Midterm 2 Flashcards
Define each primate diet and give examples of each Frugivore Folivore Insectivores Gumnivores
Frugivore- fruit -spider monkeys, guenons Folivore- leaves - colobines, howler monkeys Insectivores- insects - bushbabies Gumnivores- plant gum - mouse lemurs
What do organisms need from food?
A. Vitamins minerals trace elements to regulate bodily processes eg. Na, K, Mg, Ca…. used for fluid regulation nervous system function etc.
B. Nutritional components
1. Proteins:
Essential amino acids not manufactured by the body
2. Carbohydrates:
Energy and also roughage
Simple sugars - easily digested…glucose/fructose
Complex sugars- difficult to digest….cellulose
What should be avoided in food?
A. physical defences such a spines and thorns
Protective ants
B. Chemical defences:
Plant secondary compounds
Alkaloids: toxins leave the gut and disrupt metabolic processes such as nicotine and caffeine
Tannins : digestibility reducing agents dose-dependent example green tea green fruit
What kind of food has what you need Fruit Flowers Leaves Saps/gums Insects/meat
A. Fruit: simple sugars no protein
B. Leaves: complex carbohydrates( but difficult to digest) protein and vitamins but also secondary compounds
C. Flowers: simple sugars in nectar and protein in Pollen
D. Saps/gums: simple+ complex sugars water minerals
Insects/meat:protein, fat
What is homeostasis?
Internal body temperature maintenance by an organism
What is Basal metabolic rate?
The amount of energy needed for homeostasis
What is basal metabolic rate determined by?
Body size
The larger the body, the more energy needed to fuel it.
What is the major determinant in diet choice?
Energy
What is the formula for Keiber’s law??
.75
BMR=70(body weight)
Demonstrate keibler’s law and how it shows that larger species need fewer calories per unit body weight
Tarsier bw- 0.1kg
BMR 12.5
BMR/kg=125
Gorilla bw- 100kg
BMR 2214
BMR/kg = 22.2
Why do larger species need fewer calories per unit body weight??
- BMR devoted to maintaining internal body temp. Which gets sucked out by environment (i.e most of BMR to combat heat loss)
- heat loss occurs through skin
-amount of heat you lose and therefore the BMR needed to combat heat loss, is determined by how much skin you have
SURFACE AREA!!!!
How does surface area scale with body size? Formula
SA=(vol).67 power
Example with cubes
Smaller the cube the higher the surface area:volume ratio
Bigger cube the lower SA:VOL ratio
See slide 18 basic life problems
Being large means you have proportionately less SA for your volume
… proportionately less heat loss
Being large is good way to conserve heat (energy)
Explain how guy capacity is important factor foe diet choice
Food digestibility (how much time in stomach) called gut retention Which is a function of gut capacity which scales with body size
How does gut capacity scale with body size
Gut capacity=(body weight)1.05 power
Food digestibility improves with increased body size
What are the implications for diet choice in small animals?
- High relative BMR
- Small gut capacity
- need high quality, rapidly assimilated food
Few food choices
What are the implications for diet choice in large animals?
- Low relative BMR
- Large gut capacity
- can tolerate low quality hard to digest food
More choices
What does ultimate diet choice depend on?
Availability of food types and energy needed to harvest them
What are the interrelated factors that diet choice is governed by?
Body size
➡️SA:VOL
➡️heat loss ➡️BMR
➡️gut capacity➡️food digestibility
Food quality ➕availability
What are the basic feeding adaptations to the feeding niche?
Body size Teeth slide 37 Gut anatomy (slide 38) Body composition Behavior
What are the 3 types of teeth adaptations and what are they used for?
- Hexagon top and bottom for cutting meat
- Squares top and bottom - crushing/grinding - fruits and seeds
- Small sharp triangles top and bottom grind/ cut - leaves
What are the parts of the gut anatomy?
Stomach- primary digestion
Small intestine- primary absorption
Caecum- blind pouch.. symbiotic bacteria
Large intestine- water and some nutrient absorption
Explain the gut specializations for folivory
Stomach enlargement/ subdivision Caecum enlargement (hindgut fermentation) and ceacotrophy (ingestion of feces)
What is important to know about body composition adaptation for diet choice?
Reduction of energetically expensive tissues in folivores
Lean muscle mass
Brain size
Leaves and fruits
What are the three behavioural dietary adaptations?
- General Activity level eg. Folivores lethargic because a) reduces energy consumption
b)improves digestion - Ranging - frugivores should have larger home range with patches of food fruit
Folivores smaller ranges with more abundant and uniform food sources
leaves - Territoriality- non territorial over lapping ranges or territorial non overlapping ranges
What are the benefits of territoriality?
Reduced resource competition and reduced mate competition
What are some if the costs of territoriality?
Energetic cost to patrol
Risk of injury
Opportunity costs to feeding time lost to territory maintenance
Exclusion of neighbours resources
When should you be territorial?
When benefits out weigh the costs and when you CAN be terriorial
D=defensibility index DPL= daily path length d'= diameter of home range D=DPL/d' D > 1 permits territoriality D < 1 prohibits territoriality
Summary of diet choice adaptations
Diet choice↔️ body size ⬇️ Physical structures Teeth Gut morphology Muscle mass brains Diet choice ⬇️ Behaviour Activity level Ranging Territoriality ⬇️ Also affects details of how you actually forage
What are the Anti predator strategies of adaptation for survivial?
- Cryptic eg. Peppered moth
- Conspicuous but toxic eg. Dendrobates frogs, monarch butterfly
- Conspicuous startling - butterfly wings that look like head of snake
- conspicuous but confusing - zebra
Explain predator counter strategies
Coevolutionary arms race
Pre-evolving skills to avoid predators predators evolving skills to stay ahead of prey
Pray evolving skills to beat those skills and etc.
Eg.reduced sensitivity to aversive pray features
Eg toxin resistance for unpalatable prey
What are primates antipredator strategy
Grouping
What are the antipredator benefits to grouping
- More eyes- predator detection
- Reduce the per capita vigilance costs
- Better active defence
- Dilution effect… The selfish herd
- Improved foraging efficiency
- Better intergroup competitive ability
What are some of the costs to grouping
- More conspicuous to predators( anti predator)
- Increased food competition within groups
- Increased social competition within groups (mates, alliance groups) snd stress
- Increased risk of disease transmission
What are the two evolutionary models of grouping?
- Resource defence (Wrangham)
2. Preditation/intra group food competition (van schaik)
Resource defence evolutionary model of grouping
Explain.
Sociality (grouping) adaptation to improve resource access
I. Food is most limiting to females who try to reduce competition
ii. Females distribute themselves in space in relation to food
a. Low-quality abundant food
- females solitary
b. High-quality scarce, patchy food
- female group harvest food/ defend…
Intergroup competitive ability or
Group with Kin intra group competition
Resource defence evolutionary model of grouping
Predictions and evidence
- Groups should be composed of female kin
- Females should be active in resource defence
- Large groups should have resource access
- Females in larger groups should have higher LRS
Resource defence evolutionary model of grouping
Problems and exceptions
- Not all fruigvorous species group
- Some folivores live in very cohesive groups
- Not clear that females in larger groups have higher LRS
The evolutionary model of grouping
Preditation Intra-group food competition (Van Shaik)
Explain.
Sociality (grouping) is an adaptation to avoid predation
Size of groups constrained by intra group feeding competition
i. Grouping occurs to reduce costs of predation risk.. larger groups favored
ii. As group size ⬆️,
feeding comp. in group ⬆️thereby ⬇️food intake rate
Ultimate group size is balance between reduced predation and increased feeding competition
Optimum group size:
Food intake rate maximized
Predation risk minimized
Evolutionary models of grouping
Predation\intra-group food competition
Predictions and evidence
- Behaviour should very with predation risk
- vigilance higher in small groups
- groups are smaller on islands without predators - Terrestrial groups should be larger than arboreal groups - true!
- Smaller groups should suffer higher predation
- juvenile mortality should be higher and some small groups (resource stress?)
Evolutionary models of grouping
Predation\intra-group food competition
Problem/exceptions
- Hard to actually quantify predation risk
2. Many small vulnerable species are solitary
Predation and grouping of Galagos
Body size:small Diet: insectivore Predator pressure? High Grouping? No * Territorial? Yes Scent marking to reduce territorial costs *grouping constrained by diet choice which determined by body size Nocturnal to reduce predation risk
Predation and grouping of squirrel monkey
Body size:small Diet: fruit Predator pressure?high Grouping? Yes (20-50) Territorial? No though D>1 Defends local patches
Predation and grouping
Baboons
Body size:medium Diet: omnivore Predator pressure?yes Grouping? Yes (30-100+) Territorial? No D<1
Predation and grouping of Gorillas
Body size: very large Diet: leaves Predator pressure? Low Grouping? Yes * Territorial? No * some other factor operating... either diet choice or predation pressure favour grouping
What is a social group?
A set of conspecific animals that interact regularly more so with each other then with members of other social units or groups
