Kraus, Cornelia

[["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Physiology & Behavior"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Kraus, Cornelia"],["dc.contributor.author","Heistermann, Michael"],["dc.contributor.author","Kappeler, Peter"],["dc.date.accessioned","2018-03-23T15:10:13Z"],["dc.date.available","2018-03-23T15:10:13Z"],["dc.date.issued","1999"],["dc.description.abstract","In contrast to most anthropoid primates, sifakas (Propithecus verreauxi), like many group-living lemurs, exhibit a number of features that deviate from predictions of sexual selection theory. Despite a promiscuous mating system, they lack sexual dimorphism, suggesting that physical combat plays only a minor role in intrasexual competition for receptive females. In this study, we investigated the hypothesis that socioendocrinological mechanisms contribute to suppression of reproductive function of subordinate males. For that purpose, 10 male sifakas from five social groups were observed for 669 focal animal hours for 4 months, including the mating season, in Western Madagascar. Concomitantly, 315 fecal samples of these animals were collected and the concentration of immunoreactive testosterone was quantified by enzymeimmunoassay procedures. Clear dominance relationships existed among coresident males. Testosterone levels of dominant males were significantly higher than those of subordinates during, as well as outside, the mating season. Additionally, the increase in testosterone levels prior to the mating season was more pronounced for dominant than for subordinate males. These findings are in accordance with the hypothesis of suppression of sexual function of subordinate males, probably providing dominant males with an advantage in sperm competition. If reproductive success is mainly determined by this nonagonistic form of intrasexual competition, the results of this study contribute an important piece to the puzzle of lacking sexual dimorphism in P. verreauxi."],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13134"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.title","Physiological suppression of sexual function of subordinate males - theoretical implications for patterns of testosterone secretion, mating systems, and breeding strategies"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1063"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Oecologia"],["dc.bibliographiccitation.lastpage","1075"],["dc.bibliographiccitation.volume","178"],["dc.contributor.author","Haemaelaeinen, Anni"],["dc.contributor.author","Heistermann, Michael"],["dc.contributor.author","Kraus, Cornelia"],["dc.date.accessioned","2018-11-07T09:54:12Z"],["dc.date.available","2018-11-07T09:54:12Z"],["dc.date.issued","2015"],["dc.description.abstract","Chronic stress [i.e. long-term elevation of glucocorticoid (GC) levels] and aging have similar, negative effects on the functioning of an organism. Aged individuals' declining ability to regulate GC levels may therefore impair their ability to cope with stress, as found in humans. The coping of aged animals with long-term natural stressors is virtually unstudied, even though the ability to respond appropriately to stressors is likely integral to the reproduction and survival of wild animals. To assess the effect of age on coping with naturally fluctuating energetic demands, we measured stress hormone output via GC metabolites in faecal samples (fGCM) of wild grey mouse lemurs (Microcebus murinus) in different ecological seasons. Aged individuals were expected to exhibit elevated fGCM levels under energetically demanding conditions. In line with this prediction, we found a positive age effect in the dry season, when food and water availability are low and mating takes place, suggesting impaired coping of aged wild animals. The age effect was significantly stronger in females, the longer-lived sex. Body mass of males but not females correlated positively with fGCM in the dry season. Age or body mass did not influence fGCM significantly in the rainy season. The sex- and season-specific predictors of fGCM may reflect the differential investment of males and females into reproduction and longevity. A review of prior research indicates contradictory aging patterns in GC regulation across and even within species. The context of sampling may influence the likelihood of detecting senescent declines in GC functioning."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [KR3834/1-1]"],["dc.identifier.doi","10.1007/s00442-015-3297-3"],["dc.identifier.isi","000358089400008"],["dc.identifier.pmid","25847061"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/36484"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","1432-1939"],["dc.relation.issn","0029-8549"],["dc.title","The stress of growing old: sex- and season-specific effects of age on allostatic load in wild grey mouse lemurs"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","68"],["dc.bibliographiccitation.journal","General and Comparative Endocrinology"],["dc.bibliographiccitation.lastpage","79"],["dc.bibliographiccitation.volume","195"],["dc.contributor.author","Haemaelaeinen, Anni"],["dc.contributor.author","Heistermann, Michael"],["dc.contributor.author","Fenosoa, Zo Samuel Ella"],["dc.contributor.author","Kraus, Cornelia"],["dc.date.accessioned","2018-11-07T09:46:48Z"],["dc.date.available","2018-11-07T09:46:48Z"],["dc.date.issued","2014"],["dc.description.abstract","Reliable measurements of physiological stress are increasingly needed for eco-physiological research and for species conservation or management. Stress can be estimated by quantifying plasma glucocorticoid levels, but when this is not feasible, glucocorticoid metabolites are often measured from feces (FGCM). However, evidence is accumulating on the sensitivity of FGCM measurements to various nuisance factors. Careful species- and context-specific validations are therefore necessary to confirm the biological relevance and specificity of the method. The goals of this study were to: (1) establish and validate sampling methods and an enzymeimmunoassay to measure FGCM in the gray mouse lemur (Microcebus murinus); (2) explore causes of variability in the FGCM measurements, and; (3) assess the consequences of capturing and handling for free-living individuals by quantifying their stress responses via repeated fecal sampling within capture sessions. We further assessed the influence of different handling protocols and the animals' previous capture experience on the magnitude of the physiological response. Our validations identified the group-specific measurement of 11 beta-hydroxyetiocholanolone as the most suitable assay for monitoring adrenocortical activity. The sample water content and the animal's age were found to significantly influence baseline FGCM-levels. Most captured animals exhibited a post-capture FGCMelevation but its magnitude was not related to the handling protocol or capture experience. We found no evidence for long-term consequences of routine capturing on the animals' stress physiology. Hence the described methods can be employed to measure physiological stress in mouse lemurs in an effective and relatively non-invasive way. (C) 2013 The Authors. Published by Elsevier Inc. All rights reserved."],["dc.description.sponsorship","DFG [KR3834/1-1]"],["dc.identifier.doi","10.1016/j.ygcen.2013.10.017"],["dc.identifier.isi","000330257100008"],["dc.identifier.pmid","24212051"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11364"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34965"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Academic Press Inc Elsevier Science"],["dc.relation.issn","1095-6840"],["dc.relation.issn","0016-6480"],["dc.rights","CC BY-NC-SA 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc-sa/3.0"],["dc.title","Evaluating capture stress in wild gray mouse lemurs via repeated fecal sampling: Method validation and the influence of prior experience and handling protocols on stress responses"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","855"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Physiology & Behavior"],["dc.bibliographiccitation.lastpage","861"],["dc.bibliographiccitation.volume","66"],["dc.contributor.author","Kraus, Cornelia"],["dc.contributor.author","Heistermann, Michael"],["dc.contributor.author","Kappeler, Peter"],["dc.date.accessioned","2017-09-07T11:47:58Z"],["dc.date.available","2017-09-07T11:47:58Z"],["dc.date.issued","2002"],["dc.description.abstract","In contrast to most anthropoid primates, sifakas (Propithecus verreauxi), like many group-living lemurs, exhibit a number of features that deviate from predictions of sexual selection theory. Despite a promiscuous mating system, they lack sexual dimorphism, suggesting that physical combat plays only a minor role in intrasexual competition for receptive females. In this study, we investigated the hypothesis that socioendocrinological mechanisms contribute to suppression of reproductive function of subordinate males. For that purpose, 10 male sifakas from five social groups were observed for 669 focal animal hours for 4 months, including the mating season, in Western Madagascar. Concomitantly, 315 fecal samples of these animals were collected and the concentration of immunoreactive testosterone was quantified by enzymeimmunoassay procedures. Clear dominance relationships existed among coresident males. Testosterone levels of dominant males were significantly higher than those of subordinates during, as well as outside, the mating season. Additionally, the increase in testosterone levels prior to the mating season was more pronounced for dominant than for subordinate males. These findings are in accordance with the hypothesis of suppression of sexual function of subordinate males, probably providing dominant males with an advantage in sperm competition. If reproductive success is mainly determined by this nonagonistic form of intrasexual competition, the results of this study contribute an important piece to the puzzle of lacking sexual dimorphism in P. verreauxi."],["dc.identifier.doi","10.1016/s0031-9384(99)00024-4"],["dc.identifier.gro","3150774"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7562"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0031-9384"],["dc.subject","Intrasexual competition; Social status; Physiological suppression; Fecal testosterone; Propithecus verreauxi"],["dc.title","Physiological Suppression of Sexual Function of Subordinate MalesA Subtle Form of Intrasexual Competition Among Male Sifakas (Propithecus verreauxi)?"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","673"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","American Journal of Physical Anthropology"],["dc.bibliographiccitation.lastpage","684"],["dc.bibliographiccitation.volume","158"],["dc.contributor.author","Higham, James P."],["dc.contributor.author","Kraus, Cornelia"],["dc.contributor.author","Stahl-Hennig, Christiane"],["dc.contributor.author","Engelhardt, Antje"],["dc.contributor.author","Fuchs, Dietmar"],["dc.contributor.author","Heistermann, Michael"],["dc.date.accessioned","2018-11-07T09:48:01Z"],["dc.date.available","2018-11-07T09:48:01Z"],["dc.date.issued","2015"],["dc.description.abstract","Objectives: Health, disease, and immune function are key areas of research in studies of ecology and evolution, but work on free-ranging primates has been inhibited by a lack of direct noninvasive measures of condition. Here, we evaluate the potential usefulness of noninvasive measurement of three biomarkers, the acute-phase proteins Creactive protein (CRP) and haptoglobin, and neopterin, a by-product of macrophage activity. Materials and Methods: We took advantage of veterinary checks on captive rhesus (24) and long-tailed (3) macaques at the German Primate Center (DPZ) to analyze serum marker measures, before measuring concentrations in feces and urine, and evaluating relationships between matched serum, urine, and fecal concentrations. In a second study, we monitored excretion of these markers in response to simian immunodeficiency virus (SIV) infection and surgical tissue trauma, undertaken for a separate study. Results: We found that each biomarker could be measured in each matrix. Serum and urinary concentrations of neopterin were strongly and significantly correlated, but neither haptoglobin nor CRP concentrations in excreta proxied circulating serum concentrations. Our infection study confirmed that urinary neopterin, in particular, is a reliable marker of viral infection in macaques, but also indicated the potential of urinary and fecal CRP and haptoglobin as indicators of inflammation. Discussion: We highlight the potential of noninvasive markers of immune function, especially of urinary neopterin, which correlates strongly with serum neopterin, and is highly responsive to infection. (C) 2015 Wiley Periodicals, Inc."],["dc.description.sponsorship","German Research Council [DFG EN 719/2]"],["dc.identifier.doi","10.1002/ajpa.22821"],["dc.identifier.isi","000367669000013"],["dc.identifier.pmid","26250063"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35227"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1096-8644"],["dc.relation.issn","0002-9483"],["dc.title","Evaluating Noninvasive Markers of Nonhuman Primate Immune Activation and Inflammation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","640"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Hormones and Behavior"],["dc.bibliographiccitation.lastpage","648"],["dc.bibliographiccitation.volume","51"],["dc.contributor.author","Fichtel, Claudia"],["dc.contributor.author","Kraus, Cornelia"],["dc.contributor.author","Ganswindt, André"],["dc.contributor.author","Heistermann, Michael"],["dc.date.accessioned","2017-09-07T11:47:02Z"],["dc.date.available","2017-09-07T11:47:02Z"],["dc.date.issued","2007"],["dc.description.abstract","Studies in anthropoid primates and other mammals suggest that reproductive season, rank, reproductive skew, aggression received, and social support are the major factors influencing glucocorticoid output. In which way these are also affecting adrenal function in lemurid primates has been studied rarely. Here, we examine the influence of reproductive season and rank on glucocorticoid output in male sifakas (Propithecus verreauxi), a species characterized by high breeding seasonality, a hierarchy among males and extreme reproductive skew towards dominant males. We established a fecal assay for non-invasively monitoring adrenal activity and collected 315 fecal samples during the reproductive and birth season from 10 male sifakas living in 5 groups in Western Madagascar. We found a significant effect of season on glucocorticoid output, with males exhibiting higher fecal glucocorticoid levels during the reproductive compared to the birth season in conjunction with an increase in overall aggression rates during the former period. Moreover, our data indicate a significant effect of rank on adrenocortical activity with dominant males exhibiting higher glucocorticoid levels than subordinate males in the reproductive season. However, dominant males did not differ significantly in rates of initiated or received aggression and rates of affiliative behavior from subordinates but showed significantly lower rates of submission. Given their highly formalized dominance relationships, we conclude that higher glucocorticoid output in dominant males during the 4-month reproductive season is likely related to higher energetic demands necessary to cope with the challenges of male reproduction rather than to physical demands of increased fighting frequency to maintain dominance status. High rank in sifakas may thus carry high costs, which, however, may be outweighed by monopolization of almost all paternities. In sum, our data generally support the findings on the relationship between environmental and social factors and glucocorticoid output found in non-lemurid primates."],["dc.identifier.doi","10.1016/j.yhbeh.2007.03.005"],["dc.identifier.gro","3150580"],["dc.identifier.pmid","17448474"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/7357"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.issn","0018-506X"],["dc.subject","Male sifakas; Propithecus verreauxi; Fecal glucocorticoids; Dominance status; Rank; Mating season; Reproductive skew; ACTH challenge"],["dc.title","Influence of reproductive season and rank on fecal glucocorticoid levels in free-ranging male Verreaux's sifakas (Propithecus verreauxi)"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","222"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Folia Primatologica"],["dc.bibliographiccitation.volume","69"],["dc.contributor.author","Kraus, C."],["dc.contributor.author","Heistermann, Michael"],["dc.contributor.author","Kappeler, Peter M."],["dc.date.accessioned","2017-11-15T11:18:34Z"],["dc.date.available","2017-11-15T11:18:34Z"],["dc.date.issued","1998"],["dc.identifier.doi","10.1159/000021629"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/10005"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.publisher","Karger"],["dc.publisher.place","Freiburg"],["dc.relation.conference","German Primate Society 5th International Congress"],["dc.relation.eventlocation","Berlin"],["dc.relation.eventstart","1997-10"],["dc.relation.ispartof","German Primate Society"],["dc.title","Reproductive competition among male sifakas: the roles of sperm competition and physiological suppression"],["dc.title.subtitle","Fortpflanzungskonkurrenz zwischen Sifakamännchen: Die Rolle von Spermienkonkurrenz und physiologischer Unterdrückung"],["dc.type","conference_abstract"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]