Chapter 7 Feeding Behavior

1
Chapter 7 Feeding Behavior

• External adaptations
• Snail kite snails
• Crossbills seeds from pine cones
• Anteaters

2
2. Describe the digestive system of a bird. 
Draw a bird's digestive system, label it's parts
and give a function for each

• Herbivore bird digestion
• Crop expansion of esophagus for storage (seed
  eaters)
• Gizzard for grinding food before digestion,
  improve digestion because enzyme partially digest
  before stomach
• Ex. Wild turkey eat whole nuts, crush within 1
  hr. 52 lbs pressure
• Lots of plants but toxins, cellulose, hard
  exodermis (nuts, seeds) hard to digest
• Ceca pouches with bacteria to help break down
  fiber.
• Multiple stomach ungulates aided by bacteria
  to digest cellulose

3
2 3)Types of digestive systems
4
Typical vertebrate digestion

• Mouth ?esophagus?stomach?sm. Int ?lg int? anus

5
Types of feeders

• Omnivore average vertebrate system
• Carnivore larger intestines to digest meat
• Detritivore average vertebrate system

Average system similar to humans. Label and give
a function for each.
6
(3) Carnivore vs herbivore digestive tract

7
(3) Herbivore system deer, cow
A feeding deer is at a disadvantage because
while feeding it cannot be alert to danger. (1)
regurgitates a ball of partially chewed food from
rumen rechews, then reswallows the food, goes
to (2) the reticulum. 3) then omasurn, then
through the abomasum (4) into the intestines
where digestion is completed. 67 feet of
intestine defecate 13 X per 24 hours
8
(3) Horse digestion
9
4. Factors determining caloric need

• Animal size
• Feeding source
• Weather (temperature, moisture)
• Insulation (fur, feathers)
• Cover or shelter available
• Health of animal

10
(4) Calorie needs

• Brody (1945) kcal 140 x body wt in kg)3/4
• 5g shrew 2.63 kcal per day
• 544 Kg brown bear 15,000 kcal per day
• Elephant
• Exception birds smaller than 10 grams need more
• 5 g hummingbird needs 1200 1500 kcal per day

11
(4) Varies over time w/ env conditions and
individual status

• Pregnancy
• Maternity
• Rut season
• juvenile vs old age vs adult

12
Types of food carbohydrates (5)

• 4.2 kcal per gram
• (quick energy) Sugar, starch,
• (long term energy) cellulose, lignin, chiten
• Seeds, wood, all parts of plants Only a few can
  digest lignin and cellulose in wood (lagomorphs,
  beaver, porcupine)

13
Types of food fats (5)

• 9.5 kcal per gram
• Fats, lipids, wax, oils
• Slowly digested, energy storage (carbs converted
  to oils for long term storage).
• Grazers, browsers not really adapted for oils,
  Most carnivores are.
• Gall bladder liver
• Adaptations deer, no fall bladder, secrete bile

14
Types of food protein (5)

• 4.2 kcal per gram
• Nitrogen needed for amino acid, nucleic acid,
  enzymes for all chemical reactions
• Not abundant in plants except legumes
• Plants used as indicators due to low protein
• Clover, alfalfa, beans, peas
• Other plants tips (active growing only)

15
(6) Macro vs micronutrients

• Macronutrients needed in large quantities
• Sodium, potassium, calcium, magnesium, sulfur,
  phosporus
• Micronutrients small (micro) quantity
• Vitamins
• coprophagy eat own feces, absorb vitamins
  bacteria vitamin K biotin especially
• Minerals
• copper, cobalt, nickel, zinc, fl, iodine, chromium

16
(7) Ecology/evolution of feeding behavior

• Plant defenses co-evolved w/ herbivore strategies
  
• pine nut squirrel cones
• Squirrel strategy
• Select for high producing cones
• Stockpile cones for lean years
• Pine tree strategy
• Cones hard to open
• Cones with fewer seeds
• Seeds have increase coat thickness
• Less nutritious seeds
• Drop seeds early (sq rely on other food)
• Periodically produce no seeds at all

17
Plant defenses (7)

• Physical/ mechanical spikes, thorns, sticky
  hairs
• Roses, black locust, raspberries, blackberry

18
Plant defense chemical (7)

• Chemical/ toxins tannins, oils, resins,
  alakaloids, terpenoids, nicotine
• Tree leaves, tobacco, pine trees, sumac, poison
  oak, ivy

19
Food quality (8)

• Quality quantity vary seasonally, with weather
  changes, soil health fertility, animal
  populations
• Rabbits on sandy soil require more food
• Size of animals varies with food quality (compare
  IL white tail to coors or keys or southern
  states)
• Make up for deficiencies by bone, feces ingestion
  (antlers mice, squirrels, porcupines)
• Animals select for missing nutrients

20
Activity cycles keyed to variation in quality and
quantity (8)

• Reproduction waterfowl, songbirds time hatching
  of young to insect cycles
• Number of offspring often related to food
  availability (quality corn vs brush triplets
• Sex specific differences does eat less browse,
  bucks more

21
Age related changes in feeding in ducks (8)
Young?? Juveniles Adult (flyers)
22
(8) List at least 5 caloric values for different
food items (handout).

• Quality of food varies seasonally
• Ecosystem interruption, human impact
• Positive corn, wheat, soybeans
• Negative interrupt ecosystem, pest species not
  as nutritious (canary grass, foxtail, purple
  loosestrife).

23
Food shortages (9)

• Winter starvation few years of catastrophic
  loss (mule deer, whitetail, elk)
• Brant eelgrass collapse 2 of pop left
• Lower metabolic rates, lose antlers, sleep
  longer
• Hibernation, aestivation, torpor

24
Human induced shortages

• Deer in UP michigan fed lumber yards,
• Stopped feeding, collapse artificial high
  population for hunting Beaver Basin
• Now stopped due to chronic wasting fears gave
  to state, MI didnt have funds to supply
  commerical food all winter massive starvation

25
Cover (10)

• Fur, feathers help
• Snow
• Brush low lying, with leaves tall grasses,
  spruces, fir trees

26
Measuring cover (10)
27
Effect of Cover on wind (10)
28
Effect of snow cover (10)
29
Edge effect (10)

• Increased number of plant species at edge
• Variety in cover
• Variety in env conditions (heat, sun, etc)