It was given in my school textbook that large body size, small population size, low reproductive rate, feeding at high trophic levels, fixed migratory roots and habitats and localised and narrow range of distribution are the characteristics susceptible to extinction. I don't understand how feeding at high trophic levels and large body size could help in extinction of a species. I have learnt that arthropods can survive better because of its jointed appendages and protective covering. Does their small size help them too? Also, I didn't understand what they meant by saying 'feeding at trophic levels'.