Sexing Adult Pale-Winged Starlings Using Morphometric and Discriminant Function Analysis

Accurate sexing of birds is vital for behavioral studies but can be a real problem in the field, especially for monomorphic species. Our goal here was to characterize the morphology of male and female monomorphic pale-winged starlings (Onychognathus nabouroup), a South African sturnid whose plumage is sexually monomorphic. Morphological measurements of genetically sexed animals indicated that males were statistically larger than females for five measurements: Mass, tail length, tarsus length and wing length. By using a Discriminant Function Analysis based on the measurements taken by one ringer, we were able to predict correctly the sex of 81.10% of the birds of data collected in the field and 77.9% of museum skins independently of year of capture and ringer. The model developed here should be useful for further field studies of this species.     

Complexity in Arikara Mortuary Practice

Abstract

Traditionally, Arikara mortuary practice has been described as direct interment soon after death in wood-covered pits. This interpretation explains most of the ethnohistorical and archeological data, but not all. Some ethnohistorical, archeological, and entomological evidence suggests scaffolding prior to burial.     

Skeletal growth of the protohistoric Arikara.

The longitudinal growth of the long bones and growth in breadth of the ilium are assessed for a population of protohistoric Arikara Indians from South Dakota through the correlation of skeletal measurements with estimates of chronological age at death. Comparison of the Arikara growth data with those from other Indian samples (Indian Knoll and Late Woodland, Illinois) reveals similar rates of bone growth, when compensation is made for methodological variation. As predicted from documented variation in adult statures, the Indian samples indicate slower growth rates than those of Whites but faster than those of Eskimos.     

Seasonal Economic and Settlement Patterns of the Arikara

Abstract

That the Arikara were characterized by seasonal economic activities accompanied by varying settlement patterns during the Late Prehistoric and EarlyContact Periods is amply documented in the archaeological records and journals of the first explorers of the Missouri Valley. In spite of the abundant data, however, several aspects of the seasonal changes of economic and settlement patterns still remain subjects of speculation. Since there seems to have been so much regional and time variation in these patterns the observations presented in this report should be considered tentative.     

Morphological Differences Between Mandan And Historic Arikara Crania

Abstract

Arikara cranial measurements are compared with Mandan data to define the nature and magnitude of differences remaining at the beginning of the Historic period. A discriminant function approach is followed. Special attention is given to determining uniqueness of the two sets of crania as estimated by rates of group misclassification. Three validation procedures are applied in estimating these rates: resubstitution, jackknife, and holdout.

Several variables show significant heterogeneity between Arikara and Mandan including nasal height, maximum cranial breadth, and auricular height. Mandan crania tend to be narrower, have less nasal height, and are lower in auricular height. Functions developed for Leavenworth Arikara and Mandan crania have an accuracy of about 84 percent. Data for the Leavenworth Site are expanded with addition of a sample excavated by William H. Over 60 years ago.     

Cranial Variation and Microevolution in Arikara Skeletal Populations

Abstract

Crania from six archaeological sites in South Dakota are analyzed. Chronologically the sites fall into two groups, an early group and a late group, with A.D. 1750 as the approximate boundary between them. It is shown that the late group is morphologically diverse, while the early group is relatively homogeneous. The morphological pattern is related to the increasing intensity of evolutionary processes as the contact period progressed.     

Non-carious interproximal grooves in Arikara Indian dentitions.

The dentitions of adult Arikara Indians from the Larson site (39WW2) were examined to determine the frequency and etiology of noncarious interproximal grooves. The observations included groove morphology, loci and association with dental pathology. Approximately 30% of the individuals exhibit one or more pronounced grooves. The use of dental probes in conjunction with dietary grit is the likely responsible for interproximal grooves in this population sample.     

Microevolutionary change in Arikara Crania: a multivariate analysis

Measurements of human crania from five archaeological sites were subjected to canonical analysis. The five sites form a temporal sequence, ranging from prehistoric (ca. 1600 A.D.) to late historic (1830 A.D.), and belonging archaeologically to the Coalescent Tradition, which in South Dakota encompasses the historic Arikara Indians and their prehistoric ancestors. One canonical variate in each sex arranges the sites in their appropriate temporal sequence, presumably reflecting systematic microevolutionary change. The hypothesis that the morphological change resulted from gene flow from either White or Mandan Indian sources was tested using a two-group discriminate function. The function is found to effectively discriminate a Mandan sample and prehistoric Arikara, but becomes progressively less effective on the historic Arikara crania. This would suggest that Mandan gene flow into Arikara populations is responsible for the observed temporal variation. A similar analysis using British White crania suggests the possibility of slight White influence, but the effect is minimal compared to Mandan.     

The Avifauna from Prehistoric Arikara Sites in South Dakota

Abstract

During an approximate 15-year period from about 1950 to 1965, numerous anthropologists representing at least a dozen institutions were periodically involved in archaeological salvage of Plains sites in the Middle Missouri Valley. In many instances the cultural aspects of subsistence and the utilization of native fauna in general were not of primary interest. However, some animal bone was salvaged and this discussion involves the study of the avian remains from 51 prehistoric Arikara sites along the Missouri River in South Dakota. Approximately 3,100 bird elements, representing 22 families and about 68 species, were identified. Although mammals, especially the bison, elk, deer, and pronghorn, provided the greatest quantity of meat in the diet of these people, birds were also of special significance as supplemental food (e.g. waterfowl, grouse) and because of the part they played in the cultural and ceremonial activities of the Plains Indian. The predominance of remains of such groups as eagles, hawks, harriers, owls, and ravens in these sites is indicative of their special cultural significance; in some instances, such as eagle trapping by the Hidatsa and Mandan, they can be correlated with ethnohistoric accounts dealing with the utilization of birds.     

Coral Skeletons Defend against Ultraviolet Radiation

Background

Many coral reef organisms are photosynthetic or have evolved in tight symbiosis with photosynthetic symbionts. As such, the tissues of reef organisms are often exposed to intense solar radiation in clear tropical waters and have adapted to trap and harness photosynthetically active radiation (PAR). High levels of ultraviolet radiation (UVR) associated with sunlight, however, represent a potential problem in terms of tissue damage.

Methodology/Principal Findings

By measuring UVR and PAR reflectance from intact and ground bare coral skeletons we show that the property of calcium carbonate skeletons to absorb downwelling UVR to a significant extent, while reflecting PAR back to the overlying tissue, has biological advantages. We placed cnidarians on top of bare skeletons and a UVR reflective substrate and showed that under ambient UVR levels, UVR transmitted through the tissues of cnidarians placed on top of bare skeletons were four times lower compared to their counterparts placed on a UVR reflective white substrate. In accordance with the lower levels of UVR measured in cnidarians on top of coral skeletons, a similar drop in UVR damage to their DNA was detected. The skeletons emitted absorbed UVR as yellow fluorescence, which allows for safe dissipation of the otherwise harmful radiation.

Conclusions/Significance

Our study presents a novel defensive role for coral skeletons and reveals that the strong UVR absorbance by the skeleton can contribute to the ability of corals, and potentially other calcifiers, to thrive under UVR levels that are detrimental to most marine life.     

小鼠早期胚胎性别鉴定的研究

用改进的细胞遗传学方法制备染色体标本,鉴定了小鼠晚期桑椹胚(晚桑)、囊胚和扩展囊胚(扩囊)的性别。在实验中,利用小鼠早期胚胎染色体标本制备的理想实验参数,鉴定了242枚小鼠晚桑、囊胚和扩囊的性别,性别鉴定成功率分别为80.4％、99.0％和94.5％。以细胞遗传学方法鉴定小鼠早期胚胎性别的结果为标准,得出用间接免疫荧光法和PCR(聚合酶链反应)扩增SRY(y染色体的性别决定期)部分序列法分别鉴定100枚和26枚小鼠胚胎性别的准确率相应地为74.0％和92.3％。     

Toward A Partial Understanding Of Complexity In Arikara Mortuary Practice

Abstract

Ethnohistorical references on Arikara mortuary practice are summarized, and the recently proposed hypothesis that Arikara mortuary practice was more complex than previously suspected is evaluated. In addition, the ethnohistorical sources are reinterpreted, and it is proposed that some Arikara mortuary complexity was directly related to season of death.     

Mortality of pregnant females in Arikara villages: osteological evidence

High infant mortality and high mortality for late adolescent and young adult females suggest that obstetrical hazards may be one explanation for differences in male and female mortality curves. This possibility is investigated in Arikara skeletal series by determining the frequency of females who died with fetal remains in utero. Two females (0.9%) were so identified. Examination of the females and the fetal remains do not provide evidence that stress of childbearing was the cause of death in these cases.     

Discriminant Variables

Several fundamental properties of discriminant variables are developed. In addition, the proportionality of the discriminant variables, canonical variables and RAO principal components is demonstrated.