sentences:  Of them, 133 are rare or accidental, four have been introduced by humans, and five have been extirpated from Morocco.Non-native species which have not become established, or whose natural arrival is uncertain, are not included here.This list's taxonomic treatment (designation and sequence of orders, families and species) and nomenclature (English and scientific names) are those of "The Clements Checklist of Birds of the World", 2019 edition.