Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Monarch Butterfly Biosphere Reserve' has mentioned 'Mexico' in the following places:
Occurrence Sentence Text Source
Millions of butterflies travel south into Mexico, from Texas and then follow the Sierra Madre Oriental mountains to the preserve.
[3] The survival of the species depends on a large number of habitats from Canada, the United States and Mexico during its annual migration cycle.
[18] Within the Biosphere in Mexico, the greatest threats to the butterfly habitat are deforestation, illegal logging, unorganized tourism, forest fires and lack of cooperation among various authorities.
High unemployment, especially for youth, also provokes migration into other parts of Mexico and to the United States or Canada.
Up to a billion monarch butterflies return annually, from breeding areas as far away as Canada, to land in close-packed clusters within 14 overwintering colonies in the oyamel fir forests of central Mexico.