# California Mammals > In 1906 Frank Stephens set out to describe every mammal known from California, all 276 of them, from gray whales to bats. Between the measurements and skull notes are field observations that still speak to trackers: pocket-rat tracks around his camp, the heel and tail marks of pocket mice in dusty roads, a burrow dug open to reveal six granaries of acorns, and cougar tracks from a cat he never once saw alive. Summary by Kersey Lawrence, Original Wisdom. Updated 9 November 2026. Page: https://www.originalwisdom.com/tracking-literature/1906-stephens-california-mammals/ ## Citation and access - **Authors:** Frank Stephens - **Year published:** 1906 - **Journal or source:** Book, The West Coast Publishing Co., San Diego, California - **Full citation:** Stephens, F. 1906. California Mammals. Illustrated by W. J. Fenn. San Diego, California: The West Coast Publishing Co. - **DOI:** 10.5962/bhl.title.57008 - **Access status:** Hosted (freely available elsewhere) - **PDF:** https://www.originalwisdom.com/wp-content/uploads/2026/11/1906_Stephens_california-mammals.pdf ## Tags - **Species:** Mammals > American beaver; Mammals > Bighorn sheep; Mammals > Kangaroo rat; Mammals; Mammals > Mountain lion; Mammals > Pocket gopher; Mammals > Pocket mouse - **Region:** North America > United States - **Tracking:** Burrows; Caches; Feeding signs; Tracking; Tracks; Tracks and signs identification - **Behaviour and ecology:** Behaviour; Communication; Feeding; Food caching; Hunting; Migration - **Methods and technology:** Direct observation; Distribution mapping; Literature review - **Data type:** New field data; Review - **Observer qualification:** Reported but not validated - **Discipline:** Behaviour and ecology - **Year published:** 1906 ## Detailed keywords - **Species:** Studied: all 276 mammal species and subspecies then known from California and its offshore waters, from whales, dolphins and porpoises, deer, elk (wapiti), pronghorn and bighorn, through squirrels, beavers, mice, rats, pocket gophers, pocket mice and pocket rats (kangaroo rats), hares and rabbits, seals and sea lions, cats, dogs, raccoons, bears and weasels, to shrews, moles and bats. Examples with fuller accounts: California gray whale (Rhachianectes glaucus), Pacific right whale (Balaena japonica), Nelson bighorn (Ovis nelsoni), Gambel pocket-rat, short-eared pocket-mouse, pocket gophers (Thomomys), ground squirrels, beaver, valley coyote (Canis ochropus), cougar, grizzly bear (Ursus horribilis). The list ends with people, as “Homo sapiens americanus, American Indian”. Names and classification are those of 1906 and many have since changed. - **Location and habitat:** California, United States, and the Pacific Ocean off its shore. The book divides the state into life zones (Arctic, Boreal, Transition, Upper Austral, Lower Austral and Sub-Tropical) and named faunal areas (for example the Mojave, Colorado Valley, San Diego, Sacramento and Island faunas), shown on a map. The author’s own fieldwork was mainly in southern California, with none in the northwest and little in the northeast of the state. - **Topics:** natural history field guide; species descriptions and identification keys by order, family and genus; body and skull measurements (total length, tail, hind foot, ear) and dental formulas; distribution and life zones (after C. Hart Merriam); food and feeding; food storage in burrow granaries; burrow structure; gaits; voice; breeding; whaling and hunting; extermination and decline (grizzly bear, bighorn, right whale); state bounties on coyotes; control of ground squirrels and pocket gophers by poisoning and trapping; Indigenous Californian peoples and their 21 language groups; glossary of technical terms. - **Statistics or models:** None - **Data type:** Review: a compilation of published papers and collectors’ records, with long extracts from C. M. Scammon (1874) on marine mammals. New field data: the author’s own observations over about thirty years, mostly in southern California (dates given for some, such as an opened burrow in January and beaver signs in February and March 1903). Dates of most observations not given. ## Synopsis ### 1. What they did Frank Stephens wrote the first general guide to the mammals of California since 1857, when Baird’s volume of the Pacific Railroad Reports appeared (and that one left out marine mammals, bats and people). He aimed it at students and beginners, using technical terms only where they saved space and adding a glossary. The book works through each order, family, genus and species in turn. For each species it gives: - A short description, with measurements in millimetres and inches. The author explains how each measurement is taken, including the hind foot measured to the true heel, “what is popularly, but wrongly, called the knee” in cats, deer and dogs. - The type locality and range within California. - Notes on habitat, food, habits and breeding, where known. He calls the book “little more than a mere dry skeleton” and a compilation of the work of everyone who had collected or written on California mammals, condensed from many sources without citing each one. Where he had his own experience he added it. The book closes with a chapter on life zones, a list of all species with their zones and faunal areas, a diagram of a skull, a glossary and an index. W. J. Fenn drew the illustrations “from studies in the field.” ### 2. What they found Scope - 276 forms of mammals are listed for California, from whales to bats, with people last. - The author explains the large number by the size and length of the state and, above all, its range of climates, from subtropical desert to the snows of the Sierra Nevada. Life zones - Following C. Hart Merriam, he divides California into Arctic, Boreal, Transition, Upper Austral, Lower Austral and Sub-Tropical zones, set mainly by temperature and then moisture, with smaller “faunas” within them. He gives the characteristic mammals and birds of each. Examples of natural history from the accounts - California gray whale: found off California from November to May. The females enter the lagoons further south to give birth while males stay outside; they then travel north close to shore (quoted from Scammon). - Nelson bighorn: prefer hilly or mountainous, arid country with springs; the author saw their tracks in small valleys, but they rarely come onto level ground. A stomach he examined held mainly leaves, twigs and flowers of shrubs, even though green bunch grass was plentiful. - Gambel pocket-rat: one burrow he dug open had a nest of grass-seed hulls and six food chambers holding 149, 27, 24, 131, 139 and 26 acorns plus seeds, 42 ounces of food for an animal of 2.25 ounces. The acorns came from a tree more than 100 feet away. Entrances are usually closed by day. Their gait is a series of leaps of three to four feet. - Short-eared pocket-mouse: tracks often seen in dusty roads in the morning, recognised by the long heel marks, sometimes with the mark of the tail. - Pocket gophers: their tunnels are usually less than a foot deep, at the depth where roots are richest, and are extended daily. The earth is pushed out through side tunnels into mounds, and the openings are then closed. - Valley coyote: hunts mostly in open ground by running prey down, usually alone or in groups of three or four. A state bounty on coyotes cost the treasury heavily, brought no lasting benefit to ranchers, and was followed by a great increase in hares. - Cougar: in about thirty years in the wildest parts of the West the author never saw a live cougar outside a cage, only their tracks in sand or dust a few times. - Grizzly bear: once common, now rare and likely to become extinct soon; the few left hide in rough, brushy canyons. Pest animals - The book gives practical advice on killing ground squirrels (poison, gas, smoke, trapping, shooting) and on trapping pocket gophers in their runs. People - The section on people describes the Indigenous peoples of California and maps their 21 language groups. It reports their sharp decline after the gold rush through persecution, alcohol and introduced disease. It is written in the racial attitudes of 1906. ### 3. What they concluded - Knowledge of California’s land mammals had grown greatly in the previous fifteen years, and some material had not yet been examined by experts, so the author expected more species to be added and names to be revised. - Learning a species’ name should be the first step towards studying it, “and not the end as is but too often the case.” He hoped the book would help readers find out for themselves more of the life histories of California mammals. - The distribution of life is governed by natural laws, mainly heat, then moisture, soil and light, and California’s mountains and coast give it a greater variety of life zones than perhaps any similar area. ### 4. How tracking was or was not used This is a species guide, not a tracking study. The author draws on tracks and signs in passing as part of his field observations: bighorn tracks in desert valleys, pocket-rat tracks around his camp showing they had searched for crumbs at night, the heel and tail marks of pocket-mouse tracks in dust, cougar tracks in sand, beaver signs along the Colorado River, the mounds and closed openings of pocket gopher runs, and the structure and food stores of a pocket-rat burrow he dug open. Acorns partly eaten by pocket-rats were opened from the base, where the shell is thinnest. ### 5. Tracker or observer certification Reported but not validated. The observations are the author’s own, based on many years of fieldwork in the West, mainly southern California. His experience is not tested or described further. ### 6. Other technologies, skills or innovations - A standard set of measurements for specimens (length, tail, hind foot, ear from crown), with instructions for taking each and a conversion table between inches and millimetres. - Colours named after Ridgway’s “Nomenclature of Colors.” - A map and list linking every species to its life zone and faunal area. ### 7. Implications for conservation (from the paper) - Grizzly bears were expected to become extinct in California soon, and white hunters were held responsible for wiping out bighorn over much of their former range. - The coyote bounty is described as an “unwise law” that cost the state heavily, gave ranchers no lasting benefit and was followed by more hares, which coyotes help keep in check for vineyard owners. - At the same time, the book recommends wiping out ground squirrels and pocket gophers on farmland. ### 8. Implications for tracking (Original Wisdom's observations) _These are Original Wisdom's observations, not the authors'._ - Even in a book built mostly on skins and skulls, the author’s best behaviour notes come from tracks and signs: tracks around camp, digging open a burrow, and reading what was stored and how it was eaten. It shows how much of a small animal’s life can be read from what they leave behind. - His account of the cougar, an animal he never saw alive in thirty years but whose tracks he found, illustrates why tracks and signs are often the main evidence for elusive carnivores. - The book is a historical baseline for California’s mammals in 1906, including species since lost from the state, such as the grizzly bear. ## Cite this summary Lawrence, K. 2026. Summary of: California Mammals (Stephens, 1906). Original Wisdom, Tracking Literature. https://www.originalwisdom.com/tracking-literature/1906-stephens-california-mammals/