@phdthesis{Dammhahn2019, author = {Dammhahn, Melanie}, title = {From individual variation to community structure : paterns, determinants and consequences of within- and between-species variation in behaviour, life-history and ecology}, school = {Universit{\"a}t Potsdam}, pages = {431}, year = {2019}, language = {en} } @misc{DammhahnDingemanseNiemelaeetal.2018, author = {Dammhahn, Melanie and Dingemanse, Niels J. and Niemelae, Petri T. and Reale, Denis}, title = {Pace-of-life syndromes}, series = {Behavioral ecology and sociobiology}, volume = {72}, journal = {Behavioral ecology and sociobiology}, number = {3}, publisher = {Springer}, address = {New York}, issn = {0340-5443}, doi = {10.1007/s00265-018-2473-y}, pages = {8}, year = {2018}, abstract = {This introduction to the topical collection on Pace-of-life syndromes: a framework for the adaptive integration of behaviour, physiology, and life history provides an overview of conceptual, theoretical, methodological, and empirical progress in research on pace-of-life syndromes (POLSs) over the last decade. The topical collection has two main goals. First, we briefly describe the history of POLS research and provide a refined definition of POLS that is applicable to various key levels of variation (genetic, individual, population, species). Second, we summarise the main lessons learned from current POLS research included in this topical collection. Based on an assessment of the current state of the theoretical foundations and the empirical support of the POLS hypothesis, we propose (i) conceptual refinements of theory, particularly with respect to the role of ecology in the evolution of (sexual dimorphism in) POLS, and (ii) methodological and statistical approaches to the study of POLS at all major levels of variation. This topical collection further holds (iii) key empirical examples demonstrating how POLS structures may be studied in wild populations of (non) human animals, and (iv) a modelling paper predicting POLS under various ecological conditions. Future POLS research will profit from the development of more explicit theoretical models and stringent empirical tests of model assumptions and predictions, increased focus on how ecology shapes (sex-specific) POLS structures at multiple hierarchical levels, and the usage of appropriate statistical tests and study designs. Significance statement As an introduction to the topical collection, we summarise current conceptual, theoretical, methodological and empirical progress in research on pace-of-life syndromes (POLSs), a framework for the adaptive integration of behaviour, physiology and life history at multiple hierarchical levels of variation (genetic, individual, population, species). Mixed empirical support of POLSs, particularly at the within-species level, calls for an evaluation and refinement of the hypothesis. We provide a refined definition of POLSs facilitating testable predictions. Future research on POLSs will profit from the development of more explicit theoretical models and stringent empirical tests of model assumptions and predictions, increased focus on how ecology shapes (sex-specific) POLSs structures at multiple hierarchical levels and the usage of appropriate statistical tests and study designs.}, language = {en} } @misc{DammhahnGoodman2014, author = {Dammhahn, Melanie and Goodman, Steven M.}, title = {Trophic niche differentiation and microhabitat utilization revealed by stable isotope analyses in a dry-forest bat assemblage at Ankarana, northern Madagascar}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, issn = {1866-8372}, doi = {10.25932/publishup-41515}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-415157}, pages = {97 -- 109}, year = {2014}, abstract = {Bats are important components in tropical mammal assemblages. Unravelling the mechanisms allowing multiple syntopic bat species to coexist can provide insights into community ecology. However, dietary information on component species of these assemblages is often difficult to obtain. Here we measuredstable carbon and nitrogen isotopes in hair samples clipped from the backs of 94 specimens to indirectly examine whether trophic niche differentiation and microhabitat segregation explain the coexistence of 16 bat species at Ankarana, northern Madagascar. The assemblage ranged over 4.4\% in delta N-15 and was structured into two trophic levels with phytophagous Pteropodidae as primary consumers (c. 3\% enriched over plants) and different insectivorous bats as secondary consumers (c. 4\% enriched over primary consumers). Bat species utilizing different microhabitats formed distinct isotopic clusters (metric analyses of delta C-13-delta N-15 bi-plots), but taxa foraging in the same microhabitat did not show more pronounced trophic differentiation than those occupying different microhabitats. As revealed by multivariate analyses, no discernible feeding competition was found in the local assemblage amongst congeneric species as compared with non-congeners. In contrast to ecological niche theory, but in accordance with studies on New and Old World bat assemblages, competitive interactions appear to be relaxed at Ankarana and not a prevailing structuring force.}, language = {en} } @article{DammhahnLandryCuerrierRealeetal.2017, author = {Dammhahn, Melanie and Landry-Cuerrier, Manuelle and Reale, Denis and Garant, Dany and Humphries, Murray M.}, title = {Individual variation in energy-saving heterothermy affects survival and reproductive success}, series = {Functional ecology : an official journal of the British Ecological Society}, volume = {31}, journal = {Functional ecology : an official journal of the British Ecological Society}, publisher = {Wiley}, address = {Hoboken}, issn = {0269-8463}, doi = {10.1111/1365-2435.12797}, pages = {866 -- 875}, year = {2017}, abstract = {1. Given fundamental energetic trade-offs among growth, maintenance and reproduction, individual differences in energy saving should have consequences for survival and reproductive success. Many endotherms use periodic heterothermy to reduce energy and water requirements and individual variation in heterothermy should have fitness consequences. However, attempts to disentangle individual- and population-level variation in heterothermy are scarce. 2. Here, we quantified patterns of heterothermy of 55 free-ranging eastern chipmunks (Tamias striatus), food-hoarding hibernators. Over five hibernation periods, we obtained a total of 7108 daily individual heterothermy indices (median: 118 per individual). 3. Based on an individual reaction norm approach, we found that the use of heterothermy was repeatable and varied among individuals of the same population under similar environmental conditions. This among-individual variation had consequences for winter survival and reproductive success. Individuals using less heterothermy at the beginning of the winter had decreased survival in resource-rich but not in resource-poor years and higher reproductive success in the subsequent breeding season. 4. These results support the hypothesis that fluctuating selection maintains heterothermic diversity and suggest that individualized ecophysiology can contribute to a more thorough understanding of the evolution of energy-saving strategies in endotherms.}, language = {en} } @article{DammhahnLangeEccard2022, author = {Dammhahn, Melanie and Lange, Pauline and Eccard, Jana}, title = {The landscape of fear has individual layers}, series = {Oikos}, volume = {2022}, journal = {Oikos}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {0030-1299}, doi = {10.1111/oik.09124}, pages = {17}, year = {2022}, abstract = {Perceived predation risk varies in space and time creating a landscape of fear. This key feature of an animal's environment is classically studied as a species-specific property. However, individuals differ in how they solve the tradeoff between safety and reward and may, hence, differ consistently and predictively in perceived predation risk across landscapes. To test this hypothesis, we quantified among-individual differences in boldness and activity and exposed behaviourally phenotyped male bank voles Myodes glareolus individually to two different experimental landscapes of risks in large outdoor enclosures and provided resources as discrete food patches. We manipulated perceived predation risk via vegetation height between 2 and > 30 cm and quantified patch use indirectly via RFID-logging and giving-up densities. We statistically disentangled among-individual differences in microhabitat use from spatially varying perceived risk, i.e. landscape of fear. We found that individuals varied in mean vegetation height of their foraging microhabitats and that this microhabitat selection matched the intrinsic individual differences in perceived risk. As predicted by the patch use model, all individual's perceived higher risks when foraging in lower vegetation. However, individuals differed in their reaction norm slopes of perceived risk to vegetation height, and these differences in slopes were consistent across two different landscapes of risks and resources. We interpret these results as evidence for individual landscapes of fear, which could be predicted by among-individual differences in activity and boldness. Since perceived predation risk affects when and where to forage, among-individual differences in fear responses could act as a mode of intraspecific niche complementarity (i.e. individual niche specialization), help explain behavioural type by environment correlations, and will likely have cascading indirect effects on lower trophic levels.}, language = {en} } @misc{DammhahnMazzaSchirmeretal.2020, author = {Dammhahn, Melanie and Mazza, Valeria and Schirmer, Annika and G{\"o}ttsche, Claudia and Eccard, Jana}, title = {Of city and village mice}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {1007}, issn = {1866-8372}, doi = {10.25932/publishup-48006}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-480063}, pages = {14}, year = {2020}, abstract = {A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals' adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC.}, language = {en} } @article{DammhahnMazzaSchirmeretal.2020, author = {Dammhahn, Melanie and Mazza, Valeria and Schirmer, Annika and G{\"o}ttsche, Claudia and Eccard, Jana}, title = {Of city and village mice}, series = {Scientific Reports}, volume = {10}, journal = {Scientific Reports}, publisher = {Macmillan Publishers Limited}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-020-69998-6}, pages = {12}, year = {2020}, abstract = {A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals' adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC.}, language = {en} } @article{DammhahnRakotondramananaGoodman2015, author = {Dammhahn, Melanie and Rakotondramanana, Claude Fabienne and Goodman, Steven M.}, title = {Coexistence of morphologically similar bats (Vespertilionidae) on Madagascar: stable isotopes reveal fine-grained niche differentiation among cryptic species}, series = {Journal of tropical ecology}, volume = {31}, journal = {Journal of tropical ecology}, publisher = {Cambridge Univ. Press}, address = {New York}, issn = {0266-4674}, doi = {10.1017/S0266467414000741}, pages = {153 -- 164}, year = {2015}, abstract = {Based on niche theory, closely related and morphologically similar species are not predicted to coexist due to overlap in resource and habitat use. Local assemblages of bats often contain cryptic taxa, which co-occur despite notable similarities in morphology and ecology. We measured in two different habitat types on Madagascar levels of stable carbon and nitrogen isotopes in hair (n = 103) and faeces (n = 57) of cryptic Vespertilionidae taxa to indirectly examine whether fine-grained trophic niche differentiation explains their coexistence. In the dry deciduous forest (Kirindy), six sympatric species ranged over 6.0\% in delta N-15, i.e. two trophic levels, and 4.2\% in delta C-13 with a community mean of 11.3\% in delta N-15 and - 21.0\% in delta C-13. In the mesic forest (Antsahabe), three sympatric species ranged over one trophic level (delta N-15: 2.4\%, delta C-13: 1.0\%) with a community mean of 8.0\% delta N-15 and - 21.7\% in delta C-13. Multivariate analyses and residual permutation of Euclidian distances in delta C-13- delta N-15 bi-plots revealed in both communities distinct stable isotope signatures and species separation for the hair samples among coexisting Vespertilionidae. Intraspecific variation in faecal and hair stable isotopes did not indicate that seasonal migration might relax competition and thereby facilitate the local co-occurrence of sympatric taxa.}, language = {en} } @misc{DammhahnRakotondramananaGoodman2015, author = {Dammhahn, Melanie and Rakotondramanana, Claude Fabienne and Goodman, Steven M.}, title = {Coexistence of morphologically similar bats (Vespertilionidae) on Madagascar}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {590}, issn = {1866-8372}, doi = {10.25932/publishup-41472}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414729}, pages = {12}, year = {2015}, abstract = {Based on niche theory, closely related and morphologically similar species are not predicted to coexist due to overlap in resource and habitat use. Local assemblages of bats often contain cryptic taxa, which co-occur despite notable similarities in morphology and ecology. We measured in two different habitat types on Madagascar levels of stable carbon and nitrogen isotopes in hair (n = 103) and faeces (n = 57) of cryptic Vespertilionidae taxa to indirectly examine whether fine-grained trophic niche differentiation explains their coexistence. In the dry deciduous forest (Kirindy), six sympatric species ranged over 6.0\% in delta N-15, i.e. two trophic levels, and 4.2\% in delta C-13 with a community mean of 11.3\% in delta N-15 and - 21.0\% in delta C-13. In the mesic forest (Antsahabe), three sympatric species ranged over one trophic level (delta N-15: 2.4\%, delta C-13: 1.0\%) with a community mean of 8.0\% delta N-15 and - 21.7\% in delta C-13. Multivariate analyses and residual permutation of Euclidian distances in delta C-13- delta N-15 bi-plots revealed in both communities distinct stable isotope signatures and species separation for the hair samples among coexisting Vespertilionidae. Intraspecific variation in faecal and hair stable isotopes did not indicate that seasonal migration might relax competition and thereby facilitate the local co-occurrence of sympatric taxa.}, language = {en} } @misc{DammhahnRandriamoriaGoodman2017, author = {Dammhahn, Melanie and Randriamoria, Toky M. and Goodman, Steven M.}, title = {Broad and flexible stable isotope niches in invasive non-native Rattus spp. in anthropogenic and natural habitats of central eastern Madagascar}, series = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam Mathematisch-Naturwissenschaftliche Reihe}, number = {722}, issn = {1866-8372}, doi = {10.25932/publishup-42941}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-429419}, pages = {13}, year = {2017}, abstract = {Background: Rodents of the genus Rattus are among the most pervasive and successful invasive species, causing major vicissitudes in native ecological communities. A broad and flexible generalist diet has been suggested as key to the invasion success of Rattus spp. Here, we use an indirect approach to better understand foraging niche width, plasticity, and overlap within and between introduced Rattus spp. in anthropogenic habitats and natural humid forests of Madagascar. Results: Based on stable carbon and nitrogen isotope values measured in hair samples of 589 individual rodents, we found that Rattus rattus had an extremely wide foraging niche, encompassing the isotopic space covered by a complete endemic forest-dwelling Malagasy small mammal community. Comparisons of Bayesian standard ellipses, as well as (multivariate) mixed-modeling analyses, revealed that the stable isotope niche of R. rattus tended to change seasonally and differed between natural forests and anthropogenic habitats, indicating plasticity in feeding niches. In co-occurrence, R. rattus and Rattus norvegicus partitioned feeding niches. Isotopic mismatch of signatures of individual R. rattus and the habitat in which they were captured, indicate frequent dispersal movements for this species between natural forest and anthropogenic habitats. Conclusions: Since R. rattus are known to transmit a number of zoonoses, potentially affecting communities of endemic small mammals, as well as humans, these movements presumably increase transmission potential. Our results suggest that due to their generalist diet and potential movement between natural forest and anthropogenic habitats, Rattus spp. might affect native forest-dependent Malagasy rodents as competitors, predators, and disease vectors. The combination of these effects helps explain the invasion success of Rattus spp. and the detrimental effects of this genus on the endemic Malagasy rodent fauna.}, language = {en} }