Search

OBJECTIVES: Effective allometry research relies on appropriate size variables; however, two of the largest obstacles in subadult (ontogenetic) allometry research is small sample sizes and unknown dimensions. This study overcomes a barrier of ontogenetic allometry research by proposing alternative size variables that do not require additional calculations for use in subadult allometry research and retain general patterns among long bones when stature is used for size. MATERIALS AND METHODS Diaphyseal measurements, stature, and age were collected from computed tomography (CT) and full‐body radiographic images for a sample of subadults between birth and 13 years from the United States (U.S., n = 308) and South Africa (Z.A., n = 25). Nineteen alternative size variables were evaluated using reduced‐major‐axis regression to identify the closest one‐to‐one relationship to stature. The applicability across samples was then evaluated using the selected alternative size variables. RESULTS: Radius midshaft breadth (RMSB), femur midshaft breadth (FMSB), and the geometric mean of midshaft breadths (GM midshaft) yielded the closest isometric relationships to stature. Allometric relationships among long bones are maintained when using stature, FMSB, and GM midshaft as size variables for both the U.S. and Z.A. samples. DISCUSSION A large, modern dataset facilitated an investigation into alternative size variables that can be used for single‐bone ontogenetic allometry. Generalizability of the model suggests FMSB and GM midshaft are persistent across populations. This methodology identifies alternative size variables appropriate for other allometry research and offers a robust approach even when historically relied upon size variables are unknown. [ABSTRACT FROM AUTHOR]

Biological sex is foundational to the work of forensic anthropologists and bioarcheologists. The lack of reliable biological sex estimation methods for subadults has, thus, greatly limited forensic and bioarcheological analyses. Auricular surface elevation showed promise as a subadult sex estimation method in previous studies. This study examined two auricular surface elevation evaluation methods on four subadult samples of known age, sex, and ancestry. Samples were scored as "male," "female," or "indeterminate" and results were examined with chi‐square analysis. No consistent sex estimation pattern, accuracy, or predictive value was produced between samples. Only one test was significant using Fisher's exact test analysis (FET = 7.501, p < 0.022): the composite approach on the Hamann‐Todd sample. While age, sample size, or developmental factors may play a role in these results, clearly sample variation does as well. This study found auricular surface elevation was not a useful subadult sex estimation method. [ABSTRACT FROM AUTHOR]

Abstract: The approach to Gran Canaria's pre‐Hispanic period has traditionally been dominated by a romantic and propitious view of its indigenous populations advocating a historical evolution on the margin of the conflicts and contradictions common to any society. Yet new data indicate that the ancient Canarians were subject to high rates of internal violence linked to the island's isolation and harsh biogeographical conditions, as well as marked personal differences and a strong hierarchization of the social order. However, the effects of such a degree of violence among the subadult population remain unknown. The study of the assemblage of the victims, particularly the younger members of society, requires a global analysis of the historical conditions to determine whether this violence was exceptional or habitual. The findings of this study point to a prevalence of trauma among subadults (surpassing 20%), thus bolstering the notion of a society with widespread physical violence affecting the whole population or at least that above the age of 5 or 6 years. The data also suggest widespread violence within the framework of interpersonal relationships rather than violence directed specifically against the population's younger sector. [ABSTRACT FROM AUTHOR]

Extensive research has examined the effects of social isolation in neonatal and adult animal populations, but few studies have examined the effect of social isolation in early adulthood. Animals reaching reproductive age often experience extensive social changes as they leave their natal site, and a social stressor like isolation may uniquely affect this age group. Furthermore, adolescence is a time when sex differences in behavior become more pronounced. As such, the effects of social stressors are likely to vary by sex. In this study, we used noninvasive methods to evaluate stress responses to social change in male and female subadult chickens (Gallus gallus). Half of the birds experienced regular sessions of social isolation over the course of 2 wk, while the other half were never isolated. Subsequently, all of the animals were exposed to a suite of three novel probes, including an open-field test. We monitored the birds' behavioral (head movements) and physiological (fecal glucocorticoid metabolites, FGM) response to the tests. Our results indicate that, for subadult chickens, the effect of social isolation is sex dependent: Male FGM and behavioral responses did not change with subsequent experiences, in contrast to females. Females also exhibited more social reinstatement behavior compared to males. Our results are consistent with the expectations of differences between the sexes based on changes in the social environment due to sex-biased dispersal patterns. For both sexes, the FGM and behavioral responses varied independently, which highlights the necessity for multiple measures of stress in animal populations. [ABSTRACT FROM AUTHOR]

This paper presents the results of an examination of scurvy in the commingled subadult remains (minimum number of individuals = 70) of the Spring Street Presbyterian Church. This historic congregation in New York City had active burial vaults from 1820 to 1846. Scurvy is a vitamin C deficiency that results in haemorrhaging at the sites of muscle origin and insertion, particularly around the skull. These resulting lesions can occur in subadults undergoing growth, weaning and dietary stress. Applying diagnoses suggested by recent research, this article examines specific sites on the skull for lesions consistent with and suggestive of scurvy. Findings include 30 elements that display associated pathology. This population data are drawn from maxillae, sphenoids and orbits. Two osteobiographies are also presented. By connecting the biological data to the socio-cultural environment of the church, this article raises questions of how to interpret the presence and absence of scurvy in a commingled collection. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Late-medieval and post-medieval writings report that scurvy was a widespread condition in medieval and early historical Poland. Archaeological and historical data indicate that the diet of children was based on foods poor in vitamin C and contained small amounts of raw plant products. Also, historians emphasise that in medieval and post-medieval Poland, there were seasonal fluctuations in food availability, frequently accompanied by poor harvests. Both resulted in long periods of poor nutrition, which affected children most severely. The aim of this study was to investigate skeletal manifestations of scurvy in subadult remains from medieval and post-medieval Poland. Following standards described by Ortner and colleagues, anatomical sites pathognomonic of scurvy in subadults (<17 years) were assessed for abnormal porosity and hypertrophic bone among skeletons excavated from three sites: Ostrów Lednicki (dated to the 11th-14th centuries AD), Cedynia (10th-14th centuries AD) and Słaboszewo (14th-17th centuries AD). In total, 3.6% of all examined children were found to bear traces of vitamin C deficiency. The prevalence of scorbutic lesions was 4.5% for Cedynia, 2.6% for Ostrów Lednicki and 3.6% for Słaboszewo. The majority of affected children were less than 7 years of age. Scurvy was likely more widespread in the living populations than it appears from the calculation of skeletal markers, because some individuals might have recovered or died before obvious traces became apparent. Also, in some children, scurvy might not have reached an advanced stage, identifiable in the skeletal material. The prevalence of scurvy reflects not only dietary patterns but also food storage and preparation techniques adopted in the Polish territories during the Middle Ages, which contributed to low intakes of vitamin C. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Post-fledging dispersal and site fidelity are poorly understood, particularly for sea ducks that spend the majority of their annual cycle at sea. This is the first description of movements and their timing for first-year (juvenile) and second-year (subadult) King Eiders Somateria spectabilis in relation to their attendant females. We fitted satellite transmitters that operated for 2 years to 63 hatch-year birds and 17 attendant females at breeding areas in northern Alaska in 2006-2009. Our goals were to describe the spatio-temporal distribution of pre-breeding individuals and adult females that had been successful breeders. We also examined fidelity to wing moulting and wintering areas as well as natal philopatry. Juveniles did not appear to follow attendant adults, although they did winter in the same three general wintering areas, suggesting that genetic inheritance and social factors may have roles in the initial migration from the breeding area. Additionally, juveniles were more variable in the timing and duration of migration, moved longer distances during the winter, and were less faithful to moulting and wintering areas than adults, indicating that individual exploration and acquired navigational memory played a role in subsequent migrations. Most (75%) subadult females returned to natal areas, probably prospecting for future nesting sites, whereas subadult males were widely dispersed at sea. Timing and duration of moult migration and wing moult of adult females that were presumed to be successful breeders differed from those of unsuccessful breeders due to the extended time that the former spent on the breeding grounds. Temporal and spatial segregation of post-fledging King Eiders from adults has direct management implications in terms of resource development and population dynamics. [ABSTRACT FROM AUTHOR]

Age estimation in the subadult skeleton can be rather precise when the epiphyses and dentition are present, but incomplete or commingled remains still present a challenge. Histomorphometric age-at-death estimation methods developed for use on adults are based on the age-associated accumulation of osteons. In the growing skeleton, there is a poor correlation between osteon numbers and age until the latter half of the second decade. As a result, there has been no histological aging method for use in subadults. The analysis of the rib cortex of 72 subadults ranging in age from 2 to 21 years has identified a series of developmental changes in the bone microstructure that can be used to estimate age. This qualitative method utilizes the systematic changes in rib cortical morphology to classify ribs into one of four age phases. This method can be applied to immature skeletons in forensic, archaeological, and paleontological contexts. [ABSTRACT FROM AUTHOR]

The dentition is widely recognized as the set of developmental markers that appear to show the least variability against chronological age; these markers are thus widely used in forensic anthropological investigations. As a possible alternative, we investigate here the potential of mandibular morphology as a developmental marker for estimating age at death in subadults. The sample analyzed comprises 79 known age and sex subadult individuals of South African Bantu and African American origin. Linear measurements of ramus height were obtained from the mathematical conversion of three-dimensional landmark data. A series of regression analyses were then performed to predict age by using the measurement of ramus height; results were cross-validated using a jackknife procedure. Our results show that ramus height can be used to predict age in the subadult skeleton with accuracy, closely approaching that of standards based on the dentition (standard error rates are between ±1.1 years and ±2.4 years). [ABSTRACT FROM AUTHOR]

Estimation of stature in adult forensic cases with available long bones of the limbs is routine, but such estimation is less common in subadult cases. Long bones from subadult cases are often used to estimate age, but in some instances stature may be helpful or even critical for identification. Few published regression equations exist for consultation in such cases. Data from the longitudinal growth study conducted by the Child Research Council in Denver in the mid-1900s are utilized to produce dual-sex and single-sex regression equations for the six long bones of the limbs (humerus, radius, ulna, femur, tibia, and fibula) and for the combined femur+tibia length. All measurements are from radiographs and are of diaphyseal length. Examples show that similar results can be obtained using a two-step process of “ballpark” estimation from published tables of the Denver data, but these new regressions allow a one-step standard error estimate for the means. Regressions are further compared with those previously published by Finnish researchers, which are generally broadly comparable. More routine stature estimation in subadult cases is encouraged both as an aid to possible identification and as a test of the available regression equations. [ABSTRACT FROM AUTHOR]

There have been numerous attempts, with varying degrees of success, to differentiate males from females on the basis of the immature skeleton. We investigate here whether the mandible can discriminate immature individuals by sex; the techniques we apply are from the field of geometric morphometrics. The application of these methods in forensic anthropology is still relatively new; thus, an important aspect of this research is that it demonstrates potential applications in this discipline. The sample comprises 96 known age and sex subadult individuals; the three-dimensional coordinates of 38 landmarks are analyzed using the shape analysis software morphologika. Multivariate regressions indicated no significant sexual dimorphism in the subadult sample; this result is supported by poor cross-validated classification accuracy (59%). Our results suggest that the subadult mandible is not dimorphic (to the extent that dimorphism is not evident within the sample we studied); thus, sex determination using previously described criteria is likely to yield poor results. [ABSTRACT FROM AUTHOR]

Several weaknesses in our understanding of long-lived animal populations have persisted, mainly due to a prevalence of studies of a single local population at the expense of multisite studies. We performed a multisite capture-mark-resight analysis using 2050 Atlantic Puffins (Fratercula arctica) banded as chicks on four islands (colonies) over 24 years in the Gulf of Maine, USA and Canada. Within program MARK; encounter, apparent survival, pre- breeding movement (PBM; annual movements between colonies prior to breeding), and natal dispersal (ND) probabilities were modeled as functions of age, colony, and several covariates. Information-theoretic model selection criteria and estimated model effect sizes were used to identify important effects and select models, to estimate parameters. Encounter probabilities were extremely variable (0.10–0.95) and declined annually starting six years after bands were applied, due to changes in resighting effort, and band wear, respectively. Colony-dependent survival probabilities increased to a peak at age six years; arithmetic means from all colonies were: 0.70 for age 0–3, 0.78 for age 4, 0.81 for age 5, and 0.84 for age 6–8 years. Low adult survival (age ≥15 years) may reflect inclusion of breeding and nonbreeding adults in our sample or a bias due to band loss and illegibility. Consistent with a density-dependent prediction, the effect of colony size on survival was negative and acquired strong AICc support. However, this effect was inconsistent with strata effects in competing top models; the latter suggest that survival was lowest on the smallest island. The effects of origin and destination colony and origin colony size in PBM and ND probabilities resulted in important variation in these parameters. As few as 8% and as many as 57% of the puffins that we marked may have bred away from their natal colony, a signal of highly variable philopatry. Consistent with the con-specific attraction hypothesis, ND and PBM probabilities declined as the size of the origin colony increased. PBM probabilities were highest in the age 0–3 period, and these declined quickly with age thereafter. Strong colony and age effects in ND and PMB probabilities identify movement as a critical contributor to local population dynamics at our four study sites. [ABSTRACT FROM AUTHOR]

Reported survival rates for yearling and subadult bears in hunted black bear (Ursus americanus) populations in North America are scarce. We estimated survival rates of yearling and subadult black bears from a hunted population in western Virginia during 1999–2002. We captured 307 individual yearling and subadult bears on 2 study sites, and we attached radiotransmitters to 54 (34M:20F) 1-year-old, 52 (23M:29F) 2-year-old, and 35 (8M:27F) 3-year-old black bears. We used the known fate model in program MARK to estimate annual, nonhunting, and hunting season survival for radiomarked bears of each age and sex class. Additionally, we used mark-recapture data in the recaptures only, dead recoveries, and Burnham's combined models within program MARK to estimate survival for each age and sex class. One-, 2-, and 3-year-old female survivorship was 0.87 (95% CI 0.78–0.92), 1-year-old male survivorship was 0.32 (95% CI 0.20–0.47), and 2- and 3-year-old male survivorship was 0.59 (95% CI 0.47 – 0.71) from the Burnham's combined model. Survival rates for I-year-old females (χ² = 6.20, P= 0.01) and 2-year-old females (χ² = 7.74, P= 0.01) were higher than males in each age category, respectively. Hunter harvest accounted for 98% of all subadult bear mortality during our study. Low yearling and subadult male survival is not likely a cause for alarm due to the importance of adult female survival to population growth and the promiscuous mating system in black bear populations. [ABSTRACT FROM AUTHOR]