Adult Males (adult + male)

Distribution by Scientific Domains

Kinds of Adult Males

  • one adult male
  • young adult male

  • Terms modified by Adult Males

  • adult male albino rat
  • adult male patient
  • adult male prisoner
  • adult male rat
  • adult male sprague
  • adult male sprague-dawley rat
  • adult male wistar rat

  • Selected Abstracts

    Intra- and Inter-seasonal Variation in the Socio-Spatial Behavior of Adult Male Collared Lizards, Crotaphytus collaris (Reptilia, Crotaphytidae)

    ETHOLOGY, Issue 1 2001
    Troy A. Baird
    When individuals maintain strong inter-seasonal philopatry to the same territories, males may be able to re-establish territory occupancy without intense intra-sexual aggression, and instead spend more time courting females early in the reproductive season. Furthermore, when some males have prior experience defending the same territories, it may be necessary for young males to exhibit higher levels of aggression because they are establishing a territory for the first time. We tested these hypotheses by examining within-season (1992 and 1997) temporal variation in the social behavior of adult male collared lizards of known age and prior territorial experience in a population where inter-season philopatry to territories is high. Contrary to expectations, the frequency of aggression exhibited by males with and without prior territorial experience did not differ. The frequency of intra-sexual aggression was higher in 1992 than in 1997, perhaps because male competitors were more abundant in 1992. Although there was an interactive effect of year, male display and patrol were low at the beginning of the reproductive season in Apr. and May, reached peaks during midseason in June, and then decreased as reproduction ended in July. The size of territories showed a similar pattern, with males defending larger areas in June. Our data support the philopatry hypothesis in that the establishment of territories occurred without high levels of aggression early in the season, perhaps because territory boundaries have been well defined by high rates of patrol and advertisement during the middle of the previous season. Inter-sexual interactions were most frequent in June rather than at the beginning of the reproductive season. Adult females are producing their second clutches and yearling females are producing their first clutches in June. The high rate of inter-sexual encounters in June supports the hypothesis that males allocate more time to courtship when females are receptive because there are more reproductively active females at this time. The temporal pattern of activities in adult Crotaphytus collaris appears to function as a compromise between competing intra- and inter-sexual social demands on males, allowing males to maximize mating opportunities as well as maintain future access to productive territories. [source]

    Distribution of Adult Male and Female Baccharis concinna (Asteraceae) in the Rupestrian Fields of Serra Do Cipó, Brazil

    PLANT BIOLOGY, Issue 1 2002
    A. R. Marques
    Abstract: This study focuses on the sex ratio and spatial distribution of males and females in three populations of the endemic and restricted tropical dioecious shrub, Baccharis concinna (Asteraceae) in the mountainous region of Serra do Cipó, southeastern Brazil. The proportion of female plants in the population at lower elevation (1000 m a.s.l.) was significantly greater than of male plants. At this elevation of P/N and Ca/Al ratios in the soil were also greater indicating better nutritional status of the soils. The concentration of aluminium increased significantly with the elevation (p < 0.001), perhaps rendering soils less conducive to female plants at higher elevations. Female plants are possibly adversely affected to a greater extent by soil quality than male plants. The spatial distribution of the populations within habitat was tested by the K(t) function, where the neighbourhood of a given individual was defined by a circle with a radius (t) up to 3 m. Despite the strong tendency for aggregation, the distribution of the sexes within habitats was random and the hypothesis was not supported. The independent distribution of the sexes within habitats may be explained by nutrient homogeneity of the soils, as well as by an absence of antagonism between the sexes. Nevertheless, we found a trend for males and females to be aggregated according to their gender. [source]

    The Effect of Testosterone on Gastrocnemius Muscle Fibres in Growing and Adult Male and Female Rats: A Histochemical, Morphometric and Ultrastructural Study,

    . Üstünel
    Summary In this study, the effect of testosterone on gastrocnemius muscle fibres in growing and adult rats (male and female) was examined using histochemical, morphometric and ultrastructural techniques. After physiological saline (PS), olive oil (OvO) or olive oil + testosterone (OvOT) injections on 72 rats (growing and mature, 36 male and 36 female), the sample tissues of fibre types of the gastrocnemius muscle taken were examined by histochemical [alkaline adenosine triphosphatase (alk-ATPase), acid ATPase (ac-ATPase)], morphometric and ultrastructural techniques. In PS-injected control groups, the gastrocnemius muscle of both sexes contained all the fibre types studied [slow-oxidative muscle fibres (type I), fast-oxidative glycolytic muscle fibres (type IIA) and fast-glycolytic muscle fibres (type IIB)]. The type I fibres had the smallest diameter, type IIA had a medium diameter and type IIB fibres had the largest diameter. In OvO-injected groups, it was observed that the OvO had little effect on the gastrocnemius muscles of either sex, although there was significant enlargement of type IIB fibres. After the injection of OvOT, hypertrophy of muscle fibres was determined by morphometric study. The biggest increase in diameter was on type I fibres. In addition, degenerations on some mitochondria, accumulation of lipid droplets on type I and type II fibres, an increase in glycogen particles, bifurcation of myofibrils, an increase in the number and diameter of units resembling T tubules and an increase in ribosomal content were also observed in the same group by transmission electron microscope. Consequently, it was determined that testosterone can induce protein synthesis in gastrocnemius muscle fibres, and induces changes in shape and size, and also can change the appearance and the number of fibres. [source]

    Estimation of Age-at-Death for Adult Males Using the Acetabulum, Applied to Four Western European Populations,

    Carme Rissech Ph.D.
    Abstract:, Methods to estimate adult age from observations of skeletal elements are not very accurate and motivate the development of better methods. In this article, we test recently published method based on the acetabulum and Bayesian inference, developed using Coimbra collection (Portugal). In this study, to evaluate its utility in other populations, this methodology was applied to 394 specimens from four different documented Western European collections. Four strategies of analysis to estimate age were outlined: (a) each series separately; (b) on Lisbon collection, taken as a reference Coimbra collection; (c) on Barcelona collection, taken as a reference both Portuguese collections; and (d) on London collection taken as reference the three Iberian collections combined. Results indicate that estimates are accurate (83,100%). As might be expected, the least accurate estimates were obtained when the most distant collection was used as a reference. Observations of the fused acetabulum can be used to make accurate estimates of age for adults of any age, with less accurate estimates when a more distant reference collection is used. [source]

    Using the Acetabulum to Estimate Age at Death of Adult Males,

    Carme Rissech Ph.D.
    ABSTRACT: The acetabular region is often present and adequately preserved in adult human skeletal remains. Close morphological examination of the 242 left male os coxae from the identified collection of Coimbra (Portugal) has enabled the recognition of seven variables that can be used to estimate age at death. This paper describes these variables and argues their appropriateness by analyzing the correlation between these criteria and the age, the intra- and interobserver consistence, and the accuracy in age prediction using Bayesian inference to estimate age of identified specimens. Results show significant close correlation between the acetabular criteria and age, nonsignificant differences in intra- and interobserver test, and 89% accuracy in Bayes prediction. Obtained estimated age of the specimens had similar accuracy in all ages. These results indicate that these seven variables, based on the acetabular area, are potentially useful to estimate age at death for adult specimens. [source]

    Immunoexpression of Aromatase in Immature and Adult Males of the European Bison (Bison bonasus, Linnaeus 1758)

    I Kopera
    Contents Based on recent literature dealing with the role of oestrogens in the male gonad, attempts were undertaken to reveal the site of aromatization within the testis of the European bison (Bison bonasus). Testes were collected from culled animals living in free-ranging populations in Bialowieza Forest, Poland (nine males aged 8 months to 10 years). Moreover, to check for any alterations in the expression of testicular aromatase between American bison (Bison bison) and European bison, testes from one adult 10-year-old individual were also chosen for this study. For immunohistochemistry, 4% formaldehyde fixative was used. Both qualitative and quantitative evaluations of immunohistochemical staining were performed. Leydig cells, Sertoli cells and germ cells exhibited a positive immunoreaction for aromatase in testes of immature and sexually mature bison. A marked increase in aromatase expression was observed in three adult European individuals with impaired spermatogenesis. Consistent with recent data and those of our own, it might be suggested that the strong expression of aromatase negatively affects spermatogenic function in bison testes and may serve as a possible explanation of specific sperm defects observed in European bison bulls. On the contrary, one cannot exclude that differences in the aromatase immunoexpression levels are attributed to the homozygosity, the cause of frequent disease in European bison. [source]

    Stress experienced in utero reduces sexual dichotomies in neurogenesis, microenvironment, and cell death in the adult rat hippocampus

    Chitra D. Mandyam
    Abstract Hippocampal function and plasticity differ with gender, but the regulatory mechanisms underlying sex differences remain elusive and may be established early in life. The present study sought to elucidate sex differences in hippocampal plasticity under normal developmental conditions and in response to repetitive, predictable versus varied, unpredictable prenatal stress (PS). Adult male and diestrous female offspring of pregnant rats exposed to no stress (control), repetitive stress (PS-restraint), or a randomized sequence of varied stressors (PS-random) during the last week of pregnancy were examined for hippocampal proliferation, neurogenesis, cell death, and local microenvironment using endogenous markers. Regional volume was also estimated by stereology. Control animals had comparable proliferation and regional volume regardless of sex, but females had lower neurogenesis compared to males. Increased cell death and differential hippocampal precursor kinetics both appear to contribute to reduced neurogenesis in females. Reduced local interleukin-1beta (IL-1,) immunoreactivity (IR) in females argues for a mechanistic role for the anti-apoptotic cytokine in driving sex differences in cell death. Prenatal stress significantly impacted the hippocampus, with both stress paradigms causing robust decreases in actively proliferating cells in males and females. Several other hippocampal measures were feminized in males such as precursor kinetics, IL-1,-IR density, and cell death, reducing or abolishing some sex differences. The findings expand our understanding of the mechanisms underlying sex differences and highlight the critical role early stress can play on the balance between proliferation, neurogenesis, cell death, and hippocampal microenvironment in adulthood. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008. [source]

    Influence of dietary 2,4,6-trinitrotoluene exposure in the northern bobwhite (Colinus virginianus)

    Robert M. Gogal Jr.
    Abstract The risk to wildlife from exposure to the explosive, 2,4,6-trinitrotoluene (TNT) has been a concern at numerous military installations where it has been found in the soil. To date, no published data are available describing effects of TNT exposure in an avian species. Subchronic dietary exposure to TNT was therefore evaluated in a species of management concern at military installations, the northern bobwhite (Colinus virginianus). Adult male and female quail (n = 5/sex/dose) were given commercial feed containing 3,000, 1,500, 750, and 100 mg/kg TNT for 90 d following the determination of an acute lethal dose and a 14-d range finding study. Dietary TNT intake caused a dose-dependent decrease in total red blood cell counts, packed cell volume, total plasma protein, blood prolymphocytes, and blood lymphocytes. An increased trend in late apoptotic/necrotic blood leukocytic cells was also observed in TNT-exposed birds, as was hemosiderosis in the liver. With the exception of hemosiderosis, these trends were statistically significant yet of questionable biological significance. Since treatment-related responses in this preliminary study were variable, a conservative interpretation is suggested. However, since these treatments had concentrations that were a log-fold or more than doses in similar studies using mammals, these data suggest that northern bobwhite are less sensitive to oral exposures of TNT than mammals. [source]

    In Vivo Time-Course Changes in Ethanol Levels Sampled With Subcutaneous Microdialysis

    ALCOHOLISM, Issue 3 2008
    Eric A. Engleman
    Background:, The objective of this study was to determine time-course changes in in vivo ethanol (EtOH) concentrations using a novel subcutaneous (s.c.) microdialysis sampling technique. The hypothesis to be tested was that EtOH concentrations in the s.c. fluid would reflect blood EtOH concentrations. If this is the case, then s.c. microdialysis could allow a more detailed analysis of changes in in vivo levels of EtOH under different drinking paradigms. Methods:, Adult male and female Wistar rats and male alcohol-preferring (P) rats were used in this study. A loop-style microdialysis probe was designed for s.c. applications. After initial in vitro characterization, probes were implanted under the skin between the shoulder blades. Animals were allowed to recover 4 to 24 hours prior to microdialysis collection (2.0 ,l/min flow rate with isotonic saline). In vivo microdialysis experiments were then conducted to determine (i) the extraction fraction (or clearance) using EtOH no-net-flux (NNF) coupled with the alcohol clamp method, (ii) the dose,response and time-course effects after systemic EtOH administration and to compare with blood EtOH levels, and (iii) the time-course changes in EtOH levels during and after an EtOH drinking episode. Results:, In vivo probe recovery (extraction fraction) obtained using the alcohol clamp method was 69 ± 3%, and was comparable to the in vitro recovery of 73 ± 2%. For the EtOH dose,response experiment, rats injected i.p. with 0.5, 1.0, or 2.0 g/kg EtOH showed a clear dose,response effect in the s.c. dialysate samples. Peak concentrations (70, 123, and 203 mg%, respectively) were reached by 15 minutes after injection. In an experiment comparing levels of EtOH in s.c. dialysis and arterial blood samples in rats administered 1.0 g/kg EtOH, similar time-course changes in in vivo EtOH concentrations were observed with both i.g. and i.p. EtOH administration. In P rats drinking 15% EtOH during a 1-hour scheduled access period, EtOH levels in s.c. microdialysates rose rapidly over the session and peaked at approximately 50 mg% at 60 to 80 minutes. Conclusions:, Overall, these experiments indicate that s.c. EtOH and blood EtOH concentrations follow a similar time course. Moreover, s.c. microdialysis can be useful as an experimental approach for determining detailed time-course changes in in vivo EtOH concentrations associated with alcohol drinking episodes. [source]

    ADH Genotype Does Not Modify the Effects of Alcohol on High-Density Lipoprotein

    ALCOHOLISM, Issue 3 2003
    John B. Whitfield
    Background: Alcohol consumption has beneficial effects on mortality which are mainly due to reduction in cardiovascular disease. These are believed to be due, at least in part, to the increase in plasma high-density lipoprotein (HDL) which is associated with alcohol consumption. It has been proposed that ADH3 genotype modifies the relationships between alcohol intake and cardiovascular disease by altering the HDL response to alcohol. The aim of this paper was to test for effects of ADH2 and ADH3 genotypes on the response of HDL components to habitual alcohol consumption. Methods: Adult male and female subjects were genotyped for ADH2 and ADH3; and plasma HDL cholesterol, apolipoprotein A-I, and apolipoprotein A-II were measured. Nine hundred one subjects had both ADH2 and ADH3 genotypes and HDL cholesterol results, while 753 had both genotypes and all three lipid results. The effect of alcohol intake on the three measured HDL components, and a factor score derived from them, was estimated for each of the ADH2 and ADH3 genotype groups. Results: All the measured components of HDL increased with increasing alcohol consumption over the range of intakes studied, 0,4 drinks per day. There were no significant interactions between alcohol consumption and ADH2 or ADH3 genotypes. Conclusions: The concept that alcohol dehydrogenase genotype and alcohol metabolic rate modify the effects of alcohol on plasma HDL concentration is not supported by our results. [source]

    Population status and behaviours of the Samoan flying fox (Pteropus samoensis) on Tutuila Island, American Samoa

    JOURNAL OF ZOOLOGY, Issue 3 2001
    Anne P. Brooke
    Abstract The small population and limited range of the Samoan flying fox Pteropus samoensis has generated concern regarding the survival of this large, diurnally active bat. During 1995,96, surveys were conducted monthly in six study valleys on Tutuila Island, American Samoa, to assess population size. The amount of diurnal and nocturnal activity was investigated to gauge the accuracy of diurnal surveys, and territorial behaviours were observed to determine how they influenced local dispersion. Individuals showed long-term fidelity to a series of roosts and small core areas that were used both nocturnally and diurnally. Territorial defence was observed only of temporary feeding territories in fruiting or flowering trees. Bats defended food resources by aerial patrols and extended aerial chases in which intruders were frequently bitten. Foraging movements changed seasonally, with up to 80% of individuals observed bypassing study valleys. The mean density of bats observed within the study valleys was 6.1 bats/km2 (range = 0.9,18.5 bats/km2). Pteropus samoensis were active both nocturnally and diurnally with greatest activity in late afternoon and evening, 16:00,22:00. Because bats were most active at night, it is probable that daytime surveys of flying bats undercount the number of individuals present. Greatest densities were found in valleys that were contiguous with large tracts of forest inaccessible to people. Most observations of roosting bats were of solitary males on dead branches that jutted above the forest canopy, while females and dependant young roosted below the canopy, hidden within vegetation. Adult male,female pairs were rarely seen together other than during the mating period in August,January. The population has increased following a ban on hunting, but reliance on mature forest makes long-term species survival dependant on protection of the limited mature forest remaining and continued hunting restrictions. [source]

    Tufa Deposition in Karst Streams Can Enhance the Food Supply of the Grazing Caddisfly Melampophylax mucoreus (Limnephilidae)

    Christian Kock
    Abstract We studied the effect of carbonate depositions covering stone surfaces on the growth of larvae and the biomass of subsequent adults of the grazing limnephilid caddisfly Melampophylax mucoreus(Hagen, 1861) in a laboratory rearing experiment. M. mucoreus is mainly distributed in karst streams characterized by calcium carbonate precipitations (tufa). We reared larvae of M. mucoreus on stones covered by calcareous tufa crusts as well as on stones from which these crusts were experimentally removed to assess the influence on larval growth and the subsequent adult biomass. The rough surface of the covered stones provided a higher complexity of micro-habitats and supported algal growth compared to the smooth surface of stones without crusts. Larvae of M. mucoreus profited from the enhanced algal biofilm growth on the calcium carbonate precipitation indicated by faster larval growth and higher subsequent adult biomass. Biomass increase of larvae reared on stones covered by tufa crusts exhibited a faster biomass development (0.09 ± 0.015 mg/d) compared to the larvae reared on stones without crusts (0.06 ± 0.002 mg/d). Adult males (5.13 ± 0.25 mg) and females (7.64 ± 0.63 mg) were significantly heavier in the treatment with stones covered by tufa than their conspecifics from the treatment with uncovered stones (males: 4.26 ± 0.25 mg, p = 0.047; females: 4.96 ± 0.47 mg, p = 0.001). Additionally, males from the treatment with crust covered stones emerged significantly earlier (p = 0.003) than the males from the other treatment, whereas no significant difference was found for females. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Absence of a dominance hierarchy confirms territorial organization in male bushbuck (Tragelaphus scriptus Pallas, 1766)

    Torsten Wronski
    Abstract It has been suggested that all species of spiral-horned antelopes (Tragelaphini) lack territoriality. Furthermore, some authors suggested that bushbuck (Tragelpahus scriptus) males form dominance hierarchies. In this study, we investigated the dominance relationships in two groups of free-ranging bushbuck males in Queen Elizabeth National Park, Uganda. Adult males dominated young-adult bachelors and subadult males, but no distinct dominance relationships were found among adult males. Landau,s index of linearity revealed no linear dominance hierarchy in the study populations. Our results support the idea that adult males are territorial, and overt aggression is directed almost exclusively towards bachelors that challenge territory holders. Résumé On a suggéré que toutes les espèces d'antilopes à cornes spiralées (Tragelaphineae) ne montraient pas de territorialité. Qui plus est, certains auteurs ont suggéré que les mâles Guib harnaché (Tragelaphus scriptus) formaient des hiérarchies par dominance. Dans cette étude, nous avons cherché les relations de dominance dans deux groupes de mâles Guib harnaché vivant en liberté dans le Parc National Queen Elizabeth, en Ouganda. Les mâles adultes dominaient les jeunes mâles célibataires et les mâles sub-adultes, mais on n'a trouvé aucune relation de dominance distincte entre les mâles adultes. L'index de linéarité de Landau n'a révélé aucune hiérarchie linéaire de dominance dans les populations de l'étude. Nos résultats soutiennent l'idée que les mâles adultes sont territoriaux, et toute agression manifeste est dirigée presque exclusivement vers les jeunes célibataires qui défient ceux qui détiennent un territoire. [source]

    Reproductive biology and population variables of the Brazilian sharpnose shark Rhizoprionodon lalandii (Müller & Henle, 1839) captured in coastal waters of south-eastern Brazil

    A. C. Andrade
    Throughout 1 year, from October 2003 to September 2004, 88 visits to the landing site of a small urban fishery (APREBAN) in Rio de Janeiro city were conducted and 816 specimens of Rhizoprionodon lalandii were analysed. The sample, mostly females, was composed of two cohorts: young-of-the-year were abundant in spring and summer and adults predominated in autumn and winter. Gravid females were most abundant from April to June, whereas post-partum females composed most of the catch in August to September. Adult males were present all year although were more abundant between February and July. No neonates were captured during the study and most embryos collected measured slightly below the reported total length (LT) at time of birth (L0) for the species, suggesting that parturition may occur slightly outside the main fishing grounds or that neonates were not captured in commercial gillnets set at this time of the year. The mean LT at maturity (LT50) for males was 578 mm and females matured between 620 and 660 mm, although a precise estimate of LT50 for females could not be determined. The total length (LT) and total mass (MT) relationship was calculated for both sexes and showed no significant differences. The mean condition factor increased steadily from February to July followed by a steep decrease in values relative to females in August and September, suggesting a pupping season. The present study area can be classified as a coastal juvenile habitat and a probable mating ground for R. lalandii. [source]

    Rapid Upregulation of Aromatase mRNA and Protein Following Neural Injury in the Zebra Finch (Taeniopygia guttata)

    R. Scott Peterson
    Abstract The expression of aromatase (oestrogen synthase) within the vertebrate central nervous system (CNS) is key in the provision of local oestrogens to neural circuits. Aromatase expression appears to be exclusively neuronal under normal conditions. However, some in vitro studies suggest the presence of astrocytic aromatase in songbirds and mammals. Recently, aromatase in reactive astrocytes has been demonstrated in response to neural injury in the mammalian CNS. Since the glial aromatase expression first documented in cultures of the songbird telencephalon may reflect processes similar to those in response to mammalian neural injury, we investigated whether injury alters the pattern of aromatase-expression in the zebra finch, a species with very high levels of forebrain aromatase expression. Adult males received a penetrating neural injury to the right hemisphere and were killed either 24 or 72 h later. Controls were anaesthetized and otherwise unmanipulated. We determined the expression of aromatase mRNA and protein using in situ hybridization and immunocytochemistry, respectively. Both the transcription and translation of aromatase is dramatically upregulated around the lesion site in response to neural injury in the zebra finch forebrain. This effect is robust and rapid, occurring within 24 h of the injury itself. Cells that upregulate aromatase appear to be reactive astrocytes based upon morphology. The hemisphere contralateral to the injury and both hemispheres in control birds showed the normal, exclusively neuronal pattern of aromatase expression. The upregulation of aromatase in astrocytes may provide high levels of oestrogen available to modulate processes such as CNS repair. Injury-induced upregulation of astrocytic aromatase may be a general characteristic of the injured vertebrate brain. [source]


    Susan E. Cosens
    Abstract To determine whether Hudson Bay-Foxe Basin bowhead whales segregate on the basis of age, whales summering in northern Foxe Basin, were aerially photographed in August of 1996, 1997, and 1998. Image lengths on either the negatives or contact prints were measured and total body lengths were estimated. In all three years the majority of whales photographed were ,13.5 m long. Calves and juveniles made up 89.3%, 96.6%, and 79.3% of the total number of measured whales in 1996 (n = 28), 1997 (n = 30) and 1998 (n = 29) respectively. The number of bowheads >13.5 m, the approximate size at which females reach sexual maturity, that were photographed was directly proportional to the number of calves photographed. Our results indicate that northern Foxe Basin bowheads are part of a more widely distributed stock. Adult males and resting adult females apparently summer in another part of the range, probably northwestern Hudson Bay. Northern Foxe Basin appears to be used as a summer feeding area by cows with young-of-the-year calves and by juveniles. [source]

    Chimpanzee responses to researchers in a disturbed forest,farm mosaic at Bulindi, western Uganda

    Matthew R. McLennan
    Abstract We describe the behavior of a previously unstudied community of wild chimpanzees during opportunistic encounters with researchers in an unprotected forest,farm mosaic at Bulindi, Uganda. Data were collected during 115 encounters between May 2006 and January 2008. Individual responses were recorded during the first minute of visual contact. The most common responses were "ignore" for arboreal chimpanzees and "monitor" for terrestrial individuals. Chimpanzees rarely responded with "flight". Adult males were seen disproportionately often relative to adult females, and accounted for 90% of individual responses recorded for terrestrial animals. Entire encounters were also categorized based on the predominant response of the chimpanzee party to researcher proximity. The most frequent encounter type was "ignore" (36%), followed by "monitor" (21%), "intimidation" (18%) and "stealthy retreat" (18%). "Intimidation" encounters occurred when chimpanzees were contacted in dense forest where visibility was low, provoking intense alarm and agitation. Adult males occasionally acted together to repel researchers through aggressive mobbing and pursuit. Chimpanzee behavior during encounters reflects the familiar yet frequently agonistic relationship between apes and local people at Bulindi. The chimpanzees are not hunted but experience high levels of harassment from villagers. Human-directed aggression by chimpanzees may represent a strategy to accommodate regular disruptions to foraging effort arising from competitive encounters with people both in and outside forest. Average encounter duration and proportion of encounters categorized as "ignore" increased over time, whereas "intimidation" encounters decreased, indicating some habituation occurred during the study. Ecotourism aimed at promoting tolerance of wildlife through local revenue generation is one possible strategy for conserving great apes on public or private land. However, the data imply that habituating chimpanzees for viewing-based ecotourism in heavily human-dominated landscapes, such as Bulindi, is ill-advised since a loss of fear of humans could lead to increased negative interactions with local people. Am. J. Primatol. Am. J. Primatol. 72:907,918, 2010. © 2010 Wiley-Liss, Inc. [source]

    Social behavior in fission,fusion groups of red uakari monkeys (Cacajao calvus ucayalii)

    Mark Bowler
    Abstract Primates living in large groups that divide to forage must have social systems compatible with this mode of living. Uakari monkeys (Cacajao spp.) live in large groups and exhibit a form of fission,fusion grouping, but their social organization is poorly understood. We present some of the first data on social behavior for this genus based on a study on Cacajao calvus ucayalii. They traveled in multimale multifemale groups of highly variable sizes, with bachelor units on the periphery. Adult males were affiliative, and adult females associated with more than one adult male. Adult females typically traveled with their dependent offspring and an older juvenile within the group. In parties of two or more males, individuals engaged in previously unreported display behaviors and acted together to aggressively chase other males. Breeding was seasonal, and mating occurred away from other group members. We speculate on the social organization of C. calvus ucayalii, in which dispersal may be bisexual and peripheral males are affiliative with one another. Affiliated males appear to cooperate in fighting and displaying to other males for access to females during the breeding season. Am. J. Primatol. 71:976,987, 2009. © 2009 Wiley-Liss, Inc. [source]

    The effects of infant births on male,female relationships in Cebus capucinus

    Claire R. Sheller
    Abstract Most primates are characterized by cohesive male,female bonds that are maintained year round. While recent studies have addressed the selective pressures influencing the evolution of male,female relationships in primates, we know relatively little about the proximate mechanisms affecting them. It has been demonstrated that newborn white-faced capuchins (Cebus capucinus) attract the attention of other group members and this may be an important mechanism influencing male,female relationships. We studied two groups of C. capucinus in the Area de Conservación Guanacaste, Costa Rica, between February and July 2007. A total of 348 hr of focal data were collected on all adult males (n=6) residing in each of the study groups. During our study, 13 of the 14 group females were either pregnant or lactating, and 9 infants were born. We calculated an average daily affiliation rate between all group males combined and each adult female four weeks before and four weeks after the birth of her infant. Repeated measures ANOVAs revealed no significant changes in affiliation following infant births (F=2.262, df=1, P<0.176). Results remained nonsignificant for rank (F=1.550, df=1, P<0.260) and group membership (F=0.729, df=1, P<0.429). Infant sex was the only variable with a significant effect on affiliation rates between males and females (F=10.020, df=1, P<0.019). Adult males increased their affiliation with all adult females that gave birth to male infants (n=4), while their rates decreased with all but one of the adult females with female infants (n=4). While preliminary, these results indicate that the adult males may cultivate relationships with other males at a young age. Am. J. Primatol. 71:380,383, 2009. © 2009 Wiley-Liss, Inc. [source]

    Coat condition of ringtailed lemurs, Lemur catta at Berenty Reserve, Madagascar: I. differences by age, sex, density and tourism, 1996,2006

    Alison Jolly
    Abstract An index of coat condition can be a non-invasive tool for tracking health and stress at population level. Coat condition in ringtailed lemurs, Lemur catta, was recorded during September,November birth seasons of 1996, 1997, 1999, and 2001,2006 at Berenty Reserve, Madagascar. Condition was scored on a scale from 0: full, fluffy coat with guard hairs present, to 5: half or more of body hairless. Adult males did not differ overall from adult females. Coats were worse in adults than in 2-year-old subadults; 1-year-old juveniles were intermediate. Mothers and adult males lost coat condition as the season progressed: non-mother females maintained condition. Years 1999,2002 scored better coats than either 1996,1997 or 2003,2006. Lemurs in high population density areas had worse coats than in natural forest, but tourist presence had less effect than density. Monitoring coat condition in an apparently healthy population reveals differences between population segments, and in a forest fragment with limited immigration or emigration it can track progressive changes, correcting impressions of progressive improvement or degradation over time. Above all it gives a baseline for response to climate changes or eventual pathology. Am. J. Primatol. 71:191,198, 2009. © 2008 Wiley-Liss, Inc. [source]

    Food transfers to young and mates in wild owl monkeys (Aotus azarai)

    Christy Kaitlyn Wolovich
    Abstract Accounts of food sharing within natural populations of mammals have focused on transfers to offspring or transfers of food items that are difficult to obtain (such as meat). Five groups of socially monogamous owl monkeys (Aotus azarai azarai) in Formosa, Argentina were observed during 107,hr to determine the pattern of food sharing under natural conditions. There were a total of 42 social interactions involving food with food being transferred on eight occasions. Adult males transferred food to young more often than did adult females. All types of food that were readily obtained and eaten by all age/sex classes were transferred to young. Adult females also transferred food to their mates. This type of food sharing is very rare among animals and may have social benefits specific to monogamous mammals with paternal care. Am. J. Primatol. 70:211,221, 2008. © 2007 Wiley-Liss, Inc. [source]

    Testosterone and energetics in wild chimpanzees (Pan troglodytes schweinfurthii)

    Martin N. Muller
    Abstract Ovarian function in female hominoids is sensitive to both energy flux and energy balance, resulting in a reduced probability of conception during periods when a successful reproductive outcome is less likely. However, the extent to which energetic factors constrain gonadal function in male hominoids is not clear. We examined the effects of both acute and chronic variation in energy availability on urinary testosterone (T) levels in adult male chimpanzees. Acute changes in energy availability, which were assayed by means of observational data on feeding behavior, did not result in decreased T production for 11 individuals at Kibale National Park, Uganda. Chronic energy shortages, on the other hand, may be associated with lower T levels in this population. Adult males in Kibale (n=11), who maintain suboptimal access to energy, exhibit significantly lower urinary T levels than males in captivity (n=11), who are more sedentary and better fed. These results suggest that data on hormonal function in captive chimpanzees should be interpreted with caution because individuals may produce T at levels well above those that are typical in the wild. They also suggest that short-term variations in T levels in male hominoids are more likely to be explained by social factors than by energetic ones. Am. J. Primatol. 66:119,130, 2005. © 2005 Wiley-Liss, Inc. [source]

    Foster mother care but not prenatal morphine exposure enhances cocaine self-administration in young adult male and female rats

    I. Vathy
    Abstract The present study was designed to investigate cocaine self-administration in adult male and female rats exposed prenatally to morphine. Pregnant dams were injected two times a day with either saline, analgesic doses of morphine or no drug at all (controls) on gestation Days 11,18. One day after birth, litters were cross-fostered such that control dams were paired with one another and their litters were crossed; saline- and morphine-treated dams were paired and half of each saline litter was crossed with half of each morphine litter. Thus, each mother (control, saline, and morphine) raised half of her own and half of the adopted litter. At the age of 60 days, males and females were trained first to lever press for sucrose pellets and then for cocaine. Once the lever-pressing behavior was learned and baseline level of this activity was established, animals received a cocaine (.5 mg/kg per infusion) reward for each correct response on the active lever during the next 9-day session. The data demonstrate that adult control, saline- and morphine-exposed male rats self-administer cocaine at a similar rate independent of their prenatal treatment. Adult female rats self-administer cocaine at a higher rate than male rats. Further, saline- and morphine-exposed females in diestrus self-administer more than females in proestrus phase of the estrous cycle, while control females show no such differences. In addition, fostering induces increase in cocaine self-administration in all groups of male rats regardless of prenatal drug exposure. In females, the only fostering-induced increase is in prenatally saline-exposed female rats raised by morphine-treated foster mother. Thus, our results suggest that the prenatal drug exposure does not induce changes in lever-pressing behavior for cocaine reward in adult male and female rats, but it sensitizes the animals to postnatal stimuli such as gonadal hormones and/or rearing conditions that result in increased drug self-administration. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 49: 463-473, 2007. [source]

    Effects of nonylphenol, bisphenol a, and their mixture on the viviparous swordtail fish (Xiphophorus helleri)

    Hyeong-Il Kwak
    Abstract A number of fish species have been used for studies on endocrine disrupting chemicals (EDCs). However, despite the widespread use of oviparous fish, relatively little attention has been given to viviparous species. This study investigated the effects of EDCs in a viviparous fish and examined the possible usefulness of the fish as an alternative model for the studies on EDCs. Swordtails (Xiphophorus helleri) were exposed to nonylphenol (NP), bisphenol A (BPA), and their mixture. Both short-term (3-d) and relatively long-term (60-d) exposures were carried out using adult male and 30-d-old juvenile fish, respectively. Following the short-term exposure, both NP and BPA caused vitellogenin mRNA expression. Flow cytometric analysis and terminal deox-ynucleotidyl transferase assay on the testes of treated fish indicated reproductive damage. Histopathological analysis found degenerative and necrotic cells in seminiferous tubules following the exposure to 100 ppb NP. The testes with lesions were also associated with highly suppressed spermatogenesis. Following the long-term exposure, both NP and BPA exposures significantly affected the growth of swordtails. In all cases, the results showed that the mixture was always more potent than a single chemical and that swordtail fish can be a useful model for the study of endocrine disruptors. [source]

    Scent-Marking of Giant Otter in the Southern Pantanal, Brazil

    ETHOLOGY, Issue 3 2009
    Caroline Leuchtenberger
    Giant otters live in social groups, consisting of a mating pair and one or two litters. Groups are territorial and mark their territories often with scent-marks. Our objectives were to evaluate the frequencies of marking and over-marking according to the social status of the individuals and to define the different postures used during the marking. We observed four groups, totaling 25 individuals (five alpha males, four alpha females, seven adult females, one adult male and eight juveniles) with group size ranging between four and 13 individuals. The study was conducted between July 2006 and July 2007 in the Vermelho River and in a stretch of the Miranda River, in the Southern Pantanal. We observed the groups for a total of 2006 min and recorded 95 events of marking totaling 84.9 min. Time spent marking varied between groups and ranged from 4.3 to 44.7 min. The alpha males marked more frequently (62% of marking events, 55 min) than the alpha females (17% of marking events, 13.6 min). Of the 59 events of scent-marking by the alpha males, 32 over-marked the marks of other individuals from the group. Of the 16 events of scent-marking of the alpha females, five over-marked that of other females from the same group. When scent-marking, alpha males used the ,stepping' posture most frequently (63%), then ,fore-paw rubbing' (24%), ,latrine use' (7%), and ,body rubbing' (6%). Alpha females used the ,stepping' posture most frequently (65%), then ,latrine use' (19%) and ,fore-paw rubbing' (12%), with only one event of ,body rubbing' observed during marking. Subordinate females used the ,stepping' posture (76%) and ,latrine use' (24%) during marking. Scent-marking can play many roles in mammals and for giant otters, and the main roles appear to be communication of social and sexual status and territorial defense. [source]

    Spatial Association in a Highly Inbred Ungulate Population: Evidence of Fine-Scale Kin Recognition

    ETHOLOGY, Issue 2 2008
    Jorge Cassinello
    We present the first evidence of fine-scale kin recognition, based on a continuous measure of relatedness, in ungulates. The spatial association between herdmates of a captive population of aoudad (Ammotragus lervia), where all the individuals are related, is analysed during resting time. Our goal was to estimate which factors influence individuals' associations. The study population is highly inbred, although it does not show serious deleterious effects caused by consanguinity. It comprises a single captive herd, reproducing freely and in good conditions for more than 10 yr. It emerges that kin, measured as the coefficient of relationship between two given herdmates, is the main factor determining the spatial association (e.g. average distance) of male,male and female,female dyads, as more-related individuals tend to rest closer to each other than less-related ones. As for male,female dyads, individuals of a similar age tend to stay closer. To rule out any familiarity confounding effects, individuals' cohabitation time in the herd was added as a random factor in the analyses. Concerning the type of dyad, mother,calf dyads are characterized by higher proximity than others, particularly during the suckling period, whereas males tend to stay closer to each other than females or male,female dyads, being also more kin-related. Female social rank does not influence spatial association between herdmates. These results are related to group composition of the species in the wild, which are characterized by intense mother,calf bonds and all-male groups that are probably kin-related. It is seen that adult male,female associations are not related to kinship, but to age similarity, which is in accord with the assumption that main family groups in the wild are formed by matrilineal lines, whereas males are the dispersing sex. [source]

    Intra- and Inter-seasonal Variation in the Socio-Spatial Behavior of Adult Male Collared Lizards, Crotaphytus collaris (Reptilia, Crotaphytidae)

    ETHOLOGY, Issue 1 2001
    Troy A. Baird
    When individuals maintain strong inter-seasonal philopatry to the same territories, males may be able to re-establish territory occupancy without intense intra-sexual aggression, and instead spend more time courting females early in the reproductive season. Furthermore, when some males have prior experience defending the same territories, it may be necessary for young males to exhibit higher levels of aggression because they are establishing a territory for the first time. We tested these hypotheses by examining within-season (1992 and 1997) temporal variation in the social behavior of adult male collared lizards of known age and prior territorial experience in a population where inter-season philopatry to territories is high. Contrary to expectations, the frequency of aggression exhibited by males with and without prior territorial experience did not differ. The frequency of intra-sexual aggression was higher in 1992 than in 1997, perhaps because male competitors were more abundant in 1992. Although there was an interactive effect of year, male display and patrol were low at the beginning of the reproductive season in Apr. and May, reached peaks during midseason in June, and then decreased as reproduction ended in July. The size of territories showed a similar pattern, with males defending larger areas in June. Our data support the philopatry hypothesis in that the establishment of territories occurred without high levels of aggression early in the season, perhaps because territory boundaries have been well defined by high rates of patrol and advertisement during the middle of the previous season. Inter-sexual interactions were most frequent in June rather than at the beginning of the reproductive season. Adult females are producing their second clutches and yearling females are producing their first clutches in June. The high rate of inter-sexual encounters in June supports the hypothesis that males allocate more time to courtship when females are receptive because there are more reproductively active females at this time. The temporal pattern of activities in adult Crotaphytus collaris appears to function as a compromise between competing intra- and inter-sexual social demands on males, allowing males to maximize mating opportunities as well as maintain future access to productive territories. [source]

    Effects of Pair-Bond and Social Context on Male,Female Interactions in Captive Titi Monkeys (Callicebus moloch, Primates: Cebidae)

    ETHOLOGY, Issue 12 2000
    Eduardo Fernandez-Duque
    In monogamous species, an abiding relationship between a specific adult male and a specific adult female is a defining feature of the social system. The interactions between these individuals are influenced by many factors, including not only the history of their relationship (for example, development of a mutual bond), but also the immediate effects of the prevailing social context (for example, presence and sex of extra-pair conspecifics). In this study we examined the effects of an existing bond and of social context on interactions between adult heterosexual pairs of the monogamous titi monkeys (Callicebus moloch). Twelve adult males and 12 adult females were tested with their cagemates and with an unfamiliar partner of the opposite sex in five social contexts: (1) mated male,female pair; (2) unfamiliar pair; (3) single female; (4) single male; and (5) empty stimulus cage. Results show that mated pairs were more affiliative than unfamiliar pairs and differentiated social contexts more sharply. Males were more responsive to context than females. Distance between mates was less and physical contact was more frequent in the presence of male,female pairs or a single male, than in the presence of a single female or an empty cage. These findings suggest that the presence and sex of strangers have a stronger influence on male,female interactions when the pair has an existing relationship. [source]

    Defence of Females by Dominant Males of Artibeus jamaicensis (Chiroptera: Phyllostomidae)

    ETHOLOGY, Issue 5 2000
    Jorge Ortega
    Defence of females by dominant males of the Jamaican fruit-eating bat Artibeus jamaicensis was observed in two natural colonies over 2 yr. A log-linear model was used to evaluate the frequency distribution of visits to harems by sex, season and agonistic interaction of dominant males. Harem group size varied from four to 18 females, with one adult male in the small and medium-sized groups and two males in the large groups (> 14 females). A highly significant interaction was noted between the age and sex of the visitor and the response of the dominant male. Male visitors were attacked more often than female and juvenile visitors. Aggressive defence increased during the reproductive seasons, with dominant males showing more agonistic responses towards male visitors. An increase in the frequency of visits by male visitors was noted in harem groups that ranged in size from four to 12 females, but the frequency of male visits declined in harem groups that contained more than 14 females. [source]

    Aquaporin 11 in the developing mouse submandibular gland

    Helga S. Larsen
    Larsen HS, Ruus A-K, Schreurs O, Kanli Galtung H. Aquaporin 11 in the developing mouse submandibular gland. Eur J Oral Sci 2010; 118: 9,13. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Several aquaporins (AQPs) have been detected in mature and embryonic mammalian salivary glands (AQP1 and AQP3,AQP8). However, AQP11 has, to our knowledge, never before been described in salivary glands, but is known to be important in, for example, kidney development in mice. We therefore thought it relevant to investigate if AQP11 was present during salivary organogenesis. The submandibular salivary gland (SMG) from CD1 mice was studied during prenatal development and early postnatal development, and also in young adult male and female mice. The expression trend of the AQP11 transcript was detected using the reverse transcription,polymerase chain reaction (RT-PCR), and the temporal,spatial pattern was observed using in situ hybridization. The AQP11 transcript was first detected at embryonic day 13.5 and showed a more or less constitutive expression trend during the prenatal and early postnatal SMG development. Spatial studies demonstrated that the AQP11 transcript was present in the developing and mature duct structures at all stages studied. In the end pieces, the AQP11 transcript was reduced during glandular development. Our results point to an important role for AQP11 during salivary gland development. [source]