Frogs Flashcards
Amphibian Orders
Order Anura
- Frogs and toads
Order Caudata
- Salamanders and newts
Order Gymnophiona
- Caecilians (wormy boys)
Anura features
- short body
- protruding eyes
- large hindlimbs
- lifecycle = egg -> tadpole -> adult (mostly external fertilization
Frog Families (6)
- Pelodryadidar (tree frogs)
- Myobatrachidae (ground frogs)
- Limnodynastidar (foam-nesting ground frogs)
- Microhylidae (microhylid frogs)
- Ranidae (true frogs)
- Bufonidae (toads)
Pelodryadidae
‘Tree Frogs’
- ground and tree dwelling
- standard breeding
- Australia/PNG distribution
Myobatrachidae
‘Ground Frogs’
- ground dwelling
- broad environments
- standard (and some unique) breeding strategies
- Australia/PNG distribution
Limnodynastidae
‘Foam nesting’
- broad environments
- standard breeding from a foam nest
- Australia/PNG distribution
Microhylidae
‘Microhylid Frogs’
- Restricted to NE Aus
- Terrestrial breeding (tadpole grows inside egg)
- Global tropic and subtropic distribution
Ranidae
‘True Frogs’
- classic looking frogs
- Global distribution (only one species in Aus)
Bufonidae
‘Toads’
- introduced species in Aus
- global species variation
- pond breeders
Impacts of toads
- poison animals that eat them
- eat animals smaller than them
- outcompete native species
- indirect effects (eg. resource competition, food chains)
There is frog diversity when it is…
- warm
- wet
- mountainous
Wet tropics
- rainforest on mountains
- coastal lowlands
- isolated rainforest (changes in distribution over time)
Species distribution depends on…
- where the habitats are now and where they used to be (suitability)
- where barriers are now and where they used to be
- competition
Frog basics
- hopping movement (few walk)
- ectotherms
- moist skin (water exchange through skin)
- minimal diet specialisation (primarily invertebrates but will eat anything)
- primarily nocturnal (in AUS)
Frog mating
- mate choice dominated by calls
(only males call) - calls made up of pulses |||| …. |||| …. ||||
- differences in duration, frequency, pitch, etc.
Mating calls
- attract mates (mff)
- aggression (mfm)
- calls are sometimes combined (may start out with one call for female and end in call for male
Species discrimination
choosing a male from the right species
Sexual selection
choosing a preferred male
eg.
- pitch can indicate size
- temporal properties indicate energy expenditure
Standard breeding
- multiple eggs surrounded by jelly in water
- tadpoles form and leave eggs
- tadpole swims around (has gills)
- develops hind legs
- eventually develops body, loses tail and becomes a frog (leaves water)
Pros and cons of standard breeding
+ huge number of eggs (little investment)
+ aquatic environments have a lot of food
- NEED water for some period of time
- lots of predation in aquatic environments
Pros and cons of other breeding strategies
+ removed from high predation of aquatic environment
+ higher success per egg (parental care)
- smaller clutch size
- more parental investment
- terrestrial predation (managed by parents)
Rheobatraccus spp
gastric breeding frog
- egg fertilized externally
- egg swallowed after fertilization
- jelly on egg ceases gastric acid production
eggs hatch into tadpoles - tadpoles develop and frog emerges through mouth
Frog habitat types
- open forest
- arid areas
- swamps
- rainforest
Open forest frogs (woodlands)
- high DIVERSITY, high ABUNDANCE
- dry habitat with short periods of flooding
- explosive breeding during rain
- rapid tadpole development
- ephemeral water body survival - refuge sites during the dry season (in trees, dry cracks, covered)
