35 research outputs found
The Physics of the B Factories
This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C
Life history implications of the mother's choice for a larval habitat. Niche choice and niche conformance in the fire salamander, Salamandra salamandra
Oswald P. Life history implications of the mother's choice for a larval habitat. Niche choice and niche conformance in the fire salamander, Salamandra salamandra. Bielefeld: Universität Bielefeld; 2022.We are in the midst of a global biodiversity crisis, and many species experience drastic population declines or local extinction events. Amphibians are by far the most threatened taxon. They are highly affected by habitat loss, climate change, pollution and emerging infectious diseases such as chytridiomycosis caused by the chytrid fungus *Batrachochytrium salamandrivorans* (*Bsal*). In the European fire salamander (*Salamandra salamandra*), this fungus has led to numerous population collapses and thus, conservation efforts have increased during the last years. However, to guide conservation efforts, we need to gather more population data and more knowledge about how amphibians cope with environmental changes. Amphibians might shift to different habitats or niches (niche choice), adjust their phenotype to match the given habitat (niche conformance) or change the environment to match their phenotype (niche construction). This research aims to investigate niche choice and niche conformance in the European fire salamander as a model species for the taxon of amphibians. In particular, I studied the effects of the mother’s choice of a larval habitat on their offspring and whether the larvae can conform to their specific niche.
I investigated these questions by combining a systematic literature review, population monitoring in the field, population analyses using a new automatic photographic identification software (Amphibian and Reptile Wildbook) and behavioural experiments in the field and in the laboratory. First, I introduce the mechanisms of niche choice, niche conformance and niche construction, give some general background on amphibian declines and provide information on the study species, the European fire salamander (Chapter I). Chapter II comprises a literature review on reciprocal transfer experiments and a case study on fire salamanders. In Chapter III, I used a photographic mark-recapture approach with the Amphibians and Reptile Wildbook for population analyses with open population Jolly-Seber models. The behavioural experiments included larval risk-taking behaviour (Chapter IV) and anti-predator responses of larvae towards chemical stimuli of a predator (Chapter V). Furthermore, I tested the risk-taking behaviour from the larval stage across metamorphosis to the postmetamorphic stage (Chapter VI). In Chapter VII, I introduced a new tool for individual identification of fire salamander larvae and adults, the Amphibian and Reptile Wildbook. I discussed a potential pathway of disease transmission, the interspecific amplexus (Chapter VIII), and contributed valuable information to the biology of the European fire salamander and recommendations for captive breeding programs (Chapter IX). In the last chapter (Chapter X), I summarised the key results, put them into a larger context and discussed the implications for future research.
This work revealed that there is no clear evidence for local adaptation in amphibians indicating that phenotypic plasticity might play a larger role than genetic adaptation. I could show that fire salamander larvae conform to their habitat and that the larval habitat can affect the phenotype (e.g., risk-taking behaviour) even across metamorphosis. Furthermore, this study is the first to provide valid larval population size data and survival estimates for a population of fire salamanders in western Germany (Kottenforst forest). It also includes the first report of interspecific amplexus of a common toad and a rare amplexus of a common frog with fire salamanders. These findings stress the need for further studies investigating the underlying mechanisms of niche choice and niche conformance in salamanders and amphibians in general. It also emphasizes the importance of population monitoring in the face of global amphibian declines and the spread of *Bsal*.
In summary, this research contributes to the growing body of literature about fire salamanders, expands the basic knowledge about this species and its behaviour, establishes a new tool for population analyses and gives recommendations for captive breeding programs. Thus, this work provides new substantial information that builds the base for further research and is crucial for future conservation of the European fire salamander and other amphibian species
Risk-taking in fire salamanders
This project contains the rawdata, metadata and the link to the GitHub repository with the R script used for our paper about risk-taking behaviour in larval fire salamanders
Fire salamander population monitoring with Wildbook
Raw data for population analyses with the Amphibian and Reptile Wildbook.
The R-Script can be found at GitHub under https://github.com/qoswald/Larval-Recaptures-202
Individuelle Erkennung von Amphibien am Beispiel von Feuersalamander Alttieren und Larven, sowie Gelbbauchunken mittels Wildbook Software
Schulte L, Oswald P, Caspers B. Individuelle Erkennung von Amphibien am Beispiel von Feuersalamander Alttieren und Larven, sowie Gelbbauchunken mittels Wildbook Software. Amphibia. 2022;21(2):16-25
Different responses to predator cues in two fire salamander ecotypes
This project contains the raw data, R script, experimental designs and ARRIVE guidelines for the manuscript entitled: "Behavioural responses to chemical cues of predators differ between fire salamander larvae from two different habitats".
kairomonesoffiresal.csv: raw data for the activity test
kairomonesshelterfiresal.csv: raw data for the shelter-emergence test
kairomonesfiresal_mod_PO.R: R script
Kairomones Activity in larval salamanders_Experimental Design: experimental design for the activity test
Kairomones Shelter-emergence in larval salamanders_Experimental Design: experimental design for the shelter-emergence test
20220823_Hahn_et_al_ARRIVE: ARRIVE guideline
Behavioural responses to chemical cues of predators differ between fire salamander larvae from two different habitats
Hahn LG, Oswald P, Caspers B. Behavioural responses to chemical cues of predators differ between fire salamander larvae from two different habitats. bioRxiv. 2020.Predation is one of the strongest selection pressures, forcing prey organisms to detect predators and to display various antipredator behaviours, such as refuge-use or decreased activity. To recognise predators, chemosensory cues play a pivotal role, particularly in aquatic ecosystems. However, it is less known whether the ability to use these cues to respond with adequate antipredator behaviour varies between individuals occupying different habitats that are dissimilar in predation risk. Using field experiments, we examined antipredator behaviour of larval fire salamanders (Salamandra salamandra) from two different habitats, ponds and streams. Among other differences, ponds and streams are inhabited by habitat-specific predators, such as alpine newts (Ichthyosaura alpestris) occurring in ponds. We exposed larvae from both habitats to either chemical cues from alpine newts or a blank control (tap water) and investigated potential differences in their behavioural responses in two experiments. Pond larvae, but not stream larvae, became significantly less active when faced with chemical cues from newts compared to those faced with a control stimulus. Moreover, larvae from both habitats tested in water containing chemical cues spent significantly less time outside a shelter than those in control water. Our results demonstrate that larval fire salamanders recognise predatory newts through kairomones and alter their behaviour accordingly. However, experience with predatory newts may not be necessary to differentiate kairomones from control water, but may be beneficial for larvae to further develop their antipredator behaviour, thus representing conformance to a niche
Love is blind: interspecific amplexus of two anuran species, the Common Toad (Bufo bufo) and the European Green Frog (Pelophylax sp.), with fire salamanders (Salamandra salamandra terrestris)
Oswald P, Schulte L, Mühlenhaupt M, Caspers B. Love is blind: interspecific amplexus of two anuran species, the Common Toad (Bufo bufo) and the European Green Frog (Pelophylax sp.), with fire salamanders (Salamandra salamandra terrestris). Herpetology Notes. 15.11.2022;(15):811-815