Search for dissertations about: "vertebrate predators"

Showing result 1 - 5 of 7 swedish dissertations containing the words vertebrate predators.

2. 1. The importance of predation in benthic stream communities

   Author : Jonas Dahl; Biologiska institutionen; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Ekologi; Ecology; invertebrate predators; vertebrate predators; Predation; streams;

   Abstract : There has been considerable debate whether or not predators has any significant effects on prey densities in streams. This thesis examines the importance of predation in stream communities. I have conducted both field and laboratory studies where I have studied how both vertebrate and invertebrate predators affects benthic prey. READ MORE

4. 2. Predators in low arctic tundra and their impact on community structure and dynamics

   Author : Maano Aunapuu; Tarja Oksanen; Ola Atlegrim; Oswald J. Schmitz; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ecology; arthropods; coexistence; community dynamics; competition; food webs; hypothesis of exploitation ecosystems; intraguild predation; small mustelids; trophic cascades; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; zooekologi; Animal Ecology;

   Abstract : The abundance of predators and their impact on ecosystem dynamics is a vividly discussed topic in current ecology. In my studies, incorporating field observations, field experiments and theoretical modeling, I explored the importance of predators and predation in a low arctic tundra ecosystem in northern Norway. READ MORE

5. 3. On the protective value of conspicuous eyespots in Lepidoptera

   Author : Adrian Vallin; Sven Jakobsson; Christer Wiklund; Graeme D. Ruxton; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Ethology and behavioural ecology; Etologi och beteendeekologi;

   Abstract : Eyespots, circular patterns which resemble the general appearance of the vertebrate eye, are widespread throughout the animal kingdom and are for example, commonly found on the wings of butterflies where they have been proposed to confer protection against predation. However, empirical evidence of the adaptive value of eyespots, as well as knowledge of butterfly behaviour under the threat of predation, is scarce. READ MORE

6. 4. 100 million years of shark macroevolution : A morphometric dive into tooth shape diversity

   Author : Mohamad Bazzi; Per Ahlberg; Matt Friedman; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Sharks; Macroevolution; Extinction recovery dynamics; Geometric Morphometrics; Morphospace-Disparity Framework; Teeth; Biology with specialization in Evolutionary Organismal Biology; Biologi med inriktning mot evolutionär organismbiologi;

   Abstract : Few vertebrate clades exhibit the evolutionary longevity and versatility of sharks, which constitute nearly half of all current chondrichthyan biodiversity and represent an ecological diversity of mid-to-apex trophic-level predators in both marine and freshwater environments. The rich fossil record of shark teeth from Mesozoic and Cenozoic rocks also makes the group amenable to large-scale quantitative analyses. READ MORE

7. 5. Defence on Demand : A physiological perspective on phenotypic plasticity in anti-predator traits

   Author : Jerker Vinterstare; Enhet akvatisk ekologi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Phenotypic plasticity; inducible defences; stress physiology; cortisol; immune function; trade-offs; sexual dimorphism; crucian carp; visual ecology; predator-prey interactions; POMC pro-opiomelanocortin ; colour change; eco-immunology; Anti-predator defences; Inducible morphological defence; Phenotypic plasticity; Stress physiology; Cortisol; Immune function; Crucian carp; Predator-prey interactions; Trade-offs; Sexual dimorphism; POMC; Pro-opiomelanocortin; Visual ecology; Eye evolution; Melanin; Eco-immunology; Pace-of-life; Behavioural plasticity;

   Abstract : Almost all species face some degree of predation risk, and, hence, evolution has produced a plethora of anti-predator defences. However, anti-predator strategies require resources, and the prevailing risk of becoming prey is influenced by many factors and rarely constant across time and space. READ MORE