreme buccal cavity) Feed on social insects anteaters pangolins aardvarks Long rostrum Tubular mouths Long tongue pangolin muscles to pelvis Covered filiform papillae (small posteriorly spines) Covered stick secretions from salivary gland Echidna tongue  I. MAMMALIAN DIGESTIVE SYSTEM B. Esophagus  From buccal cavity  To stomach C. Stomach  ________ digestion common  pH simple (not forestomcachs) 1 – 4  Hydrochloric acid  I. MAMMALIAN DIGESTIVE SYSTEM C. Stomach – Foregut fermentation in mammals – Why fermentation? – Anaerobic bacteria break down cellulose – Anterior portion of many herbivorous mammals contain anaerobic bacteria – Colobine monkeys, tree sloths, camels, deer, antelope, hippos, kangaroos I. MAMMALIAN DIGESTIVE SYSTEM C. Stomach  ________(deer, antelope, cattle)  4 chambered stomach  Abomasum = ________ ________  Rumen fluid 1 ml > http://sci.waikato.ac.nz/farm/content/ 10 billion bacteria animalstructure.html  Microbial fermentation ________ ruminant energy Colobine monkeys Complex sacculated stomachs Most efficient primate leaf digestion Endosymbiotic bacteria breakdown cellulose deactiviate toxins (alkaloids) in leaves E.G. Hanuman langur eats strychnine-laced fruit  Sloths (Pilosa) Foregut fermentation + low- budget lifestyle Highly arboreal (only descend to XXXXX) 4 chambered stomach & foregut fermentation Very slow rainy season algae gestation 11.5 months 15lbs = 3 months Energy conservation well insulated fur countercurrent heat No teeth Pyloric portion stomach terminal end or sphincter Thickened Contains pebbles Gizzard like grinding Pangolin Digestive System  I. MAMMALIAN DIGESTIVE SYSTEM E. Cecum (________ fermentation) – elongated tube, opening at juncture of small and large intestine – H2O ________ – bacterial fermentation of unabsorbed plant fiber – ________ than forestomach fermentation where food particle must be small before passing from stomach – wildebeest, wallabies, rabbits, beaver, horses  I. MAMMALIAN DIGESTIVE SYSTEM D. Small Intestine  Nutrient absorption into bloodstream  Length a function of food habits  Carnivores short  Herbivores long (harder to break down plant materials)  Changes in Gut Size Voles & white-footed mice during ________ Response to increased ________ requirements or lower-quality food Most pronounced in small intestine, cecum sites of nutrient absorption Increases in gut tissue Derting and Noakes, Can. J. Zool., 1995, metabolically expensive 73:243 so only occur in ________ conditions I. MAMMALIAN DIGESTIVE SYSTEM F. Large Intestine  posterior end small intestine to rectum  function similar to cecum (H2O absorption)  Colonic portion contains microflora for fermentation in some mammals (e.g. horses, New World monkeys, pigs, and humans) II. FOOD HOARDING: A PROCESSING STRATEGY FOR MAMMALS A. Basic Information – hoarding = caching = storing II. FOOD HOARDING: A PROCESSING STRATEGY FOR MAMMALS A. Basic Information on Hoarding – hoarding = caching = storing – handling food to conserve it for _____________ – 6 orders and 30 families – short-term: carnivores – long-term: granivores, herbivores – scatter versus larder hoard Red squirrels larder hoarder 14,000 spruce cones to midden in autumn Some survive seed crop failures Fox and gray squirrels Scatter hoarders Recover cache Dec – Feb Use memory or odor (Jacobs 1991)  II. FOOD HOARDING B. Protection and Management – Against decomposition – Microbes and fungi can make cache ________ or _______ – ________ before storage Resistance to decomposition – Kangaroo rats Peppergrass seedpods Surface pits outside burrow Store in underground chambers  II. FOOD HOARDING B. Protection and Management – of green vegetation – pikas, gerbils, mountian beavers – summer harvest – cured in haypiles – pikas select vegetation high in phenolics phenolics = secondary compound potent antimicrobial properties levels decline prior to consumption Rock overhangs = barns for pikas  II. FOOD HOARDING B. Protection and Management of – Of animal foods – Animal foods ________ easily – Insectivora strategies for fresh meat Short-tailed shrews inject prey (worms, insect, mice) with toxin from submaxillary gland. Prey ________ but alive for 5 days. Moles store earthworms in fall and early winter. Mutilate anterior segment of worm and store in cool place to prevent escape  II. FOOD HOARDING B. Protection and Management – against escape – mole rats and voles nip buds from bulbs prevent sprouting – gray squirrels & white oaks Cape mole rat white oaks germinate in autumn acorn losses nutritional value squirrels notch acorns – excise embryo – prevent germination – then store – black oaks just stored not notched  II. FOOD HOARDING B. Protection and Management – against theft – hide items (________vs ________) – defend cache  II. FOOD HOARDING B. Protection and Management – Against theft – kleptoparasitim  II. FOOD HOARDING C. How Do Hoarders Relocate Caches? – ________ – Deer mice and seeds buried 2” in peat  II. FOOD HOARDING C. How Do Hoarders Relocate Caches? – Spatial ________ (grey squirrels) – Niko Tinbergen (1965) – Red fox foraging experiments  II. FOOD HOARDING Spatial Memory: Tinbergen Trials (1965) – Trial 1: tame fox hid 50 mice – 1 – 2 days later it relocated 48 of 50 of its own caches  II. FOOD HOARDING Spatial Memory: Tinbergen Trials – Trial 2: Tinbergen stored second mouse < 3 m from foxes caches – fox found only 2 of 20 Tinbergen-cached mice  II. FOOD HOARDING Spatial Memory: Tinbergen Trials – Trial 3: Tinbergen moved foxes cache 1 m away – fox found only 25% of mice displaced 1 m from cache  II. FOOD HOARDING Spatial Memory: Tinbergen Trials – Trial 4: Multiple foxes placed caches. Foxes later only found their own caches and none of the other fox’s caches