An Annotated Check List of the Mammals of Michoacán, México

In Short

This technical volume serves as a comprehensive, annotated catalog of the wild mammal species inhabiting the Mexican state of Michoacán. Compiled to support broader scientific efforts to document the region's natural resources, it provides accurate nomenclature, geographic ranges, and physical descriptions for eighty-five distinct species. By bridging the gap between field research and existing institutional collections, the work established a vital baseline for mid-twentieth-century zoological study. It remains a significant reference for researchers interested in regional mammalogy and the specific taxonomic history of Central Mexican fauna.

The Story

The project originated under the administration of President Lázaro Cárdenas, who sought to record the cultural and natural heritage of Mexico’s linguistic and regional groups. Within this framework, a collaborative committee of American and Mexican scientists organized an expedition into the heart of the Tarascan region. The primary goal was to conduct an inventory of the state's wild mammal life, a task that demanded careful field work and the subsequent verification of specimens held in museums across the United States.

The field research took place largely in 1943, with the party navigating a diverse array of elevations—from coastal lowlands to high mountain ranges. The narrative of the book is structured as a systematic traversal through these habitats, beginning with the opossum and moving through the complex orders of bats, rodents, carnivores, and ungulates. At every step, the authors provide the scientific name, the common English and Spanish designations, and the indigenous Tarascan names where known, honoring the local linguistic context of the region.

The text does not shy away from the practical complexities of scientific classification. For instance, the authors note a specific boundary change that necessitated the removal of a town, Acámbaro, from the Michoacán records, as it was reclassified into the state of Guanajuato. Such details reflect the meticulous nature of their investigation. Throughout the species accounts, the authors record their findings, sometimes noting where their traps failed to produce a specimen, and other times describing the behaviors they witnessed firsthand, such as the peculiar "two-story" burrowing habits of certain pocket gophers.

The account concludes by acknowledging that the inventory is an ongoing process. The authors identify gaps in their records—noting, for instance, that several types of bats and larger cats almost certainly inhabit the region despite lacking positive confirmation at the time of publication. By compiling their findings with references to earlier, often fragmented studies, they provide a cohesive, if incomplete, map of the state's biological richness. The final sections are dedicated to an extensive bibliography and technical notes, solidifying the work as a reference tool intended for future biologists. It is a record that closes with an invitation to others: the recognition that more intensive collecting will undoubtedly expand this list, building upon the foundations laid by this team of researchers.

How It Unfolds

The mandate for discovery The research begins as part of a national effort to document the natural resources of Michoacán, bringing together ethnologists and biologists. The team, including researchers from the University of Kansas and local Mexican institutions, prepares to catalog the wildlife of the region.

The field investigation The party conducts extensive fieldwork in 1943, traversing the state to trap and observe mammals across varying ecological zones. They record their findings with precision, often noting specific elevations and locations, and collaborate with locals who share insights about the animals.

The synthesis of data The authors merge their own primary findings with established records from the University of California Museum of Vertebrate Zoology and the Chicago Natural History Museum. They address taxonomic debates, clarify synonymies, and offer critical remarks on the physical variations observed within species.

The ongoing inquiry The volume concludes by listing the known mammals while honestly identifying what remains elusive. By providing this annotated list, the authors set a definitive baseline, expecting and encouraging subsequent generations of scientists to refine and expand upon their work.

The People

E. Raymond Hall serves as the primary architect of the checklist, bringing a rigorous, academic focus to the identification and classification of the specimens. He is driven by the desire to create an organized, reliable reference that reconciles diverse, scattered literature with actual physical evidence.

Bernardo Villa R. acts as a critical collaborator, representing the Instituto de Biología de la Universidad de México. His presence bridges the gap between international research and local expertise, facilitating the inclusion of Spanish and Tarascan nomenclature that grounds the work in its specific cultural geography.

The text also credits several secondary figures: J. R. Alcorn and Roberto Alcántar, whose contributions to the field work were essential, and the local residents like P. Luna, whose knowledge of animal habits—such as the presence of shrews in fish-rearing tanks—offered the researchers anecdotal evidence that they would later verify with specimen collection. These individuals, whether formal scientists or local guides, are united by the shared, incremental goal of documenting the state's biological diversity.

In Its Own Voice

"It is noteworthy that specimens recorded in the literature from Acámbaro, Michoacán, no longer are to be ascribed to Michoacán, since a relocation of the boundary between the states of Michoacán and Guanajuato, places Acámbaro in the latter state."

This statement highlights the precise, sometimes challenging nature of tracking biological records across evolving political landscapes.

"We recognize that the Mexican species of Artibeus are not well understood, at least by us."

The authors provide this humble admission while discussing the complexities of identifying specific fruit-eating bats found in the state.

What It's Really About

The central theme is the necessity of systematic order in the face of biological complexity. The book serves as an argument for the importance of the physical specimen; it treats the museum label and the field observation as the fundamental building blocks of scientific truth. Beyond the individual accounts, the book poses a question about the limits of knowledge: how much of the natural world remains hidden in the "probably" of an ecological survey? It explores the tension between wanting to finalize a comprehensive list and the reality of an ever-changing, partially understood landscape. It is fundamentally an exercise in humility and accuracy, demonstrating that before we can conserve or understand an environment, we must first learn the names and ranges of those who live within it.

Why Read It Today

Readers with a deep interest in the history of mammalogy, taxonomy, or the specific ecological landscape of Michoacán will find this book an essential, if austere, record. It is not written for a casual audience; its pages are dense with measurements, technical descriptions, and citations of older, sometimes obscure, journals. The experience of reading it is similar to stepping into a mid-century museum archive; it is precise, quiet, and exacting.

The value for a modern reader lies in the snapshot it provides of a 1940s landscape, capturing a moment when the classification of species was still very much a work in progress. While the scientific terminology has since evolved, the book’s commitment to documenting the specific indigenous names for these animals—such as the Tarascan words for the opossum or the coyote—offers a rare, enduring bridge between scientific taxonomy and local knowledge. It remains a testament to the persistence required in field biology, reminding the reader that every scientific consensus is built upon hundreds of small, patient hours spent in the field. Those who appreciate the mechanics of scientific discovery will find a quiet beauty in its exhaustive detail and its admission of the mysteries that still remained in the mountains of Michoacán.