Dawn M. Kaufman

Energy, water, and broad-scale geographic patterns of species richness

It is often claimed that we do not understand the forces driving the global diversity gradient. However, an extensive literature suggests that contemporary climate constrains terrestrial taxonomic richness over broad geographic extents. Here, we review the empirical literature to examine the nature and form of the relationship between climate and richness. Our goals were to document the support for the climatically based energy hypothesis, and within the constraints imposed by correlative analyses, to evaluate two versions of the hypothesis: the productivity and ambient energy hypotheses. Focusing on studies extending over 800 km, we found that measures of energy, water, or water-energy balance explain spatial variation in richness better than other climatic and non-climatic variables in 82 of 85 cases. Even when considered individually and in isolation, water/ energy variables explain on average over 60% of the variation in the richness of a wide range of plant and animal groups. Further, water variables usually represent the strongest predictors in the tropics, subtropics, and warm temperate zones, whereas energy variables (for animals) or water-energy variables (for plants) dominate in high latitudes. We conclude that the interaction between water and energy, either directly or indirectly (via plant productivity), provides a strong explanation for globally extensive plant and animal diversity gradients, but for animals there also is a latitudinal shift in the relative importance of ambient energy vs. water moving from the poles to the equator. Although contemporary climate is not the only factor influencing species richness and may not explain the diversity pattern for all taxonomic groups, it is clear that understanding water-energy dynamics is critical to future biodiversity research. Analyses that do not include water-energy variables are missing a key component for explaining broad-scale patterns of diversity.

BODY MASS OF LATE QUATERNARY MAMMALS

The purpose of this data set was to compile body mass information for all mammals on Earth so that we could investigate the patterns of body mass seen across geographic and taxonomic space and evolutionary time. We were interested in the heritability of body size across taxonomic groups (How conserved is body mass within a genus, family, and order?), in the overall pattern of body mass across continents (Do the moments and other descriptive statistics remain the same across geographic space?), and over evolutionary time (How quickly did body mass patterns iterate on the patterns seen today? Were the Pleistocene extinctions size specific on each continent, and did these events coincide with the arrival of man?). These data are also part of a larger project that seeks to integrate body mass patterns across very diverse taxa (NCEAS Working Group on Body Size in Ecology and Paleoecology: linking pattern and process across space, time, and taxonomic scales). We began with the updated version of D. E. Wilson an...

Similarity of Mammalian Body Size across the Taxonomic Hierarchy and across Space and Time

Although it is commonly assumed that closely related animals are similar in body size, the degree of similarity has not been examined across the taxonomic hierarchy. Moreover, little is known about the variation or consistency of body size patterns across geographic space or evolutionary time. Here, we draw from a data set of terrestrial, nonvolant mammals to quantify and compare patterns across the body size spectrum, the taxonomic hierarchy, continental space, and evolutionary time. We employ a variety of statistical techniques including “sib‐sib” regression, phylogenetic autocorrelation, and nested ANOVA. We find an extremely high resemblance (heritability) of size among congeneric species for mammals over ∼18 g; the result is consistent across the size spectrum. However, there is no significant relationship among the body sizes of congeneric species for mammals under ∼18 g. We suspect that life‐history and ecological parameters are so tightly constrained by allometry at diminutive size that animals can only adapt to novel ecological conditions by modifying body size. The overall distributions of size for each continental fauna and for the most diverse orders are quantitatively similar for North America, South America, and Africa, despite virtually no overlap in species composition. Differences in ordinal composition appear to account for quantitative differences between continents. For most mammalian orders, body size is highly conserved, although there is extensive overlap at all levels of the taxonomic hierarchy. The body size distribution for terrestrial mammals apparently was established early in the Tertiary, and it has remained remarkably constant over the past 50 Ma and across the major continents. Lineages have diversified in size to exploit environmental opportunities but only within limits set by allometric, ecological, and evolutionary constraints.

Diversity of New World Mammals: Universality of the Latitudinal Gradients of Species and Bauplans

Thirty years of study to demonstrate, quantify, and explain the latitudinal gradient of species richness in mammals of the New World have produced two results; a surety that such a gradient exists and a lack of consensus as to what causes the inverse relationship between species richness and latitude. If the effects of continental area are removed, the latitudinal gradient remains strong and proves to be universal for the New World. This gradient in richness occurs not only at the species level, but also at a series of macrotaxonomic levels (generic, familial, and ordinal), which represents a distribution of ecological types, or bauplans. What causes these phenomena? I assert that none of the specific explanations that have been proposed (e.g., competition or spatial heterogeneity) alone can account for the latitudinal pattern. A universal explanation is likely to be more general; I propose that there is a shift in the impact of abiotic and biotic factors that limit species along the gradient from the poles to the equator. This shift, in turn, produces a change in factors that influence species richness from one that limits the number of species in polar regions to one that limits the physical or niche space of species in the tropics. Ultimately, these phenomena produce the latitudinal gradient (as well as the Rapoports rule phenomena). Effects of abiotic and biotic factors are different for species and bauplans; species are impacted heavily by both, whereas bauplans are influenced much more strongly by abiotic factors.

Evidence for a general species-time-area relationship

The species-area relationship (SAR) plays a central role in biodiversity re- search, and recent work has increased awareness of its temporal analogue, the species- time relationship (STR). Here we provide evidence for a general species-time-area rela- tionship (STAR), in which species number is a function of the area and time span of sampling, as well as their interaction. For eight assemblages, ranging from lake zooplankton to desert rodents, this model outperformed a sampling-based model and two simpler models in which area and time had independent effects. In every case, the interaction term was negative, meaning that rates of species accumulation in space decreased with the time span of sampling, while species accumulation rates in time decreased with area sampled. Al- though questions remain about its precise functional form, the STAR provides a tool for scaling species richness across time and space, for comparing the relative rates of species turnover in space and time at different scales of sampling, and for rigorous testing of mechanisms proposed to drive community dynamics. Our results show that the SAR and STR are not separate relationships but two dimensions of one unified pattern.

Hispid Pocket Mice in Tallgrass Prairie: Abundance, Seasonal Activity, Habitat Association, and Individual Attributes

ABSTRACT. Hispid pocket mice (Chaetodipus hispidus) are found from the grasslands of the Great Plains to the deserts of the southwestern United States, but the natural history and ecology of this species have not been described in native tallgrass prairie at the eastern edge of its range. We initiated an ongoing long-term study of small mammals on Konza Prairie Biological Station, Kansas (a Long-Term Ecological Research [LTER] site), in autumn 1981. Our sampling scheme for 14 LTER sites was a 20-station trapline; small mammals were sampled in autumn and spring for 30 years and in summer for a shorter period. We combined data for these sites with those from shorter studies on Konza Prairie that used traplines and trapping grids. We recorded only 96 hispid pocket mice over the 30 years of study (>300,000 trap-nights overall). Pocket mice were more likely to be captured in autumn and summer than in spring. The earliest annual capture was on 20 March and the latest on 7 December; males emerged from torpor in spring before females, whereas females entered torpor later in autumn. Precipitation (January—September) had a tight limiting effect on maximal number of individuals that were present in autumn. Pocket mice were more common on slope prairie than on upland or lowland prairie, but burning and grazing had no effect. Their spatiotemporal distribution showed a slightly “anti-nested” pattern with only weakly preferred sites and no focal years that might indicate favorable conditions. Collectively, our data suggested the presence of 3 age classes when individual body masses (no differences between males and females) were plotted against capture date. Finally, our study illustrates the importance of long-term data sets, especially in the study of uncommon to rare species.

Abundance and Spatiotemporal Distribution of the Non-Native House Mouse in Native Tallgrass Prairie

We have sampled small mammals on the Konza Prairie Biological Station, in eastern Kansas, from autumn 1981 through the present. One part of this effort has involved sampling rodents and shrews on 14 permanent traplines (20 stations, 15-m interstation intervals and 4 consecutive nights) situated in native tallgrass prairie during each of 29 autumns and 29 springs as well as 6 summers. In these permanent sites, house mice (Mus musculus) were extremely uncommon as illustrated by average abundances of 0.023 mice/100 trap nights (TN) in autumn, 0.022 mice/100 TN in summer and 0.000 mice/100 TN in spring. Precipitation in summer influenced autumn use of tallgrass prairie by house mice; captures only occurred in autumn when precipitation was ≥300 mm in the previous summer. House mice were slightly more likely (though not significantly) to be captured in lowland than upland or hill slope prairie. The distribution of occurrence was not influenced by fire (burned or unburned) or grazing history (grazed or ungrazed). Over our total trapping efforts on Konza Prairie (sampling on the permanent traplines plus other traplines and grids), we captured only 36 house mice or about 0.01 individual/100 TN. Overall, more males (64%) than females were captured; males, on average, were larger (14.0 g) than females (10.5 g) in body size; females typically were non-reproductive (only one of 13 was pregnant) and individuals typically were trapped only once. Captures were distributed broadly in both space and time and lacked predictability (i.e., exhibited an “anti-nested” distribution of captures). These and other patterns suggest that most house mice were transients in the tallgrass prairie. Distribution and abundance of house mice also imply that this introduced species is extremely uncommon and likely will never be invasive in native tallgrass prairie.

WOMEN IN THE EARLY YEARS OF THE AMERICAN SOCIETY OF MAMMALOGISTS (1919-1949)

During the first 30 years of The American Society of Mammalogists (ASM), a small but notable group of women made significant contributions to the Society and to mammalogy in general. The limited opportunity for women in mammalogy at the time of the founding of the ASM in 1919 is evidenced by the observation that only 16 of 435 Charter Members were women. To highlight the contributions of early women mammalogists, we describe the accomplishments of 23 women in short biographical treatments. To facilitate our presentations of activities and accomplishments, each woman was placed into one of six categories, although some individuals could have been listed under more than one category. The six categories were research in the field, research in the museum, research in the laboratory, service to the ASM, other naturalists involved in the ASM, and relevant non-members.

Size Preference for Novel Objects by the Eastern Woodrat (Neotoma floridana) Under Field Conditions1

Natural objects such as branches, leaves, bones and rocks are used in the construction and maintenance of houses by eastern woodrats (Neotomafloridana; Wiley, 1980). Woodrats also use novel items, e.g., pieces of metal, introduced into their home ranges. Ireland and Hays (1969) took advantage of this tendency and examined home range size from observations of the use of numbered tinfoil balls by woodrats. We examined use of novel items, aluminum foil balls, placed in areas used by woodrats under field conditions to answer two general questions: (1) Do woodrats exhibit a size preference for novel items? (2) Does preference vary with distance between the house or burrow and the available items? All experiments were conducted on the Konza Prairie Research Natural Area (KPRNA) about 10 km south of Manhattan, Kansas. In Experiment I, foil balls were placed at 10 stations arranged as five pairs along a limestone outcrop. Each pair consisted of one station on the bare top of the outcrop and one at the base of the outcrop. The two stations in each pair were within 2 m of each other and at least 4 m from the nearest woodrat house or burrow. The five pairs were placed at 30 m intervals along the outcrop. Four sizes

A Quantitative Analysis of the Contributions of Female Mammalogists from 1919 to 1994

We quantified the contributions that women have made to mammalogy by surveying the 75 volumes (301 issues) of the Journal of Mammalogy from its origin in 1919 through 1994. Data were collected on publications (articles and notes), participation in The American Society of Mammalogists (ASM; membership, meeting attendees, committee members, and officers), and awards and honoraria. We found that women played a small, but significant, role in the Society from the outset, and that involvement in all facets has increased substantially since the late 1970s. As of 1994, women constituted 25% of the membership, and 38% of articles published in the Journal of Mammalogy contained at least one female author. We also found, however, that the actual contributions of women as measured by order of author lagged behind these figures, presumably reflecting demographic trends in the ages and positions of female mammalogists. The most frequent topics of publication have been reproduction and development, and population ecology, followed closely by behavior. More female authors have been affiliated with universities in California (11%) than in any other state or country. Since the 1970s, women have been represented on the Board of Directors of the ASM, albeit generally in low numbers. The percentage of women serving on committees has varied considerably, averaging 29% in 1994. Most heavily represented are those committees with education and outreach-oriented missions. Of the honorary memberships given by the Society, only one has been awarded to a female mam-malogist, but two of the Hartley H. T. Jackson awardees have been women. There has been one female recipient of the C. Hart Merriam Award. The percentage of female students receiving honoraria or grants-in-aid has increased significantly since the mid-1980s, and currently averages 25%. Overall, 17% of the Shadle Award winners have been women, with all but one receiving their award in the past decade.