Flashcards in Lecture 15- Monotremes II (echidna) Deck (28):
How many species of echidna are there?
-long beaked echidna (2 species but poorly described, lives in PNG)
-short beaked echidna, widespread (Australia and PNG)
How much does an echidna weigh?
-up to 6.5 kg
How long can echidnas live for?
-up to 45 years, average about 17
When are echidnas active?
-diurnal but flexible (anti predator behaviour and avoidance of extreme heatú
How do echidnas react when they see a predator?
-digging claws to dig in the ground
-dig themselves so only the spines visible and exposed= predator avoidance mechanism
-moves slowly due to reptilian pectoral girdle= but smart like cats
Where does the short beaked echidna live?
-whole of Australia and PNG (even the deserts etc= ants are everywhere)
-most widely distributed mammal in Australia
What sort of habitats do echidnas occupy?
-hot arid areas to alpine areas
-it is possible that there may be some variation in thermal ecology and energy needs in echidnas living in such different environments
How do echidnas maintain stable body temperature?
-via thermogenesis (heat production via metabolic activity)
What does heterothermic mean?
-some endotherms are heterotherms
-exhibit marked changes in Tb(body temp): torpor/hibernation
What is hypothermia?
-decline in body temperature below the narrow range normally maintained by a particular endothermic species, need to be warmed up by outside sources to get out of this
What is natural hypothermia?
-animal able to re-warm spontaneously via thermogenesis
What is the pattern for torpor/hibernation for mammals and birds?
-large drop in body temp and a reduction in metabolic rate (reflected in decrease use of O2) thus a reduction in energy use
Does duration of torpor/hibernation vary?
-yes, vary across species
-some species go into torpor every day
What is the temperature of active echidna?
What happens to an echidna in winter?
-bouts of torpor
-lowers temp tas much as to 5C
-when in hibernation cannot move
-must be in a safe place so it doesn't get predated
When do echidnas go into torpor?
-some go into torpor before winter, at a time when fattest
-some animals didn't go into torpor=when not fat enough and juveniles
-even in desert go into sort of torpor when food shortage
What is the function of torpor in echidnas?
-inhabit low productivity environments, some cold, some arid= food shortages common
-torpor= an energy saving strategy to deal with periods of low energy availability
How is echidna feeding ecology determined?
What is a myrmecophage?
-specialised in eating social insects (ants, termites) more than 75% of diet
-ants and termites high in fat compared to many other invertebrates
-echidnas are myrmecophages
What are some common characteristics of myrmecophages?
-very reduced or no teeth
-long narrow snout
-(eg. echidna, aarvark)
WHat was the result of the study looking at diet in echidnas?
-70% larvae and pupae= coleoptera= big larvae= smash them with their tongue and suck the contents out
-so there is variation from environment to environment in what they eat
WHat is the diet of echidnas?
-preference for ants, but some flexibility
-seasonal changes related to prey availability
-scrab beetle larvae (20-40% fat) important seasonall. Intake correlates with energy demands.
-maybe use electro-reception(nose poke and hold) when foraging in soil
When do echidnas breed?
-males form trains (follow females)=the first male= the highest level of testosterone
How long is gestation?
How many eggs?
1 egg laid into pouch
(1 young /1 year)
How long is incubation?
Where are the young in the beginning of their life?
-carried in pouch for 45-55 days then left in nest/burrow (get spikey then)= risk of predation at this stage