it depends on the season of the animal and the stages of his life
The theory of evolution. Please see the related links.
A change in species is when species for example animals change overtime to adapt to the type of food they eat. So that way the animal will not die because they are hungry
Evolution is a change in species over time.
If there was no change in species over time, then all fossils of that species would be identical.
Species not always change over time such sponges :D
Species can change is there is a mass extinction or if the type of species changed the type of climate or terrain which would would make the species evolve to its new environment so that it can survive.
Where are you people getting these ill posed questions? What level? Transitional forms! At the species level this would be explained as a rapid (geologically rapid) speciation event followed by years of stasis, where little morphological change is taking place.
Speciation
The links below will show you the species occurring in and around Sydney.
In order to know what species would be affected by change one needs to know the type of change you are referencing.
through evolution
through evolution