Techniques of DNA-studies on prehispanic ectoparasites (Pulex sp., Pulicidae,Siphonaptera) from Animal mummies of the Chiribaya culture,southern Peru

During a paleoparasitological survey of several animal mummies (Cavia aperea f. porcellus and Canis familiaris) from Chiribaya Baja, an archaeological site in Southern Peru, an unexpected find was made. In the well preserved fur, large numbers of mummified fleas (Pulex simulans/irritans) that parasitized the animals during life were encountered. Due to the relative recent event of the host mummification and the outstanding preservation of the fleas, an attempt for the retrieval of DNA was made. A DNA extraction and sequencing protocol for archaeological ectoparasitic remains has been established, taking additional studies for tissue and protein preservation into account. Tissue preservation was assessed with transmission electron microscopy and the protein preservation was tested through the racemisation ratios of aspartic acid. Regions of the 28S rDNA gene were successfully amplified and sequenced. Further research perspectives are outlined.     

Spatial,temporal, age,and sex related variation in the diet of South American sea lions in southern Chile

We analyzed spatial, temporal, and age/sex variation in the diet of the South American sea lions (SASL, Otaria byronia) in southern Chile via δ¹³C and δ¹⁵N isotope analysis, with emphasis on exotic farmed and feral salmonids as a source of prey for this generalist predator. Isotope mixing models show that the primary prey consumed by SASL were demersal and benthopelagic fishes. Individuals sampled in summer and in the outer coast had higher δ¹⁵N values than those from winter or from the inner coast due to consumption of high trophic level demersal fish. We also found evidence of an ontogenetic shift in isotopic niche width as measured by δ¹³C and δ¹⁵N standard ellipse areas, with juveniles showing a restricted isotopic niche width (1.0‰²) in comparison to subadult (2.2‰²) and adult males (1.9‰²). The proportion of salmonids in the diet of the SASL was negligible and lower than reported in previous studies, which may be related to a recent drop in the production of salmon aquaculture in the region. Our study suggests that the SASL are able to adapt to shifts in spatiotemporal variations in the abundance of potential prey, including feral and farmed salmonids.     

Helminth infections in Apodemus sylvaticus in southern England: interactive effects of host age, sex and year on the prevalence and abundance of infections.

Helminth parasites were studied in the wood mouse, Apodemus sylvaticus, in southern England in September of each of four successive years (1994-1997). Nine species of helminths were recorded: five nematodes (Heligmosomoides polygyrus, Syphacia stroma, Pelodera strongyloides, Trichuris muris, Capillaria murissylvatici), two cestodes (Microsomacanthus crenata, Taenia taeniaeformis) and two trematodes (Corrigia vitta, Brachylaemus recurvum). In total, 134 mice were examined and 91.8% carried at least one species of helminth. The majority of mice carried two to three species (60.5%) and the highest combination was six of the nine species recorded in the study. The patterns of between-year variations in the prevalence and abundance of infection were different for each of the six species for which sufficient quantitative data were available to enable statistical analysis. For H. polygyrus, the most important source of variation arose from between-year differences, host age and the interaction of these factors: abundance increased with host age but in 1995 the age pattern was markedly different from that in the remaining years. The abundance of C. vitta also varied significantly between years but additionally there was a strong independent age effect. For M. crenata, the year x age interaction was significant, indicating that abundance among different age cohorts varied from year to year but there was also a weak significant main effect of age arising from the youngest age cohort carrying no parasites and the oldest age cohort the heaviest infections. For P. strongyloides the only significant factor was between-year variation with 1995 being a year of exceptionally low prevalence and abundance of infection. No significant between-year variation was detected for S. stroma but there was a strong sex effect (males carrying heavier infections) and an age effect (older mice of both sexes carrying heavier infections). The abundance of Trichuris muris varied only in relation to host age, worm burdens growing in intensity with increasing age, but there was also a significant interaction between year and host sex with respect to prevalence. For the remaining three species, the prevalence of infections was too low (< 8.2%) to enable any meaningful interpretation. This analysis emphasizes the need for carefully controlled statistical procedures in aiding the interpretation and the prioritization of the factors affecting worm burdens in wild rodents.     

Anatomical patterning of visceral adipose tissue: race, sex, and age variation

Objective: We tested sex, race, and age differences in the patterning of visceral adipose tissue (VAT) and subcutaneous adipose tissue. Research Methods and Procedures: Contiguous 1‐cm‐thick magnetic resonance (MR) images of the abdomen were collected from 820 African‐American and white adults. Repeated‐measures ANOVA was used to examine the effects of image location, sex, race, and age (≥50 vs. <50 years) on adipose tissue areas. Maximum VAT area was identified for each subject from the raw data. Results: Compared to women, men had greater total VAT volume (p < 0.0001), and their maximum VAT area occurred higher in the abdomen (p < 0.0001). Among white men, maximim VAT area most frequently occurred 5 to 10 cm above L4‐L5, whereas in the other groups, maximim VAT area most frequently occurred 1 to 4 cm above L4‐L5 (p < 0.0001). African‐American men had greater total VAT volume than African‐American women (p < 0.01), but this sex difference was only significant using single images cranial to L4‐L5 + 2 cm. Age‐related increases in VAT tended to be greatest 5 to 10 cm above L4‐L5 in men and near L4‐L5 in women. Discussion: A single MR image 5 to 10 cm above L4‐L5 may allow more accurate conclusions than the L4‐L5 image regarding group differences in visceral adiposity.     

Morphometric analysis of variation in the sternum with sex and age

Age and sex‐related variations in sternum morphology may affect the thoracic injury tolerance. Male and female sternum size and shape variation was characterized for ages 0–100 from landmarks collected from 330 computed tomography scans. Homologous landmarks were analyzed using Procrustes superimposition to produce age and sex‐specific functions of 3D‐sternum morphology representing the combined size and shape variation and the isolated shape variation. Significant changes in the combined size and shape variation and isolated shape variation of the sternum were found to occur with age in both sexes. Sternal size increased from birth through age 30 and retained a similar size for ages 30–100. The manubrium expanded laterally from birth through age 30, becoming wider in relation to the sternal body. In infancy, the manubrium was 1.1–1.2 times the width of the sternal body and this width ratio increased to 1.6–1.8 for adults. The manubrium transformed from a circular shape in infancy to an oval shape in early childhood. The distal sternal body became wider in relation to the proximal sternal body from birth through age 30 and retained this characteristic throughout adulthood. The most dramatic changes in sternum morphology occur in childhood and young adulthood when the sternum is undergoing ossification. The lesser degree of ossification in the pediatric sternum may be partly responsible for the prevalence of thoracic organ injuries as opposed to thoracic skeletal injuries in pediatrics. Sternum fractures make up a larger portion of thoracic injury patterns in adults with fully ossified sternums. The lack of substantial size or shape changes in the sternum from age 30–100 suggests that the increased incidence of sternal fracture seen in the elderly may be due to cortical thickness or bone mineral density changes in the sternum as opposed to morphological changes. J. Morphol. 275:1284–1299, 2014. © 2014 Wiley Periodicals, Inc.     

Study on long bones: variation in angular traits with sex, age, and laterality

The biological problems considered in this study are sexual dimorphism in angular osteometric traits, changes in these traits with aging and their bilateral asymmetry in the same individual. The sample comprises the right and left long bones of 200 skeletons (100 males and 100 females) of Sardinian adults (Frasetto collection) for whom the sex and age at death are known. As concerns the sexual dimorphism, some angular traits of upper limb (joint axis angle of the ulna in particular) and the lower limb (condylo-diaphyseal angle of the femur and retroversion angle of the tibia) are significantly different between males and females. Torsion angles of long bones (especially the femur) were found to change with age. In sides comparison revealed a clear right-left asymmetry in our sample. The asymmetry, sexual dimorphism and changes with age are discussed in relation to varying stresses of different living activities. Our data indicate that the angular traits of long bones could be very informative in biomechanical interpretations of human activities based on skeletal remains.     

Seasonal variation in age,sex, and reproductive status of Mexican free-tailed bats

In North America, Mexican free-tailed bats (Tadarida brasiliensis mexicana) consume vast numbers of insects contributing to the economic well-being of society. Mexican free-tailed bats have declined due to historic guano mining, roost destruction, and bioaccumulation of organochlorine pesticides. Long-distance migrations and dense congregations at roosts exacerbate these declines. Wind energy development further threatens bat communities worldwide and presents emerging challenges to bat conservation. Effective mitigation of bat mortality at wind energy facilities requires baseline data on the biology of affected populations. We collected data on age, sex, and reproductive condition of Mexican free-tailed bats at a cave roost in eastern Nevada located 6 km from a 152-MW industrial wind energy facility. Over 5 years, we captured 46,353 Mexican free-tailed bats. Although just over half of the caught individuals were nonreproductive adult males (53.6%), 826 pregnant, 892 lactating, 10,101 post-lactating, and 4327 nonreproductive adult females were captured. Juveniles comprised 11.5% of captures. Female reproductive phenology was delayed relative to conspecific roosts at lower latitudes, likely due to cooler temperatures. Roost use by reproductive females and juvenile bats demonstrates this site is a maternity roost, with significant ecological and conservation value. To our knowledge, no other industrial scale wind energy facilities exist in such proximity to a heavily used bat roost in North America. Given the susceptibility of Mexican free-tailed bats to wind turbine mortality and the proximity of this roost to a wind energy facility, these data provide a foundation from which differential impacts on demographic groups can be assessed.     

Seasonal variation in the sex and age composition of the woodcock bag in Denmark

The Eurasian woodcock is a highly valued game bird in Western Europe from which c. 2.7 million individuals are harvested annually from an estimated population of 20–26 million birds. The population size and status remains uncertain due to the cryptic behaviour and widespread and solitary occurrence of woodcock, on breeding and wintering areas, making reliable population surveys difficult. Hunting bag records provide age ratios amongst bagged birds, but sex ratios remain poorly known because of the sexually monomorphic nature of this species. We used DNA analysis to determine sex ratios amongst 327 shot woodcocks from two hunting seasons in Denmark (1 October–31 January, 2012/13 and 2013/14). Based on bag totals, age ratios and sex ratios, juvenile females constituted 37%, juvenile males 27%, adult females 16% and adult males 20% of the annual woodcock bag. The female bias was related to a significant deviation from parity in the sex ratio amongst juvenile birds in October, although no such deviation was found at other times or amongst adults. Compared to limited data from other European countries, our data suggest that autumn migration of woodcock involves an initial wave of juvenile females followed by juvenile males and adults, and perhaps that males stay further north in Europe than females during autumn and winter. This migratory pattern would suggest that postponing the opening of the hunting season could reduce the hunting bag on reproductively valuable females in this polygamous species.     

Geographical variation, sex and age in Great Bittern Botaurus stellaris using coloration and morphometrics

Biometrics, plumage and bare-part colour of 87 Great Bitterns Botaurus stellaris from the UK, France, Italy, Poland and Belarus, of known sex (sexed by behaviour, DNA or dissection), were analysed to provide reliable sexing and ageing criteria for this little-known species, and to investigate geographical variation in biometrics. Four parameters were analysed: bill length, tarsus, wing length and body weight. We found little (though significant) geographical variation across Europe, but this was not clinal and we cannot exclude variation in measurement technique among observers. Males were significantly larger than females for all biometric parameters: a discriminant function based on these parameters was able to sex correctly all individuals. Body weight varied with season, especially for males. During the breeding period, lore colour was also a reliable sex-criterion. Ageing proved more difficult and required a combination of iris colour (which darkens with age) and flight-feather moult. From this, the largest sample size of known-age Great Bitterns, we conclude that most previously published criteria for age determination of this species were wrong.     

Dispersal by gray ratsnakes: Effects of sex,age and time

Dispersal is one of the most fundamental components of ecology. Dispersal is also particularly relevant in an era of unprecedented habitat loss and climate change. We used a unique dataset to examine dispersal in gray ratsnakes (Pantherophis spiloides). Over a decade, we marked and released >1,500 hatchlings while monitoring the population of ratsnakes over a large area (≈1,900 ha). We tested the hypotheses that dispersal should be (a) largely restricted to within the local population given previous genetic evidence of limited gene flow at greater distances and (b) male biased because male gray ratsnakes are under strong sexual selection. We recaptured 69 gray ratsnakes that had been marked as hatchlings after periods ranging from 1 day to 11 years. We found that dispersal distance increased with time, but was not significantly sex-biased, and that gray ratsnakes are extremely faithful to their communal hibernacula (only 2.8% of 497 juvenile and adult ratsnakes captured at least twice at communal hibernacula changed sites between years). Thus, dispersal is largely limited to the period from hatching until an individual joins a communal hibernaculum. Based on the spatial patterns of dispersal we observed, the most plausible explanation for dispersal is that hatchling ratsnakes disperse from their natal site to join a neighboring communal hibernaculum. Our study yielded the most reliable data on dispersal distances from birth by a snake to date.     

Progeny sex ratio variation in ungulates: maternal age meets environmental perturbation of demograpgy

Current models of the evolution and maintenance of mutualism stress the importance of vertical transmission and the genetic uniformity of symbionts to evolutionary stability. Here we point out that many well-known mutualistic relationships involve symbionts that are neither vertically transmitted nor genetically uniform. We have therefore re-examined some of the existing models in an attempt to identify general conditions under which horizontally acquired mutualisms might be evolutionarily stable.     

Global variation in young adult central nervous system tumor incidence by region,age, and sex from 1988 to 2012

BackgroundCentral nervous system (CNS) tumors result in tremendous morbidity and mortality. Incidence of CNS tumors in young adults is less studied. It is unknown how young adult CNS tumor incidence has changed globally in recent decades.MethodsWe used Cancer Incidence in Five Continents (CI5) data (1988–2012) to estimate incidence rates (IR), average annual percent change in incidence (AAPC; 95% confidence intervals [95% CI]), and male-to-female incidence rate ratios (IRR; 95% CI) by six histologies and age at diagnosis (20–29years, 30–39years). Tumors were classified as astrocytic, medulloblastoma, ependymal, oligodendroglial, meninges, and other embryonal. Geographic regions were defined using the United Nations Statistics Division geoscheme.ResultsThere were 78,240 CNS tumor cases included. 20–29-year-old (yo) rates were lower than 30–39 yo in most regions for astrocytic, oligodendroglial and ependymal tumors. Globally, astrocytic tumor incidence decreased (20–29 yo AAPC: − 0.70; 95% CI: − 1.32, − 0.08) while incidence increased for oligodendroglial (20–29 yo AAPC: 3.03; 95% CI: 1.57–4.51; 30–39 yo AAPC: 2.67; 95% CI: 0.79–4.58), ependymal (20–29 yo AAPC: 1.16; 95% CI: 0.31–2.03; 30–39 yo AAPC: 2.29; 95% CI: 1.14–3.46), medulloblastoma (30–39 yo AAPC: 0.6; 95% CI: 0.04–1.24) and tumors of the meninges (20–29 yo AAPC: 1.55; 95% CI: 0.04–3.07). There was a 20–40% male incidence excess in all histologies except for meninge tumors (30–39 yo IRR: 0.71; 95% CI: 0.61, 0.84).ConclusionsIncidence of oligodendroglial and ependymal tumors increased globally in 20–39 yo suggesting better diagnoses or changes in risk factors. Males had a higher incidence of CNS tumors for most tumors studied and in most regions.     

Effects of age, sex and abundance on the bathymetric pattern of American plaice in the southern Gulf of St Lawrence

American plaice Hippoglossoides platessoides density in September in the southern Gulf of St Lawrence was strongly related to depth, with peak densities at intermediate depths (70–90 m). Bathymetric pattern was similar for all ages of plaice (3–12 + year) and varied little among years. Densities were highest at similar depths for males and females, but depth distribution tended to be more spread out for females. Depth distribution was not significantly density dependent except for 10-and 11-year-old males and for females aged 12 years and older. In the three significant cases, depth distribution tended to spread out as abundance increased. Water temperature and depth were closely linked in the southern Gulf, but plaice depth preferences could not be attributed solely to temperature selection.     

Blood values of the canvasback duck by age, sex and season

Blood samples were obtained from canvasback ducklings from Manitoba and Saskatchewan and from immature and adult canvasbacks on the Mississippi River near LaCrosse, Wisconsin and the Chesapeake Bay. These samples were used to determine baseline data on red cell counts, hematocrit, total protein, glucose, cholesterol, hemaglobin and distribution of plasma proteins. Calculations were also made to determine mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. The major differences noted were between ducklings and adults. The former having higher total protein and lower hematocrit, glucose and cholesterol values. These hematologic values were collected in order to provide baseline information on apparently healthy canvasbacks, thereby providing disease investigators with a standard of comparison.     

Survivorship of a declining population of southern elephant seals, Mirounga leonina, in relation to age, sex and cohort

This study quantified both the age- and sex-specific survival rates of juveniles and adults, and tested for interannual differences in age-specific survival rates of the southern elephant seal population at Marion Island. Pups were tagged on an annual basis from 1983 onwards at Marion Island, and a consistent recapture program yielded data that was analysed using the software package MARK to obtain maximum-likelihood estimates of survival and capture probability. On average, 1st-year survival was 0.58 and 0.62, and survival rate averaged over the first 3 years of life, 0.69 and 0.74 for males and females, respectively. From years 4 to 9, the average survival rate was 0.66 and 0.75 for males and females, respectively. Survival estimates for elephant seals in their 10th–13th year are also presented, although these are based on very small sample sizes. Averages of age-specific survival estimates from the earlier (mostly 1983–1987 cohorts) and later (mostly 1988–1992 cohorts) periods were compared and considerable reductions were observed in 4th- and 5th-year male survival, and 4th-year female survival. The comparatively low adult survival is suggested as the proximate cause, and food limitation as deduced from the decline in survival of elephant seals with comparatively high energetic demands as the ultimate cause behind the population decline at Marion Island. Although not tied in with the decline of the population, 1987, 1990 and 1993 were identified as high-mortality years. Received: 14 December 1998 / Accepted: 14 June 1999