Question: how many types of finch species are there
[{'answer': 'about fifteen'}, {'provenance': [{'wikipedia_id': '328709', 'title': "Darwin's finches", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 654, 'bleu_score': 0.934495157082537, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14299619511903269769}, 'section': 'Section::::Abstract.'}]}]