Lecture 25- Animal Adaptations I Flashcards
What are the four ecological rules applied to northern animals?
- Rapoports rule
- Bergmanns rule
- Allens rule
- Glogs rule
What is rapoports rule?
Geographic ranges of species are larger at higher latitudes
Rapoports rule explains why there is ____ near the equator
Higher diversity (smaller ranges = more species in the same area)
Larger ranges = ____ species
No room for new species
Rapoports rule doesn’t hold true for all species but seems to hold true for species ______
Species > 40 degree north
What is Bergmanns rule?
Body size of individuals within a single species gets larger further north
Bergmanns rule is related to what?
- Migration ability
- Starvation resistance
- Heat conservation
- Resource availability
As temperature increases, ____ decreases
Body mass decreases
What species is a good example of bergmanns rule for northern species and describe why?
- Example = Woodpecker
- Downy woodpecker = the wing length increases further north
- Hairy woodpeckers = Body size increases further north (tropics = 40g, Alaska = 120g)
What is the heat conservation hypothesis?
Larger individuals have a reduced surface area to volume ratio (radiate less body heat)
What are some exceptions to heat conservation hypothesis?
- Generally applicable to mammals
- Mustelids and small mammals typically dont follow this rule
What is the resource availability hypothesis?
Body size is proportional to productivity
Describe mid latitude and northern large bodies animals using resource availability hypothesis
- Mid-latitude = not constrained by low resources
- Low latitudes = not constrained by competition (less species for the same resource)
What is Allens rule?
Animals adapted to cold have shorter limbs and smaller protruding body parts
Allens rule is related to what?
Surface area = volume ratio
Reduced limbs =?
Maintains core warmth
What is Glogers rule?
Individuals within related species have lighter pigment further north (based on lower levels of melanin)
What are some mechanisms of Glogers rule?
- Camoflauge
- Photoprotection (darker skin protects from UV radiation)
What are some exceptions to Glogers rule?
Polar bears = white fur but black skin
Winter is a season of decrease in what types of energy?
- Solar energy
- Thermal energy
- Nutritional energy
Describe winter energetics
Organisms must balance trade offs of energy supply with survival
What is energy budget?
How organisms allocate resources
What is the largest during the winter energy budget?
Maintenance
What are included in the energy budget?
- Maintenance
- Growth
- Reproduction
- Activity
