Faunal Remains

by Jonathan C. Driver

1
This report discusses all animal bones collected during excavations by the Crow Canyon Archaeological Center at Castle Rock Pueblo. The total site assemblage reported here is a mixture of specimens derived from a probabilistic sampling design and from judgmental placement of excavation units.

2
Most zooarchaeological interpretation requires comparison between sites or comparison of archaeological assemblages with models of animal bone frequencies derived from ethnographic or experimental studies. For example, the relative frequencies of different species at Castle Rock Pueblo must be interpreted by reference to other sites in the region. Analysis of the frequency of different parts of the skeleton has to consider models of the survival of bones of different densities and models of the effects of human behavior on the transport of different parts of a prey carcass (Lyman 1994*1).

3
The zooarchaeological data from Castle Rock Pueblo have already been compared with data from other Pueblo III assemblages in the Sand Canyon locality (Driver 1996*1, 1997*1; Driver et al. 1999*1). The data have also been incorporated into a larger study of ancient Puebloan assemblages from the northern San Juan basin (Driver 1999*1). Rather than repeat previously published material, this report offers a short summary of the zooarchaeological database and a brief consideration of bone preservation and intrasite spatial variation at Castle Rock Pueblo.

Methods

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Information about each specimen was entered on a separate line of a computerized database. The database, along with the database codes and analytical methods, will eventually be available on-line at the Crow Canyon Archaeological Center. Specimens were considered identifiable if the skeletal element could be identified. Specimens for which the element could not be determined were recorded as "unidentified." Taxonomic designations for the identified specimens ranged from general (for example, small mammal) to species name. The following fields were used to describe each specimen: provenience, taxon, element, part of element, state of fusion, breakage, modification, length, and thickness (long bones only). These fields are discussed more fully elsewhere (Driver et al. 1999*1).

Identified Taxa

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Altogether, 2,504 specimens were identified, and another 2,981 were considered unidentified (Table 1). All of the taxa identified have been found at other archaeological sites in the Northern San Juan region, and most have been identified at other sites in the Sand Canyon locality (Driver et al. 1999*1). Amphibians and reptiles were not identified precisely and are probably intrusive.

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As is the case with most Pueblo III sites in the Sand Canyon locality, the bird fauna seems impoverished when compared with that of other Southwestern sites. Other than turkeys, which were probably domestic (Munro 1994*1), birds were dominated by raptors, including a large hawk, a large falcon, and a kestrel. Four of the five owl bones are similar to those of Aegolius sp. and were collected from Structure 305. Specific identifications, however, could not be made, because a complete comparative collection of owls was unavailable. It is notable that a large part of an immature Buteo (hawk) skeleton was found on the floor of Structure 107. Twenty-two Buteo specimens were from this skeleton, and another 52 specimens (mainly vertebrae and ribs) identified only as "medium bird" are certainly from the same skeleton. This was probably a deliberately deposited bird, and it suggests that young hawks might have been kept at the site. It should be noted that most of the specimens identified only as "large bird" are probably from turkeys.

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Mammal remains were dominated by lagomorphs (jackrabbits and cottontails). Very small rodents are probably underrepresented because most small rodent bones are lost during screening. Larger rodents include members of the squirrel family (chipmunks, ground squirrels, and prairie dogs) as well as pack rats (Neotoma sp.). The problem of distinguishing intrusive rodents and lagomorphs from those that were used by people has been discussed elsewhere for Sand Canyon locality sites (Driver et al. 1999*1). Carnivores are poorly represented, and, as at many other Pueblo III sites in this area, bones of domestic dogs are scarce. Artiodactyls are rare; most of those identified to the genus level are deer.

Element Frequency

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The relative frequencies of different parts of the skeleton can provide information about cultural practices and preservation. Element frequencies for any taxon can be derived from the database in conjunction with the coding system. The most common species at Castle Rock have most parts of the skeleton represented. For cottontails, for example, Table 2 shows that the cranium, mandible, forelimbs, and hind limbs are well represented. The underrepresentation of some elements can be attributed to small size (for example, the relatively small numbers of phalanges or the predominance of larger lumbar vertebrae over smaller thoracic and cervical vertebrae), to fragility (for example, the underrepresentation of vertebrae in general), or to problems in positively identifying the genus of certain skeletal parts (for example, rib fragments). For turkeys and large birds (Table 2) there is better representation of different body areas because even the smaller skeletal elements are larger than many cottontail bones. All of the more common species seem to have been brought to the site as complete carcasses. Even the artiodactyls display quite a wide range of body parts (Table 2), especially considering the small number of specimens in the assemblage.

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One way in which preservation of fauna can be measured is to compare the relative frequencies of skeletal areas that preserve well with those that tend to preserve poorly. The simplest way to do this is to compare the frequencies of different parts of the same skeletal element. For example, in most mammals the proximal end of the humerus is much more susceptible to damage than the distal end. Using data from the cottontail assemblage, we can count the numbers of different ends of long bones for which susceptibility to damage is likely to vary. We can expect the proximal humerus and proximal tibia in cottontails to preserve poorly compared with the distal ends of those same elements, unless preservation conditions are good. For the radius, it is expected that the proximal end will preserve better. As Table 3 shows, these expectations are borne out for cottontails, suggesting that the taphonomic pathways have resulted in considerable bone loss. The same patterns can be seen for the much smaller sample of jackrabbit bones. In the bird skeleton there are less obvious differences in bone density, but the distal tibiotarsus is denser and more robust than the proximal tibiotarsus. This difference shows up well in the relative frequencies of turkey and large bird tibiotarsus ends in the Castle Rock assemblage (Table 3).

Intrasite Variation

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The faunal assemblage from Castle Rock Pueblo was collected from different types of contexts both within and outside various types of structures. Although it would be preferable to divide the assemblage in a way that would reflect the contextual details, this cannot be done, because the resulting small assemblages could not be compared meaningfully. It is necessary, therefore, to group contexts in various ways. A further problem is the diversity of taxa. In order to reduce this diversity, eight taxonomic groups were defined and are used throughout this section. The eight groups are as follows:

Herpetofauna. All amphibians and reptiles
Raptors, etc. All hawks, falcons, owls, and ravens
Turkeys. All specimens identified as turkey, plus all specimens identified as "large bird"
Lagomorphs. All lagomorphs (includes jackrabbits, cottontails, and unidentified lagomorphs)
Sciurids. All members of the squirrel family (includes chipmunks, ground squirrels, prairie dogs, and unidentified sciurids)
Other rodents. All non-sciurid rodents)
Carnivores. All carnivores
Artiodactyls. All artiodactyls

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Using classifications of context types supplied by the excavators, we can consider from which types of contexts the faunal remains were collected. Table 4 shows that fauna was collected most commonly from secondary refuse, from deposits associated with collapsed structures, from mixed deposits, from postabandonment sediments, and from de facto refuse. This means that most faunal specimens were probably from refuse deposits. Such deposits include middens as well as refuse that had been reused for construction purposes (for example, as roofing material) or that was redeposited in rooms after abandonment. The small quantities of de facto and primary refuse suggest that even faunal remains found in the fill of structures probably do not reflect the activities that took place in the structure but, rather, the refuse that was deposited in its vicinity.

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In order to compare the contents of different types of structures in different types of locations, Table 5 organizes structures into three types—kivas, rooms, and towers—by location within the site. Within-site locations were divided into four zones. Using the site grid as a reference, "south" structures are on the eastern half of the south side of the butte and in an area of large boulders on the southeast margin of the site. "South-central" structures are on the western end of the south side of the butte. "North-central" structures are on the western end of the north side of the butte. "North" structures are on the northeast periphery of the site. In order to compare the contents of structures with assemblages from open areas, midden deposits ("Nonstructure 1") are also summarized in Table 5.

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As I have noted previously (Driver et al. 1999*1), the main difference between middens and structure fills is that middens contain relatively more turkey and large bird bones (44 percent of all specimens in Nonstructure 1 as opposed to 22 percent of specimens in all the structures reported in Table 5). It is difficult to find a ready explanation for this, although the pattern has been observed at other sites in the locality. It is possible that collapsed masonry structures provide a more attractive habitat for postabandonment colonization by small mammals, and the lower frequency of turkey remains is the result of the intrusive, postabandonment addition of noncultural specimens to the fill of structures. Rodent bones are slightly more common in structures (where they make up 22 percent of all faunal elements) than in middens (where they make up 15 percent). Cottontails (which burrow) occur in higher frequencies in structures (42 percent) than in middens (30 percent), whereas jackrabbits (which do not burrow) occur in about the same proportion in both. If burrowing cottontails were responsible for lowering the relative frequency of turkey bones in structures, then we would expect to see the cottontail-to-jackrabbit ratio change between middens and structures. Indeed, cottontails account for 86 percent of the cottontail-plus-jackrabbit assemblage in middens but 92 percent in structures, suggesting that some cottontail specimens might be intrusive in structures. For all rodents (Rodentia plus Sciurdae in Table 5), it can be seen that midden assemblages contain 15 percent rodents, whereas the total assemblage from all structures contains about 22 percent rodents. This, too, supports the hypothesis that rooms attract more burrowing species.

Conclusions

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As at other Pueblo III sites in the Sand Canyon locality, the Castle Rock faunal assemblage is dominated by lagomorphs and turkeys/large birds. Meat was probably procured by local trapping of small game, combined with the production of domestic turkeys. It is difficult to assess the role of rodents in the economy, but if their presence is due to human activity, then it reinforces the picture of local trapping. Hunting of larger food animals was relatively uncommon, as was the hunting of carnivores. Most skeletal parts are represented in the more common taxa, suggesting that complete carcasses were brought to the site. Birds other than turkeys were probably hunted for purposes other than subsistence. The largely complete immature hawk skeleton from a kiva floor is the best evidence for the ceremonial or ritual use of birds.

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