Scientist cataloged by the international community as the last naturalist of the 20th century, recognized for his outstanding work in the field of zoology and nature conservation.

His interest in nature, particularly that of the tropics, led him to accept a job offer in the state of Chiapas, where he stayed forever, doing a work that has become an obligatory reference for both biologists and conservationists.

In 1942, responding to a summons issued by Dr. Rafael Pascacio Gamboa, then governor of the state of Chiapas, Álvarez del Toro traveled to Tuxtla Gutiérrez where he held the position of taxidermist and general zoologist in the recently created Department of Tropical Nurseries and Museum of Natural History, there, he collaborated with Professor Eliseo Palacios Aguilera, its director.

In recognition of his work, the Government of the State of Chiapas determined in 1980 that the Zoo be called "Zoológico Regional Miguel Alvarez del Toro" (now known, by its acronym, as ZOOMAT).

At the national level, for the first time, the alligator (Caiman crocodilus) in 1966, and river crocodile (Crocodylus acutus) in 1993; the Central American tapir (Tapirus bairdii), grison (Galictis vittata), viejo de monte (Eira barbara), as well as the longevity record of the harpy eagle (Harpia harpyja) (47 years).

Frequent adviser of various professional thesis works and research projects with topics related to Biology, Veterinary Medicine and natural resources in general.

Álvarez del Toro's work had an enormous impact on different branches of knowledge in zoology, at the same time sowing the seeds for the conservation of biodiversity in Chiapas: Giving continuity to the work initiated by Professor Eliseo Palacios Aguilera in the 40s of the 20th century, Álvarez del Toro was in charge of safeguarding the fossil pieces of Chiapas and the Paleontological Collection.

In 1942, Álvarez del Toro began what is currently the largest ornithological collection in Southeast Mexico, with a representativeness of more than eighty percent of the species registered in Chiapas.