Exploration in red knots:The role of personality in the expression of individual behaviour across contexts

All individuals show behavioural traits that are consistent over time, but differ across individuals, and affect the expression of behaviours in different situations (personality traits). This personality traits have been shown to have consistent ecological and evolutionary consequences thus, studying the variation in personality traits is important. The aim of this thesis was to identify the variation in exploratory behaviour in red knots, understand the origin of this variation, understand how variation in exploration maintained in natural populations, and whether exploration measured in experimental setups could be extrapolated to ecological contexts. We found that experience during ontogeny (i.e., exposure to a certain physical or social environment) can be important for the development of personalities in juvenile red knots. For adults, exploratory behaviour assayed in experimental setups is highly consistent within individuals and can predict other behaviours in different contexts. That is, variation in exploratory personality (i.e., slow vs. fast explorer) predicts foraging tactics and dietary choice in the wild. Exploratory behaviour also relates to variation in movement across different temporal and spatial scales in previously unforeseen ways. Specifically, slow and fast explorers show divergent movement patterns during the day and night and differ in arrival times from migration. This thesis fills a gap in the literature to link an experimentally measured personality trait to real-world behavioural strategies and demonstrates the importance of studying personality across contexts. Understanding the causes, maintenance, and consequences of animal personalities should further our understanding of population responses to environmental change, population and community dynamics, and speciation

Psychological Maltreatment of Women Inventory Short Form - Turkish adaptation

Ersoy NC, Hünler OS, Namer Y. Kadına Psikolojik Eziyet Envanteri Kısa Formu Türkçe Uyarlaması. Klinik Psikiyatri Dergisi. 2017;20(4):276-286

Exploration speed in captivity predicts foraging tactics and diet in free-living red knots

1. Variation in foraging tactics and diet is usually attributed to differences in morphology, experience and prey availability. Recently, consistent individual differences in behaviour (personality) have been shown to be associated with foraging strategies. Bolder or more exploratory individuals are predicted to have a faster pace‐of‐life and offset the costs of moving more or in risky areas, with higher energetic gains by encountering profitable foraging opportunities and prey. However, the relationship between personality, foraging and diet is poorly understood. 2. We investigated how exploratory behaviour in red knots Calidris canutus is associated with foraging tactics and diet by combining laboratory experiments, field observations and stable isotope analysis. First, we developed a mobile experimental arena to measure exploration speed in controlled settings. We validated the method by repeated testing of individuals over time and contexts. This setup allowed us to measure exploratory personality at the field site, eliminating the need to bring birds into captivity for long periods of time. After releasing birds within days of their capture, we asked whether exploration speed was associated with differences in foraging tactics and diet in the wild. 3. We found that tactile foraging red knots mainly caught hard‐shelled prey that are buried in the sediment, whereas visual foraging knots only captured soft preys located close to or on the surface. We also found that faster explorers showed a higher percentage of visual foraging than slower explorers. By contrast, morphology (bill length and gizzard size) had no significant effect on foraging tactics. Diet analysis based on δ(15)N and δ(13)C stable isotope values of plasma and red blood cells confirmed our field observations with slower explorers mainly consumed hard‐shelled prey while faster explorers consumed more soft than hard‐shelled prey. 4. Our results show that foraging tactics and diet are associated with a personality trait, independent of morphological differences. We discuss how consistent behaviour might develop early in life through positive feedbacks between foraging tactics, prey type and foraging efficiency

Enzymatic hydrolysis : optimized hydrolysis process for photosynthetic bacteriaand microalgae biomass

This thesis project is a contribution to addressing the pressing need for sustainable alternatives to fossil fuels and traditional plastics. The work focuses on enzymatic saccharification of microalgae biomass to generate a sugar-rich stream as raw material for biofuels and bioplastics production. Microalgae and cyanobacteria are highlighted for their ability to convert CO2 into valuable biomass components in the presence of light.  To enhance biomass conversion efficiency, the enzymatic hydrolysis of microalgae and cyanobacteria is explored by utilizing various enzymes to break down complex polymers into valuable sugars. Additionally, the cultivation of cyanobacteria is studied to optimize the overall process. Results indicate challenges, such as measurement uncertainty and the need for biomass pretreatment, suggesting areas for further research.  The primary objective of this thesis work is to optimize enzymatic hydrolysis processes by determining the optimal combinations of enzymes, to enhance biomass conversion efficiency. It also underscores the importance of microorganisms in transitioning to a more environmentally friendly future by offering sustainable alternatives to conventional products

Sex-specific variation of parental care in common ravens, Corvus corax

Eltern sind generell mit dem Konflikt konfrontiert, wieviel Ressourcen sie in Selbsterhaltung investieren sollen und wieviel in Fortpflanzung. Dieser Konflikt wird verstärkt, wenn die Ressourcen knapp sind. Wenn mehrere Nachkommen gleichzeitig aufgezogen werden, wird dann oft nicht gleichmässig in alle Nachkommen investiert. Da das Geschlecht und Körpergewicht der Nachkommen deren zukünftige Reproduktion beeinflusst, kann davon ausgegangen werden, dass die Eltern ihre limitierten Ressourcen selektiv nach diesen Eigenschaften verteilen. Diese selektive Verteilung von Ressourcen abhängig von Eigenschaften der Nachkommen wird in vielen verschieden Arten beobachtet, jedoch versteht man die zugrundeliegenden Mechanismen bislang nur sehr schlecht. In meiner Studie habe ich den Einfluss von individuellen und sozialen Faktoren auf die selektive Ressourcenverteilung von Eltern des Kolkraben untersucht. Kolkraben sind eine soziale Singvogelart mit geschlechtsspezifischem Grössenunterschied und beide Eltern investieren in die Aufzucht der Nachkommen. Ich habe den Einfluss des Körpergewichts, Geschlechts und der Bettelintensität der Nachkommen, und des Geschlechts der Eltern auf die Fütterungswahrscheinlichkeit der Eltern untersucht. Ausserdem habe ich den Einfluss der oben genannten individuellen Faktoren auf das Bettelverhalten, und auf die affiliativen und agonistischen Interaktionen zwischen den Eltern und Nachkommen, untersucht. Meine Resultate zeigten, dass Väter schwere Söhne bevorzugten. Dies zeigte sich in vermehrtem Füttern und mehr affiliativen Interaktionen. Mütter hingegen zeigten keine Präferenz für Geschlecht und Körpergewicht der Nachkommen. Erhöhtes Bettelverhalten erhöhte das Fütterungswahrscheinlichkeit von beiden Eltern, und leichte Weibchen und schwere Männchen bettelten selektiv häufiger zum Vater. Meine Resultate suggerieren, dass Kolkraben-Väter das Körpergewicht und Geschlecht von ihren Nachkommen als Signal nutzen und ihre Investition darauf abstimmen.Parents face a trade-off when allocating limited resources into reproduction and self-maintenance, and this generally results in differential investment in individual offspring when rearing multiple offspring simultaneously. Offspring sex and body mass influence future reproduction and, therefore, these traits may influence differential parental care. Many species show different patterns of sexual size dimorphism and sex-specific parental investment, but the underlying causes remain poorly understood. I investigated the effect of individual and social factors on differential parental investment in common ravens, sexually dimorphic songbirds that provide bi-parental care. Specifically, I assessed the effect of offspring body mass, sex, begging intensity, and parent sex on feeding probability by parents. I further investigated the individual factors that influence offspring begging behaviour, and affiliative and agonistic interactions between parent and offspring. My results showed that fathers fed and affiliated more with heavy sons, whereas mothers showed no preference. I found that begging increased the likelihood of offspring to get fed from both parents, and light females and heavy males preferentially begged more to the fathers. My results suggest that in common ravens, offspring body mass serves as a signal in father-offspring interactions

When slow explorers are fast: personality-related differences in timing of migration in red knots Calidris canutus

<p>Title: "<strong><span>When slow explorers are fast: personality-related differences in timing of migration in red knots <em>Calidris canutus</em></span></strong>"<br>Authors: Selin Ersoy; Ton G. G. Groothuis; Theunis Piersma & Allert Bijleveld</p> <p>GENERAL INFORMATION</p> <p>Date of the data collection: Catching between 14 August 2018 - 5 August 2019<br>Geographic location of data collection: Western Dutch Wadden Sea (53°15'N, 5°15'E) <br>Corresponding author information: Selin Ersoy, NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands, [email protected] </p> <p>METHODS<br>Isotope data: Red blood cell and plasma d13C and d15N isotopes collected from the blood samples of red knots.<br>Exploration speed: Movement tracjectories were collected from the recordings of the top camera during experiments in the mobile arena. We used the distance between estimated positions to calculate speed. Errors in the positioning algorithm were filtered by excluding speeds higher than 200 cm/s. An individual’s exploration speed was calculated as the average speed during each 20 min trial.</p> <p>DATA & FILE OVERVIEW</p> <p>All_Isotope_RedKnot.csv : Red blood cell and plasma d13C and d15N isotopes collected from the blood samples of juvenile and adult red knots<br>        Column 1: RingNr: Unique metal ring number of red knots. Ring were put on the legs<br>        Column 2: Type: Blood type plasma or red blood cell<br>        Column 3: Repeat: If there is a repeated samples of an individual<br>        Column 4: d15N: Nitrogen 15 Isotope value <br>        Column 5: d13C: Carbon 13 Isotope value<br>        Column 6: Comments: important commments about samples</p> <p>KnotData.csv    : Primaries and Exploration speed repeated measures from Juvenile and Adult red knots<br>        Column 1: RingNr: Unique metal ring number of red knots. Ring were put on the legs<br>        Column 2: Catch months<br>        Column 3: Catch day<br>        Column 4: Catch year<br>        Column 5: Sex (m for male, f for female)<br>        Column 6: P1: first primary score <br>        Column 7: P2: second primary score <br>        Column 8: P3: third primary score <br>        Column 9: P4: forth primary score <br>        Column 10: P5: fifth primary score <br>        Column 11: P6: sixth primary score <br>        Column 12: P7: seventh primary score <br>        Column 13: P8: eight primary score <br>        Column 14: P9: nineth primary score <br>        Column 15: P10: tenth primary score <br>        Column 16: Active moult (yes-no)<br>        Column 17: Total primary score<br>        Column 18: LogMeanF01: Exploratory score of individual measured in mobile arena (mean speed cm/sec) measured through automated tracking </p&gt