Why does a new, empty island initially have low extinction rates?
“Abundant resources and low competition” for why does a new, empty island initially have low extinction rates. This relationship follows from the ecological mechanism represented by the terms in the item, not merely from an association between their names. At equilibrium, species identities can continue to turn over even when richness is approximately stable. The model predicts a balance of rates, not an absence of colonization or extinction. The remaining alternatives—“High competition”, “High predation pressure”, “Small space”—refer to different states, processes, or scales and therefore do not express the same causal relationship. Island biogeography explains species richness as a dynamic balance between immigration and extinction. Immigration generally declines as an island fills with species, whereas extinction rises as more species divide finite area and maintain smaller populations. The cited framing is therefore most useful when treated as a conditional biological claim, with assumptions about scale and environmental context kept explicit.
Ref: Biogeography, Lomolino et al., 5th Ed., Ch. 5-8