Part 3: Animal Middens: Packrat, Woodrat, Stick-nest rat, and Hyrax

Ashworth, Allan C. 1973.

Fossil beetles from a fossil wood rat midden in western Texas. The Coleopterists Bulletin 27(3):139-140.
Midden found in Maravillas Canyon. Midden radiocarbon dated between 11,500 to 12,500 years BP. Well (1966) described plant fragments, which include pinyon pine (Pinus cembroides), juniper (Juniperus pinchotii), shrubby live-oak (Quercus pungens), and prickly pear (Opuntia macrocentra). Plants incidate woodland rather than desert vegetation. Beetle taxa identifed: Niptus abtruses, Ptinus sp., and two others (Scarabaeidae and possibly Curculionidae). Niptus abtruses lives in caves and has been found on raccoon droppings. This occurrence is within its current range. (28/Feb/2013)

Betancourt, J. L., and T. R. Van Devender 1981

Holocene Vegetation in Chaco Canyon, New Mexico. Science 214(Number 4521, 6 November 1981):656-658.
AEU SCI Q 1 S41 Examined macros from packrat middens from north side (drier side) of Chaco Canyon. Reports 24 C¹⁴ dates on material from middens, from 22 middens. Dates span 10,600 to 460 C¹⁴ yr BP. Identified 78 plant taxa from middens, representing about 25% of modern flora. Early Holocene middens contained Douglas fir (Pseudotsuga menziesii), Rocky Mountain juniper (Juniperus scopulorum), and limber pine (Pinus cf. flexilis) remains, indicating cooler and moister than present conditions. Consider these to be relicts of more extensive late Pleistocene conifer-dominated woodland. Mid-Holocene samples suggest pinyon- juniper woodland (Pinus edulis, Colorado pinyon). After 5500 yr BP, suggest conditions became more xeric. Youngest sample (460 yr BP) lacks pinyon and juniper but assemblage looks close to that from modern vegetation near the site - most taxa (87%) occur within 30 m of site. Dominated by four-winged saltbush (Atriplex canescens), cliffrose (Cowania mexicana), and Mormon tea (Ephedra torreyana). Probably resembled modern desert scrub, with a few juniper and pinyon-juniper stands in favoured locales. Records document expansion of ponderosa pine (Pinus ponderosa) in mid-Holocene, associated with greater summer rainfall (summer monsoon). [Note: seems to contradict suggestion of more xeric mid-Holocene conditions made earlier.] Do not feel that climate change can explain reduction in pinyon and juniper in late Holocene, after about 1230 yr BP. More likely due to human impact (e.g., firewood gathering), especially reflecting increased local populations. (19/04/2009).

Betancourt, J. L., T. R. Van Devender, and P. S. Martin (editors) 1990

Packrat Middens: The Last 40,000 Years of Biotic Change. University of Arizona Press, Tucson, Arizona, USA. vii + 467 pages.
AEU SCI QE 720 P119 Consists of twenty-one chapters. Nineteen chapters describing work on middens: 16 deal with packrats in North America, three deal with animals with similar midden-building behaviour from other areas (Africa, the Middle East, and Australia). These papers are listed and discussed individually elsewhere in The Dung File. The editors provide an Introduction (pp. 2-11) and a concluding Synthesis and Prospectus (pp. 435-447). The Introduction provides a fascinating glimpse of the history of packrat midden studies, from the early descriptions by EuroAmerican travellers on the Colorado Plateau (Simpson in 1849) to recent palaeoecological studies in the desert southwest. Most of the research covered in this volume is from this region. Note that there are widely divergent viewpoints here of the interpretation of the evidence. (30/Jul/2009; 21/Aug/2011)

Carrión, J. S., L. Scott, and J. C. Vogel 1999

Twentieth Century Changes in Montane Vegetation in the Eastern Free State, South Africa, Derived from Palynology of Hyrax Dung Middens. Journal of Quaternary Science 13:1-16.
AEU SCI QE 696 J86 Reviews foraging and life behaviour of hyraxes (Procavia capensis) and previous studies that show potential for long pollen sequences from hyrax dung accumulations, which often occur in arid areas where other pollen preservation sites are rare. remains are mainly from dung, not from nesting materials, which are not collected by these animals. Reviews local vegetation around the study site, a rock shelter, Rooiberg Midden II, with a predominantly grassland area. Used radiocarbon dating to assign ages to midden samples all from 20th century. [However, I don't follow the discussion of how it was possible to date these samples.] All samples contain exotic pollen types (such as Pinus and Eucalyptus) that are probably derived from trees planted around homes in the nearby town of Clarens. Paper includes some LM and SEM images of some of the palynomorphs in the samples. Generally the pollen spectra agree with the local vegetation. However, the spectra include aquatic pollen types, suggesting the hyraxes visited water pools, and some other types, such as fern spores, suggesting moist environments. Various dung-related palynomorphs, especially fungal spores (e.g., Sordariaceae, Chaetomium, Glomus, and others), and endoparasite, Trichuris, eggs, also from dung origin. Water-related pollen types thought to be from drinking water from springs, about 100 m away from the site, indicating wetter conditions earlier in 20th century. Changes in relative abundance of forest edge pollen types (Buddleja, probably Buddleja salviifolia, and Leucosidea, probably Leucosidea sericea) and grassland types are related to occurrence of wet and dry spells. Pollen changes are interpreted as reflecting environmental changes, rather than hyrax diet changes [though won't these be linked?]. These changes are also related to land use, especially grazing pressure and fuel gathering, and fire control. (06/08/2005).

Davis, O. K., and R. S. Anderson 1987

Pollen in Packrat (Neotoma) Middens: Pollen Transport and the Relationship of Pollen to Vegetation. Palynology 11:185-198.
AEU SCI QE 993 P18 Examined four types of midden materials, from modern (present) middens, including samples of packrat faecal pellets. All samples from SW USA. Good pollen recovery from midden material and well-preserved. Some pollen probably from airborne sources, that is, beyond the foraging range of the packrats. However, airborne pollen types are present in lower percentage in midden samples than in those of other sample types. Large number of taxa recovered from samples (e.g., 28 types in samples from Owl Canyon, Colorado). Faecal pellets contain a greater proportion of pollen of zoophilous types than midden samples. Some pollen probably arrives at the site through plant material brought in by the packrats. Considerable pollen may adhere to plant material. Question if some pollen may be brought in on fur of packrats. Used these data to compare pollen spectra with surrounding vegetation. Concluded that samples do represent local vegetation variability although considerable variation between small samples from within the same midden. Probably need to use larger samples. Used these data to examine fossil packrat midden samples from two sites (one each in Colorado and Arizona). Midden samples vary in age from about 14,000 yr BP to almost present. Samples from Organ Pipe Cactus National Monument (Arizona) show transition from Late Pleistocene to Holocene, reflected in reduction of pollen from pinyon-juniper woodland and increased abundance of pollen from Sonoran Desert plants (many of which are insect-pollinated, so shows local presence). At Owl Canyon (Colorado), pollen shows probable arrival of pinyon pine only within the last few hundred years. Note that they have analyzed 54 packrat middens. (21/07/2005).

Davis, O. K., and R. S. Anderson 1988

Pollen in Packrat (Neotoma) Middens: Pollen Transport and the Relationship of Pollen to Vegetation: Reply. Palynology 12:226-229.
AEU SCI QE 993 P18 Refutes and disputes the criticisms raised by Van Devender (1988) of their 1987 paper. In particular, emphasises that sample to sample variability in pollen concentrations is important in interpretation of the assemblages. Believe that this represents variable depositional processes. Note that macrofossil analyses are usually semi-quantitative and difficult to relate to vegetation. Not all pollen from a taxon necessarily from plants in immediate vicinity of midden, some from further sources. Notes that macros may also give misleading impression of abundance of plants in local vegetation (?collecting bias by packrats). Disagree that pollen data may not provide species level information, dependent partly on availability of reference material. Pollen and macros should be seen as complementary techniques. (21/07/2005).

Dial, Kenneth P. and Nicholas J. Czaplewski 1990

Do woodrat middens accurately represent the animals' environments and diets? In Packrat Middens: The Last 40,000 Years of Biotic Change, edited by J. L. Betancourt and T. R. Van Devender, pp. 43-58. University of Arizona, Tucson, Arizona, USA.
AEU SCI QE 720 P119 Woodhouse Mesa in Arizona has four species of woodrats (Neotoma albigula, Neotoma devia [Neotoma lepida], and Neotoma stephensi are residents and Neotoma cinerea are transients). Only investigated resident species. Vegetation survey, live trapping near dens, fecal pellet analysis (for diet information). Collected middens (component of den, not nest or food caches). Identified plant parts but not branches or large sticks, which were considered structure. Midden materials were very different among the three woodrat species. N. devia dominated by Ephedra, N. stephensi by Juniperus monosperma, N. albigula showed no marked concentration on any one taxon. This species was most eclectic in collecting. But species richness between middens of different woodrats doesn't vary as much. Less than half the plant species in dens' vicinity were represented in middens. Midden contents did accurately reflect animal's diets for all three species. "Relative abundance of plants in an active midden cannot be taken to represent accurately the relative abundance of plants in the environments" (p. 55), with obvious implications for palaeoenvironmental studies. Better representation of plant community when data from four or five middens combined. Single den site likely used by different woodrat species over time. Hence midden is a composite. But change of woodrat species might be incorrectly interpreted as change in vegetation, Need standardized methods for collecting data so results from different studies are comparable. Other animals may contribute to middens. Taphonomy is complex. (02/Sept/2011).

Elias, S. A., and T. R. Van Devender 1990

Fossil Insect Evidence for Late Quaternary Climate Change in the Big Bend Region, Chihuahuan Desert, Texas. Quaternary Research 34:249-261.
AEU SCI QE 696 Q24 Examined insect assemblages from packrat middens at 5 localities (Baby Vulture Den, Ernst Tinaja, Maravillas Canyon, Terlingua, and Tunnel View). Samples span >36,000 yr BP to present. Recovered 79 taxa from 23 families. Most identifications to species level (35) were from beetles. 18 beetles are indicator taxa, either temperate (grasslands) or desert indicators. Assemblages fall into two zones: earlier zone (25,000 - 12,000 yr BP) contains more temperate taxa, later zone (12,000 - present) contains more desert indicators, after 2,500 yr BO the assemblage contains only desert taxa. Discusses ecological implications of some specific taxa (carabids, dung beetles, spider beetles, darkling beetles, seed beetles, and weevils). Environmental implications are a shift from a cooler, moister conditions of Wisconsinan to hotter drier conditions through the postglacial. Contains SEM images (p. 258) of some taxa. Discusses vegetation record from Maravillas Canyon and Rio Grande Village region. Pattern is similar but vegetation changes seem to lag behind insect changes suggesting some plants (e.g., pinyon pine) persisted after shift to more arid conditions. (17/03/2002).

Finley, R. B., Jr. 1990

Woodrat Ecology and Behaviour and the Interpretation of Paleomiddens. In Packrat Middens: The Last 40,000 Years of Biotic Change, edited by J. L. Betancourt, T. R. Van Devender and P. S. Martin, pp. 28-42. University of Arizona, Tucson, Arizona, USA.
AEU SCI QE 720 P119 Short review of woodrat ( =packrat) biology and behaviour. Dens built in rock crevices are smaller. Those living in the open build "houses" within which they den; these may be large. Houses of the Dusky-footed Woodrat (Neotoma fuscipes), a Californian species, may be 2 m in height and over 2 m in diameter. The species also climbs and builds houses in trees such as live oak. Desert species often utilize cactus (cactus pads are an important source of moisture). Often difficult to determine which species made a particular den (especially where ranges overlap) and hence interpretation of contents is difficult. Analysis of range of den contents shows that between 62% and 86% plant species collected were from less than 30 m from the den. Longest movements less than 200 m. Middens build up over time and layers are added. The animals don't dig into the midden so that stratigraphy in ancient middens is likely intact. In cliffed areas, rocks are often stained with urinary and faecal material of woodrats below den ledges. Probably little degradation of material in dry desert environments. Studies of modern middens may help to understand how fast middens accumulate. May also contain species-specific biomolecule markers in urine and faecal deposits and biomolecules from food plants consumed. This is a new avenue for analysis. (21/Aug/2011)

Hadly, E. A. 1999

Fidelity of Terrestrial Vertebrate Fossils to a Modern Ecosystem. Palaeogeography, Palaeoclimatology, Palaeoecology 149:389-409.
AEU SCI QE 500 P15 Lamar Cave, Wyoming, in Yellowstone National Park. Attempt to see if fossil community accurately reflects the living community. Used modern fauna of YNP as a comparison. Cave shows 16 stratigraphic levels, down to bedrock. Samples recovered from pit in midst of deposit (no archaeological materials). Most of deposit is woodrat midden (Neotoma cinera). Lowest level dates to 2000 - 2800 yr BP. Other contributors to deposit are carnivores (wolves and coyotes); ungulate bones (mainly distal limb bones) show carnivore damage. Assemblage may be biased by collecting preferences of woodrats; their remains constitute 11% of fauna (constant over time). Collecting range of predators may also vary; deposits show evidence of prey deposited by both hawks (diurnal) and owls (nocturnal). Pellets and scat are collected by the woodrats and brought to cave. Comparison with scats/pellets from modern samples shows cave deposit is a composite and not dominated by any one carnivore type. Levels accumulated at different rates (300 years to 1400 years for lowest level). Shows that even already demarcated levels may span considerable times. Hence, is it legitimate to consider all fauna from one level as an assemblage? Assemblage from the cave shows species richness more comparable to modern fauna than the scat samples (carnivores are selective). Also, a greater chance of encountering rare taxa with a time-averaged assemblage. Assumes that assemblage represents area within about 5 km radius of site (range of collecting agents). Considered as a whole, assemblage shows 67% of (non-flying) species within YNP. Individual levels may be only 5% in contrast. But assemblage represents about 93% of species from vegetation communities immediately around site. Showed that larger sample sizes result in greater number of taxa identified. Mammals found that characterize the modern sagebrush grassland (especially small mammals). These are abundant even in small sample sizes, showing that an adequate characterization of nearby habitats can be made even from small samples. (14/04/2002).

Hebda, R., B. G. Warner, and R. A. Cannings 1990

Pollen, Plant Macrofossils, and Insects from Fossil Woodrat (Neotoma cinerea) Middens in British Columbia. Géographie physique et Quaternaire 44:227-234.
AEU SCI G1 R452 Reports on results from two sites in southcentral British Columbia. Oregon Jack Creek (e of Lillooet) dated at 1150±80 yr BP (WAT-1764) and Bull Canyon (west of Williams Lake) dated at 700±80 yr BP (WAT-1765). Both sites in dry interior with Douglas fir an important vegetation component. Pollen samples dominated by AP (especially Cupressaceae - Juniperus) but abundant NAP (especially Artemisia). Pseudotsuga pollen seems under-represented with respect to abundance in present local vegetation and strong occurrence in macrofossil assemblage. Macros are mainly from tree and shrub taxa, mostly from plants within about 50 m of midden sites. Abundant Pseudotsuga menziesii, Juniperus scopulorum and Artemisia. Beetle remains (4 genera) recovered from OJC midden. Pollen assemblage shows better presentation of dry habitat taxa than usually found in lake core samples. Authors conclude that woodrat midden research has considerable potential in this area. Paper contains some useful SEM images of macrofossils (including Lappula).

Jackson, S. T., J. L. Betancourt, M. E. Lyford, S. T. Gray, and K. A. Rylander 2005

A 40,000-year Woodrat-midden Record of Vegatational and Biogeographical Dynamics in North-eastern Utah, USA. Journal of Biogeography 32:1085-1106.
AEU SCI G 1 J855 Sites on north side of Uinta Mountains, on Utah/Wyoming border, at Dutch John Mountain. Present vegetation is woodland characterized by pinyon pine (Pinus edulis) and juniper (Juniperus osteosperma). Sixty midden sites examined; twenty-six also examined for pollen, and 48 dated. Dates spanned 375 to 35,170 C14 yr BP. Dates fall into three groups: Wisconsinan, late Pleistocene/early Holocene, and mid-late Holocene. Wisconsinan middens (4) had fewest taxa but was dominated by macros representing montane conifers, predominantly Pinus flexilis, Juniperus communis, and Pseudotsuga menziesii. Most plants grow at higher elevations today. Late glacial samples (8) show greatest number of taxa. Greater number and variety of shrub and woody taxa. Indicative of moister conditions. Vegetation represents juniper woodland, with indications of warmer and drier conditions just prior to the Holocene, signalled by occurrence of Juniperus osteosperma macros. Holocene group (33 middens) are characterized by Juniperus osteosperma. Some species from the late glacial disappear and new taxa (notably cactus, Opuntia) occur, reflecting a drying trend. Pinyon macros appear after 775 yr BP and Ephedra viridis after 500 yr BP. Both trends in these taxa also appear in the pollen data. Pinyon does not occur much further north than Dutch John Mountain, implying it is near its current range limit. Data provide evidence of plant migration history. Paper concludes with a lengthy and useful discussion of regional vegetational and climatic history in the light of these findings, including a summary for individual species (Pseudotsuga menziesii, Pinus flexilis, Juniperus scopulorum, Picea pungens, and Juniperus horizontalis). Notes that not all climate trends are apparent in the midden record. For example, the cold Younger Dryas interval is not evident here. (17/06/2006).

Jennings, S. A., and D. L. Elliott-Fiske 1993

Packrat Midden Evidence of Late Quaternary Vegetation Change in the White Mountains, California-Nevada. Quaternary Research 39:214-221.
AEU SCI QE 696 Q24 Extracted plant macroremains from eight middens from six sites. Span the range from about 19,000 - 2000 yr BP. None of the plant taxa recovered from the oldest midden are present in area today. Assemblage is dominated by Juniperus osteosperma (Utah juniper). This indicates a depression of 600 m of woodland's lower boundary. By early Holocene, midden yielded more shrub and desert taxa, similar to those in area today, and Pinus monophylla (singleleaf pinyon pine). Youngest midden contains more xeric taxa. Holocene samples are more similar to each other and to present vegetation than to the Late Pleistocene sample. Results of stable isotope (deuterium) values may indicate that warmer conditions were prevalent by early Holocene.

Nowak, C. L., R. S. Nowak, R. J. Tausch, and P. E. Wigand 1994

A 30 000 Year Record of Vegetation Dynamics at a Semi-arid Locale in the Great Basin. Journal of Vegetation Science 5:579-590.
Collected samples from a restricted area in order to assess local-scale changes. 20 midden samples, spanning 30,000 - 1,000 yr BP. Study shows that many taxa have occupied the areas continuously for most of this interval. Painted Hills site, in Virginia Mountains, northwest Nevada. Main site (18 samples) spanned 26,000 yrs. Obtained 20 C¹⁴ dates for chronologic control. Main tree taxon (Juniperus osteosperma) appears throughout the record and is still present in the area today. Similarly, most shrub taxa also appear throughout the record and are present in the area today, although a few taxa have distributions that at present are at higher elevations than the site. There is a similar pattern for graminoids and herbs, but herb taxa show a greater proportion of taxa that are not present in the area today. In addition, several taxa were found in the area after an exceptionally wet year (following a prolonged drought) and were not found in the fossil record. Suggests that drought may be an important control. Statistical examination of the data shows that there were significant changes at the Pleistocene/Holocene transition and also in the Late Pleistocene (20,000 - 30,000 year interval). Site is within 0.5 km of Lake Lahontan's highstand and can be tied to changes documented by lake levels. Changes in taxa in middens reflect mesic-xeric intervals. Cooler and moister conditions reflected in more mesic taxa. Late glacial and early Holocene saw the greatest diversity of arboreal taxa (trees and shrubs). Dramatic drop in Lake Lahontan signals change to drier conditions in the Late Pleistocene. Also reflected in plant taxa. Modern vegetation appears to have become established from the mid-Holocene onwards, showing prolonged interval of relative stability. Changes are not so dramatic as those seen in other areas, perhaps because of topographic diversity (and hence abundance of microhabitats). May also represent high genetic diversity within species, allowing tolerance of variety of conditions (genetic plasticity). Species appear to have remained in place despite significant climate change. This forms a contrast with other areas and leads to some significant questions as to why the difference. (02/07/2006).

Pearson, S. 1999

Late Holocene Biological Records from the Middens of Stick-Nest Rats in the Central Australian Arid Zone. Quaternary International 59:39-46.
AEU SCI QE 696 Q229 Examines pollen from stick-nest rat (Leporillus apicalis and Leporillus conditor - now extinct in Australia) middens. Middens are prevalent in caves and rock shelters in arid areas and most are less than 3000 years old (older middens found in the Flinders Range). Compared pollen spectra from middens with modern pollen spectra. Most data (117 samples) reported from a midden at Umbeara Station (Northern Territory). Spectra dominated by shrub and forb pollen. Scats contained large amounts of perennial shrub pollen. Stratigraphy in middens may be complex; layers may be mixed. Interpretations of ecological change need to be cautious because of coarse temporal resolution of midden samples. Potential as sources of palaeoecological information may be limited.

Scott, L. 1989

Pollen Analysis and Palaeoenvironmental Significance of Quaternary Faecal Deposits in Africa. In Environmental Quality, edited by E. Spanier, Y. Steinberger and M. Luris, pp. 65-71. Environmental Quality and Ecosystem Stability: Vol IV-B. ISEEQS Pub. Jerusalem, Israel.
Review article. Sites for pollen analysis are rare in arid Africa. Animal middens can yield palaeoenvironmental information. Hyrax (Procavia) are widespread and their midden accumulations, held together by dried urine in arid environments, include plant material and faecal pellets. Plant material can be used for C14 dating. Some midden deposits date to mid-Holocene. Midden deposits show previously moister conditions in some areas and also impact of recent pastoral and agricultural practices. Midden-derived pollen spectra appear to be a good reflection of surrounding vegetation, as indicated by modern samples. Dassie rats (Petromus) only live in Namib desert and therefore their middens have more limited potential. Hyaena coprolites from caves have also been analyzed for pollen - mostly brown hyaena (Hyaena brunnii) in southern Africa, striped hyaena (Hyaena hyaena) in northern Africa and Middle East. Tend to yield small amounts of pollen, perhaps because of oxidation (or diet??). Possible that bat guano may be useful and yield pollen too. (11/05/2002).

Scott, L. 1994

Palynology of Late Pleistocene Hyrax Middens, Southwestern Cape Province, South Africa: A Preliminary Report. Historical Biology 9:71-81.
Middens from hyrax (Procavia capensis) found in Pakhuis Pass, Cedarberg Range, now occupied by fynbos vegetation (xeric shrubs, succulents and ericoids). Middens found in a cave site, which may also have been occupied by people in the past (thus possibly explaining gaps in the midden record). Seven middens yielded 16 pollen samples and 15 C¹⁴ samples, and 2 samples for macros. Also modern samples from region were analyzed. Middens span 19,700 years to 1,270 yr BP, with gaps between 13,000 - 8,200 and 4,700 - 1,700 yr BP. Midden pollen spectra show two zones. Zone A (older than 14,000 yr BP) shows LGM vegetation with more ericoid and Stoebe- type pollen, possibly reflecting cooler conditions. Zone B, since 13,000 yr BP, has more woody and succulent pollen types. Increase in AP may reflect slightly warmer climate after LGM. Moisture conditions are more difficult to deduce. Mixture of plant types may indicate changing seasonality, with more even moisture distribution. Modern pollen spectra show very little AP. Implies region had more woody vegetation in Holocene than at present Results suggest type of fynbos vegetation has been present since LGM. (03/09/2006).

Scott, L. 1994

Past Vegetation Changes in Mountainous Areas in South Africa as Revealed by Pollen Analysis of Hyrax Middens. In Proceeding of the XIIIth Plenary Meeting AETFAT, Malawi, Vol. 2, edited by J. H. Seyani and A. C. Chikuni, pp. 1007- 1014.
Looked at three sets of hyrax (Procavia sp.) middens for pollen. Clarens midden (spans last 30 years) from a grassland area. Pollen spectra here show marked fluctuations in AP/NAP, probably related to variable woody vegetation from stock grazing and town development with possibly a rainfall signal, reflecting rapid recovery of understorey vegetation in relatively wet years. Two middens near Blydefontein in semi-arid karoo are 300 and 1200 years old. Both show reduction in grass and increase in shrubby vegetation in last 300 years, suggesting increased aridity and temperatures. Record appears in agreement with ¹⁸O-derived temperature estimates from stalagmites in Cango Caves. Finally, investigated a hyrax midden at Pakhuis Pass, Cedarberg, in fynbos vegetation area, dated 19,700 years old (oldest midden identified in Africa so far). Compared pollen spectra with those from two modern hyrax midden samples from the same area. Midden spectra show more similarity to spectra from higher elevation sites, suggesting cooler dry conditions in last glacial. (03/09/2006).

Scott, L., and C. B. Bousman 1990

Palynological Analysis of Hyrax Middens from Southern Africa. Palaeogeography, Palaeoclimatology, Palaeoecology 7:367- 379.
AEU SCI QE 500 P15 Hyrax (Procavia) middens are primarily dung accumulations, consolidated with dried urine (unlike packrat middens, which are mostly collected nest material). Pollen in hyrax middens probably from pollen rain and perhaps some diet additions. Two hyrax middens sampled from semi- arid Karoo region, near Neupoort, at Blydefontein Basin. Research associated with Later Stone Age archaeology project, focused on Meerkat Shelter. Meerkat midden may span 300 years, and Oppermanskop midden up to 1130 years, based on C-14 dates. Six surface samples collected for comparison. Pollen assemblages dominated by NAP, especially Gramineae and Compositae. However, grass pollen appears reduced in upper midden levels compared to Compositae and Chenopodiaceae pollen. Pollen record also obtained from alluvial sequence at Upper Section Pond, near Meerkat Shelter. Spectra are comparable with midden, except that pond shows more wetland elements. Overall, records show moister conditions between about 1200 to 300 yr BP, except for one drought interval (signalled by more shrubby vegetation) at about 1000 yr BP. Drier conditions generally since 300 yr BP. Could be due to climate, human activities or a combination of both. In last couple of centuries, overgrazing pressure and rangeland deterioration. Considers it unlikely that herding activities of San or Khoi people, prior to European incursion, could have had a major impact on vegetation. Hence changes in grassland (veldt), e.g., around 1000 yr BP, likely due to climate deterioration. Also supported by oxygen isotope record from ostrich eggshell. Hyrax middens seem to be good pollen traps, giving unbiased record of surrounding vegetation. (14/April/2007)

Scott, L., and B. Cooremans 1992

Pollen in Recent Procavia (Hyrax), Petromus (Dassie Rat) and Bird Dung in South Africa. Journal of Biogeography 19:205-215.
AEU SCI G 1 J855 Compared pollen assemblages from midden samples with those from surface samples from various vegetation zones in South Africa, mostly distinguished on the basis of varying aridity. Examined 23 Procavia dung samples, 4 Petromus dung samples, 1 bird guano sample, and 21 modern surface samples. Appears that most dung samples may be from contemporary (active) middens, rather than ancient ones, though the age of the samples is not discussed and this point is not clear. Pollen spectrum from the bird guano is very different and distinct, with large amounts of Poaceae pollen. This may be because the sample is old or because the birds (types unknown) are making use of different vegetation zones. Used factor analysis and multidimensional scaling to compare dung and modern samples. Although a few outliers, the dung and modern samples from the same vegetation zones group together closely, reflecting the modern vegetation. Concluded that dietary preferences of the animals is not a major factor in influencing pollen spectra, i.e., the dung samples are good indicators of contemporary vegetation. (08/04/2007).

Scott, L., and J. Vogel 1992

Short-term Changes of Climate and Vegetation Revealed by Pollen Analysis of Hyrax Dung in South Africa. Review of Palaeobotany and Palynology 74:283-291.
AEU SCI QE 901 R45 Examined pollen from modern hyrax midden near Clarens, at Rooiberg Shelter I, 16 samples from midden in total. "Bomb" C-14 (from atmospheric nuclear weapons tests) used to calibrate samples to provide an estimate of age. Determined that lowest level sample started accumulating in 1962- 1963. Also examined changing extent of woody vegetation on slopes around midden through air photos. Both agree in showing increased amounts of woody vegetation. Changes may be related to rainfall or grazing (i.e., decreased grass and more shrubs). Short-term changes in rainfall appear to be reflected in midden record, implying that such records may be useful for interpreting similar changes in the more distant past. (14/04/2007).

Smith, F. A., and J. L. Betancourt 2003

The Effect of Holocene Temperature Fluctuations on the Evolution and Ecology of Neotoma (Woodrats) in Idaho and Northwestern Utah. Quaternary Research 59:160-171.
AEU SCI QE 696 Q24 Uses faecal pellet size to estimate body size of bushy-tailed woodrats (Neotoma cinerea) from five middens. Middens are mainly mid to late Holocene in age, though one extends to around 11,000 yr BP. Pellet sizes compared to modern samples from N. cinerea and N. lepida (desert woodrat). In modern populations, body mass then correlated to temperature, with larger body mass correlated to cooler temperatures. These data then used to investigate Holocene data. Infers a distinct thermal forcing in past populations, possibly in response to possible heat stress. Adult woodrats are territorial and do not move far from "home" sites. Juveniles disperse to find new locales. Inferred pattern of temperature changes match well with those derived from nearby tree ring records. Consider that this analytical approach can yield valuable data, especially on a decadal scale, one that is often not captured by other types of proxy data.

Smith, F. A., J. L. Betancourt, and J. H. Brown 1995

Evolution in Body Size in the Woodrat Over the Past 25,000 Years of Climate Change. Science 270:2012-2014.
AEU SCI Q 1 S41 Investigating whether body size of woodrats has changed in response to climate change (larger size -> heat conservation -> colder climate). Used faecal pellet sizes as a surrogate for body size. Assume that faecal pellet widths should have decreased during and since deglaciation. Used pellets from middens from locales inhabited by woodrat (Neotoma cinerea) in dry interior western US. Pellets were dated by C¹⁴ either directly or by dates on associated macrofossils. Method tested by checking with pellets from modern individuals. Found the best relationship between body size and July (summer) temperature and strong relationship between body size and pellet size. Most complete postglacial data set from Fishmouth Cave, Utah. Shows a good relationship - estimated body size declined since last glacial event. "Corrected" data for latitudinal variation in other palaeo data sets in order to combine palaeo data from several sites to investigate body size variation. Combined data sets show same pattern as that from Fishmouth Cave. These data suggest that changes in body size within populations happen quite rapidly in response to temperature changes. Conclude that these changes are due to population changes in place, rather than in- migration of woodrats from other areas, because populations are thought to be fairly sedentary. Note that need genetic studies to confirm this. (11/04/2009).

Spaulding, W. G. 1990

Comparison of Pollen and Macrofossil Based Reconstructions of Late Quaternary Vegetation in Western North America. Review of Palaeobotany and Palynology 64:359-366.
AEU SCI QE 901 R45 Article written partly in response to comments by Hall (1986). Comparison of data from macrofossil assemblages from packrat (Neotoma spp.) middens and pollen records at two locales: Colorado Plateau middens and Chuska Mountains pollen record (SW USA), and Mojave Desert middens and Tule Springs pollen record. For the first case, the late glacial vegetation history involved shifts in main vegetation zones and compositional changes. Pollen reconstructions (for ca. 19,500 - 25,000 yr BP) show a shift in elevation of arboreal forest downslope and consequent expansion of alpine vegetation with limber pine at higher elevations than ponderosa pine. Midden data show some taxa (e.g., limber pine) extended to lower elevations than pollen-based reconstructions suggest. In the second comparison, focussing on the 14,500 - 8,000 yr BP interval, again the midden data show some vegetation zones (e.g., juniper woodland) and some taxa (e.g., limber pine) were more extensive. Middens are assumed to report local occurrence of a species and, when the same taxon appears in many middens, this suggests it may be widely distributed. Notes that middens and pollen records are showing data on different scales. Also notes that differences between the data types will increase when the records being compared are further apart.

Spaulding, W. Geoffrey, Julio L. Betancourt, Lisa K. Croft and Kenneth L. Cole 1990

Packrat middens: Their composition and methods of analysis. In Packrat Middens: The Last 40,000 Years of Biotic Change, edited by J. L. Betancourt, T. R. Van Devender and P. S. Martin, pp. 59-84. University of Arizona Tucson, Arizona, USA.
AEU SCI QE 720 P119 Fundamental and important chapter dealing with methodological issues. Includes discussion of morphology and physical properties of middens, including the role of amberat (crystallized packrat urine) as a role in preservation. May cause middens to become indurated. May be some diagenesis in older middens. Midden material needs presoaking to remove amberat as part of processing. Not clear that middens build continuously. Layers may represent a few years' occupation, then a gap. Plant data tallied in different ways. Simple occurrence data (species presence) especially of extra-local species. Discusses midden taphonomy, how plant material accumulates and builds up. Rare to try to quantify midden material because there is so much of it in even a small sample. Often reported as presence/absence data to compile a plant species list of the area around the site. Particular attention is often paid to extra-local taxa, in terms of the modern local vegetation, and what these tell about the changing plant distributions through time. Have used various indices of similarity, Simpson's, Jaccard's and Sorensen's indexes. Also estimates of species richness, which is depends on validity of identification to species level. Various methods of computing relative abundance of various taxa have been devised using adjustments based on sample weight, volume, or number of identified fragments, to allow for biases in the assemblage. Often use a five-part abundance scale. A major reason for doing midden studies is to tease out the composition and character of the local vegetation. Modern studies mostly show reasonable correlation but there may be some local species missing from middens. Can use the Bray-Curtis index for comparison. Depends also on what area is considered "local" to the site. Uses some case studies to demonstrate the problems. Difficulties of estimating the relative proportion of different taxa in the surrounding vegetation. And collecting biases of the arrivals, such as their preference for creosote bush (Larrea divaricata). Concludes that proportion of plants in middens cannot be used as an estimate of proportion of corresponding plants in surrounding vegetation. May also be concealing a selectivity due to distance (i.e., closer plants collected more), which seems obvious if the animals are minimizing effort and time of exposure to predators in their collecting activity. Essay ends with the problem of data standardization between different studies and the need for data sharing. (02/Sep/2011)

Thompson, R. S., L. Benson, and E. M. Hattori 1986

A Revised Chronology for the Last Pleistocene Lake Cycle in the Central Lahontan Basin. Quaternary Research 25:1-9.
AEU SCI QE 696 Q24 Presents radiocarbon dates from packrat middens below the highest level of Lake Lahontan, hence providing limiting dates. Middens intact and hence never inundated. Dated materials from middens that had macrofossil taxa that no longer occur in the area. Dates obtained from Juniperus cf. occidentalis remains (twigs, leaves). Dates show Lake Lahontan dropped below level of middens by at least 12,070 yr BP.

Van Devender, T. R. 1988

Pollen in Packrat (Neotoma) Middens: Pollen Transport and the Relationship of Pollen and Vegetation: Discussion. Palynology 12:221-229.
AEU SCI QE 993 P18 Detailed point by point criticism of Davis and Anderson's (1987) paper from the perspective of macrofossil analysis. Contends that pollen data may show variation in local vegetation near the site, rather than regional vegetation differences. Does not agree that small sample size and sample variability are linked - thinks that conclusion of high variability is not supported. Considers that the pollen and macros evidence should be compared for the fossil midden samples. Notes that some taxa present as macros are not identified in pollen spectra. Believes this is partly due to poorer taxonomic resolution of pollen compared to macros. Notes that some of the pollen types, especially for cactus, would include pollen from many different species with different ecologic requirements. Considers that the pollen data alone can be misleading and does not provide useful palaeovegetational reconstructions. (21/07/2005).

Van Devender, T. R., and J. I. Mead 1978

Early Holocene and Late Pleistocene Amphibians and Reptiles in Sonoran Desert Packrat Middens. Copeia 1978:464-475.
AEU BARD QL 1 C78 Provides a taxonomic list (with accession numbers and C¹⁴ dates) of faunal remains from packrat middens. Bones may be in packrat midden either because rats intentionally collect them (e.g., for construction material), or because they are remains of animals living in or near the nests, or because they were brought to caves by raptors. Includes data on 22 middens with 31 C¹⁴ dates. Total of 31 taxa listed, representing 27 species, with others identified at family or genus level. Families represented include: Bufonidae (Toads), Pelobatidae (Spadefoot Toads), Testudinidae (Tortoises), Gekkonidae (Geckos), Iguanidae (Lizards, 9 records), Telidae (Whiptail Lizards), Boidae (Boas), Colubridae (Snakes, 10 records),Crotalidae (Vipers, 3 records), and Leptotyphlopidae (Thread Snakes). Notes that most of these taxa are found in the region today but in desert scrub habitats. Plants from the packrat middens show considerable vegetation change (e.g., from more mesic woodlands to desert scrub) whereas the herpetofauna has been more stable. A few taxa were found only in Holocene samples. Shows that winters were probably not colder than today in late Pleistocene, otherwise some of these taxa would not have been able to persist in the region through the full glacial. Unclear why some species are now only restricted to deserts, as discussed especially with reference to Uta (Side-blotched Lizards). (01/08/2009).

Van Devender, T. R., R. S. Thompson, and J. L.Betancourt 1987

Vegetation History of the Deserts of Southwestern North America: The Nature and Timing of the Late Wisconsin-Holocene Transition. In North America and Adjacent Oceans During the Last Deglaciation, edited by W. F. Ruddiman and H. E. Wright Jr, pp. 323-352. The Geology of North America Volume K-3. Geological Society of North America, Boulder, Colorado, USA.
This detailed review is based on research on plant macroremains from packrat middens. Many middens have been recovered from full glacial time, as well as postglacial. Plant macroremains indicate plant distribution changes related both to temperature and precipitation variations. Many assemblages show groupings of plant taxa unlike vegetation types today. Authors consider that the evidence supports the Gleasonian view of individualistic response of plant species to environmental change. Reference list is useful as a starting place for work on this topic.

Vaughan, Terry A. 1990

Ecology of living packrats. In Packrat Middens: The Last 40,000 Years of Biotic Change, edited by J. L. Betancourt, T. R. Van Devender and P. S. Martin, pp. 14-27. University of Arizona, Tucson, Arizona, USA.
AEU SCI QE 720 P119 Concerns the biology and behaviour of living representatives of the genus Neotoma, which includes 21 species. Six species occupy the US desert southwest. All make dens, collecting vegetation and often carnivore dung and skeleton material. Need succulent plant material as a source of water, because living in dry habitats. All require shelter (rocks, shrubs or trees) but are not entirely fossorial. All build dens. Gathering radius is within 30 to 50 m of den. Den provides protection from predators, and against temperature extremes. Animals store food - they are not hibernators. Plant foods are usually low in energy and high in defensive chemicals. Often share dens with other animals, especially other small rodents whose bones may also be found in the midden deposits. Different packrat species have different food preferences. Good den sites are few and therefore are occupied by successive packrats, hence may be occupied for a long time. White-throated packrat (Neotoma albigula) eats desert plants, especially cacti (prickly pear, Platyopuntia) and saltbush (Atriplex). Middens may present an assemblage biased towards cactus. Bushy-tailed woodrat (Neotoma cinerea) builds small dens of sticks. A generalist in diet, hence middens likely a reasonable representation of plants near the den. Collects vertebrate bones, including from large mammals (bear in one example). Also collects coyote scats which contribute pollen and macros from their contents to the middens, and raptor casts as well. Desert packrat (Neotoma lepida) collects desert plants, especially woody shrubs. Also collects bones and animal scat. Generally specialises in one type of plant in the locality. Mexican packrat (Neotoma mexicana) inhabits oak, pine and juniper woodland, generally in mountain areas. Collects animal bones. Plant generalist. Stephens' packrat (Neotoma stephensi) has a very restricted range in Arizona, SW Utah and W New Mexico, always associated with juniper (Juniperus monosperma). Dens predominantly of juniper foliage. A dietary specialist on conifer leaves. Dens therefore present a highly biased assemblage. Western Arizona packrat (Neotoma lepida) is the smallest species, and is restricted to Arizona. Collects desert plants, often Mormon tea (Ephedra viridis) is a major component of local vegetation, so that's what it collects. Generally found in marginal sites, outcompeted by other packrats especially N. albigula for good den sites. Desert packrats tend to be more specialist; boreal or montane species are more generalist. Thus dens from desert packrat species do not give a good indication of surrounding vegetation. Some den sites may be occupied at different times by different packrat species and hence change in plant taxa in the midden may reflect the different species collecting preferences and not actual vegetation change over time or climate change. (21/Aug/2011)

Wells, P. V. 1966

Late Pleistocene Vegetation and Degree of Pluvial Climatic Change in the Chihuahuan Desert. Science 153(No. 3739):970-975.
AEU SCI Q 1 S41 Reports on newly-found middens in Chihuahuan Desert of west Texas. Notes the floristic peculiarities of the area at present with disjunct species on adjacent mountains. Coniferous forests on peaks the Chihuahuan Desert (Chisos Mountains) are similar to those of the southern Rockies or northern Sierra Madre. How did these species get there? One possibility if migration across the now-desert lowlands during pluvial (= glacial) intervals of Pleistocene. Evidence from packrat middens shows that this did not happen, because the lowlands remained relatively arid during this time, though still moister than present. Remains from middens include Pinyon Pine (Pinus centroides remota), Juniper (Juniperus pinchotii), Algerita (Berberis trifolia), Live Oaks (Quercus grisea and Quercus pungens) and Prickly Pear (Opuntia macrocentra). However, the middens also yield xerophytes including Lechuguilla (Agave lecheguilla), Roundflower Catclaw (Acacia roemeriana) and Sotol (Dasylirion leiophyllum). Locations of middens at present are too arid to support woodlands. The presence of pinyon pine in middens suggests woodland was about 800 m lower than present in the pluvial. Suggests that pinyon-juniper-oak woodland was probably continuous in the lowlands, which would have displaced the desert shrub vegetation or this vegetation may have continued to occur in a few restricted drier locales within woodlands. Basically, Wells is suggesting a non-analogue vegetation type. He notes that at present some desert species are found at comparatively high elevations within woodlands, on south-facing drier slopes. This is also shown by the mix of desert and woodland taxa in middens. The desert vegetation may have become segregated relatively recently, as indicated by one woodrat midden dated to about 4200 C¹⁴ yr BP. Fully glacial (ca 18,000 C¹⁴ yr BP) midden at higher elevation (1200 m) lacks Douglas Fir, Aspen, deciduous Oak, Maple and Cypress, as does a second midden dated at 36,000 C¹⁴ yr BP. Indicates that xerophilous vegetation probably extended to high elevations in full glacial times. However, these more mesic taxa are found in the Chisos Mountains now, so if they are not a remnant, then how did they get there? Suggests that mesophytic species (e.g., Douglas fir) are either a remnant from the Tertiary flora (which seems unlikely) or are a result of long-distance transport of propagules from other isolated occurrences. Proposes bird dispersal as the most likely mechanism (following Darwin's ideas). (01/08/2009).

Wells, P. V., and C. D. Jorgensen 1964

Pleistocene Wood Rat Middens and Climatic Change in Mojave Desert: A Record of Juniper Woodlands. Science 143(No. 3611, March 13 1964):1171-1174.
AEU SCI Q 1 S41 Reports on wood rat middens in Frenchman Flat area of southern Nevada. Juniper (Juniperus osteosperma) is not present in the area today, and of only restricted occurrence on regional mountain ranges and uplands. Juniper twigs and seeds from 9 wood rat middens gave C¹⁴ dates spanning 7800 to 40,000 yr BP. Wood rats (Neotoma lepida) are present in area today. Suggests juniper-pinyon woodland was about 600 m lower during much of this interval. Implies conditions likely less arid than present. This is a classic paper and one of the foundation papers of midden studies. Notes the climatic inferences from these studies, the localized collecting by the wood rats, and hence the importance of these macrofossil records as a corrective to the regional pollen records. (24/04/2009).