The literature on wood rat dens and middens is often sketchy and ambiguous. For example, words used by hunters, naturalists, and cavers to describe the "sign" at a den or cave en-

FIGURE 8.1 Bushy-tailed wood rat, Neotoma cinerea, the species of wood rat living in Porcupine Cave today.

trance have different meanings to different people. I defined my use of such terms, as widely understood by mammalo-gists, in Finley (1990:28), and I repeat and augment the definitions here.

In this chapter, I follow the convention of using "wood rat" as the common name for Neotoma, in keeping with standardized use in the mammalogy literature. "Wood rat" as used here is synonymous with the more vernacular "packrat."

cache A quantity of food materials piled or stuffed into a sheltered space, such as a crevice, log, or burrow, for later use.

den Any natural or constructed shelter used regularly for protected living space, rest, or the rearing of young, such as a rock crevice.

fecal deposit A layer consisting mainly of fecal droppings that may or may not be indurated by dried urine.

food litter Food materials brought to a place for feeding and dropped as unconsumed debris.

house A den constructed of a pile of various materials and containing one or more passages or chambers. It may be located in the open or at a site under some natural shelter, such as a tree.

midden A layer or accumulation of materials brought to or dropped at any location by an animal, usually but not necessarily the den occupant and including any other materials, such as leaves, pollen, and silt, deposited there by other means.

nest A cup or ball of soft material, such a shredded juniper bark, within a house or other den, used as a bed.

paleomidden A "fossil" midden, which has persisted long enough to survive environmental changes but has not necessarily been altered over time.

post A site used by an animal repeatedly for some function, such as feeding, urination, or scent deposition. Posts may give rise to deposits, such as food litter found either within or away from dens. Urination posts on rock ledges or cave walls often give rise to conspicuous dry stains (amberat) on walls or under ledges sheltered from the weather.

sign Any direct physical evidence of the animal activity that produced it.

urinary deposit A layer of dried urine, usually including some fecal pellets or other materials.

The term "amberat" has been used in many different ways. I have not customarily used the term because of its ambiguity. The oldest reference I have found for "amberat" is by Orr (in litt., 1957, cited in Jackson, 1965). He called it "amberat" because "It has no proper name, but smells of rats" but he was uncertain of its origin. Jackson (1965) showed a photograph of two chunks of material from Defense Cave. One was a rough chunk of indurated rat pellets and plant litter that he called "ancient cave rat guano." The other was a glossy black, solid deposit that he called "amberat."

Paleoecologists Spaulding et al. (1990:60-63) called amberat the "crystallized packrat urine" that saturates and preserves solid plant and other materials. In their lengthy discussion of the "Physical Properties of Middens" they seem to regard the term as synonymous with urine. "Amberat" is also sometimes used to refer to the glossy urine deposits that resemble a shiny black curtain on a cliff face.

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