Final answer:
Succession increases animal species diversity due to an increase in available food choices, which allows for a greater variety of organisms to coexist within an ecosystem.
Step-by-step explanation:
The question relates to the concept of ecological succession, which is a process that communities undergo as they mature over time. As succession progresses, animal species diversity tends to increase primarily because food choices increase. This diversification in food resources allows for a greater variety of organisms to coexist and thrive within the ecosystem. When more ecological niches are available, it provides opportunities for different species to fill these roles, thus increasing biodiversity.