Search for dissertations about: "Birgitta Tullberg"

Found 3 swedish dissertations containing the words Birgitta Tullberg.

2. 1. Behavioural ecology and population dynamics of an aposematic seed bug, Lygaeus equestris L. (Heteroptera, Lygaeidae)

   Author : Birgitta Sillén-Tullberg; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : .... READ MORE

4. 2. Seasonal change in defensive coloration in a shieldbug

   Author : Aleksandra I. Johansen; Gabriella Gamberale-Stille; Birgitta S. Tullberg; Graeme Ruxton; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Shield bug; colour change; protective coloration; cryptic; aposematic; behavioural change; etologi; Ethology;

   Abstract : Protective coloration such as aposematism and crypsis occurs in many insects but only a few species alter their defensive strategy during the same instar. We hypothesize the adult shield bug Graphosoma lineatum with an alternating black and non-melanised longitudinal striation exhibit such a change in defensive coloration. READ MORE

5. 3. Causes and consequences of niche differentiation between color morphs of pygmy grasshoppers

   Author : Einat Karpestam; Anders Forsman; Birgitta Tullberg; Linnéuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; color polymorphism; visual predators; Tetrix subulata; differential habitat use; niche; thermoregulation; feeding preferences; stable isotopes; Evolutionary Biology; Evolutionsbiologi;

   Abstract : In this thesis, I used the color polymorphic pygmy grasshopper, Tetrix subulata, as a model system in order to investigate the degree of niche differentiation between alternative color morphs that are present within a single population. First, I hypothesized that individuals belonging to different color morphs differ in their innate food preference due to somewhat dissimilar physiology, and in their actual food consumption due in part to differential habitat use. READ MORE